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BACKGROUND OF THE INVENTION
Probe heads for coordinate-measuring instruments have a movable part which carries the probe pin and its work-contacting probe-tip ball; upon ball contact with a workpiece, the probe pin is deflected out of its position of rest against the force of one or more springs, generally coil springs, during a work-contacting procedure. This deflection motion is necessary to protect the probe head from damage as a result of unavoidably overshooting the contact position, due to drive action in the coordinate measuring instrument. Probe heads for coordinate-measuring instruments are illustratively described in West German Pat. No. 2,347,633 and OS No. 2,743,665, corresponding to U.S. Pat. No. 4,136,458.
The design of probe heads requires, on the one hand, the largest possible free stroke for probe deflection, so that high travel speeds and short measurement times can be obtained. On the other hand, the probe head should be structurally as small as possible, to enable contact with even the workpiece locations which are most difficult to access.
It is difficult to simultaneously satisfy both these requirements, particularly if cables (e.g. electrical wiring) must be brought to the movable part of the probe head. This is necessary, for example, in the case of probe heads which, like the pressure-sensitive sensors described in West German Pat. No. 2,712,181 (U.S. Pat. No. 4,177,568), or like the probe head described in International Application WO81/01876, employ electrical components such as a piezo-oscillator; if such electrical components are arranged on the movable part itself, frequent large deflection movements in a very small space entail the danger of cable breakage. Furthermore, additional restoring forces are attributable to the cable itself; and as a result of these added forces, the precision of measurement obtainable with the probe head is reduced, or the function of the probe head can even be entirely destroyed.
Admittedly, it is known to lay cables in loops in order to assure low cable stresses, in the circumstance of relative movement between parts connected to the cable. However, such an arrangement requires large structural space.
BRIEF STATEMENT OF THE INVENTION
The object of the present invention is so to arrange the cable connection between movable and stationary parts in a very small space within a probe head of a coordinate measuring instrument that the smallest possible stresses on the cable result, even for large deflections of the probe pin.
This object is achieved for a coil-spring configuration wherein the cables are so carried by the spring (5) as to follow the turns of the spring. Particularly good results are obtained if the cables are wound around and along the length of the wire of the spring.
As a result of having wrapped cables around the wire of the spring, movement of the cable is distributed uniformly over its entire length, so that restoring forces acting on the probe pin remain at a minimum, even for extreme deflections. At the same time, the cables are securely supported over their entire length between the movable and the rigid parts of the probe head and cannot move in an undefined manner.
DETAILED DESCRIPTION
A preferred embodiment of the invention will be described below with reference to the accompanying drawing, which is generally a vertical section of a probe head of the invention.
In the drawing, the housing 1 of a probe head will be understood to be mounted to a coordinate measuring instrument (not shown). Housing 1 constitutes the stationary part of the probe head, and it contains a mount which is formed of three angularly spaced balls 7 and a carrier plate 2; the carrier plate 2 mounts a probe pin 3 and its work-contacting ball tip 4, and a coil spring 5 continuously urges plate 2 to its at-rest position of contact with all three balls 7, thus uniquely establishing the probe-mounting axis when in said at-rest position. In the modified sectional view of the drawing, only two of the three bearing balls are visible, namely, balls 7a and 7b. The spring 5 is located, concentric with the probe-mounting axis, by upper and lower spring-locating seat formations, in housing 1 and on carrier 2, respectively.
Carrier plate 2 will lift off from one or two of the bearing balls 7 upon a deflection of the probe pin 3 from its position of rest. Pin 3 is seen in the drawing to be divided into two parts, by the bonded interposition of a piezoelectric sensor 8 which supplies the contact signal. From the sensor 8, a cable connection consisting of two insulated conductors 6a and 6b leads via a first electrical-lead passage radially within the spring-locating seat formation of the housing to a socket (not shown) at the upper end of the housing 1. The piezoelectric sensor 8 is annular and concentric with the probe-mounting axis, and its central opening communicates with a second electrical-lead passage through the carrier 2 and radially within the spring-locating seat formation of the carrier.
The cable conductors are wrapped around the spring wire following the turns of the spring 5 and are thus fastened to the spring 5 over its entire length. In this way, upon every deflection of the probe pin 3, stresses acting on the cabling are distributed uniformly over its entire length.
Although the invention has been described in detail in the context of cabling for a deflectable work-contacting probe, it will be understood that other embodiments of the concept will find application, in other contexts on coordinate-measuring instruments. For example, a resiliently mounted detector which provides anti-collision protection of the entire probe head, can also be electrically served by flexible conductors that are similarly wrapped around a coil spring of the involved resilient suspension. | Electrical-lead connections between stationary and movable parts of a probe head are rendered virtually insensitive to stress by wrapped development of the lead connections along the length of a spring connection between the stationary and movable parts. | 5,930 |
REFERENCE TO PENDING PRIOR PATENT APPLICATION
[0001] This patent application claims benefit of pending prior U.S. Provisional Patent Application Ser. No. 61/441,994, filed Feb. 11, 2011 by Matthew Fonte for CRUCIBLES MADE WITH THE COLD FORM PROCESS (Attorney's Docket No. FONTE-3 PROV), which patent application is hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to crucibles in general, and more particularly to crucibles for growing crystals.
BACKGROUND OF THE INVENTION
[0003] Light emitting diodes (LEDs) are ubiquitous in modern society: they are in traffic lights, automobile interiors, backlights in cell phones, and many other applications. Their growing popularity comes from their many advantages over incandescent and fluorescent lamps including a high energy efficiency, long lifetimes, compact size, and shock resistance. Furthermore, they can emit light of a precise color, which is useful for many applications. Currently, commercial LEDs are available that emit light over the entire visible range—from red to blue, plus infrared light. One of the main problems in creating LEDs is the poor formability and consequently high cost of suitable materials available for crucible fabrication. In addition to finding a crucible material that is chemically inert during the single crystal melting growth process; the material must be thermally stable at 2,100° C. so that the crucible's growth doesn't put crystal under stress as it is cooled from the growth temperature.
Sapphire Single Crystals:
[0004] Crystal growth is a significant step for the semiconductor industry as well as for optical applications and solar industries. Sapphire single crystals are used for high power laser optics, high pressure components and substrates for LEDs. Because of the high temperatures (up to 2,200° C.) and harsh chemical environments occurring in the single crystal growth process, components in the growth chamber must be made from molybdenum or tungsten. The technique of crystal growing is a straightforward process. Al 2 O 3 (alumina) is melted in a molybdenum crucible. The melt ‘wets’ the surface of molybdenum die and moves up by capillary attraction. A sapphire ‘seed crystal’ of desired crystallinity is dipped into the melt on top of the die and ‘pulled’ or drawn out, crystallizing the Al 2 O 3 into solid sapphire, in a shape—rod, tube or sheet (ribbon)—determined by the die. Crystal orientation can be tightly controlled—any axis or plane can be produced using proper controls during growth. Uses for die-grown sapphire include:
[0000]
Sapphire fiber
Laser material
EFG bulk sapphire uses
Scalpels and ceramic parts
Bar code scanners
Military armor
Substrates for blue LEDs and
Aerospace windows and nose
laser diodes
cones
Tubes for plasma applicators
End effector on robotic arm
Chamber and viewports
Lift pins
End point windows and slits
Thermocouples
Molybdenum Crucibles:
[0005] A limitation of the production of sapphire single crystals is the difficulty in producing the pure Molybdenum (Mo) crucible. Unlike most all other metals, Molybdenum's mechanical working must be carried out above the ductile-brittle transition temperature, which can be 400° to 1,200° F. depending on the geometry of the part being formed and its thickness. Forming processes such as press brake folding of sheet or bending of rod are only possible after localized pre-heating. Gas flame and/or induction heating are required, ideally to reach red heat for as short a time as possible and only while deformation is taking place. Forming material while it's red hot is difficult due to material smearing/galling, tooling undesirably expanding with heat and tool wear/fatigue failure. There is also the concern of fire when forming metal hot and there are oil based lubricants and hydraulic lines present. Additionally, texture is an important factor during the deep drawing of sheet. Specially produced, cross-rolled sheets (deep-drawing quality) are required. So, the texture of the pre-formed blank needs to be just right or cracks will ensue. The preheating temperature before deep drawing depends on the sheet thickness and the degree of deformation required. Typically several forming passes are required, with intermediate cleaning/annealing, and re-lubrication processes between subsequent forming passes. In short, forming pure Mo is problematic and few companies have had success forming this brittle material.
[0006] Crucibles that are in production for growing sapphires can be 17″ diameter×20″ deep with wall thickness ranging from 0.040″ to 0.098″. The length to diameter ratio of this thin crucible make it challenging to produce, especially in Mo. Below is a photo of a seamless, Mo crucible made by Plansee:
[0007] See FIG. 1
[0008] This Mo crucible could weigh more than 50 lbs. Today the price of Mo is near $330 per lb. The cost in metal alone could be more than $16,000. Then there is the cost to do the fabrication of the difficult-to-form Mo material. The market today could be more than 5,000 Mo crucibles per year. There is a need to find a more practical method of producing the Mo crucibles.
SUMMARY OF THE INVENTION
[0009] In one form of the present invention, there is provided a crucible for growing crystals, the crucible being formed from Molybdenum and Rhenium.
[0010] In another form of the present invention, there is provided a crucible for growing crystals, the crucible being formed from a metal selected from Group V of the Periodic Table of the Elements.
[0011] In another form of the present invention, there is provided a crucible for growing crystals, the crucible comprising a body and a layer formed on at least a portion of the body, the layer being formed out of Molybdenum.
[0012] In another form of the present invention, there is provided a method for forming a crucible for growing crystals, the method comprising the steps of:
[0013] preheating a preform blank formed out of molybdenum or a molybdenum alloy; and
[0014] flowforming the preform blank into the shape of a crucible, wherein flowforming is performed at a temperature below the recrystallization temperature of the material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:
[0016] FIG. 1 is a photograph of a Molybdenum crucible;
[0017] FIG. 2 is a graph showing a comparison of the room-temperature tensile elongation of Mo—Re alloys;
[0018] FIG. 3 is a graph showing DBTT vs. Re for a variety of materials;
[0019] FIG. 4 is a micrograph showing a material which has not been worked significantly during a flowforming process;
[0020] FIG. 5 is a micrograph showing a material which has been worked significantly during a flowforming process;
[0021] FIG. 6 is a deep draw process, starting from sheet/disc and forming into a bowl with punch and eyes;
[0022] FIG. 7 is a cross-sectional view of flowforming a short preform into a long flowformed cylinder;
[0023] FIG. 8 is a view showing a spinning process; and
[0024] FIG. 9 is a view showing a hydroforming process.
DESCRIPTION OF THE INVENTION
[0025] Molybdenum (Mo) with Rhenium (Re)
[0026] Using Mo with 5%-20% Re increases that the material's ductility and reduces the material's ductile-brittle transition temperature (DBTT) from ˜300° C. to ˜50° C., making it cold-workable and flowformable at room temperature. The room temp elongation will increase from 8% to 50%.
[0027] See FIG. 2
[0028] See FIG. 3
[0029] The drawback to adding 5-20% Re is that Re is extremely expensive. So there could be a need to find a less expensive alternative material.
Tantalum (Ta) and Niobium (Nb) Alloy Crucibles
[0030] When alumina melts during the single crystal growth process at temperatures near 2080° C. (3,776° F.), it is not surprising that Mo is used for the crucible because it has a melting temp of 4,473° F. Years ago machining small crucibles of Mo was ok but today crucibles are 17″ diameter×19″ deep and machining solid pieces of Mo are not practical, nor economically/commercially viable. Again, the problem with Mo is that it is not formable with processes like flowforming. Using Tantalum which melts at 5,425° F. or Niobium (C-103) which melts at 4,260° F. are both better choices for large crucibles because these elements and their alloys are cold formable. Aluminum nitride (AIN) can be melted and left stable at high temperatures in inert atmospheres and melts at 2,800° C. in Ta crucibles. Ta crucibles can also work for Al 2 O 3 . Ta has a higher melting point compared to ceramics like alumina and boron carbide. Other materials such as Titanium melts at ˜3,000° F. and steels are less, so neither could work for the temperatures that sapphire single crystals are grown at. Ta and C-103 are very cold-formable and can be flowformed at Dynamic Flowform Corp. Ta and C103 are cheaper than Mo too. These alloys could be deep drawn, spun, flowformed, hydro-formed and a combination of each.
[0031] The grain size of the pure molybdenum increased substantially with increasing temperature from 1,700 to 2,300° C. The grain structure of the molybdenum will expand as the temperatures are increased for sapphire crystal growth. However, such grain growth is undesirable in a crucible because it becomes dimensionally unstable. One benefit of flowforming the Ta and Nb is the finer microstructure that will result from the cold work/plastic deformation during flow forming. A fine grain structure will help to keep the crucibles stable during grain growth at high temperatures. In addition to having flowformed grains as small as ASTM 7-14 other additive materials can be blended with the Ta and/or Nb to help keep the fine, flowformed grains from expanding and the crucible undesirably moving during annealing and raising the temperature to 2,050° C. Silicon up to 700 ppm and Thorium up to 500 ppm can be doped into pure Ta to help pin the grains at 2,400° C. (4,352° F.). A flowformed structure will have very fine grains (ASTM 7-14 grain size). Without pinning the grains, the grain growth of Ta at 2,400° C. could cause the grains to grow to ASTM 1-5, causing the crucible to be structurally weaker, more susceptible to embrittlement and dimensionally unstable.
[0032] Combining the flowforming with a doped Ta or Nb will create a crucible that has the most uniform, finest grain structure at all temperatures and will keep it the most stable during heating and cooling so not to crack the single crystal. The benefits of silicon and a stable metal oxide additions to Ta and Ta alloys also can be applied to other metals of Group V of the Periodic Table of the Elements, namely Niobium (Columbium) and Vanadium.
[0033] The first micrograph below shows the preform material that hasn't been worked much during flowforming process with large grains, ASTM 4-5. The second photo shows the same material with grains after its been worked, which are a lot smaller from the flowforming process, ASTM 10-14. Flowforming reduces the grain structure which will help with thermal stability during growing the single crystal and will help to make the crucibles optimized for an even diffusion of Carbon if required.
[0034] See FIG. 4
[0035] See FIG. 5
Ta and Nb Crucibles Carbonized
[0036] A key feature of our technique is the use of a tantalum and niobium growth crucibles. Before use, the tantalum crucible, having 1-2 mm thick walls, is annealed at 2,200-2,500° C. in a carbon-containing atmosphere. During the treatment, the crucible weight gradually increases due to the incorporation of C atoms into tantalum and the process is continued until the weight saturates (normally, in 30-40 h). The resulting weight maximum suggests that no free tantalum remains in the crucible. A three-layer structure of Ta/C—Ta—Ta/C kind is initially formed in the crucible walls during this procedure. As the crucible weight is saturating, the central layer gradually disappears due to the interaction of tantalum with carbon that is probably transported from the vapor via diffusion through small pores in the external T/C layers. Exploitation of such pre-carbonized crucibles for PVT growth of bulk AIN showed their remarkable thermal and chemical stability. The totally saturated crucibles can stay for 300-400 hours in the Al/N2 atmosphere at 2300° C. without visible degradation.
[0037] Tungsten crucibles are known to be intensively attacked by the reactive Al vapor and rapidly destroyed at high temperatures. Also, both Molybdenum and Tungsten are difficult-to-process materials exhibiting brittle behavior (especially after high temperature annealing). Unlike tungsten and molybdenum, tantalum can be easily processed before the carbonization treatment, which provides good scalability of the technology.
[0038] Combining carbon into the anneal of the Ta and Nb alloys at 2,000° C. creates Ta—Si—C and Nb—Si—C, which prevent the crucible form absorbing SiC vapors during the single crystal growth. If we combine flowformed fine grains, with Ta doped with Silicon and Thorium to prevent grain growth at crucible temps and diffuse in Carbon to seal off SiC into the tight lattice of the fine grain boundary network, you can have an optimal crucible. It will be easy to form, it will be chemically inert, dimensionally stable with no grain growth. If the Ta or Nb crucibles are so stable maybe they can be used longer or even used multiple times/reusable? Mo crucibles are a one-shot deal.
Composite Crucible:
[0039] An alternative method of producing a monolithic Mo, Ta or Nb alloy crucible is to coat the inside of a second crucible with a Mo film, creating a clad or bimetallic crucible. The substrate material can be more formable and less expensive; driving down material and fabrication costs of the composite crucible. Although this technique of coating a crucible with a Mo thin film has never been used before in the application of growing sapphire, single crystals, technically its achievable. Pure Mo has been deposited to many metallic substrates thru plasma sprayforming, chemical and vapor deposition processes, sputter process, wire arc melting, vacuum plasma spraying, vacuum arc deposition and other thin film deposition processes. Using a thick material as the crucible substrate and coating just a thin film on the inner diameter will use less of the expensive Mo, significantly reducing the part manufacturing cost.
[0040] The disadvantage of coating a dissimilar substrate is that the two materials could delaminate or crack apart during the single crystal growth process when the Al 2 O 3 (alumina) is melted in the molybdenum crucible at temperatures north of 2,000° C. because of the two materials' different coefficient of thermal expansion rates. Mo has one of the highest melting temperatures of all the elements and its coefficient of thermal expansion (CTE) is the lowest of the engineering metals:
[0000]
Coefficient of Linear Thermal Expansion (CTE), Approximate
Ranges at Room Temperature to 100° C. (212°
F.), from Lowest to Highest CTE
CTE
10 −6 /K
10 −6 /° F.
Material
2.6-3.3
1.4-1.8
Pure Silicon (Si)
2.2-6.1
1.2-3.4
Pure Osmium (Os)
4.5-4.6
2.5-2.6
Pure Tungsten (W)
0.6-8.7
0.3-4.8
Iron-cobalt-nickel alloys
4.8-5.1
2.7-2.8
Pure Molybdenum (Mo)
5.6
3.1
Pure Arsenic (As)
6.0
3.3
Pure Germanium (Ge)
6.1
3.4
Pure Hafnium (Hf)
5.7-7.0
3.2-3.9
Pure Zirconium (Zr)
6.3-6.6
3.5-3.7
Pure Cerium (Ce)
6.2-6.7
3.4-3.7
Pure Rhenium (Re)
6.5
3.6
Pure Tantalum (Ta)
4.9-8.2
2.7-4.6
Pure Chromium (Cr)
6.8
3.8
Pure Iridium (Ir)
2.0-12
1.1-6.7
Magnetically soft iron alloys
7.1
3.9
Pure Technetium (Tc)
7.2-7.3
4.0-4.1
Pure Niobium (Nb)
5.1-9.6
2.8-5.3
Pure Ruthenium (Ru)
4.5-11
2.5-6.2
Pure Praseodymium (Pr)
7.1-9.7
3.9-5.4
Beta and near beta titanium
8.3-8.5
4.6-4.7
Pure Rhodium (Rh)
8.3-8.4
4.6-4.7
Pure Vanadium (V)
5.5-11
3.1-6.3
Zirconium alloys
8.4-8.6
4.7-4.8
Pure Titanium (Ti)
8.6-8.7
4.8-4.8
Mischmetal
7.6-9.9
4.2-5.5
Unalloyed or low-alloy titanium
7.7-10
4.3-5.7
Alpha beta titanium
4.0-14
2.2-7.8
Molybdenum alloys
8.8-9.1
4.9-5.1
Pure Platinum (Pt)
7.6-11
4.2-5.9
Alpha and near alpha titanium
9.3-9.6
5.2-5.3
High-chromiun gray cast iron
9.3-9.9
5.2-5.5
Ductile high-chromium cast iron
9.1-10
5.1-5.6
Pure Gadolinium (Gd)
8.4-11
4.7-6.3
Pure Antimony (Sb)
8.6-11
4.8-6.3
Maraging steel
9.9
5.5
Protactinium (Pa)
9.8-10
5.4-5.8
Water-hardening tool steel
10-11
5.6-5.9
Molybdenum high-speed tool steel
6.8-14
3.8-7.8
Niobium alloys
9.3-12
5.2-6.5
Ferritic stainless steel
7.6-14
4.2-7.5
Pure Neodymium (Nd)
11
5.9
Cast ferritic stainless steel
8.9-12
4.9-6.9
Hot work tool steel
9.5-12
5.3-6.6
Martensitic stainless steel
9.9-12
5.5-6.5
Cast martensitic stainless steel
11
6.1
Cermet
10-12
5.6-6.6
Ductile silicon-molybdenum cast iron
10-12
5.6-6.5
Iron carbon alloys
9.3-12
5.2-6.9
Pure Terbium (Tb)
9.8-13
5.4-6.9
Cobalt chromium nickel tungsten
10-12
5.8-6.7
High-carbon high-chromium cold work tool
steel
11
6.2
Tungsten high-speed tool steel
8.5-14
4.7-7.8
Commercially pure or low-alloy nickel
11
6.3
Low-alloy special purpose tool steel
7.1-16
3.9-8.7
Pure Dysprosium (Dy)
9.3-13
5.2-7.2
Nickel molybdenum alloy steel
11-12
6.1-6.6
Pure Palladium (Pd)
11
6.3
Pure Thorium (Th)
11
6.4
Wrought iron
10-13
5.7-7.0
Oil-hardening cold work tool steel
7.6-15
4.2-8.5
Pure Scandium (Sc)
11-12
6.1-6.8
Pure Beryllium (Be)
6.3-17
3.5-9.4
Carbide
10-13
5.7-7.3
Nickel chromium molybdenum alloy steel
11-12
6.1-6.9
Shock-resisting tool steel
12
6.5
Structural steel
11-13
5.9-7.1
Air-hardening medium-alloy col
steel
11-13
6.2-7.0
High-manganese carbon steel
10-14
5.6-7.6
Malleable cast iron
12
6.6
Mold tool steel
8.8-15
4.9-8.4
Nonresulfurized carbon steel
11-14
5.9-7.5
Chromium molybdenum alloy s
9.4-15
5.2-8.2
Chromium alloy steel
12-13
6.5-7.0
Molybdenum/molybdenum sulf
steel
12
6.8
Chromium vanadium alloy steel
11-14
5.9-7.6
Cold work tool steel
11-14
6.0-7.5
Ductile medium-silicon cast iro
7.6-17
4.2-9.4
Nickel with chromium and/or in
molybdenum
11-14
6.2-7.5
Resulfurized carbon steel
12-13
6.4-7.4
High strength low-alloy steel (H
4.8-20
2.7-11
Pure Lutetium (Lu)
10-15
5.6-8.3
Duplex stainless steel
9.9-13
5.5-7.3
High strength structural steel
9.0-16
5.0-8.9
Pure Promethium (Pm)
12-13
6.5-7.4
Pure Iron (Fe)
11-14
5.9-8.0
Metal matrix composite alumin
10-15
5.6-8.6
Cobalt alloys (including Stellite
6.0-20
3.3-11
Pure Yttrium (Y)
11-15
6.0-8.5
Gray cast iron
9.0-17
5.0-9.6
Precipitation hardening stainles
13
7.4
Pure Bismuth (Bi)
7.0-20
3.9-11
Pure Holmium (Ho)
11-16
6.1-8.6
Nickel copper
13
7.4
Pure Nickel (Ni)
14
7.5
Palladium alloys
12-14
6.8-7.7
Pure Cobalt (Co)
10-17
5.6-9.6
Cast austenitic stainless steel
13-15
7.0-8.2
Gold alloys
8.1-19
4.5-11
High-nickel gray cast iron
14
7.8
Bismuth tin alloys
7.0-20
3.9-11
Pure Uranium (U)
14
7.8
Pure Gold (Au)
10-19
5.3-11
Pure Samarium (Sm)
7.9-21
4.4-12
Pure Erbium (Er)
13-16
7.0-9.0
Nickel chromium silicon gray c
14
7.8
Tungsten alloys
14-15
7.7-8.4
Beryllium alloys
12-18
6.7-10
Manganese alloy steel
10-20
5.6-11
Iron alloys
9.7-19
5.4-11
Proprietary alloy steel
15
8.5
White cast iron
12-19
6.7-10
Austenitic cast iron with graphit
8.8-22
4.9-12
Pure Thulium (Tm)
14-18
7.5-9.8
Wrought copper nickel
13-19
7.0-10
Ductile high-nickel cast iron
4.5-27
2.5-15
Pure Lanthanum (La)
16-18
8.8-10
Wrought high copper alloys
17
9.4
Cast high copper alloys
15-19
8.3-11
Wrought bronze
17-18
9.2-9.8
Cast copper
16-18
9.1-10
Wrought copper
17
9.6
Cast copper nickel silver
9.8-25
5.4-14
Austenitic stainless steel
16-19
8.9-11
Cast bronze
16-19
8.9-11
Wrought copper nickel silver
18
10
Pure Barium (Ba)
18
10
Cast copper nickel
18
10
Pure Tellurium (Te)
18-20
9.9-11
Silver alloys
indicates data missing or illegible when filed
Nickel-Iron Alloys:
[0041] Nickel-iron alloys have been developed mainly for controlled expansion and magnetic applications. The compositions of the principal NILO™ (Invar™ and Kovar™) and NILOMAG™ alloys are given below.
[0000]
Nickel-Iron materials with trade mark
names from Special Metals Corp.
Alloy
Ni
Fe
Others
NILO alloy 36
36.0
64.0
—
NILO alloy 42
42.0
58.0
—
NILO alloy 48
48.0
52.0
—
NILO alloy K
29.5
53.0
Co 17.0
NILOMAG alloy 77
77.0
13.5
Cu 5.0, Mo 4.2
[0042] NILO™ alloy K (UNS K94610/W. Nr. 1.3981), otherwise known as Kovar™ which is a nickel-iron-cobalt alloy containing approximately 29% nickel and 17% cobalt and the balance iron. Its thermal expansion characteristics match those of borosilicate glasses and alumina type ceramics. It is manufactured to a close chemistry range, yielding repeatable properties which make it eminently suitable for glass-to-metal seals in mass production applications, or where thermal stability is of paramount importance. The cost of Kovar is approximately $30/lb., whereas Mo is closer to $330/lb.
[0043] The physical and mechanical properties of Nilo™ alloy K (Kovar™) are described below:
[0000]
Coefficient of Thermal Expansion of Nilo ™ alloy K (Kovar ™) at
temperatures between 20-500° C.
Total
Temperature Range
Expansion
Mean Linear Coefficient
° C.
° F.
10 −3
10 −6 /° C.
10 −6 /° F.
20-100
68-212
0.48
6.0
3.3
20-150
68-302
6.75
5.8
3.2
20-200
68-392
0.99
5.5
3.1
20-250
68-482
1.22
5.3
2.9
20-300
68-572
1.43
5.1
2.8
20-350
68-662
1.62
4.9
2.7
20-400
68-752
1.86
4.9
2.7
20-450
68-842
2.28
5.3
2.9
20-500
68-932
2.98
6.2
3.4
[0044] The CTE of Kovar™ is very comparable to pure Mo which has CTE values ranging from 2.7 to 2.8 10 −6 /° F. If the substrate crucible is made with an appreciable thick Kovar™ material, it can be engineered to expand at the same rate as the thin film of Mo and not crack. Additionally, the Kovar is 53% iron, 29.5% nickel and 17″ cobalt, which are all elements less expensive than pure Mo, making this a cheaper alternative for the bulk of the crucible. Kovar™ is ductile with excellent room temperature formability characteristics, 42% elongation.
[0000] Tensile Yield Strength Elongation Temperature Strength (0.2% Offset) on 50 mm Reduction ° C. ° F. MPa ksi MPa ksi (2 inch) % of Area % 20 68 520 75.0 340 49.0 42 72 100 212 430 62.0 260 38.0 42 72 200 392 400 58.0 210 30.0 42 72 300 572 400 58.0 140 20.0 45 73 400 752 400 58.0 110 16.0 49 76
Mechanical properties of Kovar™ exhibiting 42% ductility at room temperature, making it quite formable
[0045] Other substrate materials could include pure Tantalum, pure Niobium or one of their alloys.
Fabrication Processes:
[0046] The Kovar™, Ta, Nb, and their alloys are all very cold-formable and can be made by any number of forming process, including but not limited to; deep drawing, spinning, hydroforming, bulge forming, flowforming, superplastic forming, roll and welding, fabricating and combinations of these processes. Because of the thin wall and the length-to-diameter ratio of the large crucibles, it would make sense to deep draw a preform and flowform to final wall thickness and length.
[0047] Deep drawing is a sheet metal forming process in which a sheet metal blank is radially drawn into a forming die by the mechanical action of a punch. It is thus a shape transformation process with material retention. The process is considered “deep” drawing when the depth of the drawn part exceeds its diameter. This is achieved by redrawing the part through a series of dies. The flange region (sheet metal in the die shoulder area) experiences a radial drawing stress and a tangential compressive stress due to the material retention property. These compressive stresses (hoop stresses) result in flange wrinkles but wrinkles can be prevented by using a blank holder, the function of which is to facilitate controlled material flow into the die radius.
[0048] See FIG. 6
[0049] Deep draw process, starting from sheet/disc and forming into a bowl with punch and dies.
[0050] Flowforming is an advanced, net shape cold metal forming process used to manufacture precise, tubular components that have large length-to-diameter ratios. A cylindrical work piece, referred to as a “preform”, is fitted over a rotating mandrel. Compression is applied by a set of three hydraulically driven, CNC-controlled rollers to the outside diameter of the preform. The desired geometry is achieved when the preform is compressed above its yield strength and plastically deformed and “made to flow”. As the preform's wall thickness is reduced by the set of three rollers, the material is lengthened and formed over the rotating mandrel. The flowforming is done cold. Although adiabatic heat is generated from the plastic deformation, the process is flooded with refrigerated coolant to dissipate the heat. This ensures that the material is always worked well below its recrystallization temperature. With flowforming “cold”, the material's strength and hardness are increased and dimensional accuracies are consistently achieved well beyond accuracies that could ever be realized through hot forming processes.
[0051] See FIG. 7
[0052] Spinning
[0053] The spinning process is fairly simple. A mandrel, also known as a form, is mounted in the drive section of a lathe. A pre-sized metal disk is then clamped against the mandrel by a pressure pad, which is attached to the tailstock. The mandrel and workpiece are then rotated together at high speeds. A localized force is then applied to the workpiece to cause it to flow over the mandrel. The force is usually applied via various levered tools. Because the final diameter of the workpiece is always less than the starting diameter, the workpiece must thicken, elongated radially, or buckle circumferentially.
[0054] See FIG. 8
[0055] Hydroforming
[0056] Hydroforming is a specialized type of die forming that uses a high pressure hydraulic fluid to press room temperature working material into a die. To hydroform aluminum into a vehicle's frame rail, a hollow tube of aluminum is placed inside a negative mold that has the shape of the desired end result. High pressure hydraulic pistons then inject a fluid at very high pressure inside the aluminum which causes it to expand until it matches the mold. The hydroformed aluminum is then removed from the mold.
[0057] See FIG. 9
Flowforming Molybdenum Crucible:
[0058] In another form of the invention, a molybdenum (or molybdenum alloy) preform blank is preheated to a temperature greater than the Ductile Brittle Transition Temperature (DBTT) and flowformed “cold” (e.g., with a coolant) at a temperature below the material's recrystallization temperature. Preheating above DBTT will make the material hot enough to flowform, the adiabatic heat from deformation will keep the material hot while flowforming, and “cold” flowforming (i.e., at a temperature below the recrystallization temperature of the material) will maintain the material's dimensional accuracies. Note that if flowforming is done at a temperature above the recrystallization temperature of the material, neither the dimensional accuracies nor the grain growth can be controlled.
Some Preferred Forms of the Invention
[0059] A crucible made of Mo—Re, Ta and Nb or an alloy thereof, that can be cold-formed to create a crucible with a very fine microstructure to help keep the crucible stable during heating and cooling during single crystal growth. Pure Mo, can be flowformed too if the preform is strategically heated above its ductile brittle transition temperature and below its recrystallization temperature and flowformed warm. The Mo preform only needs to be heated when the flowform rollers contact the preform. Once the plastic deformation of flowform process ensues, the adiabatic heat is sufficient to keep the material above the DBTT.
[0060] Using Mo with 5%-20% Re increases that the material's ductility and reduces the material's ductile-brittle transition temperature (DBTT) from ˜300° C. to ˜50° C., making it cold-workable and flowformable at room temperature. The room temp elongation will increase from 8% to 50%.
[0061] Another invention is to use a material that has a similar coefficient of thermal expansion, such as Kovar, Ta and or Nb to Mo, to allow for a thin film of Mo to be deposited to its substrate. Composite crucible made by depositing a Molybdenum film onto the bore (inner diameter) of abacking substrate crucible, i.e. a nickel-iron based metal, that has low/similar coefficient of thermal expansion rates as Mo. The nickel-iron alloys can be formed easily by conventional methods such as spinning, deep drawing and flowforming. None of which can be done easily with pure Mo. The Ni—Fe materials are significantly (an order of magnitude) cheaper than Mo, reducing material costs. The expensive Mo is applied as a coating to the Ni—Fe substrate thru any number of deposition processes, including but not limited to spray forming, sputtering, Chemical Vapor Deposition (CVP) and Physical Vapor Deposition (PVD), wire arc sprayforming, etc. Only a thin film of Mo for barrier (0.005″ to 0.100″ thick) purposes is required for high temperature requirements during the melting of the alumina. The structural integrity/strength of the crucible is achieved from the thicker backing crucible substrate, significantly reducing the material costs. The Mo barrier will shield the substrate from the higher temperatures. Furthermore, the feed stock for plasma spray forming and other deposition process can be powder metal which is Mo's cheapest form compared to mill products (wire, sheet, tube, bar, plate, billet, etc.). A composite/bimetallic crucible with dissimilar metals that have similar coefficient of thermal expansion rates will prove to reduce crucible costs' while improving manufacturability issues.
[0062] In other embodiments of the inventions, there can be three materials, one substrate or backing crucible and two layers of vacuum coatings and/or deposited thin films. Also the substrate-backing crucible can be made from other alloys that have low, similar CTE values as Mo, which could include, pure Tantalum, pure Zirconium, pure Niobium and their respective alloys. For example, pure Ta has a very high melting temperature and low CTE value, making it an attractive alternative for the substrate. Niobium alloy C103 also has very good combination of high temperature properties and with low CTE values, making it also an attractive alternative for the backing crucible. Producing crucibles for growing single crystal sapphires is just an example. These composite crucibles could be used to grow other crystals such as Aluminum Nitrate, Silicon, Ruby crystals, etc.
[0063] In plate form the Ta, Nb, Kovar alloys can be diffused together by diffusion bonding, sintering and hot isotactic pressing (HIP) and by explosively clad bonding. The clad plate can then be cold formed into a formed composite crucible.
[0064] Another technique is the use of a pre-treated tantalum or Nb growth crucible. Before use, the tantalum or niobium crucible is annealed at 2200-2500° C. in a carbon-containing atmosphere. During the treatment, the crucible weight gradually increases due to the incorporation of C atoms into tantalum or niobium and the process is continuing until the weight saturates. The resulting weight maximum suggests that no free tantalum remains in the crucible. A three-layer structure of Ta/C—Ta—Ta/C kind is initially formed in the crucible walls during this procedure. As the crucible weight is saturating, the central layer gradually disappears due to the interaction of tantalum with carbon that is probably transported from the vapor via diffusion through small pores in the external T/C layers. The Ta—C helps to keep the material more chemically inert and thermally stable during the single crystal growth process and cooling process. Have a flowformed structure with very fine grains will allow for a more uniform dispersion of the Carbon during the anneal carbonization process.
MODIFICATIONS
[0065] It should also be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention. | A crucible for growing crystals, the crucible being formed from Molybdenum and Rhenium. A crucible for growing crystals, the crucible being formed from a metal selected from Group V of the Periodic Table of the Elements. A crucible for growing crystals, the crucible comprising a body and a layer formed on at least a portion of the body, the layer being formed out of Molybdenum. | 50,760 |
The invention relates to the provision of mixtures of powders and to methods using them to produce highstrength, fine-grain sintered ceramic bodies, useful, for example, as cutting tools.
BACKGROUND OF THE INVENTION
Although many ceramic materials have been proposed as cutting tools for various applications, and some of these materials such as sintered or hot pressed silicon nitride are used quite successfully for some applications, aluminum oxide-titanium carbide is generally recognized as the best all around ceramic tool material. Commercial tools of this type are known to be produced by expensive and cumbersome hot pressing; see, by way of illustration, Ogawa et al, U.S. Pat. No. 3,580,708; Bergna et al, U.S. Pat. No. 3,542,529; and Ogawa et al, U.S. Pat. No. 4,063,908. In Brun, Lee and Szala, U.S. Pat. No. 4,515,746, a particulate mixture of powders of metal hydride, carbon and relatively inert ceramic powder, e.g., alumina are hot pressed to form useful composites comprising, for example, alumina-TiC when alumina, titanium hydride and carbon are hot pressed. Several recent disclosures, however, have shown that ceramic composites, e.g., alumina-TiC composites, can be sintered to a closed pore state, either by using specific oxides as sintering additives, e.g., Y 2 O 3 as in Kanemitsu et al, U.S. Pat. No. 4,356,272; Japanese Patent Publication 81,140,066 (Chem. Abs. 96:109112w) and Japanese Patent Publication No. 81,140,067 (Chem. Abs. 96:109111v); or by using titanium oxycarbide as in Japanese Patent Publication No. 79,103,407 (Chem. Abs. 92:63473b). Lee and Szala, U.S. Pat. Nos. 4,407,968 and 4,416,840 disclose sintering mixtures of aluminum oxide, carbon and elemental titanium or titanium hydride to composites having an Al 2 O 3 phase and a substoichiometric TiC phase. A very recent development is to use a significantly higher heating rate for the sintering process than is used in conventional practice; see Lee, Borom and Szala, U.S. Pat. No. 4,490,319.
If the heating rate of the sintering cycle is increased significantly over the current industrial practice, as disclosed in the above-mentioned U.S. Pat. No. 4,490,319, a dense, high quality ceramic article will be produced. Unfortunately, however, most commercial furnaces cannot produce high heating rates. Therefore, implementation of the new high-heating-rate process requires a sizable capital investment which decreases the economic incentives for adopting this new technology. On the other hand, addition of oxide additives in sufficient quantity to promote sintering of the ceramic powdered material to high density can alter the properties of the end products and diminish the usefulness of both the process and the product. Therefore, a method or methods which can produce materials without requiring major changes in facilities is still very much in need. The present invention solves such a need by providing new chemical compositions which can be sintered to a closed pore product with desirable properties using heating rates within the range of current industrial facilities. Moreover, if desired, the powdered ceramic mixtures provided by this invention can also be effectively densified using a rapid rate process, e g., that of the above-mentioned U.S. Pat. No. 4,490,319, to provide unexpected and desirable ultimate properties.
The following definitions are applicable to an understanding of this invention and/or the prior art:
SINTERING: development of strength and associated densification of a powder compact through the application of heat alone.
HOT PRESSING: the combined application of heat and of pressure applied through the action of a mechanical piston on the powder-filled cavity of a die. Under such conditions the pressure on the powder compact is non-uniformly applied due to die wall friction and the axial application of the piston force. Under proper conditions of temperature and pressure, densification of the compact can result.
HOT ISOSTATIC PRESSING (HIP): The simultaneous application of isostatic pressure and heat to a sample body whose porosity is to be reduced. Pressure is applied uniformly to the sample body by an inert gas. The sample body may be (a) a powder compact encapsulated in a gas impermeable, but deformable, envelope such as a tantalum foil can or a glass coating or (b) any solid substantially devoid of open porosity.
The sintered product of this invention is considered to be "substantially crystalline", because it is not atypical to encounter minor amounts of non-crystalline material (e.g. glasses) in the grain boundary phases.
This invention addresses a particularly troublesome problem encountered in the sintering of multiphase systems. Such systems frequently contain components, which will chemically interact at elevated temperatures and produce gases. If such chemical reaction proceeds fast enough to inhibit the desired densification or, if the nature of the reaction is such that it results in degradation of the system (i.e., undesirable solid, liquid or gaseous phases are produced), manufacture of the optimum product cannot be readily accomplished by sintering.
While not intending to be bound by any theory, it is believed that ceramic oxides, e.g., aluminum oxide, react with carbon or carbon-containing materials, e.g., titanium carbide, or the like, at temperatures exceeding about 1550° C., emitting gaseous materials which in turn hinder the consolidation of the mixture on further heating. Such problems seem to intensify if free carbon is introduced with the carbide or if the particle size of the powdered component in the mixture is reduced.
It has now been discovered that if an additional component is included, such problems will be minimized. Specifically, according to this invention there will be included in the ceramic powder an additive which will become an effective scavenger of the evolving gas phase from the reaction between alumina, for example, and carbon, or a source of carbon. Judiciously selected such additives will also provide enhanced properties in the sintered products.
Typical examples of the invention are the addition of small quantities of either zirconium hydride or hafnium hydride to a ceramic powder mixture, e.g., a mixture of alumina and titanium carbide, and the like. The hydrides stay relatively clean during the conventional powder processing stages, but decompose to highly reactive components at about 1000° C. This reactive metal forms oxides or carbides by reacting with the gaseous product evolving from the carbide-oxide or carbon-oxide reaction.
As a further advantage, small amounts of by-products, e.g., zirconium oxide or hafnium oxide, formed in the reaction, can also be retained in the high temperature phase to provide transformation toughening of the sintered product. In some cases, the resulting carbide from the process can dissolve into a carbide phase, for example, a titanium carbide phase, without detracting in any way from the desirable properties of the final product.
This invention is primarily described herein in respect to the Al 2 O 3 -TiC system, because this particular material system often presents the very problem in densification discussed herein above. However, the essential aspects of the sintering process disclosed herein are not dependent upon either the use of particular sintering additives, particular material proportions, or the nature of minor impurities. The process is expected to be broadly applicable to the sintering of powdered ceramic materials, that contain components which will chemically react at elevated temperatures to inhibit densification or degrade the system so that an undesirable sintered product results.
SUMMARY OF THE INVENTION
According to this invention, a mixture of powdered ceramic materials is consolidated under pressure to produce a cold pressed green compact of some preselected shape and volume, and the compact is heated to a maximum sintering temperature. The mixture contains non-inhibitory components, e.g., aluminum oxide, titanium carbide, and the like, and a source of inhibitory components, such as carbon or a carbon source, or an oxide or oxicarbide of a metal, such as titanium, magnesium, chromium, zirconium, hafnium, tungsten, or a mixture of any of the foregoing, the inhibitory components being capable of chemically interacting with the non-inhibitory components at elevated temperatures to generate gases which hinder densification or form phases undesirable for sintering. It is the essence of the invention to include in such mixtures an amount of a source of at least one component co-reactive with the inhibitory components at elevated temperatures to provide efficient densification and retention of properties in the sintered body.
In preferred aspects, the present invention contemplates the use of hot isostatic pressing after sintering; the use of ceramic mixtures comprising powdered aluminum oxide and powdered titanium carbide; and the use of additives comprising zirconium hydride, hafnium hydride or a mixture of such hydrides.
DETAILED DESCRIPTION OF THE INVENTION
The mixture of ceramic materials used in the present invention will vary widely in chemical type and proportions of ingredients used. In addition to the preferred combinations of aluminum oxide and titanium carbide, other components can be included or substituted, and the amounts varied. Merely by way of illustration, suitable starting powder mixtures, before addition of the additives of the invention can comprise:
aluminum oxide and titanium carbide, 50-50w/w, aluminum oxide and titanium carbide, 72-28w/w, aluminum oxide and zirconium oxide, 87.3-12.7w/w, aluminum oxide, titanium carbide and zirconium oxide, 63-30-7w/w,
aluminum oxide and titanium nitride, 70-30w/w, aluminum oxide and 500 ppm of magnesium oxide, commercial grade yttrium oxide powder, and many others,
ceramic oxides, like HfO 2 , BeO, Cr 2 O 3 , La 2 O 3 , ThO, UO 2 , ZrO 2 , BaZrO 3 , BeZr 2 O 7 , ThO 2 ·ZrO 2 , and mixtures and solid solutions thereof. Also ceramic carbides, such as the carbides of boron, hafnium, niobium, tantalum, vanadium, zirconium and mixtures and solid solutions thereof. Still other useful components in the ceramic powders are the borides of hafnium, niobium, tantalum, titanium, vanadium, zirconium, and mixtures and solid solutions thereof. More specifically, representatives of the borides are HfB 2 , NbB, NbB 2 , TaB, TaB 2 , TiB 2 , VB, VB 2 and ZrB 2 .
The proportions in the mixtures can vary within ranges well known to those skilled in this art. For example, the mixtures comprising alumina and titanium carbide most generally will be selected to provide products comprising 40 to 80% by weight of alumina and from about 20 to about 60% by weight of titanium carbide.
The amount of component effective to interact with the gas generating compound or gas used in the powdered mixture can vary rather widely, so long as at least enough is present to react with any inhibitory components present. Ordinarily this will range from about 0.5 to about 5 weight percent of the mixture, preferably from about 1 to about 2 weight percent. The components are introduced in conventional ways, e.g., by grinding or dry blending.
In addition to zirconium hydride and hafnium hydride, as additives there can be used the hydrides of niobium, tantalum, titanium, vanadium, mixtures thereof, and the like.
In carrying out the present process, a particulate homogeneous or at least a substantially homogeneous mixture or dispersion of ceramic powder and any sintering aid additive is formed. The components of the mixture or dispersion can be of commercial or technical grade. They can be admixed by a number of techniques such as, for example, ball milling, vibratory milling or jet milling, to produce a significantly or substantially uniform or homogeneous dispersion or mixture. The more uniform the dispersion, the more uniform is the microstructure, and therefore, the properties of the resulting sintered body.
Representative of these mixing techniques is ball milling, preferably with balls of material such as alpha-Al 2 O 3 which has low wear and which has no significant detrimental effect on the properties desired in the final product. If desired, such milling can also be used to break down any agglomerates and reduce all materials to comparable particle sizes. Milling may be carried out dry or with the charge suspended in a liquid medium inert to the ingredients. Typical liquids include ethyl alcohol and carbon tetrachloride. Milling time varies widely and depends largely on the amount and particle size reduction desired and type of milling equipment. In general, milling time ranges from about 1 hour to about 100 hours. Wet milled material can be dried by a number of conventional techniques to remove the liquid medium. Preferably, it is dried by spray drying.
In the present dispersion or mixture the average particle size ranges from about 0.1 micron to about 5 microns. An average particle size less than about 0.1 micron is not useful since it is generally difficult or impractical to compact such a powder to a density sufficient for handling purposes. On the other hand, an average particle size higher than about 5 microns will not produce the best ceramic body. Preferably the average particle size of the mixture ranges from about 0.3 micron to about 1 micron.
A number of techniques can be used to shape the powder mixture into a compact. For example, it can be extruded, injection molded, die-pressed, isostatically pressed or slip cast to produce the compact of desired shape. Any lubricants, binders or similar materials used in shaping the powder mixture should have no significant deteriorating effect on the resulting sintered body. Such materials are preferably of the type which evaporate on heating at relatively low temperatures, preferably below 500° C., leaving no significant residue. The compact should have a density at least sufficient for handling purposes, and preferably its density is as high as possible to promote densification during sintering.
The compact is placed within a furnace and provided with a partial vacuum wherein the residual vapor has no significantly deleterious effect thereon. Ordinarily, a carbon furnace is used, i.e., a furnace fabricated from elemental non-diamond carbon. This partial vacuum is provided throughout the present heating step producing the present sintered body. Preferably, upon completion of sintering, the sintered body is furnace cooled to room temperature in this partial vacuum. The partial vacuum should be at least sufficient to remove from the furnace chamber, i.e., the environment or atmosphere enveloping the compact, any excess gas generated during the heating step which would have a significantly deteriorating effect on the compact. On the other hand, the partial vacuum should not be so high as to vaporize the compact to any significant portion, i.e., higher than about 10% by volume, or the residual vapor in the environment or atmosphere enveloping the compact at sintering temperature is an inert gas such as nitrogen, helium or argon. Preferably, such gas is present during the entire heating period. A number of conventional techniques can be used to introduce and maintain the inert gas in the residual vapor. For example, the gas can be leaked in using a needle valve.
The present sintering temperature ranges from about 1650° C. to about 1950° C. Ordinarily, sintering temperatures outside this range will no produce the present sintered body. For best results the sintering temperature ranges from about 1850° C. to about 1920° C.
The particular sintering time period to produce a sintered body having a minimum Rockwell A hardness of 92 or 91 depends largely on the sintering temperature and is determinable empirically with increasing sintering temperature requiring less sintering time. Generally, however, to produce the present sintered body having a minimum Rockwell A hardness of about 92 at a sintering temperature of about 1800° C., a suitable sintering time period is about 2 hours, and to produce the sintered body with a minimum Rockwell A hardness of about 91, the sintering time period at 1800° C. would be somewhat less, i.e., about 1 hour.
Generally, the present sintered body having a minimum Rockwell A hardness of 91 has an outside surface portion which is impermeable to gas. Ordinarily, the outside surface portion of the sintered body with a minimum Rockwell A hardness of 92 is impermeable to gas. One way of determining if the outside surface portion of the sintered body is impermeable to gas can be carried out by suspending the sintered body and immersing it in water or other liquid and determining whether the thus-suspended-immersed body shows any observable weight gain. If no weight gain is observed, then the sintered body will have attained closed porosity in its entire outer surface. Alternatively, the closed porosity can be determined by careful metallographic examination of polished sections of the sintered body.
The Rockwell A hardness of the present sintered body having an outside surface portion which is impermeable to gas, can be increased by subjecting it to hot isostatic pressing. Such hot isostatic pressing can be carried out in a conventional manner. For example, the sintered body can be compressed in a pressurized gaseous atmosphere under a pressure of at least about 5000 psi, generally from about 5000 psi to about 15,000 psi, at a temperature ranging from about 1350° C. to about 1750° C. producing a sintered body having a Rockwell A hardness of about 93 or higher. The gaseous atmosphere should have no significant deleterious effect on the sintered body. Representative gases suitable for providing the pressurized gaseous atmosphere include argon, nitrogen and helium.
Ordinarily the volume fraction of pores in the present product is less than about 5% by volume and usually less than 3% by volume of the product. All, or substantially all, of the pores are closed or non-interconnecting, and generally, they are less than about 1 micron in diameter. The pores are well distributed in the product and have no significant deleterious effect thereon.
The present invention makes it possible to reproducibly and economically fabricate complex shaped ceramic articles directly. The sintered product of this invention can be produced in the form of a useful, simple, complex or hollow shaped article without machining. The dimensions of the sintered product would differ from those of the green compact by the extent of dimensional change occurring during shrinkage. The al 2 O 3 -TiC system as sintered in the practice of this invention has particular utility in the preparation of tool inserts for machining operations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is further illustrated by the following examples. In each example the powders were pre-pressed isostatically to about 50 kpsi. The compact plugs so produced were processed in the dilatometer-equipped furnace. The furnace was evacuated to 50 millimicrons vacuum, helium was introduced and was allowed to purge the furnace at one atmosphere pressure during the rest of the cycle. Natural furnace cooling was relied upon to reduce the temperature to room temperature. Where values are indicated, material density was determined by immersion density measurement. In all examples, the sintered bodies had essentially no open pores. Microstructural observations were made in most instances.
EXAMPLE 1
Seventy grams of -325 mesh titanium carbide powder was placed in a tungsten carbide/cobalt ball mill along with acetone as a vehicle. The powder was milled for 120 hrs. to reduce the particles to submicron size. One-hundred eighty grams of 0.3 micron alumina powder and 5 grams of -325 mesh zirconium hydride powder were added to the milled titanium carbide powder. The mixture was milled for 72 hours, air dried and sieved through a 50 mesh screen. For comparison purpose a control batch of powder containing no zirconium hydride was prepared following the same procedure as stated above.
Specimens of the powders were pressed to shape in a 3/4" square die at a pressure of approximately 1000 psi. The 3/8" thick specimens were further compacted by isostatic pressing at 52 kpsi (10 3 pounds per square inch) to a green density of 55% of theoretical.
The specimens were placed in a furnace and heated at a rate of 50° C./min. to 1950° C. in helium. Density of the fired specimens was determined by the immersion technique.
The sample according to this invention containing zirconium hydride achieved a density of 4.41 gm/cm 3 (98%) with no open porosity, while the sample without zirconium hydride, according to the prior art, only achieved a density of 3.71 (82%) with 15% open porosity. Both samples were then hot isostatically pressed at a temperature of 1525° C for 10 minutes at 15 kpsi gas pressure. The sample according to this invention, containing zirconium hydride, achieved essentially full density (4.50 gm/cm 3 ) with no porosity, while the sample without zirconium hydride, according to the prior art, experienced no change in density.
The hot isostatically pressed, composite made with zirconium hydride according to this invention, exhibits an extremely fine grained microstructure with essentially no residual porosity and a hardness of R a 94.5 (ASTM -18-74). X-Ray diffraction analysis indicates that the ZrH 2 additive was converted to tetragonal ZrO 2 .
EXAMPLE 2
The procedure of Example 1 was repeated, but using instead the rapid heating rate process disclosed in U.S. Pat. No. 4,490,319. The pressed powder body containing zirconium hydride was fired in helium at a heating rate of 50° C/min. up to 1500° C. followed by 400° C./min. to 1950° C. The rapid rate sintered sample after hot isostatic pressing had an extremely fine-grained highly desirable microstructure and a density of 4.48 which is 99% of theoretical.
EXAMPLE 3
Specimens of the hot isostatically pressed material made with zirconium hydride in accordance with Example 2 were ground into 1/2×1/2×3/16" cutting tools. These cutting tools were tested in cutting a nickel base superalloy at 600 surface feet per minute, at a 0.080 inch depth of cut and a 0.008 inch feed rate. The tool performance was highly acceptable and comparable to that of the best commercially available hot pressed Al 2 O 3 -TiC tools.
EXAMPLE 4
If the procedure of Example 1 is repeated, substituting hafnium hydride for the zirconium hydride, substantially the same results will be obtained.
The above-mentioned patents and publications are incorporated herein by reference.
The principles, preferred embodiments and mode of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein, however, is not to be construed as limited to the particular forms disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the invention. | High-strength, fine-grain, multi-phase substantially crystalline sintered ceramic bodies are produced by a process comprising the steps of cold pressing, followed by sintering at a high temperature, of a mixture of different powdered ceramic materials containing non-inhibitory components and a source of inhibitory components that can chemically interact at elevated temperatures generate gases which hinder densification or form phases undesirable for sintering provided that there is also included in the mixture an amount of a source of a component co-reactive with the gases produced by the inhibitory components at elevated temperature to achieve efficient densification and retention of properties in the sintered body. | 23,510 |
This application relates to evacuation systems for offshore drilling platforms.
BACKGROUND OF THE INVENTION
The offshore drilling industry and the technology associated with it have developed rapidly in the last twenty years. The drilling rigs in use today have evolved into sophisticated structures, designed and built to withstand the severest of environmental conditions and to operate in very deep waters. Advanced computer technology has contributed substantially to bring platform development to its present position. Computers are integral, for example, to the collection and evaluation of geological and seismic date, to the operation of dynamically positioned platforms, and to methods of well control.
In spite of the advanced state of technology, accidents requiring evacuation from drilling platforms still occur. Such accidents may include, for example, fire on board. In addition to this type of accident, environmental conditions off certain coasts, such as off Eastern Canada, are especially severe with extremes of wind and wave, and a frequency of storms above that found in other areas. Both accidents and weather conditions may necessitate evacuation of the platform. Such occurences have in recent years lead to loss of life by virtue of the inadequacies of the evacuation systems.
Unfortunately, evacuation systems and the component parts of those systems have not kept pace with the rapid development of technology in the platform itself. There are currently, in particular, shortcomings in all three major components of evacuation. These components are the mustering and boarding procedure, the launch and the removal of the survival craft from the area of the platform. As a result, there is a critical need for a safe means of evacuation of a drilling platform in last resort situations.
PRIOR ART
A number of systems for evacuation of ocean-going vessels have been devised over a long period of years. These generally have been concerned with the specific manner of launch of lifeboats from ships.
Among early examples is that illustrated in U.S. Pat. No. 582,069, granted May 4, 1897, to Leslie, and illustrating a launch system in which a pair of davits of elongated configuration are attached to pivot downwardly from a ship's side to launch a lifeboat at some distance from the ship. The boat simply floats off the davits as they are lowered into the water.
A similar example is illustrated in U.S. Pat. No. 609,532, issued Aug. 23, 1898 to Cappellini. That patent illustrates a similar pair of pivoting davits which in this case are controlled in their descent by a hydraulic system. Of note in this early patent is the system allowing the ship's captain to launch the lifeboats from the bridge through a series of exploding blocks. The lifeboat will be deposited at some distance from the side of the ship.
U.S. Pat. No. 2,091,327, issued Aug. 31, 1937, to McPartland illustrates a further example of the rotating davit type of launch system which deposits the lifeboat some distance from the side of the ship. The boat simply floats off the davit as the davit is lowered toward water level.
Finally, U.S. Pat. No. 2,398,274, issued Apr. 9, 1946, to Albert, illustrates a launching and pick-up device for patrol boats, launches or the like. The launching and pick up platform is mounted on rotating davits and is lowered by a series of cables connected to the davits and the platform. The boat simply floats off the platform when the platform is lowered below water level. In this case the small boat is launched quite close to the mother ship. Of note, the direction of launch is such that the launched boat enters the water with a direction of travel aimed directly at, or, presumably, away from the mother ship.
In all these cases the systems include means for maintaining the trim of the survival craft during launch.
More recently, evacuation systems have been proposed for offshore drilling platforms which incorporate a number of the features of these early patents, including a rotating davit fixed to the side of the platform. Other proposals include free-fall type systems in which the escape craft is launched by free fall from tracks near the surface of the platform.
None of these systems deal adequately with the range of problems which must be addressed in order to establish a safe and reliable system.
Accordingly, the present system has been developed to overcome problems inherent in various of the prior art systems.
SUMMARY OF THE INVENTION
A system has now been developed which in its various embodiments is directed at improvements in the ability of personnel to board a survival craft, in the launch structures and procedures, in removal after launch from the area of the platform and in survival craft location by rescue ships when at sea.
Accordingly, in a first embodiment the invention provides an offshore evacuation system for drilling rigs or platforms comprising a launch structure for survival craft; the structure comprising at least one support strut adapted to be pivotally attached at one end thereof to the platform superstructure and carrying at the other end thereof a support cradle for survival craft, and rotatable between an upper position and a lower position; and means for effecting rotation of said launch structure from said upper to said lower position; and a closed passageway leading from the platform accommodation unit to the loading position of the survival craft and being in sealing relationship with the survival craft.
In a further embodiment, there is provided an offshore evacuation system for drilling rigs or platforms comprising a launch structure for a survival craft; the structure comprising at least one support strut pivotally attached at one end thereof to the platform superstructure and carrying at the other end thereof a support cradle for a survival craft; the structure rotatable between an upper load position and a lower launch position and means for effecting rotation of said launch structure from said upper to said lower position; and an onboard computer for said survival craft for monitoring environmental and platform conditions and for controlling the launch of said survival craft.
GENERAL DESCRIPTION OF THE INVENTION
A number of specific problems can readily be isolated which require solutions in the optimum system. A first problem lies in getting the crew to the boats in the most expeditious and safest manner. A second problem is in providing in the boat a "safe haven" prior to launch which enables the crew to delay launch to the last possible minute. A third problem is in reducing the complexities of launch and removing to as a great an extend as possible the human element. During launch it is essential that the boat be deposited at a safe distance from the platform to avoid collisions with the platform after launch. Finally, the problem of navigation following launch must be addressed, again to avoid collisions with the platform and to allow for quick location and retrieval of the boat from the sea. A complete system must deal with all of these problems, and the present invention in its various embodiments addresses these difficulities.
In broad form as noted above the invention includes a launch system for a totally enclosed motor propelled survival craft. Some such craft are known and others are under development. They must meet rigid regulatory requirements and they are not in themselves the subject matter of the present invention. The basic system may be enhanced by a closed companionway entry system to the craft and a computer controlled evacuation sequence.
The mechanical aspect of the launching system includes a rotating davit arrangement which is secured for rotation to the platform girders. Lowering of the davits is accomplished by means of a winch and cable arrangement. The preferred configuration for the davit system is an inverted V shape with a support member extending from the top thereof. While the preferred configuration is one in which the launch structure would accommodate a single survival craft only, it is also contemplated that the structure could if required accommodate a pair of survival craft. The single boat configuration is preferred because of a general feeling that larger craft are safer. However, particularly in a transition period where it might be economically attractive to utilize a platform's existing boats, the structure can be adapted to a two boat situation.
In the preferred case where a single survival craft is utilized, the support member at the top of the inverted V-shaped davit carries a U-shaped cradle support. Attached for rotation within the arms of the U-shaped cradle support is a survival craft support cradle. The cradle rotates to maintain the longitudinal axis of the craft in a horizontal position; i.e., to maintain trim, and, when the support structure pivots down to water level and below, the rescue craft simply floats off the cradle.
The permanent support structure in the loading area of the craft preferably includes a pair of stanchions with arms extending above the survival craft to secure the craft in the cradle prior to lowering.
The launch sequence is preferably computer controlled. When the survival craft is loaded and the latch manually closed, the computer begins to monitor and control the launch. Various control sequences can be proposed, and that discussed here is by way of example.
Upon sensing that the survival craft hatches are all sealed and closed, the computer provides suitable signals to the control person. When the first steps have been verified the computer will indicate that the craft is ready for launch.
As indicated, the survival craft satisfies the safe haven concept. That is to say, the craft provides an airtight enclosure which enables the platform crew to take refuge within the craft to avoid hazardous gases, fire and the like. Once the crew is in the craft with hatches closed, the actual launch of the craft can be delayed until it is determined that remaining with the platform will endanger the lives of the crew members. Since evacuation of the platform will only take place during time of maximum stress on crew members, it is highly desirable that the escape procedure be as automated as possible. It is for that reason that the present invention contemplates the availability of a launch sequence controlled entirely by computer. Obviously, the system is always subject to a manual override. The following descirbes generally the additional functions which can advantageously be carried out under microprocessor control.
When the survival craft is fully loaded or is otherwise ready for launch, as indicated by the sealing of the hatches on the craft, the launch sequence can shift to computer control. As a first step in this sequence, as indicated above, the microprocessor may ensure that weight distribution in the craft is acceptable for launch. This would be of particular importance in those situations where the craft was only partially filled.
The control system would then by visual and/or audible signal indicate that the craft is ready for launch. It is then necessary for the critical decision to be taken by the control person as to whether the crew is to remain in the survival craft as a safe haven at the platform or to continue with a full fledged evacuation. This decision is clearly based on a number of factors dealing with conditions exterior to the survival craft. For example, such data as time, wind speed and direction, wave height, general sea state, trim and list condition of the rig, condition of the well, presence of hazardous gases or fire are all factors which will influence a decision to abandon a rig. All such conditions are remotely monitored by the survival craft onboard computer.
Assuming a decision is made to evacuate the platform, a launch sequence initiator switch will be activated. Such a switch is preferably in the form of a large area push button. The reduced manual dexterity coincident with the wearing of an immersion suit requires that such switches be readily accessible with limited manipulation.
The second step in the automatic procedure contemplates a series of system activation steps. These include engine start up, sprinkler system activaton (may be delayed until craft is launched), onboard compressed air system activation (to create a positive pressure inside the survival craft to ensure that no hazardous gases are drawn in), and activation of the radio directional finder (RDF). The onboard computer through the RDF or the onboard compass automatically controls the course of the survival craft. A signal is received by the RDF from the platform standby vessel which will have positioned itself to effect rescue from the survival craft, following launch, and the survival craft will automatically set a course for the standby vessel.
In the preferred situation the survival craft is provided with a radar transponder to aid in location of the craft in the water by a rescue vessel.
Initiation of these systems completes preparation for launch, and a further visual and/or audible signal indicates this state of final readiness to the control person. Assuming the launch is to go forward, an actual launch initiation switch is activated. The effect of this action is to release the brake on the launch cable winch to thereby begin the lowering of the support frame. The frame is lowered at a controlled rate and, when it reaches water level, the survival craft simply floats off its cradle. The support frame continues to lower into the water to ensure that it is well clear of the survival craft. At this point the craft engine is at full throttle to ensure that the craft is not swept back into collision with the platform structure. The engaging of the transmission of the survival craft power train and application of full throttle is achieved automatically upon separation of the craft from the cradle. At this point a preprogrammed compass course followed after a preset time interval by an RDF signal from the standby vessel guides the survival craft away from the platform and toward the standby vessel.
A further preferred feature of the present invention is the presence of an enclosed airtight companionway connected through airtight seals at one end to the rear entry of the survival craft and at the other end to the accommodation area of the platform. This companionway provides protected and hazard-free access to the survival craft, thereby avoiding both the obstructions which arise from time to time on deck areas, and adverse environmental conditions, including fire and hazardous gases. The companionway is provided with emergency lighting and also acts as a heated storage area for immersion suits and lifejackets. Along with those stored in the accommodation area, the supply is sufficient to comply with regulatory requirements. Preferably the suits and jackets stored in the sealed companionway are in addition to the regular complement stored in the accommodation area.
It is much preferred that a single survival craft be utilized, since conditions prevailing at the time of an evacuation are such that difficulties in accounting for crew members are dramatically deceased by having a single assembly point. As well, the task of the standby vessel in dealing with the survival craft is simplified where only one such craft is present in the water.
A further distinct advantage to the use of a single larger craft is in its added space and seaworthiness. Both factors contribute to passenger morale and reduce the likelihood of seasickness.
Nonetheless, it is contemplated that a second and similar unit can be provided at the opposite end of the platform to be used as a backup unit should conditions prevent the crew from reaching the primary craft.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate embodiments of the invention:
FIG. 1 is a top plan view of a semisubmersible drilling platform incorporating the system of the invention;
FIG. 2 is a side elevation of the platform of FIGURE 1;
FIG. 3 is a side elevation of a survival craft support structure in the raised position;
FIG. 4 is a top plane view of a survival craft support structure and cradle;
FIG. 5 is a plan view of a platform accommodation area including an evacuation companionway; and
FIG. 6 is a flow chart for one embodiment of the computer controlled launch sequence.
While the invention will be described in conjunction with illustrated embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description, similar features in the drawings have been given similar reference numerals.
The drilling platform 10 is typical and is therefore useful in describing the invention. However, it will be readily apparent that the invention is applicable to a wide variety of drilling platforms having various specific configuraitons and layouts. The illustrated platform will therefore not be described in detail, the detail being apparent to those skilled in the art.
As illustrated, the evacuation structure 12 is installed at the bow 14 of the platform 10. In the preferred case a similar structure would be installed at the stern 16 of the platform 10. Each such structure would support a survival craft 18 capable of accommodating the entire crew of the platform 10. The usual required standard for evacuation capacity is two hundred per cent of the platform's complement. Accordingly, the installation of two of the systems of the invention, one at bow and one at stern, would fulfill this requirement.
The major components of the evacuation system of the present invention include the survival craft support structure 20, the onboard computer 22 (not illustrated), and the closed passageway 24. The totally enclosed motor propelled survival craft 18 is not in itself a part of the invention, inasmuch as conventional such craft could be modified to fit into the inventive system. It should be emphasized that it is not necessary that all of these components be present for all applications of the inventive system. For example, in some cases the closed passageway may not be present, although it is not to be implied that it is not highly preferable that the passageway be present in all cases. As well, in certain applications the onboard computer control functions may be modified or absent, although, again, it is highly preferable that the complete system be present in all cases.
With particular reference to FIGS. 3 and 4, the survival craft support structure 20 comprises the extended A-frame 28 and the cradle support structure 30. The A-frame 28 is rotatably connected at 32 and 34 on the main transverse girder 36. The main transverse girder 36 is at approximate pontoon level on a semisubmersible platform.
The rotation of the A-frame 28 is controlled by a winch and cable system comprising a winch 38 at deck level and a cable 40 secured to the A-frame 28 or the cradle support structure 30.
The cradle support structure 30 comprises an extension 42 to the A-frame 28, a transverse member 44 secured across the end of extension 42, and pair of upstanding arms 46. Structure 30 is in the plane of the A-frame 28.
Rotatably connected to the arms 46 is a survival craft support cradle 48. The cradle may take any of a large number of configurations but in one of its simpler forms as illustrated consists of a pair of elongated elements 50 and 52 from which are hung a pair of slings 58 and 60 each comprising a pair of vertical members 62 and 64 and transverse members 66 and 68. Vertical members 62 and 63 are of such length that elongated elements 50 and 52 are positioned immediately below the gunwales of the survival craft 18. The positioning of elements 50 and 52 with respect to the gunwales prevent the craft 18 from falling off of cradle 48 should the rig or platform sustain a significant list. Fixed to the transverse members 66, and 68 is a keel support member 70 which engage the keel or bottom of the hull of the survival craft 18. The survival craft 18 rests within this support cradle 48. As clearly illustrated in the drawings, no part of the launch structure extends above survival craft 18. As well, the cable 40 is attached to A-frame 28 or cradle support structure 30 below the level of support cradle 48.
The support cradle 48 is rotatably attached to the upstanding arms 46 by means of the pivot mechanisms 72 and 74 on the horizontal axis AA. Mechanisms 72 and 74 are such as to maintain the trim position of the support cradle 48 and thus of the survival craft 18 during the course of lowering the craft 18 into the sea. This is preferably achieved by a positive gear train which will not be susceptible to wind or water effects. A cable and reel system would also be very suitable.
It should be noted that the A-frame structure was chosen to provide adequate strength in the transverse direction. It is not of critical importance, however, that this particular configuration of structure be provided. It is only necessary that the structure have the pivoting capability and the strength required to withstand wind and wave effects.
As illustrated particularly in FIGS. 1 and 5, a decking structure 76 is provided at platform deck level to provide access to the survival craft 18 and to the support cradle 48 for maintenance purposes. As well, the decking structure 76 provides a support for the closed passageway to be discussed below.
In order to maintain the survival craft 18 securely in the support cradle 48 when in the storage position, at least one pair of stanchions 78 and 80 are provided extending upwardly from the decking structure 76. These stanchions include at the top thereof transversely extending members 82 and 84. These last contact the upper structure of the survival craft 18 and maintain its position. When a launch takes place, the support cradle 48 with the survival craft 18 simply drops away from members 82 and 84, leaving the craft 18 free to float off the cradle when the cradle is lowered into the water.
The survival craft 18 may take any one of a large number of configurations. All of these must meet applicable government regulations. As a minimum all will be totally enclosed and motor propelled. A positive pressure is maintained in the craft when in use to ensure that hazardous gases are not drawn inside. The craft is preferably equipped with individual high-backed seats with a four-point safety harness.
It is much preferred that the sequence of steps necessary to launch the survival craft be controlled by an onboard computer. The computer will have an onboard power supply but will be capable of interfacing with the drilling platform main computer. The following evacuation sequence is typical of those which might be utilized. The system is flow charted in FIG. 6. When an evacuation alarm sounds, all crew members will proceed to the survival craft 18, picking up immersion suits and lifejackets en route. When all crew members are accounted for the survival craft hatch will be closed and sealed. At this point the onboard computer becomes an integral part of the evacuation procedure. Following confirmation by the onboard computer that the entry hatch or hatches have been sealed, the computer will indicate that the survival craft is ready for launch.
It is then necessary for the control person to come to a final decision relative to evacuation. The onboard computer will provide information from various sources which will place the control person in a position to come to a decision. The computer, as indicated above, will monitor a substantial number of environmental factors and other indicators of the condition of the platform. For example, these will include wind speed and direction, wave height, general sea state, trim and list condition of the rig, information relative to the well and data relative to the presence or absence of hazardous gases.
All switches and controls, whether of the push button, lever or other type, are designed to enable easy operation by an operator enclosed in an immersion suit and lifejacket. The immersion suit substantially reduces manual dexerity, so that large and readily accessible controls are essential.
If a decision is made to proceed with evacuation, a switch is activiated to initiate the launch sequence. The computer will then activate a number of systems in preparation for survival craft launch. These functions preferably include the start up of the engine, activation of the onboard compressed air system and activation of the radio directional finder (RDF).
At this point the computer monitors internal air pressure and CO 2 levels and makes appropriate adjustments.
When this series of steps has been completed, completion is indicated to the control person via a visual and/or audible indicator. the control person then activates a launch switch. The computer then releases the cable winch brake and the cable 40 is fed out at a controlled rate to lower the support structure 20. That structure pivots about the connecting points 32 and 34 on girder 36 and the survival craft 18 arcs outwardly and downwardly in the support cradle 48 away from the platform 10.
As the support structure reaches and slips below the surface of the sea, the survival craft floats off the cradle 48. The structure 26 continues to pivot below the surface of the sea so that there is no possibility of further interference with the survival craft 18.
At the same time, the computer engages the survival craft transmission and applies maximum power to the survival craft engine. The survival craft then begins to move directly away from the platform. A preferred method of sensing launch is to have a contact pair between the cradle and the survival craft of which contact is broken when the craft begins to float off the cradle.
At this point also the system activates a sea water sprinkler to ensure a constant flow of water over the survival craft. This system is of particular significance in case of fire on the platform and possibly on the surrounding water.
Removal of the survival craft from the area of the platform is preferably conducted in two stages. In the first stage the craft is guided by the computer on a preset compass course, making use of an onboard compass to maintain the course. In the second stage, after a preset time has elapsed, the RDF takes over the course setting function, and the computer guides the craft according to signals received from the RDF. The theory here is that the craft will be guided on the preprogrammed compass course for a sufficient time to allow the craft to be well clear of the rig. The craft can then move on an RDF signal beam transmitted by the platform standby vessel.
The separation of the craft from the cradle also initiates in the computer the elapsed time counter which will determine the time during which the craft is controlled by the preprogrammed compass course.
The second survival craft, if also launched, is similarly computer controlled to move away from the platform to a prearranged area from which this craft also will be guided by the standby vessel RDF signal to effect a rendezvous. The initial computer controlled course will ensure that the survival craft is at all times well clear of the platform.
The survival craft is preferably provided with a radar transponder to enable the standby vessel to more easily locate the craft in the water. The transponder would also be activated automatically at launch.
With reference particularly to FIGS. 2 and 5, a closed passageway 24 is illustrated extending from the accommodation unit 92 to the rear of the survival craft 18. The passageway 24 is joined by air tight seals to the side wall 94 of the accommodation unit 92. As well, an airtight seal exists between the passageway 24 and the rear of the survival craft 18. The survival craft hatch 96 is within the sealed passageway.
A preferred location for the accommodation unit end of the passageway 24 is the mess area 98 in the accommodation unit 92. The hatchway 100 leading from mess area 98 to passageway 24 also has an airtight seal. Passageway 24 may also be provided with airtight hatches leading from the passageway to the deck 102 between the accommodation unit 92 and the end of platform 10.
The closed passageway provides a quick, obstruction-free means of moving from the accommodation area to the survival craft. At any time by far the majority of personnel on the platform will be located in the accommodation unit. Accordingly, the closed passageway provides direct access for those people from the accommodation unit for substantially horizontal or lateral entry into the survival craft. This factor can be of immense importance when keeping in mind that it will be only in extreme conditions that an evacution will take place. In these situations the deck area may be obscured by smoke, there may be fire aboard, high seas, wind and list may result in obstacles breaking loose and moving about the deck area, and there may be hazardous gases in the air. The use of the closed and sealed passageway will avoid all of these difficulties, and entry into the survival craft can be rapidly accomplished by a large crew.
It should be added that the location of the passageway can of course be varied to suit the particular configuration of the platform. As well, additional closed passageway can be located on other areas of the platform to avoid particular hazards.
The closed passageway also provides heated and protected storage for immersion suits and lifejackets. The primary source of these items would continue to be in the accommodation unit and as otherwise conventionally located. However, the additional supply of this evacuation equipment enables those not otherwise able to get to the equipment to obtain it immediately prior to boarding the survival craft. There has thus been described a complete system for fast and safe evacuation of a drilling platform. The system specifically avoids a substantial number of problems presented by earlier systems.
Thus it has been apparent that there has been provided in accordance with the invention an offshore evacuation system for drilling rigs or platforms that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the invention. | There is provided a new and useful offshore evacuation system for drilling rigs or platforms comprising a launch structure for a survival craft; the structure comprising at least one support strut adapted to be pivotally attached at one end thereof to the platform superstructure and carrying at the other end thereof at least one support cradle for survival craft, and rotatable between an upper position and a lower position; and means for effecting rotation of said launch structure from said upper to said lower position; and a closed companionway leading from the platform accommodation unit to the loading position of the survival craft and being in sealing relationship with the survival craft. | 31,472 |
BACKGROUND OF THE INVENTION
This invention relates to face type shaft seals and more particularly to face type shaft seals for liquid metal pumps.
Typically primary coolant pumps used in large commercial nuclear power plants have controlled leakage face type seals to retain and confine the radioactive fluid within the pressure containment boundary of the pump. These seals are constructed to operate at moderately high system pressure. This system pressure is therefore utilized as the prime parameter to ensure operational reliability under normal conditions. However, these seals are also required to operate reliably for short periods of time at system pressure conditions far below the normal operating pressure. Prior controlled leakage face type seals are particularly sensitive in this region and are subject to rubbing at low pressure if thermal and/or pressure excursions are experienced.
The face type shaft seal must be capable of operating under normal operating conditions and also at start-up conditions. During normal operating conditions, a liquid film is generally developed between the two seal faces so as to prevent metal-to-metal contact of the two seal faces. However, during initial rotation of the pump shaft, there is generally an insufficient liquid film between the two faces so that a small amount of metal-to-metal rubbing may occur. This is generally not a serious problem because in most seals the metal is of a type that is capable of withstanding slight contact for a minimal amount of time.
In liquid metal pumps developed to date the pump has employed a shaft seal utilizing oil to maintain separation between the two seal faces. In the liquid metal pumps, since the alkali metal coolant being pumped is at a temperature of approximately 400° to 500° C., the pump shaft length must be increased so that the seal can be located a sufficient distance from the heat source so that the seal may be operated without deteriorating due to the extreme temperature of the alkali metal coolant. For example, a typical liquid metal pump shaft is generally more than twice the length of the pump shaft in a typical pressurized water reactor coolant pump. Of course, the increased pump shaft length results in a substantial increase in capital cost for the pump.
In analyzing the liquid metal fast breeder reactor, it becomes apparent that the gas-buffered, oil-lubricated seals of the coolant pump should be replaced by a pump shaft seal capable of operating near the liquid metal coolant. Such a pump shaft seal may be one in which the liquid metal coolant for the nuclear reactor is used as the liquid film between the two faces of the shaft seal. By using such a design, it is possible to greatly reduce the length of the pump shaft and thereby greatly reduce the capital cost of the liquid metal pump. A basic requirement of this type seal, however, is that it be a non-contacting type. This requirement is based on two facts. First, because of compatibility considerations with hot alkali metal, conventional said materials, such as carbon-graphite cannot be considered. As a result, both faces of the seal package must be manufactured from alkali metal compatible metals or ceramics, such as Stellite, carbides, or alumina. None of these materials have self-lubricating, properties, thus introducing a high degree of probability of severe scoring upon initiation of rotation of a contact-type face seal. Secondly, the fluid being sealed, such as sodium, has little if any lubricating ability and is an excellent reducing agent. By the removal of the beneficial boundary lubricant oxide layers, some of the proposed seal materials may quickly possess extremely clean metal surfaces with high self-welding tendencies.
Therefore, what is needed is a face type shaft seal that is capable of being operated in a liquid metal environment.
SUMMARY OF THE INVENTION
A face type shaft seal for liquid metal pumps comprises a non-contacting seal in which at least one seal face has spiral grooves therein. Both seal faces are gold plated which ensures complete wetting of the seal faces with the liquid metal coolant which thereby establishes a thin liquid metal film between the two seal faces thus preventing contact of the two seal faces. Upon shaft rotation, a pumping action of the spiral grooves is initiated, displacing the liquid metal toward the seal dam thus pressure-loading the seal. Therefore, no contact between the seal faces occurs before or during shaft rotation and the pumping action provides a driving force preventing fluid leakage.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter of the invention, it is believed the invention will be better understood from the following description, taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a partial cross-sectional view in elevation of a liquid metal pump;
FIG. 2 is a view along lines II--II of FIG. 1; and
FIG. 3 is a detail drawing of the seal faces in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to reduce the pump shaft length in a liquid metal pump, it is necessary to employ a liquid metal seal capable of operating in a liquid metal environment. The liquid metal seal must be non-contacting both when the pump shaft is not rotating and when the pump shaft is rotating. The invention described herein is a face type shaft seal for a liquid metal pump wherein the two faces of the seal are non-contacting when both the pump shaft is not rotating and when the pump shaft is rotating.
Referring to FIG. 1, the liquid metal pump is referred to generally as 20 and comprises a housing 22 which encloses a motor 24, pump shaft 26, and pump impeller 28. Motor 24 is connected to pump impeller 28 by means of pump shaft 26 as is commonly understood in the art. The action of motor 24 causes pump shaft 26 to rotate thereby rotating pump impeller 28. The rotation of pump impeller 28 causes liquid metal to be pumped through the nuclear reactor primary coolant system. A seal ring 30 is attached to housing 22 and surrounds pump shaft 26 thereby defining a first annulus 32 therebetween. First annulus 32 allows pump shaft 26 to rotate without contacting seal ring 30. Seal ring 30 has a first seal face 34 on the top thereof. A seal assembly 36 is attached to pump shaft 26 by means of a locking screw 38 and comprises a first member 40 that is a substantially cylindrical member disposed around pump shaft 26. A first contacting seal 42 which may be a metal O-ring is disposed in first member 40 and in contact with pump shaft 26 to prevent leakage therebetween. A second member 44 which may be substantially cylindrical is disposed around first member 40 in a sliding relationship. A second contacting seal 46 which may be a metal bellows type seal is disposed in first member 40 and in contact with second member 44 to seal the annulus between first member 40 and second member 44 while allowing second member 44 to slide vertically relative to first member 40. Second member 44 also has a slot near the top end thereof that allows second member 44 to slide relative to first member 40 without interfering with locking screw 38. A seal runner 48 is attached to the lower end of second member 44 so as to face seal ring 30. Seal runner 48 has a second seal face 50 that is arranged to confront first seal face 34. A biasing mechanism 52 which may be a single spring or a series of springs is disposed in first member 40 and extends into contact with second member 44 for urging first member 44 toward seal ring 30. The action of biasing mechanism 52 serves to urge second seal face 50 toward first seal face 34.
Referring now to FIGS. 2 and 3, seal ring 30 is bolted to housing 22 by means of bolts 54. A series of spriral grooves 56 are etched in first seal face 34. Of course, the spiral grooves in the alternative may be etched in second seal face 50. Spiral grooves 56 are etched to have a depth of approximately 0.0005 to 0.0015 inches. Both first seal face 34 and second seal face 50 are electroplated with a thin film of gold which may have a thickness of approximately 0.0001-0.0005 inches. Seal runner 48 is arranged as shown in FIG. 3 so that spiral grooves 56 extend beyond the inside diameter of seal runner 48 and terminate short of the outside diameter thereof. By having spiral grooves 56 extend beyond the inside diameter of seal runner 48, liquid metal is allowed to fill spiral grooves 56 and create a thin film of liquid metal between first seal face 34 and second seal face 50 thereby preventing metal-to-metal contact of first seal face 34 and second seal face 50. The liquid metal to be sealed may be chosen from those liquid metal coolants well known in the art such as sodium or a sodium-potassium mixture.
The key to achieving a successfully operating metal-to-metal seal combination operable in an alkali metal environment lies in ensuring that both seal surfaces are totally wetted by the sealed medium before operation is initiated. The surface phenomenon of a liquid, known as wetting, refers to the situation wherein the adhesive force between the molecules of the liquid metal of the seal and the molecules of the material of the seal faces is greater than the cohesive force between the molecules of liquid metal. In this case, wetting of the seal surfaces results in a thin film of liquid metal being established between first seal face 34 and second seal face 50 thereby preventing metal-to-metal contact of the seal faces. Wetting is accomplished in this manner by the thin film of gold that is electroplated to the seal faces. In this way, a thin film of alkali metal is tenaciously held to the seal surfaces and prevented from being totally forced from between the surfaces. In addition, liquid metal remains in the bottom of each spiral groove 56. During assembly the components are brought into abutting relationship and a closure force is exerted that is sufficient to contain a liquid metal at initial start-up pressure. The seal surfaces are then initially wetted with liquid metal. Once motor 24 has been activated, the rotation of pump shaft 26 and pump impeller 28 causes liquid metal to be forced through first annulus 32 and between first seal face 34 and second seal face 50. However, the rotation of seal runner 48 relative to seal ring 30 together with the action of spiral grooves 56 creates a pumping action which forces the liquid metal back toward first annulus 32 thus limiting the leakage between first seal face 34 and second seal face 50. The spiral groove-type seal combines hydrostatic and hydrodynamic features to provide a non-contacting, low-leakage face seal. Investigators have postulated that the hydrodynamic forces arise from a slider-bearing effect of the spiral grooves land area and from the pressure patterns developed by the spiral grooves. Thus, no contact between the seal faces occurs during shaft rotation, and the pumping action provides a driving force preventing fluid leakage. Furthermore, the initial establishment of the thin film of liquid metal between the seal faces caused by the wetting action of the gold-plated surfaces ensures that there is no metal-to-metal contact at initiation of rotation of the seal surfaces. Therefore, it can be seen that the invention provides a face type shaft seal for a liquid metal pump wherein the seal faces are non-contacting both at start-up and during operation of the pump. | A face type shaft seal for liquid metal pumps comprises a non-contacting seal in which at least one seal face has spiral grooves therein. The seal faces are gold plated and designed so that the liquid metal wets the seal faces and creates a thin layer of liquid metal between the two seal faces during both rotation of the pump shaft and non-rotation of the pump shaft. The thin layer of liquid metal prevents contact of the two seal faces during initial rotation of the pump shaft. | 11,653 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 849,555, filed Nov. 8, 1977, now abandoned, which was a division of application Ser. No. 574,446 filed May 5, 1975 and now U.S. Pat. No. 4,163,971.
BACKGROUND OF THE INVENTION
This invention relates to a panel for displaying analog limits and values, and particularly to a bar graph analog display panel for displaying a value which may vary between certain limits and must be continuously monitored.
In industrial processes, it is frequently necessary continuously to measure and monitor conditions such as temperatures, pressure, flow, etc., which are critical to the process. Frequently, transducers convert the parameter to be measured to an electrical value which is then displayed by a D'Arsonval meter movement. Ideally, in a D'Arsonval meter movement, the displacement of a pointer is proportional to the magnitude of an input current. This current is a known function of the input parameter to be measured so that the pointer displacement is a measure of the input parameter. Thus, the information is displayed in the form of a displacement which is continuously analogous to the input parameter.
Another electronic device which generates a displacement analog of an electrical value transduced from a parameter to be measured is a servo indicator. Here, a motor drives an indicator, and an electrical equivalent of the motor position is compared with the input value. When the motor reaches a null balance, the indicator displays a value corresponding to the parameter to be measured.
Process parameters may also be displayed digitally. A multi-digit number is displayed which indicates the value of the input parameter.
All of these displays have certain disadvantages. Both the D'Arsonval movement and the servo system involve the use of moving parts which are susceptible to destruction or failure as a result of shocks. Servo indicators are subject to hysteresis errors. An all-electronic digital indicator is rugged and has no moving parts. However, it requires mental calculation on the part of the observer to determine how far the value has strayed from an ideal value or from between desired limits.
Analog displays yield more information about a parameter than just its magnitude. By observing the pointer or scale, it can be noted that the variable is steady or drifting up and down and that it is, or is not, near some particular reference point. This type of information is generally called "rate information" or "trend information". Trend information is particularly useful when many instruments are grouped together, all of which are monitoring different parameters of a process. By viewing the magnitudes and trends of all measurements, a clearer picture of the process can be reached than by observing single measurements only. Furthermore, in many cases, it is desirable to know if a measured parameter is close to a danger point. By providing an index mark, it is possible to spot an approaching problem quickly using trend information.
Recently a new type of display device has been developed and marketed under the trademark SELF-SCAN. Basically, this is composed of a multi-element gas discharge device in which the area of illumination is moved around a display by selective excitation of the elements. In one version, a large number of cathode elements are printed on an insulating substrate. A transparent cover for this pattern carries a transparent anode surface on its underside. The interior between the cover and the pattern is filled with an ionizable gas. A glow discharge is generated between the anode plate and the cathode elements. A keep-alive anode forms a continuous discharge with a keep-alive cathode. The gap between them provides a continuous source of metastable ions. The system is energized so that the glow at any electrode can transfer only between adjacent gaps. A reset cathode near the keep-alive gap transfers the glow to a reset gap formed between the reset cathode and the transparent anode. The remaining cathodes are connected in three groups so that the glow can be constrained to travel along the display by opening the cathode which has the glow and grounding the next cathode in the desired phase sequence. The length of the illuminated area represents a quantized indication of an input parameter having trend information. Such devices have a number of disadvantages in the display of monitored analog information. They merely display a process parameter without displaying the range or limits within which this process parameter may vary. While the variable range may be painted behind the bar, it is desirable that the limits of this range be made variable so that they can be reset.
An object of the invention is to improve the display device itself so that it is capable of furnishing variable range or limit information.
SUMMARY OF THE INVENTION
According to a feature of the invention, the above object is attained in whole or in part, by forming a row of cathode display electrodes in an enclosure having an ionizable gas and spacing an anode electrode within the enclosure close enough to the cathode display electrodes to permit a visible discharge of a given intensity when a predetermined discharge voltage is applied between a cathode display electrode and the anode. Also, reset electrodes are provided at both ends of the row of cathode display electrodes so that successive scanning can start from either end of the bar. Circuit means energizes the anode electrode and scans the cathode display electrodes from one reset electrode at one end of the row until a band whose length corresponds to one set point value is illuminated, and then ceases scanning until the remaining portion of the scan cycle would produce an illuminated band from the second set point value to the upper limit.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a display panel embodying the invention and a schematic and logic diagram of a system for operating the panel;
FIG. 2 is an isometric drawing of a display panel used in FIG. 1 and embodying features of the invention; and
FIG. 3 is a schematic representation of the unit in FIG. 2 illustrating the manner in which the unit may be illuminated.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a drive circuit C operates a bar graph display D. The bar graph display D is shown only partially in FIG. 1. Details of the display D appear in FIG. 2.
In FIGS. 1 and 2, the upper surface of a substrate 10 supports two rows of two hundred three aligned printed wiring cathodes 12 and 14 which form two bar graphs A and B of the display D. Every third cathode 12 is interconnected by three conductors to form phase 1A cathodes, phase 2A cathodes, and phase 3A cathodes as shown. Similarly, three separate conductors connect respective third ones of the cathodes 14 to form phase 1B cathodes, phase 2B cathodes, and phase 3B cathodes.
An insulating spacer 16 in the shape of a frame rests on the top peripheral edge of the substrate 10. The spacer separates the cathodes 12 and 14 from two transparent anodes 18 and 20 printed over the areas shown on the bottom face of a transparent cover plate 22. The anode 18 overlies the cathodes 12, and the anode 20 overlies the cathodes 14. The substrate 10, spacer 16 and plate 22 are sealed to form a gas-tight unit which contains an ionizable gas such as neon.
Two reset cathodes RA1 and RA2 are printed on the substrate 10 at the extreme ends of the cathodes 12 and connected to the substrate edge. Reset cathodes RB1 and RB2 are printed on the substrate 10 at the ends of the cathodes 14 and connected to opposite end edges of the substrate. The anodes 18 and 20 are sufficiently long to overlie the reset cathodes.
Extending between the reset cathode RA1 and the reset cathode RB1 but spaced therefrom by one intercathode step is a keep-alive cathode 24 printed on the substrate 10 and connected to a terminal. Extending from the reset cathode RA2 to the reset cathode RB2 is a second keep-alive cathode 26, also spaced from each of the reset cathodes by one intercathode step. Above the keep-alive cathodes 24 and 26 on the under surface of the plate 22 are keep-alive anodes 28 and 30 connected to otherwise unidentified terminals.
To drive the bar graph display D, the driver circuit C establishes a 250 volt potential between the keep-alive cathode 24 and the keep-alive anode 28, as well as between the keep-alive cathode 26 and the keep-alive anode 30, sufficient to ionize the gases between the elements 24 and 28 and between the elements 26 and 30 and to maintain the gas in its ionized state.
The keep-alive gaps between the keep-alive anodes and cathodes provide a continuous source of metastable ions in response to the power supplied. This provides the starting point for the entire operation.
In order to illuminate the portion of the bar A corresponding to an analog value, circuit C grounds the reset cathode RA1, and a positive potential is applied to the anode 18. This potential, together with the internal geometry of the display and the gas mixture, is selected so that the glow at any electrode can transfer between, but only between, adjacent anode-to-cathode gaps. The glow in the keep-alive gap at the cathode 24 now transfers to the anode-cathode reset gap. The driver circuit C then grounds the phase 1A cathodes and ungrounds or opens the reset cathode RA1. The glow now transfers from the reset cathode RA1 to the nearest phase 1A cathode. The circuit C then grounds the phase 2A cathodes and transfers the glow to the nearest phase 2A cathodes. Similarly, the driver circuit C then grounds the phase A3 cathodes and opens the phase A2 cathodes to transfer the glow to the nearest phase A3 cathode. By continuously grounding the phase 1, phase 2, and phase 3 cathodes in sequence and ungrounding the other cathodes, the driver C constrains the glow to travel along the display. Effectively, the driver circuit C opens the cathode which has the glow and grounds the next cathode in the desired phase sequence. The travel of the glow along the bar A continues until a point is reached that corresponds to the analog of the value to be displayed. The anode 18 is then de-energized, and the continuing scan along the cathodes fails to produce a glow.
After the circuit C has grounded the cathodes 12 a total number of two hundred three times so that the scan reaches the top, the driver circuit C waits to be recycled, at which time it again grounds the reset cathode RA1 and repeats the sequence. The basic parameters of the system establish the length of an entire display time within each cycle to be between ten and twenty-five milliseconds. In a preferred embodiment, the cycles are synchronized with a power line of 50 or 60 Hz. The cycles and the scanning speed, i.e., the inter-gap glow transfers, are sufficiently rapid and frequent so that a portion of the bar A corresponding to the analog value of the input voltage appears to be continuously illuminated. That is, the persistance of an observer's eye sees an illuminated bar portion extending from the reset cathode through the furthest cathode at which a glow has been introduced by grounding of the cathode and operation of the anode 18. This is shown in FIG. 3.
The system of FIG. 1 also displays a visual range or limits within which the input value shown in bar A is supposed to vary. The driver circuit C does this by illuminating the bottom portion of the bar B from the reset cathode RB1 to a lower set point established by a lower set point control LS and by illuminating the top of the bar B from the reset cathode RB2 down to an upper set point established by an upper set point control US in the driver circuit C. The unilluminated portion in the bar B represents the range. As shown in FIG. 3, the bar A is illuminated to a value V and the bar B between the bottom and a lower location LL and between the top and an upper location UL. If the system is to monitor a process variable that is permitted to vary between the ranges established between the upper set point and lower set point shown as UL and LL, an observer can note that the value V is between the set points. If the value V falls below the value LL or rises above the value UL, the observer is informed that the variable to be monitored has increased or decreased beyond the permitted range. In order to inform an observer more readily that the input value has increased or decreased beyond the permitted range, either the upper or the lower illuminated portion of the bar B is flashed when the input value causes the illuminated portion of the bar A to fall outside the permissible range.
In the driver circuit C, a flip-flop 40 synchronizes an oscillator 42 to a power line through a buffer amplifier 44. The resulting synchronization prevents stroboscopic interaction between ambient lighting and the display. When a positive zero crossing of the power line voltage occurs, buffer amplifier 44 enables the flip-flop 40, which in turn starts the oscillator 42. The latter produces clock pulses which drive an N stage counter 46. When the counter reaches the number 203, it triggers a 20 microsecond delay generator 48 which creates a reset pulse. At the end of this measurement cycle, the reset pulse disables flip-flop 40 which turns off the oscillator 42 until the next positive zero crossing of the power line at the buffer amplifier 44. The oscillator frequency is chosen to ensure that a measurement cycle is shorter than the interval between the power line voltage positive zero crossings. In this case, the measurement cycle is less than 16 ms, whereas the positive zero crossings occur every 162/3 ms for 60 Hz or 20 ms for 50 μs. The number 203 equals the number of electrodes 12 and also the number of electrodes 14 in the respective bars A and B. One of these cathodes represents zero on the scale. Therefore, to indicate an overscale condition, there are 203 states in the counter 46, and N must equal at least 203. Since the length of the measurement cycle is N pulses, the oscillator 42 produces N pulses in somewhat less time than one cycle of the power line. Therefore, the oscillator 42 operates at a frequency greater than N times the power line frequency.
The oscillator 42 drives two 3-phase cathode drivers 50 and 52, and an N-stage counter 46. The drivers 50 and 52 are illustrated as rotating selector switches which step one position for each pulse applied by the oscillator 42. In the successive positions of the driver 50, it successively and repeatedly grounds the phase 1A, phase 2A, and phase 3A cathodes. When the reset cathode has been grounded and the glow transferred from the keep-alive cathode, this repeatedly transfers the ionization glow from between the reset gap through the successive gaps along the bar A. While the driver 50 is shown as a rotating selector switch, it may be representative of any type of logic arrangement capable of performing this function. In a preferred embodiment, suitable buffer amplifiers exist between the driver 50 and the cathodes 12. The driver 52 performs the same function with the cathodes 14. However, intervening between the driver 52 and the cathodes, or any buffer amplifiers which may be used, is a phase reversing circuit shown as a double pole, double throw switch, which may represent any suitable logic circuit that performs this function. The driver 50 advances the input display, while the driver 52 advances the set point display.
The N stage counter 46 drives an N level digital-to-analog converter 54. The latter provides an output voltage proportional to the number in the counter. Thus, as the count increases from zero on each clock pulse from the N stage counter, the converter exhibits a voltage which increases linearly with the clock pulses or time, one level of increase for each clock pulse. Hence, each clock pulse advances the display one bar element and increases the converter output one unit of voltage.
The output of the digital-to-analog converter 54 is applied to a comparator 56 which compares this voltage to the input voltage. The input voltage is a preconditioned version of a parameter to be measured. A transducer, compressor, expander or other device conditions the input signal for operation in this environment. As long as the input voltage exceeds the converter 54 voltage, the comparator 56 produces a logic zero signal. During this time, a NOR gate 58 produces a logic 1 that permits an anode driver AD1 to apply the required glow-producing anode voltage at the anode 18. As long as this occurs, the anode 18 remains positive and the driver 50 advances the display of the discharge glow from cathode to cathode along the bar A. The NOR gate 58 forms part of an over and under range flashing circuit 60 through which the output of the comparator 56 passes.
When the output of converter 54 equals or exceeds the input voltage, the comparator 56 produces a logic 1 signal. An AND gate 62 combines this signal with a logic 1 signal from the Q terminal of a normally reset S-R flip-flop 64 to produce a logic 1 signal. The NOR gate 58 then produces a logic zero signal that causes the anode driver AD1 to ground the anode 18. The display of glow discharge along the bar A ceases advancing. The portion of the bar A along which the glow advanced is proportional to the input signal. The clock pulse 42 continues ineffectively to drive the driver 50 until the counter 46 advances to the number 203. After a 20 microsecond delay produced by the delay 48, the flip-flop 40 is reset and the oscillator 42 stops generating clock pulses.
Upon the next zero crossing of the voltage in the power line, the amplifier 44 again sets the flip-flop 40 and the process is repeated at the rate of the power line frequency. The continued glow advance over the section of the bar proportional to the value of the input produces what appears to be a persistent bar-shaped glow along the bar A corresponding to the value of the input.
An over-range and under-range comparison is made by examining the state of the comparator 56 at reset time and at full scale, as discussed more fully in parent application, Ser. No. 574,446 referred to above.
In summary, the bar B displays high and low set points, between which the indication in the bar A is supposed to lie for proper operation. To generate the set points, two potentiometers US and LS generate upper and lower set point command voltages. Comparators 76 and 78 compare these set point voltages with the output of the converter 54. From the start of each counting cycle after reset, the comparator 78 produces a logic zero until the lower set point is reached. Similarly, the comparator 76 produces a logic zero until the higher set point is reached. An OR gate 80 passes the logic zero value through an AND gate 82 and a NOR gate 84. An anode driver AD2 energizes the anode 20. This occurs as the driver 52 scans the bar B from bottom to top by advancing the glow from the reset cathode RB1 along the phase 1B cathodes, phase 2B cathodes, and phase 3B cathodes (14). When the lowest set point is reached, the comparator 78, which operates as a pulse width modulator, produces a logic 1 output. In the meantime, the comparator 76 is still producing a logic zero output. The logic 1 from the comparator 78 passes through OR gate 80 and the AND gate 82. The logic 1 at the input of the NOR gate 84 constrains the anode drive AD2 to inhibit the anode 20 voltage so that glow advance along the bar B stops. During this time, the logic zero output from the comparator 76 has disabled a NOR gate 88 which has enabled the AND gate 82. When the converter 54 potential reaches the upper set point at the potentiometer US, the comparator 76 produces a logic 1. The NOR gate 88 produces a logic zero that turns off gate 82 and prevents the NOR gate 84 from further inhibiting the anode driver 82. Thus, the anode 20 is energized. At the same time, a monostable multivibrator 92 produces a pulse that reverses the polarity on a switch 94 shown as a double pole, double throw switch but capable of being embodied as a logic circuit. This reverses the phase of the driver circuit 52. At the same time, the pulse from the monostable 92 actuates the reset cathode RB2 so that the various phases of cathodes 14 are scanned downwardly. As long as the anode 20 is energized, illumination of the ionizable gas between the gaps from the cathodes 14 to the anode 20 continues in sequence. When the N stage counter reaches the count 203, flip-flop 40 is reset which produces an anode inhibiting voltage at NOR gate 84 until the next zero crossing from the power line.
Because the bar B was illuminated by scanning from the top only from the time the converter 54 voltage reached the upper set voltage to the end of the count 203, only the portion of the bar from the top to the upper set voltage is illuminated beyond the earlier illumination of the portion below the lower set voltage.
Thus, when the lower set point is reached, signals from the comparator 78 hold the set point display cathodes in the reset mode without the anode energized. When the upper set point is reached, another signal from the comparator 76 reverses the counting sequence of the cathode drivers. At this time, the upper reset cathode is grounded, the anode energized and the driver 52 reversed. A discharge has now been formed at the top of the set point display bar B and counts down until full scale is reached and the measurement cycle ended. Therefore, the length of the bar illuminated to represent the upper set point is actually equal to the difference between the full scale and the upper set point.
Parent application Ser. No. 574,446 is incorporated herein by reference. Such parent application, as already noted, discloses an alarm circuit for operating when the input voltage falls below the low set point voltage or exceeds the high set voltage. | The display panel comprises a gas-filled envelope which contains a series of aligned cathode electrodes, an anode for the series, and a reset cathode at each end of the series of cathodes. The system includes a driving circuit which repeatedly scans along the series of aligned cathode electrodes by sequentially grounding the aligned electrodes and repeating the process cyclically. Within each cycle, a pulse width modulator energizes the anode, which is opposite the cathode electrodes, for a period of time corresponding to an input value. Sequential glow discharges thus occur between the cathodes and the anode over a portion of the anode length. The discharges occur with sufficient rapidity so that they are observed as an illuminated portion of a bar formed by the electrodes. The panel is particularly suited for producing two illuminated bands or bars separated from each other. Desired upper and lower set point limits for the input quantity determine the lengths of the bands and the separation between them. The separate bands are initiated from opposite ends of the series of cathode electrodes by first energizing the reset cathodes. The driver forms one band from one end of the aligned electrodes and the other band from the other end of the aligned electrodes. | 22,266 |
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates to a swabbing device for molds of a bottle making machine, and more particularly, to a swabbing device for molds which are made of various kinds of materials to be used for a bottle making machine wherein a multiplicity of bottle forming sections are aligned.
2. Description of Related Art
A bottle making machine is generally provided, for instance, with a blank mold and neck-ring mold for forming a parison which shapes a neck-ring portion and a body portion of a bottle, and a blow mold and bottom mold for finishing the parison formed by the blank mold and neck-ring mold, wherein a gob which is a melted lump of glass is fed into a bottle forming section.
The temperature of the gob which is fed to the blank mold and neck-ring mold ranges as high as 1070° C.-1150° C. when the gob is supplied, and it causes the gob to adhere to metal and other materials easily. The mold releasing operation can not, therefore, be performed smoothly when a bottle is formed by the molds as described above. There is a problem especially when the gob is formed into a shape with the blank mold and neck-ring mold under high temperature.
In order to cope with such a difficulty, it has heretofore been practiced to manually swab the blank mold, neck-ring mold and a baffle with a swabbing agent periodically. In the case of a blank mold, for instance, it is desired to perform a swabbing operation at intervals of 10-20 minutes.
On the other hand, with a view to eliminate said manual swabbing operation or to prolong the intervals necessary for a swabbing operation, it has been practiced to spray a mold releasing agent automatically, or to adhere a mold releasing agent to the surface of a mold by baking, or to provide a dried precoated layer, or to adhere soot produced out of incomplete combustion of acetylene to a metal mold.
When a mold releasing agent is applied manually, oil adheres closely to the surface of a mold forming an oil film thereon to achieve satisfactory mold releasing. However, said manual application has to be conducted frequently under a noise and high temperature which eventually requires time and much labor. It is, therefore, desired to curtail the frequency of operation for application.
It is also dangerous when the manual application is conducted to a mold which is frequently opened and closed (for instance, at an interval of less than two seconds). For this reason, such a swabbing operation is closely observed by the Labor Standards Inspection Office and other competent institutions. Heretofore, a forming operation has been conducted at a speed of around six shots per minute. However, with the recent high-speed operation, the speed has increased more than 2.5 times. Under the circumstances, in the case when a forming operation exceeds 14 or 15 shots per minute, it is practiced to interrupt the forming operation during a swabbing operation in order to prevent the danger which adversely affect the productivity.
When a swabbing operation is performed by means of spray, only a particle of oil is put on the surface of a mold and it is likely to be removed by a particle of glass easily. The swabbing effect thus remains short, about half of the life as compared with the case of said manual swabbing operation. A swabbing operation should, therefore, be conducted at a short cycle, i.e. at intervals of 5-10 minutes. A supplementary operation by a manual swabbing is thus required to increase the duration of intervals.
There is another difficulty that an application can not be fully conducted all over the surface of a mold thus inviting partial checking and insufficient formation by stains. Further, on some occasion, a swabbing is done onto unnecessary portion of a mold to cause insufficient exhaustion thereat which adversely affect a forming effect. The surface of a product is thus made rough, and the product is easily stained compared with a product manufactured by the manual swabbing. For this reason, the appearance of a product can not be formed satisfactorily.
Moreover, a precoated layer is dissipated by itself, since it will evaporate as carbon dioxide when a hot gob fed to a mold comes in contact with the layer. The precoated layer is thus reduced every time when a forming operation is conducted, and the life of the layer expires in two-six hours. The life appears to be longer as compared with that of the case of the manual swabbing, however, said reduced precoated layer can not be replenished by a supplementary operation. It is, therefore, necessary to change a mold every time when the life of the precoated layer is expired by the reduction of the layer. The cycle for exchanging a mold is, therefore, short which causes a raise in manufacturing cost and lowers the productivity.
In the case of a treatment where an Alblack, which is a soot being sold on the market, is used, acetylene generates an intense heat with oxygen so that operation efficiency is lowered and an environment is worsen. Further, the bottom thickness of a product is excessively thickened, and it sometimes necessitates to change the design of a mold.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a swabbing device for molds of a bottle making machine which is capable of automatically performing a mold swabbing operation just like the case of a manual swabbing whereby the danger in the manual swabbing is prevented with elimination or reduction of labor, and fulfilling a rapid and precise swabbing operation in a high-speed forming operation thus improving the quality of a product and the productivity.
It is another object of the present invention to provide a swabbing device for molds of a bottle making machine which is capable of lowering manufacturing cost, and at the same time, accomplishing high efficiency wherein the whole body of a robot is moved to a location of a mold provided in each one of bottle forming sections to rapidly carry a swabbing member, and with a simple robotic action of swabbing onto a mold, the robot is able to swab all the molds provided in each section.
It is a further object of the present invention to provide a swabbing device for molds of a bottle making machine which is capable of fulfilling a precise swabbing operation at a low cost wherein a specified swabbing location of a robot corresponding to each one of the molds is adequately discriminated with a simple procedure to precisely perform an automatic swabbing operation by the robot at a proper location as predetermined.
It is a still further object of the present invention to provide a swabbing device for molds of bottle making machine which is capable of preventing a lowering of bottle manufacturing efficiency without adversely affecting a regular bottle manufacturing cycle, and eliminating or lessening a timing loss which is caused by a swabbing operation.
A further object of the present invention is to provide a swabbing device for molds of a bottle making machine which is capable of accomplishing a satisfactory swabbing operation which compares favorably with a manual swabbing operation wherein an impregnated material such as cloth and string are provided around a core member, and a swabbing agent is impregnated into the impregnated material for a swabbing operation.
These and other objects and features of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings which illustrate specific embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view roughly showing a part of bottle making machine to which the present invention is applied.
FIG. 2 is a plan view showing a part of the bottle making machine shown in FIG. 1.
FIG. 3 is a perspective view showing a robot provided with the bottle making machine shown in FIG. 1.
FIG. 4 is a plan view showing a condition how a blank mold is opened.
FIG. 5 is a sectional view showing a part of a kind of swabbing member.
FIG. 6 is a sectional view showing a part of another kind of swabbing member.
FIG. 7 is a block diagram showing a control circuit of the robot and bottle making machine.
FIG. 8 is a block diagram showing a control circuit of the robot and bottle making machine in another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to accompanying drawings, description will now be made hereinafter on embodiments of a bottle making machine to which the present invention is applied.
In the bottle making machine of the present embodiment, there are provided bottle forming sections 3, for instance, 6-12 sections, laterally aligned as shown in FIGS. 1 and 2 wherein a blank mold 1 combined with an unillustrated neck-ring mold and a baffle, and a blow mold 2 combined with an unillustrated bottom mold are arranged. As shown in FIGS. 1, 2 and 4, the blank mold 1 is arranged to be automatically opened and closed right and left by an unillustrated air cylinder or the like in parallel movement. It may also be arranged to be rotatably opened and closed centering around a hinge.
The blank mold 1 is combined with a neck-ring mold at the lower portion and a baffle at the upper portion, and through a delivery mechanism, a gob which is a melted lump of glass prepared for bottle manufacturing is fed into each one of blank molds 1 in a predetermined order. The blank mold 1 then forms the neck-ring portion of a bottle, and the body and bottom portions of the bottle are shaped to form a parison.
The parison which is formed in the blank mold 1 is transferred to the blow mold 2 to be formed into a predetermined shape of bottle.
A timing for feeding the gob to each one of the blank molds 1 is set for subsequently repeating operations of rough formation of a bottle by the blank mold 1 at each one of bottle forming sections 3, and subsequent finishing formation of the bottle by the blow mold 2 at regular intervals.
At a side of the bottle making machine, a straight guide 5 is provided along a direction the bottle forming sections 3 are aligned, and both ends are held by a leg member 6. To the straight guide 5, the base 21 of a robot 7 is slidably held to be driven in reciprocating motion along the straight guide 5 by a linear motor 51 provided between the straight guide 5 and base 21.
The linear motor 51 consists of, for instance, a permanent magnet 51a on the base 21 and an electromagnet 51b on the side of the straight guide 5. However, in place of the linear motor 51, an AC servomotor may also be utilized.
On one of the leg members 6, there is provided an operation box 8 for giving instructions to control actions of the robot 7.
The robot 7 in the present embodiment is arranged to be easily and rapidly moved to a location opposite to a blank mold 1 provided in each one of the bottle forming sections 3 without resorting to any robotic action by the movement along the straight guide 5 so that any device which possesses a function to perform a swabbing action to a mold within a necessary range of action may be utilized when a swabbing operation is performed for the blank mold 1, and the neck-ring mold and the baffle combined therewith.
As illustrated in detail, the one shown in the FIG. 3 is a simple joint type provided with four joints of first to fourth joints 11-13 and 40 whereby a straight reciprocating movement of the robot 7 in a direction shown by an arrow 41 in FIGS. 1 and 2, a rotating action around the first, second and third joints 11-13, an action of the swing of the pendulum around the fourth joint 40 as shown by an arrow 42 in the FIGS. 3 and 4, and various actions in which said actions are combined can be performed. A swabbing member 26 can thus be rubbed over a necessary range of the surface of various metal molds.
Not limiting to such an arrangement as described above, six-joints type robot, seven-joints type robot or the like provided with a rotating shaft which rotates in various directions may selectively be utilized according to a requirement. The reciprocating movement or other arrangement may also be selectively adopted according to a requirement. Not only the action of the swing of the pendulum of the swabbing member 26, it may also be arranged to rotate it on its own axis, or to rotate it in an orbital motion, or to move it vertically.
The robot 7 is provided with motors 14-16, 43 for each one of the first-fourth joints 11-13, 40 for its rotating action around the joints (refer to FIG. 3), and through the base 21 which is slidably fitted and held to a straight guide 5, signals are delivered and received between a microcomputer 22 in the operation box 8 to control a reciprocating movement along the straight guide 5, and rotating actions around said first-third joints 11-13. An AC servomotor, stepping motor or the like may selectively be utilized for the motors 14-16 according to a method of control which is to be applied.
The microcomputer 22 controls the robot 7 to perform a swabbing operation correlatively with bottle making action of the bottle making machine in each one of the bottle forming sections 3. The microcomputer 22 is, therefore, arranged to deliver and receive signals between a microcomputer 32 which controls actions of the bottle making machine.
The position of movement of the robot 7 along the straight guide 5 may be measured from the amount of movement by setting a home position of the robot 7.
In the present embodiment, a position indication 23 is provided in each one of the bottle forming sections 3 corresponding to a central position in a longitudinal direction of the straight guide 5, and a position sensor 24 is provided at the lower front center of the base 21 of the robot 7. The position sensor 24 detects the position indication 23 when the sensor 24 is positioned opposite to the position indication 23 in a direction perpendicular to the longitudinal direction of the straight guide 5, and by a signal of the detection, the microcomputer 22 makes a judgment that the center of the blank mold 1 which is positioned opposite to the position sensor 24 and the center of the robot 7 are opposite to each other (refer to FIGS. 1-3).
An ultrasonic sensor, laser sensor or the like may be utilized in place of the position indication 23 and position sensor 24. A device which is arranged to mechanically detect a position may also be adopted.
A chuck 25 is provided at the tip of the robot 7 to removably attach the swabbing member 26 for performing a swabbing operation to the blank mold 1. Adjacent to the bottle making machine, there is provided a stacker 27 for storing various kinds of swabbing members 26. The robot 7 is thus able to selectively use one of the swabbing members stored in the stacker 27 corresponding to a required mold and swabbing condition.
For the selective use of the swabbing member 26, the stacker 27 is provided with a position indication 28 at a location where each kind of swabbing members 26 is stored as shown in FIG. 2. By detecting the position indication 28 with the position sensor 24, the microcomputer 22 makes a judgment that the robot 7 is positioned at a proper location opposite to a location where each swabbing member 26 is stored.
As shown in FIGS. 2 and 3, a swabbing agent supply pipe line 29 is connected with the chuck 25 for feeding a swabbing agent to a swabbing member 26 which is attached thereto. The swabbing member 26 is provided with an impregnated material 26b such as cloth and string around its core member 26a as shown in FIGS. 1, 4, 5 and 6. The swabbing member 26 may, therefore, be manufactured in any shape according to a requirement to be stored in the stacker 27.
In the core member 26a, there is provided a liquid passing path 26d which vertically runs through from the upper end to the lower end. The liquid passing path 26d is provided with openings 26c to the surface of the core member 26a where the impregnated material 26b is attached, and a swabbing agent fed through the swabbing agent supply pipe line 29 is forwarded to the liquid passing path 26d in the core member 26a through a check valve 31 provided with the chuck 25. Through the openings 26c, the swabbing agent spontaneously permeates into the impregnated material 26b around the core member 26a by the capillarity. Accordingly, when the swabbing member 26 is rubbed against the surface of blank mold 1, the swabbing agent impregnated in the impregnated material 26b is applied all over the surface of the metal mold like the case of the manual swabbing whereby elimination or reduction of labor may be accomplished.
There is no danger which might occur in a manual swabbing operation. Since a rapid and precise swabbing operation can be performed based on a condition preliminarily set, a swabbing may be conducted at a speed of around 16-20 shots per minute, and the quality of product and the productivity are improved.
The check valve 31 is arranged not to leak a swabbing agent which is fed to the chuck 25 when the swabbing member 26 is removed from the chuck 25. Since a swabbing agent is fed to the swabbing member 26 in spontaneous permeation from within the core member 26a to the impregnated material 26b, supply pressure of the swabbing agent through the swabbing agent supply pipe line 29 may be set, for instance, at a small pressure of 1-2 kg/cm 2 G. Even when a supply pressure is given by pump, a spontaneous flow of the swabbing agent is prevented without the check valve since the pump is stopped when a swabbing operation is not performed.
By making an arrangement to impregnate a swabbing agent into an impregnated material 26b from within the core member 26a, impregnation can be accomplished by forcibly feeding the swabbing agent through the core member 26a whenever and wherever the swabbing member 26 is positioned.
The chuck 25 is also provided with a click stopper 33 for elastically locking a swabbing member 26 in order to remove the attached swabbing member 26 with a proper amount of force. However, any type of locking means may be adopted. For instance, it may be arranged to lock and remove the swabbing member 26 by relative movement of the chuck 25 of robot 7 and the swabbing member 26 stored in the stacker 27.
FIG. 7 is a block diagram showing a control circuit for controlling actions of the bottle making machine and robot 7 by utilizing the microcomputers 22 and 32. In the present embodiment, the microcomputer 22 adopts a numerical control system for the robot 7, however, any type of control system such as a playback system or the like may be adopted according to a requirement.
The operation box 8 is connected with the microcomputer 22 for giving instructions of numerical control. It is also arranged to indicate confirmation of various operating conditions.
To an output side of the microcomputer 22, there are connected a linear motor driving circuit 65 in the straight guide section, first-fourth joints motor driving circuits 66-69 for driving each one of the motors 14-16, 43, and a swabbing agent supply pump driving circuit 70 for performing various operations. The position sensor 24 and other input are connected to an input side for properly performing said actions.
To an input side of the microcomputer 32, an operation panel 34 is connected for inputting various conditions in a bottle manufacturing process, and for indicating confirmation of various actions. Other input of various sensors is also connected for controlling various actions.
To an output side of the microcomputer 32, there are connected a blank mold opening/closing action driving circuit 61, blow mold opening/closing action driving circuit 62, bottle transfer driving circuit 63 from a blank mold 1 to a blow mold 2, finished bottle discharge action driving circuit 64, and other output.
With the arrangement as described above, the robot 7 is moved to and stopped at each position where the blank mold 1 provided in each one of the bottle forming sections 3 and the center of the robot 7 correspond with each other, and at each position where the swabbing member 26 stored in the stacker 27 and the center of the robot 7 correspond with each other.
With a necessary swabbing member 26 installed, the robot 7 is moved to a location where each one of the blank molds 1 is positioned, and rubs against each blank mold 1 as shown in the FIG. 4 to accomplish a swabbing operation in the same action as in a manual swabbing operation.
According to the experiments conducted by the inventor, it was found that the production of satisfactory bottles in the blank mold and neck-ring mold can only last for about an hour in the case of a swabbing by an automatic spray method. When a production time has exceeded one hour, there occurred such defects as wash board, wrinkles and laps, chilling, and insufficient feeding of gob into the blank mold. In the neck-ring mold, such defects as screw check, body seam check and the like were observed.
On the contrary, in the case of a swabbing performed by the robot 7 in the present embodiment, the production of satisfactory bottles in the blank mold continued for about eight hours, and about six hours in the neck-ring mold respectively.
When an automatic swabbing operation is conducted by the robot 7 in the present embodiment using a super hard alloyed material composed of Cu, Co, Ni and W (Item No. KRC-15 manufactured by Kobe Steel Co., Ltd.) which is treated by composite metal plating (Ni+P+SiC, Ni+P+W) for the neck-ring mold, the generation of defective checks and the like were restrained covering a shortage of swabbing agent. In sum, a forming capability is further improved when an alloyed material composed of Ni, Co, Cu and W which does not wet so easily is used in manufacturing metal molds.
A metal mold is applied to the present embodiment, however, any mold which is made of other materials other than metal may also be applied.
In the present invention, it may be arranged to provide a swabbing agent supply source such as a swabbing agent storage chamber for feeding a swabbing agent to the swabbing member, and by moving the swabbing member to the swabbing agent supply source by the robot, the swabbing agent is impregnated when they come in contact with each other. In this case, by making use of intervals between swabbing operations, or by making use of the time when the swabbing member is stored in the stacker, it may be arranged to impregnate the swabbing member by dipping it in the swabbing agent storage chamber.
FIG. 8 shows another embodiment of the present invention which differs from the previous embodiment on the points that an order of movement of the robot to each one of the molds in the bottle forming sections for a swabbing operation is predetermined, and that when there is a defective mold, the robot is voluntarily moved to such a mold. Further, the straight movement of the robot is made by a servomotor which utilizes a fluid such as air.
Description will now be made on the points of difference referring to the FIG. 8. Like parts and circuits are shown by corresponding reference characters throughout the views of drawings, and repeated descriptions will be omitted.
When the robot is controlled by the microcomputer 22, if there is not any defect in a product being manufactured such as wrinkles and laps, wash board, screw check and the like, the robot which is positioned at a home position is moved in consecutive order from one end to another in the sections aligned, i.e. from a small numbered section to a large numbered section assuming that each section is numbered starting from a home position of the robot. When a mold positioned opposite to the robot is opened and empty, the robot is stopped thereat for a swabbing operation, and each time a swabbing operation is completed, the robot is moved to the next section. When a swabbing operation is finished at the last section, the robot is returned to the home position to be ready for the next swabbing operation.
A servomotor driving circuit 165 is, therefore, connected to the microcomputer 22 for the straight movement of the robot. By adopting a servomotor, particularly an air servomotor, a straight movement mechanism may be provided at a low cost. Further, a position of the robot where it is moved can be found simply by an encoder, and a position control can be easily conducted. There may occur an error of 2 mm or so for the position control, however, it does not matter particularly.
An interval for moving the robot may be optionally set by an inputting means provided in the operation box 8. In the present embodiment, it can be set within a range of 0-60 minutes. At present, the setting is selectively made at intervals of 5, 10, 15, 20 minutes corresponding to a product forming condition. The timing when a mold in each section is opened and become empty is detected by a timing sensor 101 which is connected to the microcomputer 22, and based on a detection signal, a required time is obtained from the time a mold in each forming section is opened after a forming operation is completed until the mold is emptied.
When operator judges that there occurred such defects as wrinkles and laps, wash board, screw check and the like in a product being manufactured in one of the forming sections, the operator specify the section from a group of keys 102 provided on the operation box 8. The robot is thus moved to the specified section preferentially voluntarily by an interruption control. When the preferential swabbing operation is completed at the specified section, the operation is returned to an ordinary mode of control for movement.
When a plurality of specified sections are set, for instance, the preferential swabbing operation may be conducted in order of setting which has been set. Other order may also be selected.
Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein. | A robot carries a swabbing member to a position of each mold to rub the swabbing member against each one of the molds. The swabbing member feeds a swabbing agent to the surface of each mold where it comes in contact with, and rubs the agent thereinto. | 26,715 |
This is a continuation of application Ser. No. 557,333, filed Jul. 23, 1990, now abandoned, which, in turn, is a continuation-in-part of application U.S. Ser. No. 208,200, filed Jun. 17, 1988, now abandoned.
This invention relates to the separation of compounds having a molecular weight of less than 1000 daltons from bio-polymers. In particular, it relates to novel packing supports useful in liquid chromatography (LC) and solid phase extraction (SPE) techniques for separating drugs, metabolites, etc. from mixtures containing water soluble proteins.
BACKGROUND OF THE INVENTION
It is frequently necessary to confirm the presence of drug substances, their metabolites, etc., in serum or plasma and/or to measure the concentrations of these compounds. In other cases, it is necessary to separate bio-polymers from smaller substances as a step in purifying substances from biological or from biomass mixtures. Such analyses are carried out using liquid chromatographic systems as illustrated in FIG. 1 of the drawings. The invention is compatible with high performance liquid chromatographic systems but is not limited to them.
Most of the published data and methods in this area of research relate to the LC analysis of drugs, metabolites, etc., in serum or plasma. The ways the mixtures are sampled can be classified as indirect and direct sampling. Indirect sampling involves treatment of the sample to remove the proteins, e.g. by precipitation, followed by extraction of the compound(s) of interest into a protein-free solvent system. Although this method involves multi-step preparation before the sample can be analyzed by a particular LC method, it still attracts much of the practical attention. Direct sampling, or direct injection of the untreated sample on an LC analytical column, causes clogging of the column, resulting in increasing pressure drop, peak broadening, variation of retention times, etc., unless special precautions are taken. After each sample injection, or after a few injections, the column must be thoroughly washed to remove precipitated proteins, particularly when larger serum samples (≧10 μl) are needed to detect the analytes of interest at their therapeutic or biological levels.
A partial solution to the above problems was found in a combination of an analytical column and a precolumn and two delivery pumps in a column switching system. Usually, the serum sample is loaded onto a short precolumn under mobile phase conditions in which only the drug(s) elute onto the analytical column. When all the components of interest elute from the precolumn to the analytical column, a valve is switched so that one pump continues to deliver mobile phase for elution of the compounds of interest from the analytical column for separation, while the second pump delivers a washing solution to the precolumn for removal of the proteins. To avoid clogging, the precolumn is filled with relatively large particles, usually 20-40 μm, and is replaced frequently to avoid deterioration of the analytical column (W. Rothe, et al., J. Chromatog. 222 (1981) 13). Usually, both columns are filled with reversed phase packing, e.g. C 8 or C 18 bonded to a silica support.
To avoid protein accumulation in the precolumn and to speed up the washing step, a less hydrophobic packing has been used, butyl modified methacrylate, as manufactured by TosoH, Japan, and sold under the tradename TOYOPEARL™ BT-650M. In the loading cycle, 10-50% saturated ammonium sulfate (NH 4 ) 2 SO 4 aqueous mobile phase is used. Under such conditions, serum proteins are retained on the precolumn and the drugs elute to load the reversed phase analytical column. Then, by column switching, the analytical column is separately programmed, while the precolumn is cleaned of the retained proteins, using a buffer solution of lower ionic strength (G. Tamai, et al., Chromatographia 21 (1986) 519).
In another study, a polystyrene divinylbenzene resin, manufactured by Rohm and Haas, USA, and sold under the tradename Amberlite® XAD-2, was used as the packing in the precolumn to retain methaqualone (MTQ), while eluting the plasma proteins. After all the proteins are washed away (with a pH 9.3 buffer solution), the mobile phase is adjusted to elute MTQ (R. A. Hux, et al., Anal. Chem. 34 (1982) 113).
Another example of a two-modal HPLC system combines size exclusion chromatography (SEC) and reversed phase chromatography (RPLC) using two columns in a column switching system. Following exclusion of the biopolymers from the SEC column, the later eluting band of smaller molecular size compounds was backflushed to the RPLC analytical column (S. F. Chang, et al., J. Pharm. Sci. 72 (1983) 236).
All the above examples employ column switching which requires an elaborate chromatographic system, including a second solvent delivery system, a second column and a switching system. Moreover, the operation of the switching system itself requires labor or investment in additional control equipment.
A completely different approach was undertaken by Pinkerton, et al. (U.S. Pat. No. 4,544,485). They redesigned the packing of the analytical column in such a way that the proteins elute in the excluded volume (void volume) and the analytes are retained and separated on the same analytical column. This was accomplished by chemically modifying a hydrophilic diol phase with a hydrophobic oligopeptide, e.g. glycyl-(L-phenylalanine)n, where n=1,2, or 3. It is crucial to their invention that the diol phase is bonded to a porous silica gel having a pore diameter smaller than 80 angstroms. Following this modification, the phenylalanine moiety is enzymatically cleaved from the diol ligand with a protease. The cleavage is restricted to surface areas that are accessible to the protease, resulting in a support for which the diol ligands are only present on the external surface, while L-phenylalanine modified ligands are present in the internal surface, i.e., the pores of the packing material. The ligands that are not accessible to the enzyme are similarly not accessible to the serum proteins. Thus, these proteins are excluded from entering the pores and elute in the void volume, while the smaller molecules (e.g., drugs) can interact with the hydrophobic phenylalanine ligands (U.S. Pat. No. 4,544,485). This support, named internal surface reverse phase liquid chromatographic packing (IS-RP), can be used to analyze many serum sample without the damaging accumulation of proteinaceous precipitate seen on regular RPLC columns.
Conceptually, the study of Yoshida, et al., (Chromatographia 19 (1985) 466) is similar to that of Pinkerton. They adsorbed denatured plasma proteins on C 18 silica supports having small pore diameter. These supports no longer retained plasma proteins, but still showed reversed phase characteristics for smaller analytes. The phenomenon is depicted as similar to that of Pinkerton's model, or as having the proteinaceous precipitation limited to the externally exposed surface, thereby making the external surface hydrophilic, while keeping the non-exposed internal C 18 surface free of such precipitation and accessible for (hydrophobic) interaction with small compounds.
Thus an object of this invention is to provide a novel packing material for liquid chromatography which will allow the direct injection of biological fluids into the column.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and a hydrophobic underlayer.
Still another object of this invention is to provide a chromatographic column which will shield and exclude large biopolymers but permit the partitioning of and hydrophobic interaction with small analytes.
Yet another object of this invention is to provide a novel shielded hydrophobic phase packing for chromatography adapted to bond to porous and non-porous silica supports.
Another object of this invention is to provide a chromatographic phase having a covalently bonded micellar surface.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and an anionic underlayer.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and a cationic underlayer.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and a chelating underlayer.
These and other objects of this invention may be seen by reference to the present specifications, claims, and drawings.
THE INVENTION
We have discovered shielded stationary-phase packing materials useful for liquid chromatography analysis and/or solid-phase extraction of mixtures containing proteinaceous compounds and small analytes, comprising:
a support;
an internal leash bonded to the support and bearing functionality that interacts with the small analytes; and
an external hydrophilic moiety bonded to the internal leash to form a hydrophilic external layer;
whereby the external hydrophilic external layer forms a water solvated interface which allows the small analytes to diffuse and interact with the internal leash but prevents interaction between the internal leash and the proteinaceous compounds.
In an alternative embodiment, we have discovered a shielded stationary-phase packing material for liquid chromatography analysis and/or solid-phase extraction of mixtures containing proteinaceous compounds and small analytes, comprising:
a support;
a hydrophilic polymeric network covalently bonded to the support; and
regions embedded within the network which contain functionality which interacts with the small analytes;
whereby small analytes will diffuse through the network and interact with the embedded regions and proteinaceous compounds will be excluded from such interaction.
We have further discovered a method of making these shielded stationary-phase packing materials, chromatography columns packed with these shielded stationary-phase packing materials, a method of liquid chromatographic separation which uses these chromatography columns, and a method of solid-phase extraction which uses these shielded stationary-phase packing materials.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a new concept providing novel LC or SPE packing materials which discriminate between water soluble proteins and smaller analytes on the bases of hydrophobic, ionic or other interactions. The novel LC or SPE packings of the present invention are (bonded) porous or non-porous supports in which an external, polar hydrophilic layer shields an underlayer which interacts with the small analytes, or in which pockets that interact with the small analytes are enclaved by a hydrophilic network. The underlayer or enclaved pockets may interact with the small analytes through hydrophobic, acidic, basic, ionic, chelating, or π--π bonding, or they may have other characteristics that cause them to interact and prevent or retard the elution of the small analytes. The present invention deals with supports having a bonded "micellar" layer, in which the micelles contain external polar and hydrophilic groups which are exposed to the mobile phase while shielding an underlayer that interacts with the small analytes. The present invention deals with a hydrophilic polymeric network that shields an underlayer that interacts with the small analytes, or such a network that contains enclaved regions that interact with the small analytes. Such hydrophilic shielding, when properly manipulated, can prevent water soluble proteins from interacting with the shielded part of the supports while allowing smaller substances to be retained or retarded by the interactive region, through hydrophobic, ionic, chelating or other interaction. These novel packings are termed shielded stationary phase (SSP).
The SSP packings of this invention are intended to eliminate the need for sample preparation procedures beyond the removal of particulate substances before the LC analysis. The packings are designed to elute the water soluble proteins, e.g. serum proteins, completely, or almost completely, in the void volume, and to retain drugs, metabolites, etc. Similarly, the packings of this invention can be used for separation of smaller analytes from water soluble proteins in the technique known as solid phase extraction, for small sample volumes to large scale industrial volumes. The SSP packing materials of the invention are conveniently produced from commercially available porous or non-porous silica supports, the surface of which is chemically modified with ligands or networks as described above. Similarly, the SSP packings can conveniently be produced from resins by modifying the surfaces of commercially available porous and nonporous materials, or by the direct preparation of such.
The use of micellar mobile phases in HPLC of proteins, e.g., nonionic surfactants, has been established in a number of studies, including use of direct plasma and serum injections (J. D. Dorsey, Chromatography 2 (1987) 13). Under these conditions, using for example a C 18 silica column, and a surfactant containing mobile phase, the surfactant saturates the stationary phase to form a double layer having a polar hydrophilic external interphase. The adsorption of many surfactants to such a reversed phase is strong enough to maintain the double layer even long after the additive has been removed from the mobile phase. Many water soluble proteins elute from such a column in the void volume, when the surfactant is selected from a groups of preferred detergents, e.g. the Tweens, bis-polyethyleneoxide derivatives of a fatty acid ester of sorbitol, as long as the double layer exists.
Albumins are known to associate with the Tweens and similar detergents below their critical micellar concentration (CMC) through hydrophobic patches located at the surface of these macromolecules, e.g. bovine serum albumin has four principal binding sites to adsorb deoxycholate, a biological "detergent" (A. Helenius, et al., Biochimica et Biophysica Acta 415 (1979) 29). A detergent-C 18 double layer can thus be drastically depleted of detergent molecules by injections of large serum samples due to the competitive adsorption of the serum albumin molecules to the surfactant.
Our invention attempts to mimic the chromatographic behavior of water soluble proteins on a "detergent modified" reversed phase by bonding appropriately designed ligands or polymeric phases to silica supports. Our invention is a new concept for chromatography in that it provides a covalently bonded micellar surface. The support consists of a non-polar spacer (R) which is interactive with small analytes and which is bonded to the support, and a hydrophilic end group (P). For a silica gel support (S) this can be represented by (S).tbd.Si--(R)--(P). The spacer R may be a hydrophobic moiety, in which case it will be a long chain aliphatic moiety, preferably containing 6-20 methylene groups, a crosslinked hydrocarbon, or a moiety that contains aryl groups. R may be a weak or strong anion-exchange group for ion pairing of acidic analytes, or a weak or strong cation-exchange group for ion pairing of basic analytes, or it may be a π--π donor to associate π--π acceptor analytes, or conversely a π--πacceptor to associate π--π donor analytes. It may bear chelating groups or other functional groups that will interact with the small analytes by complex formation. R may also be a combination of the groups and moieties described above. A preferred combination exists when R is a hydrophobic moiety which is substituted with weak or strong anion-exchange groups or weak or strong cation-exchange groups or π--π donor or acceptor groups or chelating groups, or combinations of these groups. P is the hydrophilic head containing one or more polar functional groups, and (S).tbd.Si is a siloxane bond (Si--O--Si) to the silica gel support. Alternatively, a hydrophilic polymeric network will shield an interactive, i.e. hydrophobic, cationic, anionic, chelating and the like, underlayer R or such a network containing interactive enclaved regions which provides a bonded phase with hydrophilic exterior, P, and interactive interior, R.
A particular advantage of the shielded stationary phase is the ability to select a phase from among the interactive underlayers or enclaved regions described above such that the retention times of particular analytes in chromatographic separations may be adjusted to resolve them from the large frontal peak of the proteins, or from other small analytes in a sample. One or more of the interactions described above may be employed to increase specific selectivity for particular analytes and make possible direct, quantitative analyses of complex mixtures such as biological matrix samples.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates a typical liquid chromatography system that consists of a solvent reservoir (10), sequentially connected to a pump (12), a mixer (14), an injector (16), a column (18), a detector (20), and a recorder or data collection unit (22). The column (18) is the device that contains the shielded stationary phase involved in the chromatographic separation.
FIG. 2 schematically shows the separation mechanism of a "micellar" shielded hydrophobic phase. The external polar heads form a hydrophilic layer (P) that is exposed to the protein and shields the hydrophobic underlayer (R). The proteins (G) come in contact with the noninteracting hydrophilic layer (P) while the small analytes (A) are partitioned and retained by the hydrophobic under layer (R).
FIG. 3 schematically shows the separation mechanism of a shielded hydrophobic phase consisting of hydrophobic pockets (R) enclaved by a hydrophilic network (P). Small analytes (A) can penetrate through the network and interact with the hydrophobic pockets, while larger proteins (G) are prevented from such an interaction.
FIG. 4 is a comparison of three chromatograms, A--human serum, B--propranolol (30), and C--propranolol (30) spiked human serum, as resolved upon Phase 1. N,N-bis(2'-methoxyethyl)-11-aminoundecylsilyl (see Example 1 and Table I).
Sample:
A) 20 μl injection of human serum
B) 1.0 μl injection containing 5 mg/ml propranolol in methanol
C) 2.0 μl injection containing 0.2 mg/ml of 30 in human serum
Column Dimensions: 15 cm×4.6 mm
Mobile Phase: 0.5M NH 4 OAc, adjusted to pH 6.0 with glacial acetic acid
Flow Rate: 2.0 ml/min.
Temperature: ambient
Detection: UV at 280 nm, 1.0 AUFS, ATTN 4
Chart Speed: 0.5 cm/min.
FIG. 5 is a comparison of two chromatograms, A--human serum spiked with trimethoprim (32), carbamazepine (34) and propranolol (30) and B--the same drugs in methanol, as resolved upon ω-(sulfonazide)alkylsilyl, Phase 3 (Example 3).
Sample:
A) 10 μl injection containing a 0.2 mg/ml or each drug in a 2:2:1:solution of human serum:mobile phase:methanol
B) 25 μl of 1 mg/ml of each drug in methanol
Column Dimensions: 5.0 cm×4.6 mm
Mobile Phase: 180 mM NH 4 OAc:ACN (90:10) (pH 7.0)
Flow Rate: 2.0 ml/min.
Chart Speed: 0.5 cm/min.
Temperature: ambient
Detection: UV at 280 nm, 0.5 AUFS, ATTN 2
FIG. 6 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon (10-carbomethoxydecyl)dimethylsilyl. Phase 4 (Example 4).
Sample: 10 μl injection of a 1:1 calf serum: 25 mg/ml trimethoprim (32) in 10% aqueous methanol. Chromatographic conditions as described in FIG. 5, except: 0.1 AUFS, ATTN 8.
FIG. 7 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon N,N'-bis(2-hydroxyethyl)ethylenediamino modified (10-carboxydecyl)dimethylsilyl, Phase 5. Chromatographic conditions as described in FIG. 6.
FIG. 8 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon 10 cyanodecylsilyl, Phase 6. Chromatographic conditions as described in FIG. 6.
FIG. 9 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon N-(3'-propylsulfonic acid)-11-undecylaminosilyl, Phase 7 (Example 7). Chromatographic conditions as described in FIG. 6.
FIG. 10 shows three chromatograms, A--theophylline (36), B--phenobarbital (38), and C--carbamazepine (34) of spiked calf serum at or below the therapeutic levels as resolved upon Phase 8 (Example 8).
Sample: 10 μl injection containing 10 μg/ml of each drug in calf serum
Column Dimensions: 15 cm×4.6 mm
Mobile Phase:
A--180 mM NH 4 OAc,
B and C--180 mM NH 4O Ac/ACN 95:5
Flow Rate: 2.0 cm/min.
Detection: UV at 254 nm, 0.001 AUFS, ATTN 8
Chart Speed: 5 mm/min.
FIG. 11 is a comparison of two chromatograms. A--ibuprofen (40) in human serum after Advil® ingestion and B--ibuprofen (40) standard, upon Phase 8 (Example 8).
Sample:
A--10 μl of human serum taken from a blood sample 90 minutes after ingestion of two Advil tablets
B--5 μl of ibuprofen standard (0.5 mg/ml in methanol)
Column Dimensions: 15 cm×4.6 mm
Mobile Phase: 180 mN NH 4 OAc/ACN/THF 95:5:1
Flow Rate: 2.0 ml/min.
Chart Speed: 5 mm/min.
Detection: UV at 273 nm, 0.001 AUFS, ATTN 4
FIG. 12 shows the purification of carbamazepine (34) form spiked calf serum upon Phase 8 (Example 8).
Sample:
250 μl injection of 5 μg/ml carbamazepine (34) in calf serum.
A--1.0 ml fraction was collected and 250 μl reinjected the protein containing fraction.
B--The carbamazepine (34) fraction was collected in a 2 ml fraction and 250 μl of the carbamazepine (34) fraction was reinjected (0.625 μg/ml)
Column Dimensions: 15 cm×4.6 mm
Mobile Phase:
A--180 mM NH 4 OAc
B--ACN
Gradient Profile:
______________________________________Time % A % B______________________________________0.0 100 05.0 100 05.1 85 1515.0 85 1515.1 100 020.0 100 0______________________________________
Flow rate: 2.0 ml/min.
Detection: UV at 285 nm, 0.032 AUFS
Chart Speed: 0.5 cm/min.
FIG. 13 represents, in schematic form, a cross-sectional view of a pore, 1, in the silica gel support, 2, with the hydrophilic shield, 3, and the shielded, interactive region, 4, which interacts with the small analytes.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and in particular to FIG. 1, 10 represents a solvent reservoir connected to a mixer 12 which in turn is connected to a pump 14. Pump 14 is connected to a conventional injector 16, through which the sample to be analyzed is injected into the connected column 18 which contains the shielded hydrophobic phase, the subject of this invention. The column 18 is connected to a conventional chromatographic detector 20 which in turn is connected to a recorder 22. Recorder 22 graphs the chromatogram of the sample analysis. A continuous flow of solvent proceeds from the solvent reservoir 10 through the detector 20.
FIG. 2 schematically shows the interaction of a "micellar" shielded hydrophobic phase packed in the column 18. To the support (s) (usually silica gel) is bonded a hydrophobic spacer R.
The P groups form a hydrophilic and water solvated layer and the R groups a hydrophobic underlayer. The P layer prevents large bio-polymer molecules G from interacting with the underlayer R. Smaller analytes A may pass through and interact with the hydrophobic underlayer R.
FIG. 3 shows a hydrophilic network P bonding the silica support (s) to hydrophobic R group (such as alkyl, aryl, etc.).
Use of a properly designed polar hydrophilic head P excludes water soluble bio-polymers, by steric hindrance, from interacting with the underlying hydrophobic spacer R. On the other hand, small analytes are "solubilized" by the R-groups as they penetrate the hydrophilic polar layer. FIG. 2 schematically shows the chromatographic interactions of SSP with a sample consisting of bio-polymer and an analyte. The polar portion of the bonded phase will screen the bio-polymer from the hydrophobic regions of the bonded phase, resulting in its rapid elution. Under the same chromatographic conditions, the smaller analyte "solubilized" by the hydrophobic regions of the bonded phase is retained and thus separated from the larger macromolecules.
FIG. 3 describes a hydrophilic water solvated network containing enclaved hydrophobic moieties R. In a similar mechanism, the larger proteins G are screened by this network from interacting with the enclaved hydrophobic moieties R which are accessible to the smaller analytes A, resulting in fast elution of the former and retention of the latter compounds.
A large variety of high performance silica gel bonded phases have been synthesized and evaluated as SSP material for direct injection of serum, plasma, or body fluids containing drugs. These phases are set forth in the following listing as Phase 1 to Phase 8 and are illustrated by Examples and/or Figures in the drawings.
FIG. 13 represents a cross-sectional view of a pore, 1, in the silica gel support, 2, with an interactive phase, 4, bonded to the support, and a hydrophilic shield, 3, which shields the interactive phase from large, water-soluble biopolymers in the liquid being analyzed. This liquid fills the pores, 1, and carries the small, hydrophobic analytes, the large, water-soluble biopolymers, and other components. The large, water-soluble biopolymers are unable to penetrate the hydrophilic shield while the small analytes are small enough to penetrate it readily and interact with the interactive phase, producing the desired chromatographic separation.
In the drawings FIGS. 4-12 represent chromatograms. The following number designations represent peaks in the chromatogram indicating the presence of the following drugs:
(30) propranolol
(32) trimethoprim
(34) carbamazepine
(36) theophylline
(38) phenobarbital
(40) ibuprofen
SILICA GEL BONDED PHASES
Phase 1.tbd.Si(CH 2 ) 11 N(CH 2 CH 2 OCH 3 ) 2
Phase 2.tbd.Si(CH 2 ) 10 CON(CH 2 CH 2 OCH 3 ) 2
Phase 3.tbd.Si(CH 2 ) n SO 2 N 3 where n=7-10
Phase 4--Si(CH 3 ) 2 (CH 3 ) 10 CO 2 CH 3
Phase 5--Si(CH 3 ) 2 (CH 2 ) 10 CON(CH 2 CH 2 OH)(CH 2 CH 2 NRCH 2 CH 2 OH) where (R)=--H and/or --CO(CH 2 ) 10 Si(CH 3 ) 2 --
Phase 6.tbd.Si(CH 2 ) 10 CN
Phase 7.tbd.Si(CH 2 ) 11 NHCH 2 CH 2 CH 2 SO 3 H
Phase 8 ##STR1## where 0≦k, l, m, n≦50, R 1 =--CONH(CH 2 ) 3 Si.tbd.(S), (S)=silica gel, Si--(S)=Si--O--Si, and R 2 , R 3 =R 1 and/or another network of the same connected through a --CO-- bond and/or H, and or alkyl, and/or carboxylate, and/or alkanamide.
Phase 9 A mixed phase containing Phase 8 and (S).tbd.Si(CH 2 ) 3 N(CH 3 ) 2 in approximately equal surface concentration.
Phase 10 A mixed phase containing Phase 8 and (S).tbd.Si(CH 2 ) 3 N+(CH 3 ) 3 in approximately equal surface concentration.
Phase 11 A mixed phase containing Phase 8 in which R 1 is (S).tbd.Si(CH 2 ) 3 NH(CH 2 ) 2 NHCO--, and (S).tbd.Si(CH 2 ) 3 N+(C 4 H 9 ) 3 in approximately equal surface concentration.
Phase 12 A mixed phase containing Phase 8 and (S).tbd.Si(CH 2 ) 3 NHCO(CH 2 ) 2 CO 2 H in approximately equal surface concentration.
Phase 13 A mixed phase containing Phase 8 in which R 2 is ##STR2## in approximately equal surface concentration.
These phases demonstrate that the interactive region of the phase, R, may be selected from a wide variety of functionalities, including but not limited to, hydrophobic, weak-base anion exchange, strong-base anion exchange, weak-acid cation exchange and strong-acid cation exchange functionalities. Phases 1 through 8 have defined hydrophobic and hydrophilic regions and are covalently bonded to the chromatographic matrix. The bonded ligand of Phases 1-7 have a hydrophobic region R consisting of a hydrocarbon chain, --(CH 2 ) n -- where n=6 to 20, more preferably 7 to 11 and still more preferably 10 or 11, and a polar hydrophilic head P. The hydrophobic region, R, is also referred to herein as a "leash", as it both spaces the polar group from the support and tethers the polar group to the support. Phase 8 is a bonded hydrophilic polyether network enclaving hydrophobic phenyl groups bonded to the network through bis carbamate groups.
Phases 9 through 13 have regions R and P in which R is a hydrophobic group or a weak or strong cation-exchange group or a weak or strong anion-exchange group. The preferred phase contains as regions R both regions R a which are hydrophobic, and R b which are weak or strong cation-exchange groups or weak or strong anion-exchange groups or chelating groups or π--π accepting or donating groups. R a may be any of the hydrophobic groups described herein, and preferably one of the hydrophobic groups of Phases 1 through 8. The R b group may be attached to the R a group, as for example to the nitrogen in R 2 or R 3 of Phase 8, or to the silane silicon of Phase 8, in which case the R b group is shielded by the hydrophilic polymer network of the phase. Alternatively the R b group may be attached to the silica surface through an alkylsilyl, alkylaminosilyl or alkylamidosilyl group directly, and mixed-bonded with phases 1-7, in which case it will be shielded by the hydrophilic groups of neighboring hydrophobic leash-hydrophilic head micelles. The R b group in Phase 9 is --N(CH 3 ) 2 , a weakly basic anion exchanger; in Phase 10 it is --N + (CH 3 ) 3 , a strongly basic anion exchanger; in Phase 11 it is --N + (C 4 H 9 ) 3 , another strongly basic anion exchanger; in Phase 12 it is --CO 2 H, a weakly acidic cation exchanger; and in Phase 13 it is --SO 3 H, a strongly acidic cation exchanger.
These phases also demonstrate that the polar head P may be selected from a wide variety of functionalities including, but not limited to: amines, amides, esters, ethers, alcohols, azides, carboxylic acids, cyano groups, thiols, diols, amino acids, nitriles, sulfonic acids, ureas, and the like, or a combination of such. All of these phases have shown retention of small drug analytes while excluding serum proteins when tested with drug containing serum. FIGS. 4-12 illustrate various chromatographic separations as carried out with different SSP supports. In a typical chromatographic separation on an SSP, the bio-polymer will elute completely, or almost completely, in the void volume, while the analyte elutes later.
The SSP supports can be simply slurry packed into standard liquid chromatography columns and used with standard HPLC equipment. Such a combination allows for the direct, on-line resolution of small analytes from a complex bio-polymer matrix in a single and simple chromatographic step. The SSP supports solve, in a new and novel way, the problem of direct, on-line analysis of analytes in bio-matrices such as serum or plasma. An example for commercial applications of this invention is the direct analysis of drugs, metabolites, etc., from serum, plasma, saliva, urine, or other body fluids as is often performed in the pharmaceutical industry, clinical and drug testing laboratories, toxicology studies, etc.
The following examples are intended to illustrate the invention, and are not to limit it except as limited by the claims. All percentages herein are by weight unless otherwise indicated, and all reagents are of good commercial quality unless otherwise indicated.
EXAMPLE 1
N,N-bis(2'-methoxyethyl)-11-aminoundecylsilyl, Phase 1.tbd.Si(CH 2 ) 11 N(CH 2 CH 2 OCH 3 ) 2 N,N-bis(2'-Methoxyethyl)-11-(triethoxysilyl)undecylamine, (II)
To a solution of 16.8 g 10-undecenal in 25 ml methylene chloride, crystals of di-μ-chlorodichlorobis(ethylene)-diplatinum (II) were added and the solution heated to 40°-45° C. A solution of 16.4 g triethoxysilane in 25 ml methylene chloride was added dropwise over a period of 90 minutes. After reagent addition was completed, the rection mixture was heated for an additional 30 minutes. The mixture was fractionated and the product, 11-triethoxysilylundecanal (I) was obtained at 65° C. at 0.2 mm Hg at a 30% yield.
A solution of 6.0 g of I and 3.0 g of bis(2-methoxyethyl)amine in 100 ml absolute ethanol containing 0.25 g 10% Pd/C was hydrogenated in a Parr instrument for 90 minutes at room temperature. The mixture was filtered and the alcohol removed under reduced pressure. The residue was purified by column chromatography using 100 g dry silica gel, starting with toluene and increasing the polarity with ethyl acetate. The product, (II), eluted at 50% and 100% ethyl acetate fractions.
BONDING
A solution of (II) in 15 ml toluene was added to 4.0 g of silica gel (5-μm particle size, 100 m 2 /g surface area, 12.5 nm average pore diameter) placed in a 50 ml glass ampule. The mixture was slurried to homogeneity and the solvent was removed under vacuum while the slurry was continuously agitated. Ammonia (gaseous) was added to the evacuated mixture, then the ampule was sealed and heated at 100° C. overnight. The mixture was thoroughly washed with methylene chloride, then methanol, and then dried. From the elemental analysis: C--6.72% (silica blank C--0.41%), a ligand coverage of 3.13 μmol/m 2 was calculated for C 17 H 37 NO 3 Si, (═Si(OH)--(CH 2 ) 11 N(CH 2 CH 2 OCH 3 ) 2 ).
A 15 cm×4.6 mm column was slurry packed at pressure above 52 MegaPascals. Human serum spiked with the drugs listed in Table I was directly injected through injector 16 onto column 20 containing phase 1. The column resolved the drugs from the human serum components (see Table I). FIG. 4 shows the chromatographic resolution of propranolol and other drugs from spiked human serum using the procedures of Example 1.
TABLE I______________________________________RETENTION TIMES FOR DRUGS FROM SPIKEDHUMAN SERUM ON PHASE 1Drug Retention Time (min.) Mobile Phase______________________________________Theophylline 1.78 1Propranolol 5.00 1Propranolol 2.52 2Quinidine 1.97(a) 2Carbamazepine 33.58 1Carbamazepine 12.96 2Desipramine 4.25 2Column Dimensions: 15 cm × 4.6 mmFlow Rate: 2.0 ml/min.______________________________________ 1. 0.5M NH.sub.4 OAc aqueous solution adjusted to pH 6.0 with glacial acetic acid 2. 0.5M NH.sub.4 OAc pH 5.0 adjusted with H.sub.3 PO.sub.4 : 2propanol: THF 500:25:1 (a) Not completely resolved from minor serum components
EXAMPLE 2
N,N-bis(2'-methoxyethyl)-11-silylundecanamide, Phase 2 .tbd.Si(CH 2 ) 10 CON(CH 2 CH 2 OCH 3 ) 2
The material was prepared from N-hydroxysuccinimido 11-(triethoxysilyl)undecanoate which was treated with an equivalent of bis-(2-methoxyethyl)amine in methylene chloride in the presence of an equivalent of triethylamine. The product, N,N-bis-(2'-methoxyethyl)-11-(triethoxysilyl)undecanamide (III), was purified by column chromatography on a ten-fold w/w silica gel column, starting with toluene and increasing polarity with ethyl acetate. The product, an oil, eluted at 20% ethylene acetate with approximately 80% yield.
Bonding as for (II) Example 1 using 6.0 g of the same silica and impregnating with 1.65 g of (III) in 20 ml hexane yielded the N,N-bis-(2'-methoxyethyl)-11-undecanamide, Phase 2.
Elemental analysis: C--3.64, H--1.13, and N--0.40%. From the carbon percentage a coverage of 3.14 μmol/m 2 was calculated for C 17 H 35 --NO 4 Si (Si(OH)--(CH 2 ) 10 CON(CH 2 CH 2 OCH 3 ) 2 ) ligand. A 15 cm×4.6 mm column was slurry packed at pressures above 52 MegaPascals. Human serum spiked with the drugs listed in Table II was directly injected through injector 16 onto column 20 containing phase 2. The column retained the drugs as listed in Table II.
TABLE II______________________________________RETENTION TIMES FOR DRUGS ON PHASE 1Drug Retention Time (min.) Mobile Phase______________________________________Caffeine 1.11 1Acetaminophen 1.69 1Propranolol 18.01 1______________________________________ (1) 0.05M ammonium acetate, 0.1M potassium chloride (pH 3.0)/MeOH 80:20
EXAMPLE 3
ω-(sulfonazido)alkylsilyl, Phase 3 .tbd.Si(CH 2 ) n SO 2 N 3 n=7-10
To 10 g of SUPELCOSIL™ silica (5-μm particle size, 10-nm pore size) in a 100 ml round bottom flask were added 10 ml of AZ-CUP MC Azidosilane reagent (Hercules, Inc., Wilmington, Del.), 25 ml of methylene chloride and 25 ml of toluene. The mixture was refluxed for eight hours, cooled, filtered, washed with 3×100 ml of methylene chloride, followed by 3×100 ml of methanol, and oven dried at 80° C. Elemental analysis: C--8.92, H--1.82, N--1.07, and S--0.58%. The resultant bonded phase was slurring packed at pressures above 34 MegaPascals into a 5 cm×4.6 mm column. Human serum spiked with the drugs listed in Table III were directly injected through injector 16, onto column 20, containing phase 3. FIG. 5 shows the chromatographic resolution of trimethoprim (32), carbamazepine (34), and propranolol (30) from the spiked human serum sample.
Table III indicates the retention time for other drugs using the procedure of Example 3.
TABLE III______________________________________RETENTION TIME FOR DRUGS AND TEST PROBESFROM SPIKED HUMAN SERUM ON THE SULFAZIDEPHASE 3Test Compound Retention Time (min.)______________________________________Uracil 0.37Theophylline 0.54Caffeine 0.71Acetaminophen 0.54Trimethoprim (32) 3.34Carbamazepine (34) 4.50Codeine 2.92Hydrochlorothiazide 1.16Procainamide 2.04Propranolol (30) 13.52______________________________________
Column Dimensions: 5 cm×4.6 mm
Mobile Phase: 180 nM NH 4 OAc:ACN (90:10) (pH 7.0)
Flow Rate: 2.0 ml/min.
EXAMPLE 4
(10-carbomethoxydecyl)dimethylsilyl, Phase 4 --Si(CH 3 ) 2 (CH 2 ) 10 CO 2 CH 3
To 5.0 g of SUPELCOSIL™ silica (5-μm particle size, 10-nm pore size) in a round bottom flask was added 2.0 ml of (10-carboxymethoxydecyl)dimethylchlorosilane dissolved in 50 ml of dried toluene. The mixture was refluxed for 14 hours, cooled, filtered, washed with 3×100 ml of toluene followed by 3.×100 ml of methanol, and dried. Elemental analysis: C--5.66, and H--1.22%. A bonded phase coverage of 2.40 μmol/m 2 was calculated for C 14 H 29 O 2 Si ligand. A 5 cm×4.6 column was slurry packed with this material at pressures above 41 MegaPascals. The resultant column containing phase 4 was capable of baseline resolution of trimethoprim from calf serum (FIG. 6) directly injected through injector 16.
EXAMPLE 5
N,N'-bis(2-hydroxyethyl)ethylenediamino modified 11-dimethylsilylundecanoic acid (IV), Phase 5 --Si(CH 3 ) 2 (CH 2 ) 10 CON(CH 2 CH 2 OH(CH 2 CH 2 NRCH 2 OH) R=H and/or CO(CH 2 ) 10 Si(CH 3 ) 2 --
A 3.8 g sample of phase 4 was hydrolyzed with 50 ml 1:1 methanol:water mix adjusted to pH 2.85 using glacial acetic acid. The mixture was shaken overnight, filtered and washed with 3×50 ml of 1:1 methanol:water, followed by 3×50 ml of methanol, and dried to yield (IV). A 3.6 g of (IV) was placed in a flask with 1.0 g of N,N'-bis(2-hydroxyethyl)ethylene diamine and 1.1 g of EEDQ (1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline) dissolved in 40 ml of dry THF. The mixture was shaken for six hours at room temperature. The mixture was filtered, washed with 3×100 ml of dry THF, followed by 3×100 ml of methanol, and dried. Elemental analysis:C--9.13, H--1.71, and N--1.57%. From the carbon percentage a coverage of 3.07 μmol/m 2 or 2.06 μmol/m 2 was calculated for (R=H) C 19 H 41 N 2 O 3 Si or for (R=CO(CH 2 ) 10 Si(CH 3 ) 2 --) C 32 N 66 N 2 O 4 Si 2 , respectively. A 5.0 cm×4.6 mm column was slurry packed at pressures above 41 MegaPascals. The resulting column containing Phase 5 gave a baseline resolution of trimethoprim from calf serum (FIG. 7) when injected directly through injector 16.
EXAMPLE 6
10-cyanodecylsilyl, Phase 6 .tbd.Si(CH 2 ) 10 CN
To 10 g of oven dried SULPELCOSIL™ silica (5-μm particle size, 10-nm pore size) in a 250 ml round bottom flask was added 2.5 ml of 10-cyanodecyltrichlorosilane and 75 ml of toluene. The mixture was refluxed for five hours and then 1.5 ml of trimethylchlorosilane was added and the mixture was refluxed an additional hour. The mixture was cooled, filtered, and washed with 3×100 ml of toluene followed by 3×100 ml of methanol, and dried.
Elemental Analysis: C--8.38, H--1.56, and N--0.98%. A bonded phase coverage of 4.03 μmol/m 2 was calculated for a C 11 H 22 NOSi ligand, (.tbd.Si(OH)(CH 2 )CN).
A 5.0 cm×4.6 mm column was slurry packed at pressures above 41 MegaPascals. The resultant column containing Phase 6 gave a baseline resolution of trimethoprim from calf serum (FIG. 8) when injected directly through injector 16.
EXAMPLE 7
N-(3'-propylsulfonic acid)-11-undecylaminosilyl, Phase 7 .tbd.Si--(CH 2 ) 11 NHCH 2 CH 2 CH 2 SO 3 H
Preparation of 11-(undecylamine)trimethoxysilane
According to Freifelder (J. Am. Chem. Soc. 82 (1960) 2386) by hydrogenating 10-(trimethoxysilyl)cyanodecane in the presence of 5% Rh/alumina in 12% methanolic ammonia solution instead of ethanolic solution. The product was fractionated b.p. 145°-147° C. at 0.25 mm Hg, 50% yield.
11-Aminoundecylsilyl Phase:
5.3 g of (11-undecylamine)trimethoxysilane was dissolved in 75 ml toluene and added to 20.4 g. of SUPELCOSIL™ silica (5-μm particle size, 10-nm pore size). The mixture was refluxed for seven hours, cooled, filtered, washed with 3.0×50 ml of toluene, followed by 3×50 ml of methanol, and dried.
Elemental analysis: C--6.68, H--1.38, N--0.54%. From the carbon percentage, a coverage of 3.38 μmol/m 2 was calculated for a C 12 H 27 NOSi ligand.
Phase 7 Preparation: to 5.0 g of the 11-aminoundecylsilyl phase dried at 65° C. under high vacuum was added 1.2 g of 1,3-propane sultone dissolved in 35 ml of methylene chloride, followed by 75 ml of methylene chloride containing 250 μl of pyridine. The mixture was shaken at room temperature for several minutes and then refluxed for three hours. The mixture was filtered, washed with 3×100 ml of methylene chloride, followed by 3×100 ml of methanol, and dried. Elemental analysis: C--8.58, H--1.60, N--1.40, and S--0.83%. From the carbon percentage, a coverage of 3.41 μmol/m 2 was calculated for a C 15 H 33 O 3 SSi ligand. A 5.0 cm×4.6 mm column was slurry packed at pressures above 41 MegaPascals. The resultant column containing Phase 7 gave a baseline resolution of trimethoprim from calf serum (FIG. 9) when injected directly through injector 16.
EXAMPLE 8
Urethane-modified 3-propylamine, Phase 8
.tbd.SiCH.sub.2 CH.sub.2 CH.sub.2 NHCONHR
where R=branched polyethylene oxide with terminal hydroxyl groups substituted with tolydiisocyanate: ##STR3## where 0≦k, l, m, n≦50, R 1 =.tbd.SiCH 2 CH 2 CH 2 NHCONHR, (S)=silica gel, Si--(S)=Si--O--Si, and R 2 , R 3 =R 1 and/or another network of the same connected through a --CO-- bond and/or H, and or alkyl, and/or carboxylate, and/or alkanamide.
To 30 g of dry SUPELCOSIL silica (5-μm particle size, 10-nm pore size) 20 g of 3-aminopropyltrimethoxysilane and 300 ml of toluene were added. The suspension was heated to reflux for 16 hours, and the reaction mixture was filtered and washed with 300 ml of toluene followed by 300 ml of methanol and dried at 60° C. under nitrogen for 10 hours.
To 600 ml of toluene in a 1000 ml round bottom flask was added 5.0 g of Hypol FHP 2000 polymer (W. R. Grace, Co., Lexington, Mass.). The polymer was completely dissolved by shaking and sonicating. To the solution 12.5 g of the 3-aminopropyltrimethoxysilane-bonded silica from the step above was added. The suspension was refluxed for three hours. To the mixture was added 0.2 g of 1,4-diazabicyclo-(2,2,2)octane dissolved in 10 ml of toluene, and the mixture was refluxed for an additional three hours. The "hot" mixture was filtered, washed with toluene, methylene chloride and methanol, and oven dried. Elemental analysis: C--10.41, H--1.66, and N--1.30%.
A 15 cm×4.6 mm column was slurry packed at pressures above 52 MegaPascals. The column resolved various drugs from calf and human sera. FIG. 10 shows carbamazepine-, phenobarbital- and theophylline-spiked human serum samples as resolved on a column containing Phase 8 by directly injecting the spiked samples through injector 16. FIG. 11 shows the resolution of ingested ibuprofen from human serum. FIG. 12 shows the trace enrichment/purification by a step-wise elution of a carbamazepine-spiked calf serum and the chromatographic results of the collected protein and drug containing fractions. This evaluation demonstrates the application of the packing material for trace enrichment, which could be applied in solid phase extraction of small volumes up to large scale industrial levels.
EXAMPLE 9
R=--N(CH 3 ) 2 , Phase 9
To 7.12 g of SUPELCOSIL™DB silica (5μm particle size, 10 nm pore size) previously conditioned at 85% humidity (allowing to equilibrate over a saturated aqueous solution of lithium chloride) were added 5.6 mmole (1.16 g) of N,N-dimethyl-3-aminopropyltrimethoxysilane, 5.6 mmole (1.0 g) 3-aminopropyltrimethoxysilane and 100 ml toluene. The mixture was suspended and refluxed for 4 hours. The mixture was filtered, and the solid material was washed with 200 ml toluene, then 200 ml methylene chloride, and finally 200 ml methanol. The solid product was dried at 60° C. under nitrogen for four hours followed by two hours at high vacuum. To the dried solid product a solution of 2.8 g Hypol FHP 2000 polymer (W. R. Grace Company, Lexington, Mass. in 100 ml of dry toluene was added. The mixture was suspended and refluxed for one hour; 1.0 ml of hexylamine was added and suspended, and the mixture was refluxed for one additional hour. The solid product was filtered hot and washed with 200 ml each of toluene, methylene chloride and methanol. The solid product was dried at 60° C. under nitrogen for four hours. To the solid product 50 ml of dry pyridine and 4.0 ml of acetic anhydride were added. The mixture was agitated for 10 hours, then filtered and washed with 100 ml toluene, 200 ml methylene chloride and 300 ml methanol. The solid product was dried at 60° C. under nitrogen for four hours.
Elemental analysis: C--14.95%; H--2.33%; N--1.99%.
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 9. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicylic acid and benzoic acid are shown in Table IV, below.
EXAMPLE 10
R=--N + (CH 3 ) 3 , Phase 10
Phase 10 was prepared according to the procedure of Example 9, above, except that 3 μmole per square meter of silica surface of a 50% methanolic solution of N-(3-trimethoxysilylpropyl)trimethylammonium chloride was used in place of the N,N-dimethyl-3-aminopropyltrimethoxysilane, and 3 μmol per square meter of silica surface of the 3-aminopropyltrimethoxysilane was used.
Elemental analysis: C--15.83% and N--1.92%.
A 4.6-mm×15-column was slurry packed at 59 MegaPascals with Phase 10. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicylic acid and benzoic acid are shown in Table IV, below.
EXAMPLE 11
R=--N + (C 4 H 9 ) 3 , Phase 11
Phase 11 was prepared according to the procedure of Example 9, except that 3 μmole per square meter of silica surface of a 50% methanolic solution of N-(3-trimethoxysilylpropyl)tributylammonium bromide and 3 μmole per square meter of silica surface of N-(2-aminoethyl)-3-aminopropyltrimethylsilane were substituted for the N,N-dimethyl-3-aminopropyltrimethoxysilane and 3-aminopropyltrimethoxysilane of Example 9.
Elemental analysis: C--15.85% and N--2.40%
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 11. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicyclic acid and benzoic acid are shown in Table IV, below.
TABLE IV______________________________________CAPACITY FACTOR RESULTS FORCHROMATOGRAPHIC SEPARATION WITHBASIC MODIFIED PHASE 8SeparatedComponent Phase 8 Phase 9 Phase 10 Phase 11______________________________________Chloramphenicol 2.54 4.04 5.61 5.20Salicylic Acid 2.05 5.20 10.20 23.19Benzoic Acid 1.16 2.19 3.66 4.44Total Serum 11.5 10.8 11.6 12.0Protein Area,(million counts)______________________________________
Chromatographic Conditions
Mobile Phase: 95% 180 mM NH4OAc (aq) pH=7.0/5% AcN
Flow: 2.0 ml/min
Injection Volume: 10 μl
Concentration and Detection:
Chloramphenicol, 10 μg/ml, 278 nm, 0.016 AUFS
Salicylic Acid, 25 μg/ml, 280 nm, 0.008 AUFS
Benzoic Acid, 10 μg/ml, 254 nm, 0.016 AUFS or 0.032 AUFS
Serum, neat, 254 nm, 0.016 AUFS
Temperature: Ambient.
NOTE--The Capacity factor, C i , is defined as ##EQU1## where V i is the elution volume of compound i and V o is the elution volume of an unretained compound (V o is also termed the void volume).
EXAMPLE 12
R=--CO 2 H, Phase 12
Phase 12 was prepared according to the procedure of Example 9, except that only 20 μmole per square meter of silica surface of the 3-aminopropyltrimethoxysilane and no other aminosilane was used; subsequent to the addition of the pyridine but prior to the addition of the acetic anhydride, 0.15 g/g of silica of succinic anhydride was added and the mixture was agitated for 22 hours; and in the final washing of the solid product the first rinse was with water, followed by 50% aqueous methanol and finally methanol.
Elemental analysis: C--16.69%, H--2.48%, and N--2.23%.
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 12. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicylic acid and benzoic acid are shown in Table V, below.
EXAMPLE 13
R=--SO 3 H, Phase 13
Phase 13 was prepared according to the procedure of Example 12, except that the reaction mixture was cooled to room temperature and instead of the hexylamine, a solution of 1.5 g hexamethylenediamine in 50 ml of toluene for each 10 g of silica gel was added and the mixture was agitated for three hours. In addition, prior to adding the acetic anhydride the solid product is dried under high vacuum at 60° C. for two hours; 4 μmole per square meter of silica surface of 3-fluorosulfonylbenzenesulfonyl chloride was substituted for the succinic anhydride; and following the final washing step the solid product was dried under high vacuum at 60° C. for two hours. A calculated amount of 3 μmole per gram of silica, based on the pretreatment weight of silica used in this example, of tetrabutylammonium hydroxide in a 40% aqueous solution was evaporated to dryness under vacuum for three hours at ambient temperature, dissolved in 4 ml/g of silica of dry pyridine, and added to the silica. The mixture was agitated at room temperature for 20 hours, filtered and washed thoroughly with 1:9 acetonitrile:water containing 180 mmole ammonium acetate, followed by washing with water and then methanol. The solid product was dried at 60° C. under nitrogen for four hours.
Elemental analysis:
Prior to final treatment step- C--16.14%, H--2.48%, N--2.35%, S--0.75% and F--0.20%
Final product- C--16.19%, H--2.48%, N--1.83%, S--0.55% and F--0.050%.
Despite the presence of fluoride in the final product, the material that was almost completely inactive to ion exchange prior to the tetrabutylammonium hydroxide treatment became an active ion-exchange material following this treatment.
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 13. The operating conditions and results of chromatographically separating a mixture of chloramphenicol, salicylic acid and benzoic acid are shown in Table V, below.
TABLE V______________________________________CAPACITY FACTOR RESULTS FORCHROMATOGRAPHIC SEPARATION WITHACID-MODIFIED PHASE 8Separated Phase 8 Phase 12 Phase 13Component pH 7 pH 4 pH 7 pH 4 pH 7 pH 4______________________________________Chloramiphenicol 2.54 2.25 3.79 3.16 4.06 3.53Trimethoprim 2.56 0.30 4.83 0.25 4.02 2.21Propranolol 2.94 0.85 8.40 0.76 9.80 6.00Total Serum 11.5 11.1 11.7 12.0 11.4 10.0Protein Area(million counts)______________________________________
Chromatographic Conditions
Mobile Phase:
for pH 7--95% 180 mM NH 4 OAc (aq) pH=7.0/5% AcN
for pH 4--95% 90 mM NH 4 OAc (aq) pH=4.0/5% AcN
Flow: 2.0 ml/min
Injection Volume: 10 μl
Concentration and Detection:
Chloramphenicol, 10 μg/ml, 278 nm, 0.016 AUFS
Trimethoprim, 25 μg/ml, 254 nm, 0.016 AUFS
Propranolol, 25 μg/ml, 254 nm, 0.016 AUFS
Serum, neat, 254 nm, 0.016 AUFS
Temperature: Ambient.
NOTE--Chloramphenicol, trimethoprim and propranolol values were determined in a serum matrix. | Novel packing materials are provided for liquid chromatography and/or solid phase extraction columns which will allow direct injection of biological fluids. These packing materials have a hydrophilic exterior layer and a hydrophobic, charged or otherwise selective portion that forms an underlayer or is embedded in the hydrophilic layer. During a chromatographic process large water soluble biopolymers will be in contact with the hydrophilic outer layer and be shielded from interacting with the underlayer or embedded portion and elute unretained. Small analytes, on the other hand, can be fully partitioned throughout the exterior and interior layers and are retained by hydrophobic or electrostatic interactions. Using such packings the direct analyses of plasma or serum for drug analysis is demonstrated. | 54,464 |
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to an image forming device of an electro-photographic system, electro-static recording system, or the like. Particularly, the present invention relates to an image forming device that forms an image on a sheet-like medium by transferring an image such as a developed image (toner image) formed on the surface of a latent image carrier such as a photosensitive body on a sheet-like medium conveyed by a conveying belt.
2) Description of the Related Art
Electro-photographic printers as image forming devices, for example, have generally the structure as shown in FIG. 8. The electro-photographic printer 1 shown in FIG. 8 consists of a color printing engine 2, paper cassettes 3 and 4, a sheet feeding unit 5, a sheet ejecting unit 6, a sheet stacker 7, a power supply/control unit 8, and others.
In the electro-photographic printer 1, the transfer paper (sheet-like medium, sheet) 18 to be printed are stored in the sheet cassettes 3 and 4. At the time of printing, the transfer paper 18 is sent out of the sheet feeding unit 5 and then guided by means of the conveying roller 23 along the conveying guide (transfer path) 24 to the color printing engine 2. The transfer paper 18 which is color-printed by the color printing engine 2 (to be described later) is guided via the conveying guide (conveying path) 24 and the sheet ejecting unit 6 and then ejected into the sheet stacker 7.
The power supply/control unit 8 has the function of supplying electric power for the operation of the printer 1 to various portions and controlling the whole operation of the printer 1 including the printing operation of the color printing engine 2.
The printer 1 shown in FIG. 8 includes a double-sided surface mechanism (not shown) that reverses the transfer paper 18 with one surface printed to the side of the sheet ejecting unit 6 to perform a double-sided surface printing on the transfer paper 18 and a conveying guide (conveying path) 24A that again sends the transfer paper 18 reversed by the double-sided mechanism to the color printing engine 2.
Generally speaking, the color printing engine 2 which performs a color image printing operation includes four printing units 10Y, 10M, 10C, and 10K, a fixing unit 16, an endless electrostatic adsorption belt (conveying belt, transfer belt) 17 of a resin which conveys the transfer paper 18.
The printing unit 10Y is formed of a photosensitive body (transfer drum, latent image carrier) 11, a front charger 12, an optical unit 13, a developing unit 14, and a transfer roller 15 in order to transfer a toner image of yellow (Y) on the transfer paper 18. The printing unit 10M is formed of a photosensitive body (transfer drum, latent image carrier) 11, a front charger 12, an optical unit 13, a developing unit 14, and a transfer roller 15 in order to transfer a toner image of magenta (M) on the transfer paper 18. The printing unit 10C is formed of a photosensitive body (transfer drum, latent image carrier) 11, a front charger 12, an optical unit 13, a developing unit 14, and a transfer roller 15 in order to transfer a toner image of cyan (C) on the transfer paper 18. The printing unit 10K is formed of a photosensitive body (transfer drum, latent image carrier) 11, a front charger 12, an optical unit 13, a developing unit 14, and a transfer roller 15 in order to transfer a toner image of black (B) on the transfer paper 18. The printing units 10Y, 10M, 10C and 10K are arranged nearly in parallel along the electrostatic adsorption belt 17.
The photosensitive body 11 is rotatably driven by means of a drive motor (not shown). The front charger 12 charges evenly the surface of the photosensitive body 11. The optical unit 13 projects an image light corresponding to recording information (information regarding print data) on the surface of the photosensitive body 11. The optical unit 13 exposes a pattern corresponding to print data on the surface of the photosensitive body 11 to form an electrostatic latent image.
The developing unit 14 develops the electrostatic latent image formed on the surface of the photosensitive body 11. In fact, the developing process is performed by supplying toner on the surface of the photosensitive body 11 and then forming a toner image (latent image, developing image) which is visible. The transfer rollers 15 are arranged so as to confront the photosensitive bodies 11, thus sandwiching the electrostatic adsorption belt (or the transfer paper 18) 17. The toner image on the photosensitive body 11 is transferred onto the transfer paper 18 by sandwiching the transfer paper 18 conveyed by the electrostatic adsorption belt 17 between the transfer roller 15 and the photosensitive body 11.
Further, when the transfer paper 18 on which a toner image of each color is transferred by means of the printing units 10Y, 10M, 10C and 10K is conveyed, the fixing unit 16 fixes the toner image formed on the transfer paper 18 onto the transfer paper 18 thermally, or under pressure, lighting, or the like.
The electrostatic adsorption belt 17 is endlessly wound around the drive roller 19, the following roller 20, and tensioning rollers (tensioners) 21 and 22, and is driven by transmitting the rotational drive force of the drive motor (refer to numeral 25 in FIG. 9) by means of the drive roller 19. The transfer paper 18 which is electrically charged by means of the corona charger (refer to numeral 26 in FIG. 9) is electrostatistically adsorbed on the outer surface (the surface confronting the photosensitive body 11) and then is conveyed sequentially to the printing units 10Y, 10M, 10C and 10K.
In order to arrange in order the front ends of plural sheets of transfer paper 18, the resist roller (not shown) is arranged just in front of the image transfer point (the image transfer point made by the photosensitive body 11 and the transfer roller 15) of the transfer paper 18 in each of the printing units 10Y, 10M, 10C and 10K.
In the electro-photographic printer 1 with the above-mentioned structure shown in FIG. 8, the transfer paper 18 is transmitted from the sheet cassette 3 or 4 onto the transfer belt 17 of the color printing engine 2 via the sheet feeding unit 5. Then the transfer belt 17 transmits the transfer paper 18 to the fixing unit 16 by passing through the printing units 10Y, 10M, 10C and 10K.
While the transfer paper 18 passes through the printing units 10Y, 10M, 10C and 10K, a toner image of each color (Y, M, C, K) is transferred on the transfer paper 18. While the transfer paper 18 passes through the fixing unit 16, the toner image is fixed on the transfer paper 18.
When a printing operation is performed by overlaying sequentially different colors on the transfer paper 18 in the printing units 10Y, 10M, 10C and 10K, a color image is formed on the transfer paper 18.
The sheet conveying velocity of the electrostatic adsorption belt 17 is set to the same as that of the conveying roller 23 arranged upstream to the electrostatic adsorption belt 17. However, it is very difficult to match completely two sheet conveying velocities to each other because of the accuracy in dimension of the constituent member of the eletrostatic adsorption belt 17, the accuracy in dimension of the pair of the conveying rollers 23, the accuracy in revolution of the drive motor (refer to numerals 25 and 30 in FIG. 9) for the drive roller 19 or the conveying roller 23, wear of the conveying roller 23, and others.
When two sheet conveying velocities do not match to each other, bending and fluttering occur in the transfer paper 18 at the portion where the transfer paper 18 is transmitted from the conveying system including the conveying roller 23 to the conveying system including the electrostatic adsorption belt 17. The fluttering causes the unstable state of the transfer paper 18 at the image transfer point of each of the printing units 10Y, 10M, 10C and 10K, thus occurring the shear and variation in printing due to the printing units 10Y, 10M, 10C and 10K. As a result, the printing accuracy is deteriorated.
Further, it has been proposed that the conveying system 32, for example, shown in FIG. 9 is prepared in the front stage of the color printing engine 2 to convey the transfer paper 18 at high speed. That is, the conveying system 32 includes conveying rollers 28 and 29 which are driven at high speed by means of the drive motor 30. The conveying rollers 28 and 29 convey the transfer paper 18 immediately before the color printing unit 2 (the conveying system including the electrostatic adsorption belt 17).
The clutch 31 is arranged between the conveying roller 28 arranged just before the color printing unit 2 and the drive motor 30. The problem of the difference in velocity between the conveying system including the electrostatic adsorption belt 17 and the conveying system 32 can be eliminated by coupling on or off the clutch 31 while the transfer paper 18 is conveyed at a high speed. The drive motor 25 which drives the electrostatic adsorption belt 17 belongs to a different system from the conveying system 32 including the drive motor 30. The drive motors 25 and 30 drive respectively the conveying systems at completely different speed.
That is, with the clutch 31 coupled, the conveying rollers 28 and 29 feed the transfer paper 18 into the color printing unit 2. When the rear end of the transfer paper 18 passes through the position of the conveying roller 29, the clutch 31 is coupled off so that the conveying roller 28 is changed in its idle mode. At this time, the front end of the transfer paper 18 reaches the upper surface of the electrostatic adsorption belt 17. Thereafter, the transfer paper 18 is fed at the conveying speed of the conveying system including the electrostatic adsorption belt 17. The conveying roller 28 also co-rotates at the conveying speed.
Referring to FIG. 9, numeral 26 represents a corona charger. In the color printing engine 2, the corona charger 26 is arranged near to the portion where the sheet-like medium 18 is fed from the conveying system 32 and charges the transfer paper 18 fed onto the electrostatic adsorption belt 17 to be adsorbed on the electrostatic adsorption belt 17. The corona charger 26 is not illustrated in FIG. 8.
However, compared with the example described with FIG. 8, it is more difficult to eliminate completely the problem of the difference in velocity between the conveying system including the electrostatic adsorption belt 17 and the conveying system 32 even if the clutch 31 is coupled on or off.
For example, when the conveying speed of the pair of the conveying rollers 23 or 28 is smaller than that of the electrostatic adsorption belt 17, the pair of the conveying rollers 23 or 28 pulls relatively the rear portion of the transfer paper 18. This phenomenon causes the positional displacement of the transfer paper 18 to the electrostatic adsorption belt 17. The phenomenon also may cause the transfer failure due to the deformation of the electrostatic adsorption belt 17 shown in FIG. 10(a) as well as the displacement in transfer position between the toner image of the first color and the toner image of the second color. Moreover, at the moment when the end of the transfer paper 18 has passed through the pair of the conveying rollers 23 or 28, the electrostatic adsorption belt 17 can be quickly recovered. Hence, the shocking operation may cause transfer variations.
When the conveying speed of the pair of the conveying rollers 23 or 28 is larger than that of the electrostatic adsorption belt 17, the pair of the conveying rollers 23 or 28 pushes out the rear portion of the transfer paper 18 relatively. Therefore, since the electrostatic adsorption belt 17 may deform or the transfer paper 18 is lifted from the electrostatic adsorption belt 17 as shown in FIG. 10(b), the before-mentioned troubles occur.
This problem becomes more remarkable in the case of a large-sized transfer paper 18. Further, the problem become a significant demerit in the copier market demanding high-quality images, particularly in the color copier market demanding the improved color reproducibility. The positional shear of the transfer paper 18 on the electrostatic adsorption belt 17 may cause jamming when an adsorption failure or adsorption jam induces or the transfer paper is peeled from the electrostatic adsorption belt 17 in the post process.
SUMMARY OF THE INVENTION
The present invention is made to overcome the above mentioned problems. An object of the present invention is to provide an image forming device that can surely prevent a flutter of the sheet-like medium in the feeding portion even when there is a small difference in velocity between the conveying belt and the pre-conveying system at the time of feeding a sheet-like medium acting as a transfer paper onto the conveying belt, whereby a high-quality image can be obtained without causing any transfer failure, jam, or the like.
In order to achieve the above objects, according to the present invention, the image forming device is characterized by a printing unit for performing a printing operation on a sheet-like medium by transferring a developed image on the sheet-like medium at an image transfer point; a conveying belt for conveying the sheet-like medium along a conveying path formed so as to pass over the image transfer point by means of the printing unit; a conveying system for conveying the sheet-like medium on the conveying belt; a driving system for respectively driving the conveying belt and the sheet-like medium by means of different drive systems; and a pressure roller mounted in an idle mode on the conveying belt and near to the portion where the sheet-like medium is fed from the conveying system, the sheet-like medium being transferred from the conveying system onto the conveying belt while being sandwiched between the pressure roller and the conveying belt.
Each of plural printing units is arranged for each of plural colors to form a color image by overlaying the plural colors; and the conveying belt conveys the sheet-like medium along a conveying path to perform continuously a printing operation on the sheet-like medium by means of each of the printing units, the conveying path being formed so as to pass over the image transfer point by means of each of the printing units.
Further, the image forming device includes a power supply for supplying electric power to said pressure roller; and the pressure roller acts as a charger that electrically charges the sheet-like medium.
As described above, even when there is somewhat a difference in velocity between the conveying belt and the pre-conveying system, the fluttering of a sheet-like medium can be certainly prevented in the feeding portion by feeding a sheet-like medium from the conveying system onto the conveying belt while being sandwiched between the pressure roller and the conveying belt.
As described above, the image forming device according to the present invention has the advantage of forming high-quality images without producing any transfer failure or jamming since the fluttering of a sheet-like medium can be certainly prevented in the feeding portion by feeding a sheet-like medium from the conveying system onto the conveying belt while being sandwiched between the pressure roller and the conveying belt.
Particularly, when a color image is formed by overlaying plural colors with a printing unit for each color, high-quality images can be formed without any color shift.
Since the pressure roller acts as a charger that electrically charges the sheet-like medium, it is not needed to arrange another charger that makes the conveying belt to adsorb the sheet-like medium. This feature contributes to the device configuration simplified and slimmed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side sectional view schematically showing the main portion of an image forming device according to an embodiment of the present invention;
FIG. 2 is a side sectional view schematically showing the main portion of an image forming device to explain the operation of a present embodiment;
FIG. 3 is a side sectional view schematically showing the main portion of an image forming device to explain the operation of present embodiment;
FIG. 4 is a side sectional view schematically showing the main portion of an image forming device to explain the operation of a present embodiment;
FIG. 5 is a side sectional view schematically showing the main portion of an image forming device to explain the operation of a present embodiment;
FIG. 6 is a side sectional view schematically showing the main portion of an image forming device according to a modified embodiment of the present invention;
FIG. 7 is a side sectional view schematically showing the main portion of an image forming device according to another modified embodiment of the present invention;
FIG. 8 is a side sectional view schematically showing the internal structure of a general image forming device;
FIG. 9 is a side sectional view schematically showing the main portion of a general image forming device having a high-speed sheet conveying system;
FIG. 10(a) is a diagram used for explaining that an operation status occurs due to the difference in velocity between a conveying system using an electro-static adsorption belt and another conveying system; and
FIG. 10(b) is a diagram used for explaining that an operation status occurs due to the difference in velocity between a conveying system using an electrostatic adsorption belt and another conveying system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Let us explain an embodiment of the present invention with reference to the attached drawings.
FIG. 1 is a side-sectional view schematically illustrating the major portion of an image forming device as an embodiment of the present invention. The image forming device according to the present embodiment relates to the electro-photographic printer 1 before-mentioned with FIG. 8. The main portion (the feature of the present invention) shown in FIG. 1 has nearly the same configuration as the example including the conveying system 32 shown in FIG. 9. Hence, in FIGS. 1 to 7, like elements represented with like numerals shown in FIGS. 8 and 9. The detailed explanation of the same elements will be omitted here.
As depicted in FIG. 1, the color printing engine 2 includes four printing units 10Y, 10M, 10C and 10K (refer to FIG. 8). Each of the printing units 10Y, 10M, 10C and 10K transfers a toner image onto the transfer paper (sheet-like medium) 18 at the image transfer point 42 formed between the photosensitive body 11 and the transfer roller 15. In FIG. 1, the photosensitive body 11 and the transfer roller 15 in each of the printing units 10Y and 10M are illustrated, but other corresponding portions are omitted.
In order to perform the continuous printing operation of the printing units 10Y, 10M, 10C and 10K to the transfer paper 18, the electrostatic adsorption belt 17 acting as a conveying belt feeds the transfer paper 18 along the endless conveying path passing through the image transfer points 42 of the printing units 10Y, 10M, 10C and 10K.
The electrostatic adsorption belt 17, as described before, is wound endlessly around the drive roller 19, the following roller 20 and the tension rollers (tensioners) 21 and 22. The electrostatic adsorption belt 17 is driven by the revolution drive force of the drive motor (drive system) 25 transmitted via the drive roller 19 to feed sequentially the transfer paper 18 onto its outer surface (the surface confronting the photosensitive body 11) to the printing units 10Y, 10M, 10C and 10K.
Further, in the color printing engine 2, the corona charger 26 is arranged adjacent to the portion where the sheet-like medium 18 is transmitted from the conveying system 32. The corona charger 26 electrically charges the transfer paper 18 to adsorb the transfer paper 18 sent onto the electrostatic adsorption belt 17.
A conveying system 32 is arranged in the front stage of the color printing engine 2 to feed the transfer paper 18 to the electrostatic adsorption belt 17 at a high speed. Like the system shown in FIG. 9, the conveying system 32 includes conveying rollers 28 and 29 which are rotatably driven at a high speed by means of the drive motor (drive system) 30. The transfer paper 18 is conveyed immediately before the color printing unit 2 (the conveying system including the electrostatic adsorption belt 17) by means of the conveying rollers 28 and 29.
A clutch 31 is arranged between the conveying roller 28 arranged just before the color printing engine 2 and the drive motor 30. The clutch 31 is coupled on or off according to the procedure explained with FIGS. 2 to 5 when the transfer paper 18 is fed from the conveying system 32 to the system including the electrostatic adsorption belt 17. The drive motor 25 to drive the electrostatic adsorption belt 17 belongs to a system completely different from the conveying system 32 including the drive motor 30. The drive motor 35 drives respectively the conveying systems at completely different speeds.
In the present embodiment, a pressure roller (a following roller) 40 is mounted in a freely movable state on the electrostatic adsorption belt 17 and near to the portion where the transfer paper 18 is fed from the conveying system 32 and at the position which it confronts the following roller 20 on the upper side to the corona charger 26. The system is constructed such that the transfer paper 18 is fed from the conveying system 32 onto the electrostatic adsorption belt 17 while it is sandwiched between the pressure roller 40 and the electrostatic adsorption belt (following roller 20) 17.
The pressure roller 40 is supported on one end of the lever member 43 (member shown with chain double-dashed lines in FIG. 1), with its both sides being in rotatable state. The other end of the lever member 43 is rotatably supported to the side plate (not shown) which supports rotatably on both ends of the drive roller 19 and the following roller 20. The lever member 43 can rock. The pressure roller 40 is always pressed against the electrostatic adsorption belt (following roller 20) 17 by its weight and rocks somewhat with the lever member 43 according to the thickness of the transfer paper 18 fed from the conveying system 32.
The operation of the present embodiment with above-mentioned structure will be explained below by referring to FIGS. 2 to 5, together with the on/off procedure of the clutch 31.
As shown in FIG. 2, before reaching the conveying roller 28, the transfer paper 18 is conveyed by driving the conveying roller 29 by means of the motor 30, with the clutch 31 coupled off.
As shown in FIG. 3, when the transfer paper 18 reaches the conveying roller 28, the clutch 31 is changed to its on state so that the motor 30 drives the conveying rollers 28 and 29 to feed the transfer paper 18. In such a state, the transfer paper 18 is fed out from the conveying system 32 to the electrostatic adsorption belt 17 while the end portion for the transfer paper 18 is sandwiched between the pressure roller 40 and the electrostatic adsorption roller (following roller 20) 17. At this time, the transfer paper 18 is electrically charged by means of the corona charger 26 and then adsorbed on the electrostatic adsorption belt 17.
As shown in FIG. 4, the conveying roller 28 becomes an idle mode by switching the clutch 31 and the drive motor 30 to off state at the time when the rear end of the transfer paper 18 passes through the position of the transfer roller 29. Thereafter, the transfer paper 18 is conveyed at the conveying velocity of the conveying system including the electrostatic adsorption belt 17. While the conveying roller 28 is co-rotated at its conveying speed, the transfer paper 18 is fed onto the electrostatic adsorption belt 17, as shown in FIG. 5.
Since the transfer paper 18 is sandwiched between the pressure roller 40 and the electrostatic adsorption roller 17 (the following roller 20), the deformation of the electrostatic adsorption belt 17 and the positional shift and fluttering of the transfer paper 18, as shown in FIGS. 10(a) and 10(b), can be surely prevented. Consequently, since the motion of the transfer paper 18 can be stable, it is eliminated that the component of the difference in velocity between the conveying system including the electrostatic belt 17 and the conveying system 32 is transferred at the image transfer point 42.
As a result, a high-quality image can be formed without bringing about the transfer failure or jamming. Particularly, in the case of the formation of a color image, the positional shift of a toner image of each color can be surely suppressed by overlaying toner images of colors used in the printing units 10Y, 10M, 10C and 10K. Thus a high-quality color image with no color shift can be formed.
In the above-mentioned embodiment, the example in which the transfer roller 15 is used in each of the printing units 10Y, 10M, 10C and 10K to transfer the toner image formed on the photosensitive body 11 onto the transfer paper 18 has been explained. However, instead of the transfer roller 15, the corona charger 15A may be used as shown in FIG. 6. The corona charger 15A produces the potential difference between the transfer paper 18 and the photosensitive body 11 at the image transfer point of each of the printing units 10Y, 10M, 10C and 10K by charging the transfer paper 18. Then the potential difference allows the toner image on the photosensitive body 11 to be transferred onto the transfer paper 18. In this case, the same function and effect as those in the above-mentioned embodiment can be achieved by mounting the pressure roller 40.
As shown in FIG. 7, a power supply 41 that supplies the pressure roller 40 shown in FIGS. 1 to 6 can be connected and the pressure roller 40 can work as a charger that electrically charges the transfer roller 40. In this case, it is unnecessary to arrange differently the corona charger 26 (see FIGS. 1 to 6 and 9) that adsorbs the transfer paper 18 to the electrostatic adsorption belt 17. The system configuration can be simplified and slimmed.
Further, in the present embodiment, the case where the conveying system 32 is arranged upper side of the color printing engine 2 for the purpose of its high-speed operation has been explained. However, the present invention is applicable to the case where a different conveying system (such as the conveying roller 23 and the conveying guide 24) is arranged as shown in FIG. 8. Thus the same function and effect as those in the above-mentioned embodiment can be obtained. | An image forming device that can surely prevent a flutter of a sheet-like medium in the feeding portion even when there is a difference in velocity between the conveying belt and the front conveying system at the time of feeding a sheet-like medium onto the conveying belt, thereby obtaining a high-quality image. The image forming device includes a pressure roller mounted in an idle mode on the conveying belt and near to the portion where the transfer paper is fed from the conveying system, the transfer paper being transferred from the conveying system onto the conveying belt while being sandwiched between the pressure roller and the conveying belt. The image forming device is applicable to printers of electro-photographic system, electro-static recording system, or the like. | 27,153 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an auxiliary method for setting vehicle satellite navigating destinations to assist users to set destinations in a vehicle navigation host.
[0003] 2. Description of the Prior Art
[0004] In the past driving a car to a destination relies on maps by following the roads shown thereon. Due to fast business and community developments, the road system becomes very complicated. Nowadays it is not uncommon that even a destination a few blocks away could be difficult to reach directly due to the restrictions of one-way streets, no-left turn roads, overpasses, rivers, and the like. Hence a desired driving route often has to be planned ahead. The navigation system now equipped in many vehicles is a helpful tool for drivers to select the optimum route. However at present setting a destination on the vehicle navigation host mostly has to use a remote controller to do selection or search on the map. The remote controller has a limited number of keys. Hence users have to move slowing through the direction keys to the destination to do setting, or move to a landmark close to the destination (such as a government building, park, or the like), then move the direction keys from the landmark to the desired destination for setting. It is inconvenient, and also does not conform to the using habit of most users. As users generally know the street or road and city of the destination before searching, to find out the destination through the direction keys on a display screen about seven inches or smaller is not practical or helpful.
[0005] Moreover, nowadays many people planning their travel and trip by accessing the Internet and downloading the geographic location of the visiting areas or hotels. Users generally have to print the maps appeared on the Web pages and use the maps as the guide during actual driving. It also is not convenient.
SUMMARY OF THE INVENTION
[0006] Therefore the object of the present invention is to resolve the disadvantages of the conventional vehicle navigation host such as difficult to set destinations and not practical. The present invention provides an auxiliary method for setting vehicle satellite navigating destinations. The method includes a procedure as follow:
[0007] (1) selecting a destination file from Web pages on a Web site;
[0008] (2) downloading the destination file into a navigation host;
[0009] (3) setting up an interim file in the memory unit of the navigation host;
[0010] (4) starting the navigation host to check and update the interim file; and
[0011] (5) planning the navigation route.
[0012] In the auxiliary method set forth above, the data source of the destination file is outside the navigation host, such as selecting from Web pages of a Web site, and is downloaded into the memory unit of the navigation host through radio transmission or a memory card.
[0013] In one aspect, the Web pages have electronic maps corresponding to the navigation system of the navigation host. Users or other people can select a destination on the maps to set up a destination file.
[0014] In another aspect, the destination file includes at least longitude and latitude data of the destination.
[0015] In yet another aspect, the destination file includes one or more picture related to the destination to be displayed on the navigation host to show the exact appearance of the destination.
[0016] In still another aspect, the destination file includes address data.
[0017] In another aspect, the destination file may be expanded to become a destination file folder which contains one or more destination file.
[0018] In another aspect, the destination file has a sub-file name consisting of common and selected characters for identification.
[0019] In another aspect, the navigation host includes one or more memory unit which contains a data file of a preset destination, and one or more interim file which may be updated anytime desired.
[0020] In another aspect, the navigation host includes one or more memory unit which may be a removable memory card device.
[0021] In another aspect, the navigation host includes a software for reading the interim file to set a navigation route to the destination, and to search as desired files stored in the memory card that have been added or modified, and treat the file data as the destination file for user selection to serve the destination of the navigation route.
[0022] In another aspect, the navigation host includes a software which has a directory for destination selection. The directory has a menu named by the destination file name or destination file folder so that when user selects the menu item the navigation host opens the destination file or folder.
[0023] In another aspect, the source of the destination file is obtained by E-mail.
[0024] In another aspect, the destination file data include visiting site introductions appeared on the Web pages that have location information on the electronic map for setting up a destination file.
[0025] In another aspect, the destination file includes interesting spots such as restaurants, hotels, shopping stores, service centers, entertainment sites, amusement parks, gas stations, and the like.
[0026] By means of the invention, the electronic maps on the Web pages of a Web site may be selected to build a destination file. Interesting spots may be selected and planned and added to the destination file. The destination file data may be obtained by E-mail, and may also be downloaded to the navigation host for planning the navigation route. Thus it can overcome the problems occurred to the conventional routing data that are not adequate or practical.
[0027] The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a block diagram of the structure of the navigation host of the invention.
[0029] FIG. 2 is the main flow chart of the method of the invention.
[0030] FIG. 3 is the secondary flow chart- 1 of the invention.
[0031] FIG. 4 is the secondary flow chart- 2 of the invention.
[0032] FIG. 5 is a flow chart for entering the destination in the navigation host of the invention.
[0033] FIG. 6 is another flow chart for entering the destination in the navigation host of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Referring to FIG. 1 , the navigation host 1 according to the invention includes:
[0035] a satellite positioning device 11 to receive satellite signals;
[0036] a positioning calculator 12 to receive the signals of the satellite positioning device 11 for downstream processing;
[0037] a memory unit 13 to store data of the navigation host 1 , such as maps, destination data, and the like. It contains one or more destination data file and one or more interim file which may be updated anytime;
[0038] a longitude and latitude comparing and processing unit 14 to receive the signals of the satellite positioning device 11 and mate the electronic maps of the memory unit 13 to mark the location of the navigation host 1 ;
[0039] a display unit 15 to display the navigation maps, current position and other related data; and
[0040] an access interface 16 to receive external data, such as read/write interfaces including infrared transceivers, radio transceivers (FM, AM, wireless LAN), Bluetooth transceivers, card readers (CF, MD, SM, SD, MMC, MS), optical disk drives, and the like.
[0041] By means of the construction set forth above, a user can use a network device to link and access Web sites to search destinations, and select the ones desired on the map of the Web pages, and order the Web page program to generate a destination file to be used by the vehicle navigation host 1 . The procedure (referring to FIG. 2 ) is as follow: p 1 (1) select a destination file on the Web pages of a Web site (step 200 ): link the network to the Web site which has electronic maps compatible to the navigation host 1 . Search a destination desired through the electronic map program of the Web site by maps or keywords. Once the destination is chosen, user can add related text descriptions or pictures, and set up a destination file with a sub-file name. The file includes the longitude and latitude coordinates of the destination, and the text and pictures entered by the user;
(2) download the destination file into the navigation host (step 300 ): after the destination is set up (referring to FIG. 5 ), the file may be output and stored in a memory card (step 311 and 312 ). Insert the memory card into the navigation host (step 313 ). The navigation host reads or downloads the destination file into the memory unit 13 (step 315 ). Or transfer the destination file by radio transmission to the navigation host 1 (step 314 and 315 ) through a wireless communication system 7 such as a GSM or CDMA module (also referring to FIG. 1 ). The wireless communication system 7 can transmit the destination file to the navigation host 1 ; (3) build an interim file in the memory unit of the navigation host (step 400 ): the memory unit 13 of the navigation host 1 has a preset destination data file and an interim file which may be updated anytime desired. When the destination file is transmitted to the memory unit 13 , it is stored in the interim file; (4) start the navigation host to check and update the interim file (step 500 ): when the navigation host 1 starts operation, it checks whether there are updating data for the content of the interim file. If yes, update the file; and (5) plan the navigation route (step 600 ): the navigation host 1 configures a route to the destination according to the longitude and latitude data in the interim file, and stores the route in the destination data file to be used in the navigation process.
[0046] The navigation host 1 includes a software for reading the interim file to set the destination of the navigation route.
[0047] The destination file may be expanded to become a destination file folder with a common sub-file name. The navigation host 1 can selectively read the sub-file name like inquiring a directory to search the destination file or destination file folder. It also serves as a basis to differentiate the external destination files.
[0048] In the step 200 of select a destination file on the Web pages of a Web site as shown in FIG. 3 , first, search the electronic maps on the Web site that correspond to the navigation host 1 (step 211 ); next, find out the destination on the electronic maps (step 212 ); then finish setup of the destination file (step 213 ).
[0049] Moreover, in the step 200 of select a destination file on the Web pages of a Web site, the destination file data include site introductions from the Web pages. As shown in FIG. 4 , first, search the electronic maps corresponding to the navigation host 1 on the Web site (step 221 ); select the interesting spot location on the electronic maps (step 222 ); store data (step 223 ); continue selection and searching (step 224 ); finish setup of the destination file (step 225 ). The destination file further includes introduction text, pictures, special scenic sites, folklore and special features. The interesting spots may include landmarks such as restaurants, hotels, shopping stores, service centers, entertainment sites, amusement parks, gas stations, and the like.
[0050] In the step 300 of download the destination file into the navigation host, the destination file may be sent by E-mail to a computer or handset of the user of the navigation host 1 . Then the file is transmitted to the navigation host 1 according to the procedure shown in FIG. 6 . Namely, output the destination file (step 321 ); transmit the file by E-mail (step 322 ); store the file in a memory card (step 323 ); insert the memory card into the navigation host 1 (step 324 ); load the destination file into the memory unit 13 of the navigation host 1 (step 326 ); or output the destination file directly by wireless transmission to the memory unit of the navigation host 1 (step 325 and 326 ).
[0051] In summary, the invention provides a method for setting destination that better suits the habits of people and computer users. It overcomes the restrictions occurred to the conventional navigation system. It also breaks the limitation of the conventional technique that displays only maps or address text. Instead, a destination file is directly delivered to the navigation host in the vehicle so that users can find out the geographical location easily. | An auxiliary method for setting vehicle satellite navigating destinations aims to build a destination file from electronic map data of Web pages of a Web site. The data source of the destination file may be retrieved by E-mail. The destination file data are downloaded by radio transmission or through a memory card into a memory unit of a navigation host to enable the navigation host to perform navigation route planning thereby to overcome the problem of inadequate data or poor usability occurred to the conventional route planning. | 13,554 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent Application No. 60/810,995, filed Jun. 5, 2006, which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT
This invention was made, in part, with government support under Grant Number F49620-02-0359 awarded by AFOSR MURI and Grant Number 200-2002-00528 awarded by NIOSH/CDCP. The United States government may have certain rights in this invention.
FIELD OF THE INVENTION
The present invention is directed generally to apparatuses, systems, and methods utilizing capillary action and, more specifically, to methods and apparatuses to control the movement or placement of liquids or other materials in micro-devices and nano-devices.
BACKGROUND OF THE INVENTION
Single-chip electronic noses, enabled by full on-chip integration of gas chemical microsensors with signal-conditioning electronics have tremendous medical, environmental and safety applications. Gravimetric detection is an important sensing modality for these microsystems.
Commercially available mass-sensitive devices for volatile organic compound detection use piezoelectric quartz substrates. Thickness shear mode resonators (TSMR), also known as quartz micro-balances (QMB) (Patel, R., Zhou, R. Zinszer, K., and F. Josse, “Real-time detection of organic compounds in liquid environments using polymer-coated thickness shear mode quartz resonators”, Analytical Chemistry, vol. 72, no. 20, p. 4888-4898, 2000) (Schierbaum, K. D., Gerlach, A., Haug, M., and W. Gopel, “Selective detection of organic molecules with polymers and supramolecular compounds: application of capacitance, quartz microbalance, and calorimetric transducers”, Sensors and Actuators A, 31, p. 130-137, 1992), and Rayleigh surface acoustic wave (SAW) devices (Ricco, A. J., Kepley, L. J., Thomas, R. C., Sun, L., and R. M. Crooks, “Self-assembling monolayers on SAW devices for selective chemical detection”, IEEE Solid-State Sensor & Actuator Workshop, Hilton Head, S.C. June 22-25, p. 114-117, 1992) are examples of such devices. However, these piezoelectric devices have not been fully integrated with on chip electronics. In contrast, resonant cantilever chemical microsensors integrated with CMOS have been demonstrated (A. Hierlemann and H. Baltes, “CMOS-based chemical microsensors”, Analyst, 128, p. 15-28, 2003). Prior work on cantilever mass sensors includes detection of humidity, mercury vapor, and volatile organic compounds (Lange, D., Hagleitner, C., Hierlemann, A., Brand, O., and H. Baltes, “Complementary Metal Oxide Semiconductor Cantilever Arrays on a Single Chip: Mass-Sensitive Detection of Volatile Organic Compounds”, Analytical Chemistry, vol. 74., no. 13, p. 3084-3095, 2002) as well as biomolecular recognition in a liquid media (Fritz, J., Bailer, M. K., Lang, H. P., Rothuizen, H., Vettiger, P., Meyer, E., Guntherodt, H. J., Gerber, Ch., and J. K. Gimzewski, “Translating biomolecular recognition into nanomechanics”, Science, 288, p. 316-318, 2000.). Post-CMOS micromachining has been used to make fully integrated mass sensitive oscillators with pico-gram resolution (H. Baltes, D. Lange, A. Koll, “The electronic nose in Lilliput,” IEEE Spectrum, 9, 35, (1998)). These devices were formed through deposition of precise amounts of a chemically sensitive layer onto relatively wide cantilevers.
Another example of a CMOS-MEMS resonant gas sensor used electrostatic actuation and detection to form a free-running oscillator (S. S. Bedair and G. K. Fedder, “CMOS MEMS Oscillator for Gas Chemical Detection,” Proceedings of IEEE Sensors, Vienna, Austria, Oct. 24-27, 2004). A cantilever beam suspended a plate made large enough to accommodate drops of chemically sensitive polymer placed directly onto the plate using drop-on-demand ink jet deposition. Ink jet deposition can functionalize each cantilever in an arrayed structure with a separate polymer. This non-contact technology is scalable for large arrays, easy to use, versatile, and faster than other means of coating such as from micro-capillaries and drop casting from pipettes (A. Bietsch, J. Zhang, M. Hegner, H. P. Lang, and C. Gerber, “Rapid functionalization of cantilever array sensors by inkjet printing”, 2004 Nanotechnology 15 873-880). Other thin film application methods include dip pen and shadow mask processing which are both time consuming processes.
Another prior microfluidic system is described in U.S. patent application, 20050064581 and in a corresponding paper (T. P. Burg, A. R. Mirza, N. Milovic, C. H. Tsau, G. A. Popescu, J. S. Foster and S. R. Manalis, “Vacuum-packaged suspended microchannel resonant maass sensor for biomolecular detection,” J. Microelectromechanical Systems, December 2006). These prior art documents describe an enclosed microchannel. Material is flowed into the channel to functionalize sidewalls of the channel to capture biomolecules on the sidewalls. However, the channel in these works is not used or taught as a wicking structure for deposition of a non-liquid material, such as polymers, that fills or partly fills the channel. Specifically, the patent application describes a microfluidic channel to detect analyte that may have a liquid or gel in the channel. The analyte is flowed into the microchannel. The gel may be delivered by pressure flow or electrophoresis, but no description or teaching of gel deposition through wicking is provided. The invention requires an enclosed microchannel for analyte delivery through flow, and in order to package in vacuum.
It is beneficial to further scale down the size of the resonant microstructure to achieve an increased mass sensitivity and reduced cost. Scaling cantilevers down to micro- and nano-scale dimensions is achievable with optical or piezoresistive resonant detection. However, microstructures with low-noise electrostatic actuation and detection require narrow air gaps that are generally incompatible with existing polymer deposition techniques.
Accordingly, there is a need for improved apparatuses and methods to control polymer addition to micro-cantilevers and nano-cantilevers for biological and chemical sensing. Those and other advantages of the present invention will be described in more detail hereinbelow.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed generally to apparatuses, systems, and methods utilizing capillary action. The present invention has many applications and many variations. For example, the present invention may be used in the operation of sensors. The present invention may be used to fill a space between two or more parts. In some embodiments, the present invention may be used to carry an adhesive to a desired location to fix two or more parts together. In other embodiments the present invention may be used to provide a dielectric between two or more electrodes or contacts. In another embodiment, the present invention may be used in a chemo resistor device in which electrically resistive material is positioned between two or more electrodes or contacts. The present invention may also be used with a mass sensor for gas chemical sensing applications. The present invention may also be used with many different fluids and materials, and in many specific applications such as to control material addition to micro-cantilevers and nano-cantilevers for biological sensing, chemical sensing, and other sensing.
In one specific embodiment, the present invention will be described in terms of apparatuses and methods to mass load a microstructure with polymer without affecting nearby gaps. Precise amounts of polymer or other materials, which may be suspended in solution, are wicked onto the microstructure through capillary action of micro-grooves formed along the length of the beam. The polymer or other material is left on the microstructure after drying of the solvent. Scaling down the mass of the mass sensitive cantilever leads to a higher mass sensitivity which leads to highly sensitive gas chemical sensing applications. The technique enables design of low-mass polymer-loaded cantilevers with electrostatic actuation and capacitive sensing for integrated gas chemical detector arrays.
The present invention may also include two or more devices formed in a single apparatus or on a single substrate. The single apparatus or substrate may contain several devices of the same type, such as to perform same test or operation many times. Alternatively, the single apparatus or substrate may contain several devices of different types, such as to perform a variety of different tests. In some embodiments, the devices receive different materials in their respective target areas, and in some embodiments they receive the same materials. As a result, redundant or different testing, sensing, or other functions may be performed on a single structure.
Although the present invention will generally be described in terms of specific embodiments, many variations, modifications, and other applications are possible with the present invention. These and other teachings, variations, and advantages of the present invention will become apparent from the following detailed description of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings for the purpose of illustrating the embodiments, and not for purposes of limiting the invention, wherein:
FIG. 1 illustrates one embodiment of an apparatus according to the present invention.
FIGS. 2 a - 2 h illustrate embodiments of wicking devices according to the present invention.
FIG. 3 a illustrates one embodiment of a gravimetric micro-cantilever resonant sensor according to the present invention.
FIGS. 3 b and 3 c illustrate cross-sectional views along lines IIIb-IIIb and IIIc-IIIc, respectively, in FIG. 3 a.
FIGS. 4 a and 4 b illustrate an embodiment of an electrostatically actuated resonator with differential comb drive and sensing electrodes.
FIG. 5 illustrates one embodiment of a solution delivery to the resonator.
FIG. 6 illustrates one embodiment of an oscillator gas sensor schematic. The electrostatically actuated resonator is placed in a feedback loop with off-chip electronics for oscillation.
FIG. 7 illustrates one embodiment of post CMOS processing steps: (a) CMOS chip from foundry, (b) Reactive-ion etch of dielectric layers, (c) DRIE of silicon substrate, (d) isotropic etch of silicon substrate, (e) Ink jet deposition of polymer solution.
FIG. 8 illustrates an example of a beam pinned under stator electrodes after direct ink jet deposition onto cantilever.
FIG. 9 a - 9 d illustrate one embodiment of a device before and after solution deposition in the well:(a) entrance from well to micro-channel which extends along the length of the resonator, (b) resonator at the base with polystyrene, (c) tip of resonator without polystyrene, (d) tip of resonator with polystyrene.
FIG. 9 e illustrates frequency response of one embodiment of a device before and after polystyrene deposition into a 2 μm channel in the device.
FIGS. 10 a - 10 g are scanning electron micrographs of several embodiments of the present invention.
FIG. 11 illustrates one embodiment of a gas test setup according to the present invention.
FIG. 12 illustrates spectrum analyzer output of resonant frequency shifts due to ethanol, IPA, and acetone gas flows according to one embodiment of the present invention.
FIGS. 13 a and 13 b illustrate another embodiment of the present invention in which one or more channels are used to provide an adhesive to secure two objects together.
FIGS. 13 c and 13 d illustrate another embodiment of the present invention in which a suspended beam is used for form a space or gap.
FIGS. 14 and 15 illustrate another embodiment of the present invention in which parts of an object or layer are joined with a material according to the present invention.
FIG. 16 illustrates one embodiment of a system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be generally described in terms of specific examples and embodiments, although many variations and modifications are possible. For example, although the present invention is sometimes described in connection with the use of polystyrene, many other materials may be used with the present invention. For example, the present invention may be used with materials that can be delivered with solvents, and other materials in solution and fluids. For example, these materials can be active polymers, nano particles, polymer composites, biomolecules, solgel, electro- and magneto-active polymers, adhesives, and sealants. Furthermore, the present invention may be constructed in scales other than those specifically defined herein. For example, specific dimensions are provided in some examples, although smaller devices may be desirable to provide additional sensitivity in some applications, and larger devices may be desirable in other applications. Similarly, the use of the term “micro”, such as in “micro-cantilever”, “microstructure”, “micro-capillary”, and others, is illustrative and is not a limitation of the present invention. For example, the present invention may also be used at nano-scales or at smaller or larger scales.
FIG. 1 illustrates one embodiment of an apparatus according to the present invention. In this embodiment the apparatus 10 is a sensor, although the apparatus of the present invention may take other forms, such as in assembling parts for microelectromechanical systems, providing adhesive, sealant, or other material between two or more parts, and in other applications.
In FIG. 1 the sensor 10 includes wicking device 12 , a fluid well 14 , motion sensors 16 , actuators 18 , and a fluid dispenser 19 .
The wicking device 12 carries a fluid along a channel (not shown) in the wicking device 12 via capillary action. The wicking device 12 may be an elongated structure, such as a straight beam, or it may be a curved structure, or it may have other shapes. In some embodiments the wicking device is cantilevered, although it is not required to be cantilevered. The channel will be described in more detail hereinbelow and may take different forms, such as a gap between two surfaces, a groove or recess formed in a surface, or a passage through an object. In some embodiments, the material is deposited in the fluid well 14 and is wicked into the wicking device 12 , so that the deposited material does not interfere or contact any other parts of the devices, such as the motion sensors 16 or the actuators 18 .
In some embodiments the wicking device 12 will be suspended. As used herein, a “suspended” wicking device 12 means a significant portion of the wicking device 12 is surrounded by air, or void, or ambient conditions other than structural elements used to support the wicking device 12 . For example, in some embodiments the wicking device 12 is in the form of a cantilevered beam supported at one end and suspended in air (or in other conditions) for most of its length. In other embodiments, the wicking device 12 is in the form of an object or layer formed over a recess, in which at least a portion of the object or layer is suspended over the recess. In some embodiments, the wicking device 12 can be formed from two or more parts or pieces, and in some cases all parts or pieces are suspended, and in other cases some parts or pieces are suspended and other parts or pieces are not suspended. Although several embodiments of the present invention will be described in terms of a suspended wicking device, advantages of the present invention may also be realized with wicking devices 12 that are not suspended in any way.
The fluid well 14 is the source of the fluid that is carried along the channel in the wicking device 12 via capillary action. The fluid well 14 is significantly larger than the channel in the wicking device 12 and directly receives the fluid, such as through an ink jet deposition or through other means such as micro capillaries and pipettes, dip pen, and shadow mask processing. The fluid well 14 will sometimes be referred to as a “target area”, “target well area”, and other names. These terms are interchangeable.
The motion sensors 16 detect motion of the wicking device 12 . The motion sensors 16 are not required in the present invention, and some embodiments illustrated herein do not use the motion sensors 16 .
The actuators 18 cause the wicking device 12 to move. The actuators 18 may, for example, cause motion through the application of electrostatic forces, or through other means. The actuators 18 are not required in the present invention, and some embodiments illustrated herein do not use the actuators 18 .
The fluid dispenser 19 is oriented to dispense fluid into the fluid well. The fluid dispenser 19 may be, for example, drop-on-demand ink jet device, or a micro-pipette device, or a dip pen device, or it may be other forms of fluid dispensers 19 . Unlike the prior art, the present invention dispenses or deposits the fluid into a fluid well 14 , from which it is wicked onto the channel 20 or channels of the wicking device 12 . Many variations are possible with the fluid dispenser 19 . For example; there may be a dedicated fluid dispenser 19 for each fluid well, or one fluid dispenser 19 may be used with more than one fluid well 14 , such as by moving the fluid well 14 , moving the fluid dispenser 19 , or otherwise changing the orientation of the fluid well 14 and the fluid dispenser 19 . In some embodiments of the present invention, the fluid dispenser 19 is integrated into the device including the fluid well 14 , and in other embodiments the fluid dispenser 19 is separate from the rest of the device and is engaged with the apparatus 10 when it is needed.
The sensor 10 illustrated in FIG. 1 is a gravimetric sensor in which the actuators 18 cause the wicking device to move, and the motion sensors 16 measure the movement. The frequency response of the wicking device is indicative of the mass, and the distribution of mass, of the wicking device 12 and any material deposited or absorbed on the wicking device 12 . The frequency response of an empty wicking device 12 can be established, so that any change in the response is indicate of the additional material added to the wicking device 12 . In this way, the mass of material deposited on the wicking device can be determined. A mass sensitive material can be deposited onto the wicking device. In this way, the mass of an additional material absorbed into the mass sensitive material on the wicking device can be determined. For example, the additional material to be determined can be a gas chemical analyte absorbed into a mass sensitive polymer. The present invention is not limited to use in gravimetric sensors, and may be used in other types of sensors 10 , such as chemo-resist sensors, capacitive sensors, or other types of sensors. The present invention can also be used in apparatuses other than sensors, as will be described in more detail hereinbelow.
Many variations are possible with the present invention. For example, the sensor 10 may or may not include motion sensors 16 and actuators 18 , or may contain a more or fewer motion sensors 16 and actuators 18 than shown herein. For example, a sensor 10 may include only one motion sensor 16 or actuator 18 , or it may include more than two motion sensors 16 and actuators 18 . Similarly, more than one fluid well 14 may be used, and more than one wicking device 12 may be used in the sensor 10 . More than one wicking device 12 may be used for each fluid well 14 . The sensor 10 may also include devices not shown in this figure, such as devices for applying and measuring electrical current and voltage, and other devices. In some embodiments, the sensor 10 includes sources of controlled electrical voltage or current, and devices for measuring one or more electrical characteristics, such as voltage, resistance, current, capacitance, and electro-magnetic fields. These embodiments may also include motion sensors 16 and actuators 18 , or the embodiments may exclude one or both of motion sensors 16 and actuators 18 .
FIG. 2 a illustrates one embodiment of a wicking device 12 according to the present invention. The wicking device 12 includes a channel 20 formed in the wicking device 12 . The channel is in the form of a groove 20 and is defined by three surfaces of the wicking device 12 .
FIG. 2 b illustrates another embodiment of the wicking device 12 in which the wicking device 12 is formed from two parallel plates and the channel 20 is defined by the space between the two plates. Although the plates are illustrated as being parallel, they may also be non-parallel.
FIG. 2 c illustrates another embodiment of the wicking device 12 in which two plates are oriented vertically and the channel 20 is formed between the vertical plates. In other embodiments the plates may have other orientations, such as 45 degrees and others.
FIG. 2 d illustrates another embodiment of the wicking device 12 in which one or more supports 22 are provided between the plates of the wicking device 12 . The supports 22 resist the forces applied to the plates from the capillary action of fluids between the plates. As a result, the supports prevent the plates of the wicking device 12 from bending inward and touching each other.
Supports may also be included in other orientations of channels, such as in FIG. 2 c . Supports 22 are shown in FIG. 2 d as cylindrical and in the center of the channel, but supports can also be rectangular or other shapes and can be located at other locations in the channel.
FIG. 2 e illustrates another embodiment of the wicking device in which at least one plate includes an opening 24 . One or more plates or other parts of the wicking device 12 may include one or more openings. The openings may be of any shape, spacing, and orientation. The opening 24 reduces the mass of the wicking device and, in some applications, allows for increased sensitivity.
FIG. 2 f illustrates another embodiment of the wicking device 12 in which more than two plates are used. In that embodiment, two of the plates 26 are electrical conductors, and the other two plates 28 are electrical insulators. This embodiment may be used, for example, when the sensor is measuring capacitance with the fluid in the channel 20 of the wicking device 12 .
FIG. 2 g illustrates another embodiment of the wicking device 12 in which the structure of the electrical conductor 26 and insulator 28 vary from the previous embodiment. In this embodiment, one of the electrical conductors 26 is embedded with one of the electrical insulators 28 . These and other variations are possible.
FIG. 2 h illustrates another embodiment of the wicking device. In this embodiment, the channel 20 is formed in a more complex cross-sectional shape than in the previous embodiments. Also, there are several electrical conductors 26 and electrical insulators 28 on the walls of the channel 12 . This embodiment may be used, for example, to measure electrical resistance of the material in the channel 20 . Many combinations of measurements may be taken from the various electrical conductors 26 . In other embodiments, for example, different numbers of electrical conductors 26 , in different orientations, may be used. The electrical conductors 26 may be exposed to the channel 20 along the entire length of the channel, or the electrical conductors 26 may be exposed only in selected portions of the channel 20 , such as at the end or at other locations.
Many other variations of the wicking device 12 are also possible. For example, although the wicking devices 12 are shown as being open at their ends, they may also be capped or closed at the ends, and the wicking devices 12 may include different numbers, orientations, and structures of plates and other components forming the wicking device 12 and defining the channel 20 . In some embodiments, the channel 20 is tapered at the free end so as to wick more liquid to that end and, thereby, deposit addition material there. This results in non-uniform distribution of material, with more material at the free end where the device is more sensitive to mass. This embodiment, for example, may allow for the use of less liquid and less material while achieving greater sensitivity.
In another embodiment, a wider channel is used, thereby resulting in a larger volume that can be carried on wicking device 12 . However, if the same volume of liquid is used, the liquid and the material carried in the liquid will be driven to the free end of the wicking device 12 , resulting in all or most of the liquid and material at or near the free end of the wicking device 12 . As a result, there will be a non-uniform distribution of liquid and material along the wicking device 12 .
In another embodiment, the channel 20 may be non-linear. For example, the channel 20 may branch into several side channels, the channel 20 may include one or more “t” junctions, the channel 20 may include circular path components, the channel 20 may include a square spiral path component, and the channel 20 may include other path features and combinations of features. Similarly, the wicking device 12 may also have a shape other than a uniform, linear shape along its length.
Several embodiments of the present invention will now be described to illustrate the present invention. Those embodiments are illustrative, and not limiting. Other variations and embodiments of the present invention are also possible.
Micro-Cantilever Design
FIG. 3 a is an image of an actual gravimetric micro-cantilever sensor 10 constructed according to one embodiment of the present invention. FIGS. 3 b and 3 c illustrate cross-sectional views along lines and respectively, in FIG. 3 a . FIGS. 4 a and 4 b illustrate close up views of the beam microstructures forming the wicking device 12 , the motion sensors 16 , and the actuators 18 . The reservoir or target well area 14 for solution delivery is placed at the base of the cantilevered beam 12 , which is a movable structure in this embodiment.
FIG. 3 b illustrates a cross-sectional view along line IIIb-IIIb of the invention illustrated in FIG. 3 a . FIG. 3 b shows the wicking device 12 suspended above a substrate 36 . The substrate may be silicon, such as when semiconductor fabrication techniques are used to make the present invention. However, other materials and other fabrication techniques may also be used.
FIG. 3 c illustrates a cross-sectional view along line IIIc-IIIc of the invention illustrated in FIG. 3 a . FIG. 3 c shows the fluid well 14 built on a substrate 36 and with walls made from conductive 26 and insulating 28 materials such as those used to make the wicking device 12 and described hereinabove. In other embodiments, different materials and structures may be used to form the well 14 and its associated parts.
FIGS. 4 a and 4 b illustrate the structure of the device including the cantilevered beam, a differential comb drive 18 , and motion sensing electrodes 16 . The wicking device 12 is anchored 46 at one end (see FIG. 4 b ), such as to a substrate, and is free to move or resonate at the other end. Ink jetting technology is used to deposit solution into the fluid well 14 which is sized to accommodate the volume of the drop emitted from the ink jet. In the illustrated embodiment the target area 14 includes grooves or ridges 40 to facilitate capillary motion of the fluid towards the groove 20 of the wicking device 12 . The ridges 40 are omitted from the cross-section in FIG. 3C for simplicity.
This non-contact technology is scalable for large arrays, easy to use, faster than other means of coating such as micro capillaries and pipettes, and versatile. Other thin film application methods include dip pen and shadow mask processing which are both time consuming processes. Ink jetting is an excellent technology for functionalizing each individual cantilever separately in an arrayed structure. Although the present invention will be discussed in terms of using ink jetting, other application technologies may also be used.
In one embodiment of the present invention, the solution is deposited into the reservoir 14 and the solution is wicked into the 2 μm wide groove 20 running the length of the micro-cantilever 12 , which is 4 μm wide. Once the solvent from the solution evaporates and dries, the polymer which was cast in solution is left in the 2 μm groove 20 . This process of depositing polymer onto a micro-cantilever 12 is done without destruction of the device. Such a delivery system using ink-jet printing technology is significant because the approximate volume of the drop, 3×10 −14 m 3 , is greater than the volume of the micro-cantilever 12, 1.4×10 −15 m 3 , by more than an order of magnitude. The present invention teaches a method for depositing polymer onto a micro-cantilever 12 without destruction of the device. Polymer delivery to the cantilever 12 leads to gas chemical sensing and other applications by using a mass sensitive polymer. The combination of a sensitive layer with an electrostatically actuated cantilever 12 yields a mass sensitive detector. On chip electronics can be integrated with this mass sensor for motion detection using capacitive detection. Applications of this fabrication method may include mass sensing and chemo-resistive sensing for gas chemical detection.
In the illustrated embodiments the resonant structure 12 is a simple 120 μm-long, 4 μm-wide beam with a 2 μm-wide micro-groove 20 running along the length of the beam, although other dimensions are possible with the present invention. Motion is parallel to the surface of the silicon substrate. Differential comb drives 18 with seven rotor fingers are located near the end of the beam 12 for lateral electrostatic actuation. The stator fingers are suspended by three cantilever beams connected in parallel and sized identically to the resonator cantilever beam 12 . Any curl from vertical stress gradient is matched to ensure the stator 18 and movable comb fingers are aligned in the same plane. Motion sensing of the plate is implemented using capacitive comb electrodes 16 placed on both sides of the main beam 12 and located further toward the base from the actuation combs. A limit stop 42 is located between the actuator 18 and sense combs of the motion sensor 16 . The beam 12 , sensors 16 , actuators 18 , limit stops 42 , and their associated structures are suspended over a silicon etch pit 44 .
A target well 14 area is located at the base of the cantilever 12 to collect the jetted drops. The well 14 has an approximate depth of 9 μm and a maximum width of 165 μm. The well 14 narrows in width toward the base of the cantilever 12 at a 45° angle on each side. Other sizes and shapes are also possible for the target well 14 area.
Although FIGS. 3 a , 3 b , 3 c , 4 a , and 4 b illustrate a single apparatus 10 , the present invention may include multiple apparatuses 10 in a single device or on a single substrate. For example, multiple apparatuses 10 may be used to perform redundant tests to ensure accuracy. Alternatively, different apparatuses 10 may perform different tests to provide a wide variety of information. As a result, a single device may contain a single apparatus 10 , or it may contain multiple apparatuses in which there are several versions of the same apparatus 10 , or in which there are several different apparatuses 10 . The apparatuses 10 may, for example, receive the same material in their respective target wells 14 , or they may receive different materials. For example, these different materials can be different polymers each with different mass sensitivity to various gas chemical analytes.
FIG. 5 illustrates a schematic of the transition region between the well 14 and the groove 20 . A pressure difference exists between the two surfaces of the liquid/gas interface (R. Aoyama, M. Seki, J. W. Hong, T. Fujii, and I. Endo, “Novel Liquid Injection Method with Wedge-Shaped Microchannel on a PDMS Microchip System for Diagnostic Analyses,” Journal of MEMS, p. 1232, (2001)). This differential pressure is:
Δ P XC = 2 γ cos θ C ( 1 W X - 1 W C ) ( 1 )
where γ is the surface tension, θ C is the contact angle, W X is the width of the well and W C is the width of the micro-groove 20 running along the length of the cantilever 12 . This causes a flow of the solution by capillary action from the well 14 to the resonator 12 . Once the solvent dries polymer is left in the micro-channel in the resonator 12 .
Oscillator Design
FIG. 6 illustrates a block diagram of the closed-loop feedback system 50 to sustain the resonant oscillation. A dc polarizing voltage, V dc 52 , is applied to the movable beam 12 . The resonator velocity is detected by measuring the motional displacement current, V dc dC/dt, through the comb finger capacitors. An on-chip preamplifier 54 produces a voltage, V s , that is proportional to the difference of the current through the differential capacitors formed by the sense comb electrodes.
An external amplifier 56 placed in series with the on-chip pre-amplifier 54 provides 40 dB of gain and −90° of phase shift at the mechanical resonance. This phase compensation is needed for free running oscillation. In this implementation, only one side of the differential actuator is used. During free oscillation, the actuator voltage amplitude is 0.2 V with a dc polarizing voltage of 23.0 V. A spectrum analyzer 58 is used to monitor the output of the amplifier 56 and determine differences in the resonance frequency of the device movable beam 12 .
The calculated resonant frequency from layout dimensions and prior to polymer deposition is 250 kHz. With analyte addition, a change in the mass of the cantilever 12 changes the resonance frequency. The mass sensitivity (gm/Hz) is:
Δ m Δ f = - 4 π ( m b + m poly ) 3 2 k = - 2 ( m b + m poly ) f o ( 2 )
where m b is the mass of the beam, m poly is the mass of the polystyrene or other material being measured, k is the spring constant of the cantilever, and f o is the resonance frequency of the cantilever 12 . The calculated mass sensitivity for this device is 76 fg/Hz. The sensitivity (Hz/ppm) of the micro-balance due to analyte concentration is calculated as follows (see, S. S. Bedair and G. K. Fedder, “CMOS MEMS Oscillator for Gas Chemical Detection,” Proceedings of IEEE Sensors, Vienna, Austria, Oct. 24-27, 2004):
Δ f Δ C air = Δ f Δ m Δ m Δ C air = - f o 2 ( m b + m poly ) K PG V poly ( 3 )
where C air is the concentration of the analyte in air, K PG is the partition coefficient associated with the particular polymer/analyte combination, and V poly is the volume of the polymer on the beam 12 . The volume of polymer to fill the micro-groove 20 is 7.2×10-16 m 3 . Assuming that the micro-groove 20 is filled with polystyrene the concentration sensitivity to ethanol, 2-propanol, and acetone is calculated to be 0.006 Hz/ppm, 0.005 Hz/ppm, and 0.01 Hz/ppm, respectively. Other materials will result in a different sensitivity of the device 10 .
Fabrication
FIG. 7 illustrates one method of fabricating a sensor 10 according to the present invention. The sensor 10 was fabricated in the SiGe 0.35 μm BiCMOS technology from Jazz Semiconductor (Newport Beach, CA) followed by post-CMOS micromachining (G. K. Fedder, S. Santhanum, M. L. Reed, S. C. Eagle, D. F. Guillou, M. S. C. Lu, and L. R. Carley, “Laminated high-aspect-ratio microstructures in a conventional CMOS process,” Proceedings of the 9 th IEEE International Workshop on Micro Electro Mechanical Systems (MEMS '96), San Diego, Calif., Feb. 15-17, 1996, pp. 13-18). As illustrated in FIG. 7( a ), the structures 60 that will form the sensor are embedded in silicon oxide-based layers 62 or other material used in the fabrication process. Metal interconnect layers 64 are also present.
After foundry CMOS fabrication, three dry etch steps are used for definition and release of the structures 60 , as illustrated in FIG. 7( b ). The intermetal dielectric layers are etched using an anisotropic CHF 3 /O 2 reactive-ion etch (RIE) ( FIG. 7( b )) where the top metal layer 66 acts as a mask defining the pattern of the structure. A subsequent undercutting of the structures 60 by a Si etch is performed using an anisotropic deep reactive-ion etch (DRIE) to form a recess 70 in the bulk silicon 72 ( FIG.7( c )) followed by an SF 6 /O 2 isotropic etch ( FIG. 7( d )) of the bulk silicon 72 to form the undercut 74 of the structures 60 for structural release of the metal and dielectric stack 60 . In the illustrated embodiment, the sidewalls and bottom of the micro-grooves are defined by the metal- 3 and metal- 1 layer, respectively, in the CMOS technology.
In FIG. 7( e ) the chemically sensitive polymer dissolved in solvent 76 is deposited using a piezoelectric drop-on-demand ink jet purchased from MicroFab Technologies (Plano, Tex.). The orifice of the ink jet is 30 μm in diameter and the average drop size is 31 μm in diameter. An x-y stage (Aerotech Inc.) that moves the device under the ink jet provides positional accuracy of 0.2 μm.
Although the present invention has been described in terms of one embodiment with regard to FIGS. 7( a )- 7 ( e ), other variations and modifications are also possible with the present invention. For example, different devices, such as different types of sensors as well as devices other than sensors, may be used with the present invention. Similarly, other structures and other materials may be used with the present invention. In addition, other processes and technologies, such as other micromachining and nanomachining processes and technologies may also be used to manufacture apparatuses according to the present invention.
Polymer Delivery Results
FIG. 8 illustrates an attempt to directly deposit material onto a cantilever wicking device 12 . Polymer deposition tests used two mg/mL polystyrene mixed in a 1:1 mixture of HPLC grade toluene and xylene at room temperature. The solution was then sonicated for ten minutes.
As expected, attempts to directly deposit onto the cantilever 12 result in the destruction of the device 10 . This occurs because the ink-jetted drop volume (˜33 pL) greatly exceeds the target cantilever 12 size. The wicking device 12 is pinned under the actuating electrodes 18 due to surface tension effects rendering it inoperable. In addition, the deposited material covers both the cantilevered wicking device 12 and surrounding structures, such as actuators 18 and motion sensors 16 . As a result, even if the wicking device 12 were to remain in, or be returned to, a functioning state, the apparatus 10 would not function because other parts of the apparatus 10 are covered in the material that was supposed to be deposited only on the wicking device 12 .
FIGS. 9 a - 9 d illustrate loading material onto the cantilever 12 according to the present invention. In that example, six drops of solution (two mg/mL polystyrene in 1 toluene:1 xylene) were deposited onto the target area at the base of the cantilever beam 12 . The polymer wicks onto the cantilever beam 12 and the solvent then evaporates. A view at the base of the cantilever micro-channel 20 is shown in FIG. 9( a ) and FIG. 9( b ) before and after polystyrene deposition, respectively. The tip of the micro-channel resonator 12 with and without polystyrene is shown in FIG. 9( c ) and FIG. 9( d ), respectively. The device was successfully operated with electrostatic actuation.
FIG. 9 e illustrates the frequency response of the cantilever 12 before and after polystyrene loading. The resonance frequency shifted down by 5400 Hz. This corresponds to an added polymer mass of 410pg. The calculated mass of polystyrene in six drops of solution is 396 pg.
FIG. 10 a - 10 g are scanning electron micrographs (“SEM”) illustrating several embodiments of the present invention after material deposition. In these embodiments, the material deposited is a polymer, although other materials may also be used with the present invention.
FIG. 10 a is a top view SEM after polymer deposition. FIG. 10 b is a cross-sectional view along line Xb-Xb in FIG. 10 a . FIG. 10 b shows material at the tip of the wicking device 12 after polymer deposition. FIGS. 10 a and 10 b illustrate an embodiment of the present invention in which the channel 20 is a vertical slot type channel, having a channel width and height of 1.5 μm and 3.2 μm, respectively.
FIG. 10 c is a top view SEM after polymer deposition of another embodiment of the present invention. FIG. 10 d is a cross-sectional view along line Xd-Xd in FIG. 10 c . FIG. 10 d shows material at the tip of the wicking device 12 after polymer deposition. FIGS. 10 c and 10 d illustrate an embodiment of the present invention in which the channel 20 is a vertical slot type channel, having a channel width and height of 2.4 μm and 4.8 μm, respectively.
FIG. 10 e is a top view SEM after polymer deposition of another embodiment of the present invention. FIG. 10 f is a cross-sectional view along line Xf-Xf in FIG. 10 e . FIG. 10 f shows material at the tip of the wicking device 12 after polymer deposition. FIGS. 10 e and 10 f illustrate an embodiment of the present invention in which the channel 20 is a vertical slot type channel, having a channel width and height of 2.8 μm and 4.8 μm, respectively.
FIG. 10 g is a cross-section view of the tip of a wicking device 12 after polymer deposition. The channel 20 in the wicking device 12 is a vertical groove type. The channel width and height are 1.5 μm and 3.5 μm, respectively.
Gas Test Measurements
FIG. 11 illustrates a gas test system 80 according to one embodiment of the present invention. Gas analytes are introduced with nitrogen as the carrier gas. The nitrogen supply 82 is connected through an adjustable flow-meter 84 and a 2-way ball valve 86 . The flow-meter 84 has a minimum flow rate of 0.21 liters per minute (Lpm) and a maximum rate of 1.21 Lpm. One outlet of the ball valve 86 connects to a T-connector 88 for direct connection of the carrier gas and analyte vapor to the test chamber 90 . The other outlet of the ball valve 86 is connected to the inlet of a bubbler 92 which is submersed in the liquid form of the analyte of interest. The outlet of the bubbler 92 is connected to the through a valve 94 and the T-connector 88 to the test chamber 90 .
Tests were performed with ethanol, 2-propanol, and acetone. N 2 was flowed at 1 Lpm through the chamber using an external bubbler until an equilibrium concentration is reached. In these initial tests, the equilibrium concentration was not measured but is assumed to be at or close to the saturation concentration of the corresponding vapor at a temperature of 300 K and a pressure of 1 atm.
FIG. 12 illustrates the free-running oscillator responses to ethanol, 2-propanol, and acetone flows. The mechanical resonance frequency with no exposure to analyte is 204.499 kHz. The oscillator signal has a 65 dB SNR and a 3 dB width of 3 Hz limited by the 3 Hz resolution bandwidth of the spectrum analyzer. From the frequency shifts in FIG. 12 , the amount in grams of ethanol, 2-propanol, and acetone loaded into the polystyrene is calculated to be approximately 1.5 pg, 2.6 pg, and 9.9 pg, respectively.
Conclusions
The gas tests successfully demonstrate an organic vapor detector using the CMOS-MEMS self-excited resonator oscillator. The polymer loading method that exploits capillary action in the micro-groove enables design of narrow-gap electrostatic combs alongside the micro-cantilever. Compatibility with ink jet polymer delivery enables loading of different polymers to individual cantilever sensors. The precise amount of polymer loading with this method should lead to repeatable results from device to device.
Scaling down the cantilever size led to a high mass sensitivity of 76 fg/Hz for the 4 μm-wide cantilever design. With further design maturation, further device scaling and incorporation of further materials onto the wicking devices on the cantlivers, the technology should lead to highly sensitive gas chemical gravimetric sensor arrays on chip.
Other Embodiments
FIGS. 13 a and 13 b illustrate another application of the present invention in which one or more channels 20 are used to provide an adhesive to secure a first object 100 to a second object 102 . In FIG. 13 a , the first 100 and second 102 objects are apart and a force 104 presses them together. In FIG. 13 b , the first 100 and second 102 objects are together, and one or more channels 20 in the second object 102 are used to carry adhesive to an interface between the first 100 and second 102 objects. After the adhesive dries the first 100 and second 102 objects are bonded together.
This application of the present invention may be used, for example, to assemble parts, such as parts used to create microelectromechanical systems, or other parts. In the illustrated embodiment, the first object 100 includes offsets or stops 106 which engage the second object 102 and provide for a predetermined spacing or gap 108 between the first 100 and second 102 objects. This may allow, for example for very small and/or very precise gaps or spaces to be formed.
Narrow gaps, for example, smaller than possible with conventional photolithographic techniques, with electrodes at either side of the gap are of interest for providing high electrostatic forces and high capacitance sensitivity. In other embodiments, stops 106 may be omitted, and two or more parts may be assembled in different orientations. Many other variations and modification are possible with this application of the present invention.
FIGS. 13 c and 13 d illustrate another embodiment of the present invention in which material, such as an adhesive, is deposited in the well 14 and wicked through the channel 20 . Part of the channel is defined by a moveable beam 109 . When the material flows through the portion of the channel 20 formed by the moveable beam 109 , the surface tension of the material causes the beam 109 to bend inward. If the material is an adhesive, it will dry and fix the beam 109 in that position. In the illustrated embodiment, the bent beam 109 engages stops 106 limiting the motion of the beam and forming a space or gap 108 .
FIG. 14 illustrates another application of the present invention in which the channel 12 is an opening or void in an object or layer 110 . In the illustrated embodiment, the channel 20 . defines a circular portion 112 within the larger object 110 . In this embodiment, an adhesive or other material is provided in the fluid well 14 , from which the material flows into the channel 20 and fills the channel 20 . The material filling the channel 20 may be flexible and allow for relative movement between the circular portion 112 and the larger object, or it may have some other function. Many different shapes 114 and other variations of this embodiment may be practiced with the present invention.
FIG. 15 illustrates a cross-section view along line XV-XV of the apparatus illustrated in FIG. 14 . The two portions 110 , 112 of the top layer are joined by the material in the channel 20 .
In this embodiment, an opening 114 exists below the two portions 110 , 112 of the top layer and a lower layer 116 , although it is not required for an opening 114 to exist below the two portions 110 , 112 of the top layer. The material filling the channel can be used to seal the opening 114 from the outside ambient. For example, this sealing can be used to keep liquids from entering area 114 , or can be used to seal liquids inside area 114 .
FIG. 16 illustrates a system 120 according to the present invention. In that embodiment, several apparatuses 10 , such as that illustrated in FIG. 1 , are on a single substrate 122 or material. FIG. 16 illustrates the apparatuses 10 as being “sensors”, although any apparatus 10 , or any combination of different types of apparatuses, may be formed in this manner. Accordingly, the present invention allows for a large number of apparatuses to be made or used as part of a single system 120 or unit. In some embodiments, the apparatuses 10 may all be the same, such as to perform the same test multiple times on the same or different samples. In other embodiments, the apparatuses may be different, such as to provide for a variety of functions from a single system 120 .
Many variations and modifications are possible with the present invention. For example, the present invention may be used in the operation of sensors. The present invention may be used to fill a space between, or to connect, two or more parts. In some embodiments, the present invention may be used to carry an adhesive to a desired location to fix two or more parts together. In other embodiments the present invention may be used to provide a dielectric between two or more electrodes or contacts. In another embodiment, the present invention may be used in a chemo resistor device in which electrically resistive material is positioned between two or more electrodes or contacts. In another embodiment, the present invention may be used as an electrostatic actuator. The present invention may also be used with a mass sensor for gas chemical sensing applications. The present invention may also be used with other fluids and materials and in other applications, such as chemo-resistive fabrication and devices, chemo-capacitive fabrication and devices, applying adhesives for capping or otherwise connecting devices, and other applications. In addition, different materials and structures may be used with the present invention. For example, some embodiments are described in terms of particular materials, although different materials may also be used. Similarly, some of the embodiments herein show a particular number and orientation of material layers used to create the various parts of the present invention. Those examples are illustrative and not limiting, and different numbers and orientations of layers may be used with the present invention. Those and other variations of the present invention are possible.
The present invention may also include two or more devices formed in a single apparatus or on a single substrate. The single apparatus or substrate may contain several devices of the same type, or it may contain different types of devices. In some embodiments, the devices receive different materials in their respective target areas, and in some embodiments they receive the same materials. As a result, different testing, sensing, or other functions may be performed on a single structure.
These and other variations and modifications of the present invention are possible and contemplated, and it is intended that the foregoing specification and the following claims cover such modifications and variations. | Apparatuses, systems, and methods utilizing capillary action and to control the movement or placement of liquids or other materials in micro-devices and nano-devices. In some embodiments, the present invention may be used to control polymer addition to micro-cantilevers and nano-cantilevers for biological sensing, chemical sensing, and other sensing. In other embodiments, the present invention may be used to deliver adhesives, dielectrics, chemo resistor materials, and other materials to micro-devices and nano-devices. | 53,560 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2006/069104, filed Nov. 30, 2006 and claims the benefit thereof. The International Application claims the benefits of European application No. 05026378.9 filed Dec. 2, 2005, both of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to an alloy as described in the claims, a protective layer for protecting a component against corrosion and/or oxidation at high temperatures and a component as described in the claims.
[0003] The invention relates in particular to a protective layer for a component that consists of a nickel-base or cobalt-base superalloy.
BACKGROUND OF THE INVENTION
[0004] Numerous protective layers for metallic components that are supposed to increase the corrosion resistance and/or oxidation resistance of said components are known from the prior art. Most of these protective layers are known under the collective name MCrAlX, where M stands for at least one of the elements selected from the group consisting of iron, cobalt and nickel and further essential constituents are chromium, aluminum and X=Yttrium, wherein the latter may also be partially or completely replaced by an equivalent element selected from the group consisting of scandium and the rare earth elements.
[0005] Typical coatings of this type are known from U.S. Pat. Nos. 4,005,989 and 4,034,142.
[0006] U.S. Pat. No. 6,280,857 B1 discloses a protective layer which contains the elements cobalt, chromium and aluminum, based on nickel, with the optional addition of rhenium and obligatory admixtures of yttrium and silicon.
[0007] EP 1 439 245 A1 discloses a cobalt-based rhenium-containing layer.
[0008] The objective of increasing the inlet temperatures of both stationery gas turbines and aircraft engines is of considerable significance in the specialist field of gas turbines, since the inlet temperatures are important variables determining the thermodynamic efficiencies which can be achieved by gas turbines. The use of specially developed alloys as base materials for components which are to be exposed to high thermal stresses, such as guide vanes and rotor blades, and in particular the use of single-crystal superalloys, allows the use of inlet temperatures of well over 1000° C. Nowadays, the prior art permits inlet temperatures of 950° C. and above in the case of stationary gas turbines and 1100° C. and above in the case of gas turbines for aircraft engines.
[0009] Examples of the structure of a turbine blade or vane having a single-crystal substrate, which for its part may be of complex structure, are revealed by WO 91/01433 A1.
[0010] Whereas the physical load-bearing capacity of the base materials which have by now been developed for the highly stressed components does not present any major problems with a view to possible further increases in the inlet temperatures, protective layers have to be employed to achieve sufficient resistance to oxidation and corrosion. In addition to the sufficient chemical stability of a protective layer under the attacks expected from flue gases at temperatures of the order of magnitude of 1000° C., a protective layer also has to have sufficiently good mechanical properties, not least with a view to the mechanical interaction between the protective layer and the base material. In particular, the protective layer must be sufficiently ductile to enable any deformation of the base material to be followed and not to crack, since points of attack for oxidation and corrosion would be created in this way. This typically gives rise to the problem that an increase in the levels of elements such as aluminum and chromium, which can increase the resistance of a protective layer to oxidation and corrosion, leads to a deterioration in the ductility of the protective layer, which means that mechanical failure, in particular the formation of cracks, is likely under mechanical loading which usually occurs in a gas turbine.
SUMMARY OF INVENTION
[0011] Accordingly, the invention is based on the object of providing an alloy and a protective layer which has a good high-temperature stability with regard to corrosion and oxidation, good long-term stability and, moreover, is particularly well matched to mechanical stresses which are expected at a high temperature in particular in a gas turbine.
[0012] The object is achieved by the alloy as claimed in the claims and the protective layer as claimed in the claims.
[0013] A further object of the invention is to provide a component which offers increased protection against corrosion and oxidation.
[0014] This object is achieved by the component as claimed in the claims, in particular a component of a gas turbine or steam turbine, which for protection against corrosion and oxidation at high temperatures, has a protective layer of the type described above.
[0015] The subclaims list further advantageous measures.
[0016] The measures listed in the subclaims can be combined with one another as desired in advantageous ways.
[0017] The invention is based on the discovery, inter alia, that the desired protective layer has brittle precipitates in the layer and also in the transition region between the protective layer and the base material. These brittle phases, the formation of which increases over time and with use temperature, in operation lead to highly pronounced longitudinal cracks in the layer and in the layer/base material interface, with subsequent layer detachment. The interaction with carbon, which can diffuse out of the base material into the layer or diffuses into the layer through the surface during a heat treatment in the furnace, additionally increases the brittleness of the precipitates. The susceptibility to cracking is boosted still further by oxidation of the brittle precipitates.
[0018] In this context, the influence of nickel, which determines thermal and mechanical properties, is also important.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention is explained in more detail below. In the drawing:
[0020] FIG. 1 shows a layer system having a protective layer,
[0021] FIG. 2 shows compositions of superalloys,
[0022] FIG. 3 shows a gas turbine,
[0023] FIG. 5 shows a perspective view of a turbine blade or vane, and
[0024] FIG. 4 shows a perspective view of a combustion chamber.
DETAILED DESCRIPTION OF INVENTION
[0025] According to the invention, a protective layer 7 ( FIG. 1 ) for protecting a component against corrosion and oxidation at high temperature comprises the following elements (details of amounts in wt %):
[0026] 27% to 31% nickel
[0027] 23% to 29% chromium
[0028] 7% to 11% aluminum
[0029] 0.5% to 0.7% yttrium and/or at least one metal selected from the group consisting of scandium and the rare earth elements, optionally 0.6% to 0.8% silicon, and/or optionally 0.5% to 0.7% zirconium, remainder cobalt (CoNiCrAlY).
[0030] It is preferable for either only silicon or zirconium to be added.
[0031] Particular exemplary embodiments are:
[0032] 1) Co-30Ni-28Cr-8Al-0.6Y
[0033] 2) Co-30Ni-28Cr-8Al-0.6Y-0.7Si
[0034] 3) Co-28Ni-24Cr-10Al-0.6Y-0.6Zr.
[0035] It should be noted that the levels of the individual elements are specifically adapted with a view to their actions. Surprisingly, the selection of 27 wt % to 31 wt % nickel significantly and disproportionately improves the thermal and mechanical properties of the protective layer 7 .
[0036] In conjunction with the reduction in brittle phases, which have negative effects in particular with relatively elevated mechanical properties, the reduction in the mechanical stresses resulting from the selected nickel content improves the mechanical properties.
[0037] The protective layer, with a good resistance to corrosion, has a particularly good resistance to oxidation and is furthermore distinguished by especially good ductility properties, making it particularly well qualified for use in a gas turbine with a further increase in the inlet temperature. Scarcely any embrittlement occurs during operation.
[0038] The trace elements in the powder to be sprayed, which form precipitates and therefore constitute sources of embrittlement, also play an important role.
[0039] The powders are applied, for example, by plasma spraying (APS, LPPS, VPS, . . . ). Other processes are also conceivable (PVP, CVD, cold spraying).
[0040] The protective layer 7 described also acts as a bonding layer to a superalloy.
[0041] Further layers, in particular ceramic thermal barrier coatings 10 , can be applied to this protective layer 7 .
[0042] In this component, the protective layer 7 is advantageously applied to a substrate 4 made from a nickel-base or cobalt-base superalloy.
[0043] A suitable substrate has in particular the following composition (details in wt %):
[0000]
0.1% to 0.15%
Carbon
18% to 22%
Chromium
18% to 19%
Cobalt
0% to 2%
Tungsten
0% to 4%
Molybdenum
0% to 1.5%
Tantalum
0% to 1%
Niobium
1% to 3%
Aluminum
2% to 4%
Titanium
0% to 0.75%
Hafnium
[0044] optionally small quantities of boron and/or zirconium, remainder nickel.
[0045] Compositions of this type are known as casting alloys under the names GTD222, IN939, IN6203 and Udimet 500.
[0046] Further alternatives for the substrate of the component are listed in FIG. 2 .
[0047] The thickness of the protective layer 7 on the component 1 is preferably between approximately 100 μm and 300 μm.
[0048] The protective layer 7 is particularly suitable for protecting a component against corrosion and oxidation when the component is exposed to a flue gas at a material temperature of around 950° C., and in the case of aircraft turbines even around 1100° C.
[0049] The protective layer 7 according to the invention is therefore particularly well qualified for protecting a component of a gas turbine 100 , in particular a guide vane 120 , rotor blade 130 or other component, which is exposed to hot gas upstream of or in the turbine of the gas turbine.
[0050] The protective layer 7 can be used as an overlay (the protective layer is the outer layer) or as a bond coat (the protective layer is an interlayer).
[0051] FIG. 1 shows a layer system 1 as a component.
[0052] The layer system 1 comprises a substrate 4 .
[0053] The substrate 4 may be metallic and/or ceramic. In particular in the case of turbine components, such as for example turbine rotor blades 120 ( FIG. 5 ) or turbine guide vanes 130 ( FIGS. 3 , 5 ), combustion chamber linings 155 ( FIG. 4 ) and other housing parts of a steam or gas turbine 100 ( FIG. 3 ), the substrate 4 consists of a nickel-base, cobalt-base or iron-base superalloy.
[0054] It is preferable to use cobalt-base or nickel-base superalloys.
[0055] The protective layer 7 according to the invention is present on the substrate 4 .
[0056] It is preferable for this protective layer 7 to be applied by LPPS (low pressure plasma spraying).
[0057] It can be used as the outer layer (not shown) or as the interlayer ( FIG. 1 ).
[0058] In the latter case, a ceramic thermal barrier coating 10 is present on the protective layer 7 .
[0059] The protective layer 7 can be applied to newly produced components and refurbished components.
[0060] Refurbishment means that after they have been used, layers (thermal barrier coating) may have to be detached from components 1 and corrosion and oxidation products removed, for example by an acid treatment (acid stripping). If appropriate, cracks also have to be repaired. This can be followed by recoating of a component of this type, since the substrate 4 is very expensive.
[0061] FIG. 3 shows by way of example a partial longitudinal section through a gas turbine 100 .
[0062] In its interior, the gas turbine 100 has a rotor 103 which is mounted such that it can rotate about an axis of rotation 102 , has a shaft 102 , and is also referred to as the turbine rotor.
[0063] An intake casing 104 , a compressor 105 , a for example toric combustion chamber 110 , in particular an annular combustion chamber, with a plurality of coaxially arranged burners 107 , a turbine 108 and the exhaust gas casing 109 follow one another along the rotor 103 .
[0064] The annular combustion chamber 110 is in communication with a for example annular hot gas duct 111 . There, by way of example, four successive turbine stages 112 form the turbine 108 .
[0065] Each turbine stage 112 is formed for example from two blade rings. As seen in the direction of flow of a working medium 113 , a guide vane row 115 is followed in the hot gas duct 111 by a row 125 formed from rotor blades 120 .
[0066] The guide vanes 130 are secured to an inner casing 138 of a stator 143 , whereas the rotor blades 120 belonging to a row 125 are arranged on the rotor 103 , for example by means of a turbine disk 133 .
[0067] A generator (not shown) is coupled to the rotor 103 .
[0068] While the gas turbine 100 is operating, air 135 is drawn in through the intake casing 104 and compressed by the compressor 105 . The compressed air provided at the turbine end of the compressor 105 is passed to the burners 107 , where it is mixed with a fuel. The mixture is then burnt in the combustion chamber 110 , forming the working medium 113 . From there, the working medium 113 flows along the hot gas duct 111 past the guide vanes 130 and the rotor blades 120 . The working medium 113 is expanded at the rotor blades 120 , transferring its momentum, so that the rotor blades 120 drive the rotor 103 and the latter in turn drives the generator coupled to it.
[0069] While the gas turbine 100 is operating, the components which are exposed to the hot working medium 113 are subject to thermal stresses. The guide vanes 130 and rotor blades 120 of the first turbine stage 112 , as seen in the direction of flow of the working medium 113 , together with the heat shield elements which line the annular combustion chamber 110 , are subject to the highest thermal stresses.
[0070] To be able to withstand the temperatures which prevail there, they can be cooled by means of a coolant.
[0071] Substrates of the components may likewise have a directional structure, i.e. they are in single-crystal form (SX structure) or have only longitudinally oriented grains (DS structure).
[0072] By way of example, iron-base, nickel-base or cobalt-base superalloys are used as material for the components, in particular for the turbine blade or vane 120 , 130 and components of the combustion chamber 110 .
[0073] Superalloys of this type are known for example from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO60/44949; these documents form part of the disclosure with regard to the chemical composition of the alloys.
[0074] The guide vane 130 has a guide vane root (not shown here) facing the inner casing 138 of the turbine 108 and a guide vane head at the opposite end from the guide vane root. The guide vane head faces the rotor 103 and is fixed to a securing ring 140 of the stator 143 .
[0075] FIG. 5 shows a perspective view of a rotor blade 120 or guide vane 130 of a turbomachine, which extends along a longitudinal axis 121 .
[0076] The turbomachine may be a gas turbine of an aircraft or of a power plant for generating electricity, a steam turbine or a compressor.
[0077] The blade or vane 120 , 130 has, in succession along the longitudinal axis 121 , a securing region 400 , an adjoining blade or vane platform 403 , a main blade or vane part 406 and a blade or vane tip 415 .
[0078] As a guide vane 130 , the vane 130 may have a further platform (not shown) at its vane tip 415 .
[0079] A blade or vane root 183 , which is used to secure the rotor blades 120 , 130 to a shaft or a disk (not shown), is formed in the securing region 400 .
[0080] The blade or vane root 183 is designed, for example, in hammerhead form. Other configurations, such as a fir-tree or dovetail root, are possible.
[0081] The blade or vane 120 , 130 has a leading edge 409 and a trailing edge 412 for a medium which flows past the main blade or vane part 406 .
[0082] In the case of conventional blades or vanes 120 , 130 , by way of example solid metallic materials, in particular superalloys, are used in all regions 400 , 403 , 406 of the blade or vane 120 , 130 .
[0083] Superalloys of this type are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949; these documents form part of the disclosure with regard to the chemical composition of the alloy.
[0084] The blade or vane 120 , 130 may in this case be produced by a casting process, also by means of directional solidification, by a forging process, by a milling process or combinations thereof.
[0085] Workpieces with a single-crystal structure or structures are used as components for machines which, in operation, are exposed to high mechanical, thermal and/or chemical stresses.
[0086] Single-crystal workpieces of this type are produced, for example, by directional solidification from the melt. This involves casting processes in which the liquid metallic alloy solidifies to form the single-crystal structure, i.e. the single-crystal workpiece, or solidifies directionally.
[0087] In this case, dendritic crystals are oriented along the direction of heat flow and form either a columnar crystalline grain structure (i.e. grains which run over the entire length of the workpiece and are referred to here, in accordance with the language customarily used, as directionally solidified) or a single-crystal structure, i.e. the entire workpiece consists of one single crystal. In these processes, a transition to globular (polycrystalline) solidification needs to be avoided, since non-directional growth inevitably forms transverse and longitudinal grain boundaries, which negate the favorable properties of the directionally solidified or single-crystal component.
[0088] Where the text refers in general terms to directionally solidified microstructures, this is to be understood as meaning both single crystals, which do not have any grain boundaries or at most have small-angle grain boundaries, and columnar crystal structures, which do have grain boundaries running in the longitudinal direction but do not have any transverse grain boundaries. This second form of crystalline structures is also described as directionally solidified microstructures. (directionally solidified structures).
[0089] Processes of this type are known from U.S. Pat. No. 6,024,792 and EP 0 892 090 A1; these documents form part of the disclosure with regard to the solidification process.
[0090] The blades or vanes 120 , 130 may likewise have protective layers 7 according to the invention protecting against corrosion or oxidation. The density is preferably 95% of the theoretical density. A protective aluminum oxide layer (TGO=thermally grown oxide layer) is formed on the MCrAlX layer (as an interlayer or as the outermost layer).
[0091] It is also possible for a thermal barrier coating, which is preferably the outermost layer and consists for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, to be present on the MCrAlX.
[0092] The thermal barrier coating covers the entire MCrAlX layer.
[0093] Columnar grains are produced in the thermal barrier coating by means of suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0094] Other coating processes are conceivable, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may have grains that are porous and/or include micro-cracks or macro-cracks in order to improve the resistance to thermal shocks. Therefore, the thermal barrier coating is preferably more porous than the MCrAlX layer.
[0095] The blade or vane 120 , 130 may be hollow or solid in form. If the blade or vane 120 , 130 is to be cooled, it is hollow and may also have film-cooling holes 418 (indicated by dashed lines).
[0096] FIG. 4 shows a combustion chamber 110 of the gas turbine 100 . The combustion chamber 110 is configured, for example, as what is known as an annular combustion chamber, in which a multiplicity of burners 107 , which generate flames 156 and are arranged circumferentially around an axis of rotation 102 , open out into a common combustion chamber space 154 . For this purpose, the combustion chamber 110 overall is of annular configuration positioned around the axis of rotation 102 .
[0097] To achieve a relatively high efficiency, the combustion chamber 110 is designed for a relatively high temperature of the working medium M of approximately 1000° C. to 1600° C. To allow a relatively long service life even with these operating parameters, which are unfavorable for the materials, the combustion chamber wall 153 is provided, on its side which faces the working medium M, with an inner lining formed from heat shield elements 155 .
[0098] A cooling system may also be provided for the heat shield elements 155 and/or their holding elements, on account of the high temperatures in the interior of the combustion chamber 110 . The heat shield elements 155 are then for example hollow and may also have cooling holes (not shown) which open out into the combustion chamber space 154 .
[0099] On the working medium side, each heat shield element 155 made from an alloy is equipped with a particularly heat-resistant protective layer (MCrAlX layer and/or ceramic coating) or is made from material that is able to withstand high temperatures (solid ceramic bricks).
[0100] These protective layers 7 may be similar to those used for the turbine blades or vanes 120 , 130 , i.e. for example MCrAlX: M is at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and/or silicon and/or at least one of the rare earth elements, or hafnium (Hf). Alloys of this type are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.
[0101] A for example ceramic thermal barrier coating, consisting for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, may also be present on the MCrAlX.
[0102] Columnar grains are produced in the thermal barrier coating by suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0103] Other coating processes are conceivable, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may have grains that are porous and/or include micro-cracks or macro-cracks in order to improve the resistance to thermal shocks.
[0104] Refurbishment means that after they have been used, protective layers may have to be removed from turbine blades or vanes 120 , 130 , heat shield elements 155 (e.g. by sand-blasting). Then, the corrosion and/or oxidation layers and products are removed.
[0105] If appropriate, cracks in the turbine blade or vane 120 , 130 or the heat shield element 155 are also repaired. This is followed by recoating of the turbine blades or vanes 120 , 130 , heat shield elements 155 , after which the turbine blades or vanes 120 , 130 or the heat shield elements 155 can be reused. | Known protective layers with a high Cr content and additionally a silicon form brittle phases, which become even more brittle under the influence of carbon during use. The protective layer according to the invention has the composition 27% to 31% nickel, 23% to 29% chromium, 7% to 11% aluminum, 0.5% to 0.7% yttrium and/or at least one equivalent metal from the group comprising scandium and rare earth elements, optionally 0.6% to 0.8% silicon, optionally 0.5% to 0.7% zirconium and the remainder cobalt. | 26,046 |
FIELD OF THE INVENTION
[0001] The present invention relates to a highly efficient process for producing isoxazoline derivatives.
BACKGROUND OF THE INVENTION
[0002] Isoxazoline derivatives represented by the general formula (1)
[0000]
[0000] wherein Ar 1 represents an aryl group which may be substituted; Ar 2 represents another aryl group, which may be substituted as well, and may or may not be the same as Ar 1 ; R represents electron withdrawing group including but not limited to alkoxycarbonyl, aryloxycarbonyl, aminocarbonyl, cyano, alkylcarbonyl, arylcarbonyl, formyl, alkylsulfinyl, arylsulfinyl, alkylsulfonyl or arylsulfonyl are compounds that are widely used in the field of agriculture. One particular example of the isoxazoline derivatives is ethyl 5,5-diphenyl-3-isoxazolinecarboxylate (commercially known as isoxadifen-ethyl) which is used as a safener in a herbicide for corn production (WO 01/54501/A2 by Syngenta participations AG) and as an insecticide (WO 2006/8110 A1 by Bayer cropscience AG). The estimated worldwide annual consumption of isoxadifen-ethyl is 800 to 1000 tons.
[0003] Heretofore, the isoxazoline derivatives represented by the formula (1) are generally prepared through dipolar [2+3] cycloaddition of the corresponding alkenes represented by the general formula (2)
[0000]
[0000] and 1-chloro-oxime represented by the general formula (3) (DE 4331448 A1 19950323)
[0000]
[0000] wherein R 1 , R 2 and R are as defined as above.
[0004] Another prior art process for preparing the isoxazoline derivatives represented by the formula (1) is the [2+3] dipolar cycloaddition of alkenes represented by the formula (2) with nitro compounds represented by the general formula (4) (Tetra. Asymmetry, 2008, 19, 2850-2855)
[0000]
[0000] wherein R is as defined above.
[0005] These two processes to prepare the isoxazoline derivatives are generally well-known in the prior art. However, the disadvantages of the processes are also generally recognized in the field, particularly for preparing ethyl 5,5-diphenyl-3-isooxazolinecarboxylate:
[0006] A) Both of these two processes are low efficiency: through these processes the isoxazoline derivative is produced in modest yield (86% yield using one equivalent of ethyl 2-chloro-2-hydroxyiminoacetate and 1.5 equivalents of 1,1-diphenylethene (DE 4331448 A1 19950323), and 75% yield when the nitro compound used (Tetra. Asymmetry, 2008, 19, 2850-2855));
[0007] B) The materials used in these processes are expensive because they have to be made in two or three steps from more common materials; for example, the alkene, 1,1-diphenylethene represented by the general formula (2), wherein R 1 , R 2 are Phenyls, is commonly made by the reaction of the corresponding diphenyl ketone and the Grignard reagent in an anhydrous pyrophoric ethereal solvent, followed by dehydrogenation with strong acid; and the ethyl 2-chloro-2-hydroxyiminoacetate represented by the general formula (3), wherein R is ethoxycarbonyl, is generally prepared from glycine via esterification with large excess of thionyl chloride, a process through which a large quality of hydrogen chloride and sulphur dioxide are released; followed by oxidation with nitrite under acidic conditions, and the ethyl 2-chloro-2-hydroxyiminoacetate was obtained in only 55-76% overall yield (Bulletin of the Chemical Society of Japan, 1971, 44, 219); and the synthesis of the nitro compounds (4) is achieved in 60-78% yield through nitration of ethyl acetoacetate with fumic nitric acid in acetic anhydride (U.S. Pat. No. 5,162,572 A1 1992). Overall, the existing processes for producing the isoxazoline derivatives represented by the general formula (1) are of low efficiency, highly expensive, and environmentally costly. As a result, there is real need for a novel cost-effective process to improve the production yield and ease the environmental concern.
[0008] Cyclopropane derivatives with vicinal electron donor and acceptor substituents are able to be subjected to heterolytic ring cleavage to form 1,3 zwitterionic intermediates (Reissig, H.-U. Topics of Current Chemistry, 144, 73, 1988). In particular, when treated with unsaturated electrophiles they undergo [2+3] type reactions to form five membered carbon or heterocyclic compounds (Shimada, S.; Hashimoto, Y.; Sudo, A.; Hasegawa, M.; Saigo, K. Journal of Organic Chemistry, 57, 7126, 1992; Graziano, M. L.; Isece, M. R.; Cermola, F. Journal of Chemical Research, (S) 82, (M) 0622, 1996). Among these unsaturated electrophiles, nitrosylation reagents including NOCI, NOBr, NOBF 4 , NaNO 2 —CF 3 CO 2 H have been reported to react with cyclopropane derivatives to form isoxazoline derivatives or/and isoxazodine derivatives: cyclopropane derivatives that have been reported to react with NOCI include ethyl 2,2-dimethoxycyclopropanyl carboxylate, ethyl 2,2-dimethoxy-3,3-dimethylcyclopropanyl carboxylate, ethyl 2-ethoxy-cyclopropanyl carboxylate, ethyl 2,2-dimethoxy-3-methylcyclopropanyl carboxylate (Cermola, F.; Gioia, L. D.; Graziano, M. L.; Isece, M. R.; Journal of Chemical Research 677-681, 2005); cyclopropane derivatives that have been reported to react with NOBF 4 include ethyl 2-ethoxy-cyclopropanyl carboxylate (Cermola, F.; Gioia, L. D.; Graziano, M. L.; Isece, M. R.; Journal of Chemical Research 677-681, 2005), 1,1-dichloro-2-arylcyclopropane (Lin, S.-T.; Kuo, S.-H.; Yang, F.-M. Journal of Organic Chemistry, 62, 5229, 1997), 1-aryl-2-arylcyclopropane (Mizuno, K.; Ichinose, N.; Tamai, T.; Otsuji, Y. Journal of Organic Chemistry, 57, 4669-4675, 1992), phenylcyclopropane (Kim, E. K.; Kochi, J. K. Journal of American Chemical Society, 113, 4962, 1991); cyclopropane derivatives that have been reported to react with NaNO 2 —CF 3 CO 2 H include ethyl 2-arylcyclopropanyl carboxylate (Kadzhaeva, A. Z.; Trofimova, E. V.; Fedotov, A. N.; Potekhin, K. A.; Gazzaeva, R. A.; Mochalov, S. S.; Zefirov, N. S. Journal of Heterocyclic Compounds 45, 595, 2009). However, examples presented in these publications listed above clearly demonstrate that the reaction of nitrosylation reagents and cyclopropanes is not feasible as a method for preparing isoxazoline derivatives, as the reaction generally delivers a mixture composed of the desired isoxazoline derivatives, isoxazlidine derivatives and other non-cyclic compounds. And the desired isoxazoline derivatives were generated only in low yields.
[0009] This invention discloses a novel process to prepare isoxazoline derivatives represented by the general formula (1) in high efficiency from easy accessible materials. Therefore, it addresses the need for a more cost-effective and more environmentally friendly technology for the synthesis process. This need is solved by the subject matter disclosed herein.
SUMMARY OF THE INVENTION
[0010] This invention provides an efficient process to produce the isoxazolidine derivatives represented by the general formula (1)
[0000]
[0000] wherein Ar 1 , Ar 2 represent aryl groups that may contain one to five substituents that include but not limited to halide, alkyloxy, alkyl, aryl, carbonyl, nitro, cyano; and Ar 2 may or may not be the same as Ar 1 ; R represents an electron withdrawing group including but not limited to alkoxylcarbonyl, aryloxylcarbonyl, aminocarbonyl, cyano, alkylcarbonyl, arylcarbonyl, formyl, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl from the corresponding cyclopropane derivatives represented by the general formula (5)
[0000]
[0000] wherein Ar 1 , Ar 2 and R are as defined above, with electrophilic nitrosylation reagents including but not limited to nitrosylchloride, nitrosylbromide, nitrosylsulfuric acid or a combination of sodium nitrite or potassium nitrite with strong acid including but not limited to sulphuric acid, trifluoroacetic acid, hydrogen chloride or nitric acid, or with Lewis acid including but not limited to BF 3 , AlCl 3 in the solvent including but not limited to acetic acid, trifluoroacetic acid, sulphuric acid, halogenated solvent such as dicloromethane, 1,2-dichloroethane etc., aromatic solvent such as benzene, toluene, chlorobenzene etc.; aliphatic ether, aliphatic ester, acetonitrile, at the temperature ranging from −20° C. to 100° C.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The applicant has discovered an efficient process to prepare the isoxazoline derivatives represented in the general formula (1)
[0000]
[0000] by reacting the cyclopropane derivatives represented in the general formula (5)
[0000]
[0000] with an electrophilic nitrosylation reagent; wherein Ar 1 , Ar 2 in both formula (1) and (5) represent aryl groups that may be substituted, and Ar 2 may or may not be the same as Ar 1 ; R represents electron withdrawing group including but not limited to alkoxylcarbonyl, aryloxylcarbonyl, aminocarbonyl, cyano, alkylcarbonyl, arylcarbonyl, formyl, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, nitro; and the electrophilic nitrosylation reagents include but not limited to nitrosylchloride, nitrosylbromide, nitrosylsulfuric acid and electrophilic nitrosylation reagents composed of at least one member of nitrites including but not limited to lithium nitrite, sodium nitrite or potassium nitrite and one member of strong acids including but not limited to sulphuric acid, trifluoroacetic acid, hydrogen chloride nitric acid, or with Lewis acid including but not limited to BF 3 , AlCl 3 in the solvent including but not limited to acetic acid, trifluoroacetic acid, sulphuric acid, halogenated solvent such as dicloromethane, 1,2-dichloroethane etc.; aromatic solvent such as benzene, toluene, chlorobenzene etc.; aliphatic ether, aliphatic ester, acetonitrile at the temperature ranging from −20° C. to 100° C.
[0012] The invention is described in details via preparation of ethyl 5,5-diphenyl-3-isoxazolinecarboxylate. The corresponding cyclopropane derivative, ethyl 2,2-diphenylcyclopropanylcarboxylate, is prepared via an amended known one step process: diphenyl diazomethane solution was efficient, economic and environmentally benign produced by oxidizing diphenylketone hydrazine with either yellow mercury oxide (Synlett, 11, 1623-1626, 2010; Yu, J.; Lian, G.; Zhang, D. Synthetic communications, 37, 37-46, 2007), manganese dioxide (Tetrahedron, 54, 6867-6896, 1998) or sodium hypochlorite (Tokushima, I.-K.; Naruto, I.-W.; Tokushima, M.-S. PCT/JP94/02124); and decomposition of diphenyl diazomethane in the presence of ethyl acrylate at 50° C. produces ethyl 2,2-diphenylcyclopropylcarboxylate in greater than 94% overall yield. The ethyl 2,2-diphenylcyclopropanylcarboxylate thus prepared is normally contaminated with less than five percent of various impurities depending on the exact method used. The presence of impurities in the cyclopropane derivatives obtained does not have significant impact on the production of the isoxazoline derivatives.
[0013] Non-limiting examples of electrophilic nitrosylation reagent used in the reaction of this invention include nitrosylchloride, nitrosylbromide, nitrosylsulfuric acid or a combination of nitrite salt including but not limited to sodium nitrite or potassium nitrite with strong acid including but not limited to sulphuric acid, trifluoroacetic acid, hydrogen chloride, nitric acid, or with strong Lewis acid including but not limited to boron trifluoride, aluminium trichloride.
[0014] Non-limiting examples of solvent used in the reaction of this invention include acetic acid, trifluoroacetic acid, sulphuric acid, nitric acid, halogenated solvent such as dichloromethane, 1,2-dichloroethane; aromatic solvent such as benzene, toluene, chlorobenzene; aliphatic ether, aliphatic ester, acetonitrile.
[0015] The mole ratio of nitrosylation reagent to the cyclopropane derivatives represented by the general formula (5) varies from 1:1 to 10:1. And the most preferred ratio is approximately 1.1:1.
[0016] The concentration of the cyclopropane derivatives represented by the general formula (5) used in the reaction can range from 0.01 mole per litre to 10.0 mole per litre, the preferable concentration is within the range of 0.1 mole per litre to 5.0 mole per litre.
[0017] In this invention, the reaction is a strong exothermic process. It is preferable to maintain the reactants at the temperature as low as possible while slowly mixing the nitrosylation reagent mentioned above with the cyclopropane derivatives represented by the general formula (5). Generally the reaction temperature needs to be maintained below 100° C., and more preferred below 40° C.
[0018] The Examples listed below illustrate methods for preparing the isoxazoline derivatives according to the invention.
EXAMPLES
Example 1
Synthesis of 2,2-diphenylcyclopropanyl carboxylate ethyl ester
[0019] Diphenylketone hydrazone (3.92 g, 20 mmol) was mixed with yellow mercury oxide (4.33 g, 20 mmol) in 40 mL petroleum. The mixture was stirred at the temperature less than 20° C. for 16 hours. The deep red solution of diphenyl diazomethane in petroleum was added into ethyl acrylate (6.0 g, 60 mmol) at 50° C. in ten minutes. When the red colour fade off the solvent and excess of ethyl acrylate were removed under reduced pressure and the crude product obtained was further purified over silica chromatography to furnish 2,2-diphenylcyclopropanyl carboxylate ethyl ester 5.11 g (96% yield) as a pale yellow oil. 1 H NMR (400 MHz, CDCl 3 ): 7.36-7.17 (10H, m), 4.00-3.83 (2H, m), 2.54 (1H, dd, J=8.3, 6.0 Hz), 2.17 (1H, dd, J=1H, dd, 6.0, 4.8 Hz), 1.59 (1H, dd, J=8.3, 4.8 Hz), 1.01 (3H, t, J=7.1 Hz).
Example 2
Synthesis of 2,2-diphenylcyclopropanyl carboxylate ethyl ester
[0020] Diphenylketone hydrazone (8.9 g, 45.4 mmol) in DCM (19 mL) was mixed with KI (0.45 g) in water (0.6 mL) and benzyldimethyloctylammonium chloride (10 mg). To the mixture was added the aqueous solution composing of 25% NaOH (27 mL), water (18 mL), and sodium chlorite (12-14%, 28 mL) at 5° C. with vigorous stirring. Twenty minutes later after addition, the stirring was turned off to let the reaction mixture separate. The red DCM solution was separated and dried over anhydrous Na 2 SO 4 . After removing the desiccant, the solvent was removed under reduced pressure; the residue was re-dissolved in hexane, and the unreacted hydrazone and side product was insoluble in hexane and removed by filtration. The red hexane diphenyl diazomethane solution was added to ethyl acrylate (13.6 g, 136 mmol) at 50° C. within 30 mints. When the red colour fade off the solvent and excess of ethyl acrylate was removed under reduced pressure to give crude product with 94% purity in 56-94% yield.
Experiment 3
Synthesis of 2,2-diphenylcyclopropanyl carboxylate ethyl ester
[0021] To the solution of diphenylketone hydrazone (45 g, 0.227 mol) in 220 mL chloroform was added activated MnO 2 (Aldrich, 85%, 49.4 g, 0.567 mol). The mixture was vigorously stirred at the temperature less than 20° C. until all starting material had been consumed. The solid was removed by filtration over celite. And the deep red solution was added to 68 g ethyl acrylate at 50° C. in 40 mints. When the red colour fade off, the chloroform (more than 200 mL) and excess ethyl acrylate (37 g) were collected by distillation; and the crude product obtained containing great than 96% of 2,2-diphenylcyclopropanyl carboxylate ethyl ester.
Experiment 4
Synthesis of 5,5-diphenylisoxazoline carboxylate ethyl ester
[0022] The cyclopropane derivative, 2,2-diphenylcyclopropanyl carboxylate ethyl ester (0.97 g, 3.7 mmol) was dissolved in 3.7 mL CF 3 CO 2 H. Into the solution was added NaNO 2 (0.28 g, 4.0 mmol, 1.1 eq.) in several ports so that the reaction temperature did not excess 40° C. After addition, the reactants were stirred at room temperature (about 18° C.) for half an hour. And the reactants were poured into an iced water and extracted with diethyl ether (2×20 mL); the ethereal solutions were combined and subsequently washed with sat. NaHCO 3 (2×20 mL), then water (20 mL) and brine (20 mL). The washed ethereal solution was then dried over anhydrous Na 2 SO 4 . After removing the desiccant, the ethereal solution was concentrated to obtain a light brown oil. The crude product 1 H NMR of the crude product showed that the reaction was clean and a virtual 100% yield. The crude product was further purified over silica chromatography (Rf: 0.45, eluent: 20% ethyl acetate in petrol) to obtain 5,5-diphenylisoxazoline carboxylate ethyl ester 0.958 g (89% yield) as a white solide. 1 H NMR (400 MHz, CDCl 3 ): 7.41-7.26 (10H, m), 4.34 (2H, q, J=7.1 Hz), 3.86 (2H, s), 1.36 (3H, t, J=7.1 Hz). 13 C NMR (400 MHz, CDCl 3 ): 160.54, 151.09, 142.99, 128.54, 128.02, 125.95, 94.79, 62.15, 46.78, 14.12.
Example 5
Synthesis of 5,5-diphenylisoxazoline carboxylate ethyl ester
[0023] The cyclopropane derivative, 2,2-diphenylcyclopropanyl carboxylate ethyl ester (1.0 g, 3.8 mmol) was dissolved in 4.0 mL AcOH at room temperature (18° C.). Into the solution was carefully added 2.0 mL concentrated H 2 SO 4 , followed by adding NaNO 2 (0.29 g, 4.1 mmol, 1.1 eq) in several portions so that the reaction temperature did not excess 40° C. After addition, the reactants were stirred at room temperature (about 18° C.) for half an hour before the reactants were poured into iced water and extracted with diethyl ether (2×20 mL), the ethereal solutions were combined and washed with sat. NaHCO 3 (2×20 mL), then water (20 mL) and brine (20 mL). The washed ethereal solution was then dried over Na 2 SO 4 . After removing the desiccant, the ethereal solution was concentrated to furnish a thick oily product. The 1 H NMR of the crude product showed that the reaction was clean and the yield was virtually 100%. The thick oily crude product was stirred with 10 mL petrol to give a pale yellow solid 1.07 g, 97% yield.
Example 6
Synthesis of 5,5-diphenylisoxazoline carboxylate ethyl ester
[0024] The crude cyclopropane derivative, 2,2-diphenylcyclopropanyl carboxylate ethyl ester (generated through the reported one step procedure as a crude product in 107% yield) (1.14 g, 4.3 mmol) was dissolved in 4.0 mL AcOH at room temperature (18° C.). Into the solution was carefully added 2.0 mL concentrated H 2 SO 4 , followed by adding NaNO 2 (0.33 g, 4.7 mmol, 1.1 eq) in several portions so that the reaction temperature did not excess 40° C. After addition, the reactants were stirred at room temperature (about 18° C.) for half an hour. And the reactants were poured into an iced water and extracted with diethyl ether (2×20 mL), the ethereal solutions were combined and washed with sat. NaHCO 3 (2×20 mL), then water (20 mL) and brine (20 mL) in sequence. The washed ethereal solution was then dried over Na 2 SO 4 . After removing the desiccant, the ethereal solution was concentrated to furnish a thick oily crude product. The 1 H NMR of the crude product showed that the reaction was clean and a virtual 100% yield. The thick oily crude product was stirred with 10 mL petrol to give a pale yellow solid 1.15 g, 91% yield (97% over yield in two steps based on diphenyl ketone hydrazine).
Example 7
Synthesis of 5,5-diphenylisoxazoline carboxylate ethyl ester
[0025] The crude cyclopropane derivative, 2,2-diphenylcyclopropanyl carboxylate ethyl ester (generated through the reported one step procedure as a crude product in 107% yield) (21.3 g, 80 mmol) was dissolved in 80.0 mL AcOH at room temperature (18° C.). Into the solution was carefully added 40.0 mL concentrated H 2 SO 4 , followed by adding NaNO 2 (6.1 g, 88 mmol, 1.1 eq) in several portions so that the reaction temperature did not excess 40° C. After addition, the reactants were stirred at room temperature (about 18° C.) for half an hour. And the reactants were poured into an iced water and extracted with diethyl ether (2×200 mL), the ethereal solutions were combined and washed with sat. NaHCO 3 (2×100 mL), then water (100 mL) and brine (50 mL) in sequence. The washed ethereal solution was then dried over Na 2 SO 4 . After removing the desiccant, the ethereal solution was concentrated to furnish a thick oily crude product. The 1 H NMR of the crude product showed that the reaction was clean and a virtual 100% yield. The thick oily crude product was stirred with 10 mL petrol to give a pale yellow solid 21.7 g, 92% yield (98% over yield in two steps based on diphenyl ketone hydrazine). | A process for producing isoxazoline derivatives by ring-opening and cyclization of the corresponding cyclopropane derivatives with electrophilic nitrosylation reagents. | 21,730 |
BACKGROUND OF THE INVENTION
The invention relates to a semiconductor diode laser--often referred to as laser for short hereinafter--with a semiconductor body comprising a substrate of a first conductivity type and situated thereon a semiconductor layer structure with at least a first cladding layer of the first conductivity type, a second cladding layer of a second conductivity type opposed to the first, and between the first and second cladding layers an active layer and a pn junction which, given a sufficient current strength in the forward direction, is capable of generating monochromatic coherent electromagnetic radiation in a strip-shaped active region situated within a resonance cavity formed between two end faces, the active layer comprising one or several quantum well layers of a first semiconductor material which are mutually separated or surrounded by barrier layers of a second semiconductor material, while the second cladding layer and the substrate are electrically connected to connection conductors and a first portion of the quantum well and barrier layers forming part of the active layer has a compression stress because the semiconductor material in the first portion has a lattice constant which is greater than that of the substrate, and a second portion of said layers has a tensile stress because the semiconductor material in the second portion has a lattice constant which is smaller than that of the substrate. It is noted that the term "barrier layers" also refers to so-called separate confinement layers. The invention also relates to a method of manufacturing such a laser.
Such a laser is known from the U.S. Pat. published under No. 5,373,166 on Dec. 13th, 1994. The laser disclosed therein is manufactured in the InP/InGaAsP material system which corresponds to the wavelength region from 1 to 1.5 μm, and utilizes a Multi Quantum Well (MQW) active layer in which the quantum well and barrier layers comprise a material with a lattice constant which is alternately greater than and smaller than that of the substrate. A greater lattice constant results in a compression stress of the relevant layer, a smaller in a tensile stress. Such a laser has a starting current which is much lower than that of a laser in which all layers exactly match the substrate owing to the influence of the stresses on the shape and position of the valency and conduction band. The known laser is stress-compensated, i.e. the total compression stress is approximately equal to the total tensile stress. In other words, the product of the absolute value of the relative difference in lattice constant and the thickness is the same for both types of layers. Defects in the active layer of the laser will occur less readily thanks to this stress compensation, which benefits useful product life. In addition, such a laser also has a strongly reduced starting current.
A disadvantage of the known laser is that it has too short a life, especially if the laser is manufactured in the GaAs/AlGaAs or the InGaP/InAlGaP material system. This is sometimes a disadvantage in the application in an optical disc system, laser printer, or bar code reader, especially if a high power level is desired there.
SUMMARY OF THE INVENTION
The present invention has for its object inter alia to provide a laser which has not only a low starting current but also a very long life, especially with a comparatively low laser emission wavelength and a high (optical) power emission.
A semiconductor diode laser of the kind mentioned in the opening paragraph is for this purpose characterized in that the relative deviation of the lattice constant compared with that of the substrate and the thicknesses of the two portions of the active layer are so chosen that the total tensile stress in the active layer is greater than the total compression stress, so that part of the stress is compensated and the resulting stress in the active layer is a tensile stress. The invention is based first of all on the surprising recognition that stresses in layers forming part of the active layer are relaxed adjacent the end face. A layer with a compression stress has an increase in its bandgap as a result of this stress, which increase, however, disappears wholly or partly near the end face owing to stress relaxation, so that the bandgap is smaller close to the end face than it is farther away from it. A tensile stress results in a reduction in the bandgap, which again disappears close to the end face owing to relaxation, so that the active layer has a greater bandgap close to an end face in this case. The invention is further based on the recognition that the first case is unfavourable because the absorption of the generated radiation increases near the end face then. The heat generated thereby leads to degradation of the laser. The second case on the other hand is favourable. In fact, an increased bandgap leads to a decreased absorption and thus to a lower degradation, especially a lower so-called end face or mirror degradation of the laser. In the known laser, where both kinds of stress are compensated, the effects thereof and those of any occurring relaxation on the bandgap are compensated. As a result, the known laser has an active layer which has a (substantially) constant bandgap over the entire length of the resonance cavity. In a laser according to the invention, however, which is as it were overcompensated, the bandgap near the end face is greater than elsewhere owing to the net tensile stress. The end face degradation of such a laser is accordingly small and laser life is long, also in the case of a high optical power. In addition, the laser according to the invention profits from the partial compensation of the stresses. This indeed causes the laser to have a particularly low starting current. Furthermore, the active layer of the laser may comprise a comparatively great number of layers or comparatively thick layers each having a stress. This brings with it further advantages, such as a better confinement and a comparatively great wavelength of the generated radiation. The risk of defects arising has already been considerably reduced by the partial compensation. The resulting laser has a particularly long useful life.
It is noted that said effects of a compression or tensile stress on shape and position of valency and conduction bands, and thus on the value of the bandgap, relate exclusively to the influence of mechanical stresses. In practice, the choice of a different lattice constant also implies the choice of a different material--including the choice of a different material composition--which has a much stronger influence on the bandgap. In the case of a compression stress, this means that the bandgap of the active layer is considerably smaller than if there were no stress. In the case of a tensile stress, the bandgap is much greater. The influence of a change in composition, however, is the same over the entire length of the resonance cavity and is unchangeable. Although very important for the direction in which and the degree to which the wavelength of the generated radiation is shifted, the latter effect (which is superimposed on the effects described further above) does not detract from the validity of the discussion in the preceding paragraph.
A method according to the invention whereby on a substrate of a first conductivity type a semiconductor layer structure is provided with at least a first cladding layer of a first conductivity type, an active layer, and a second cladding layer of a second conductivity type opposed to the first, and the active layer is formed by one or several quantum well layers of a first semiconductor material mutually separated or surrounded by barrier layers of a second semiconductor material, the second cladding layer and the substrate being provided with electrical connection conductors, while the first and the second semiconductor material or the compositions thereof are so chosen that a first portion of the layers forming part of the active layer has a lattice constant smaller than that of the substrate, and a second portion has a lattice constant greater than that of the substrate, is characterized in that the values of the differences in lattice constant and the thicknesses of the two portions are so chosen that the opposed stresses in the active layer do not fully compensate one another and the resulting stress is a tensile stress. Lasers according to the invention are obtained by such a method in a simple manner.
In a first embodiment of a laser according to the invention, the first portion of the active layer comprises at least one quantum well layer with a greater tensile stress and the second portion of the active layer comprises at least one barrier layer with a smaller compression stress. The words greater and smaller here mean greater or smaller than the stress in the other portion. The resulting stress depends, as stated above, not only on the degree to which the lattice constant of the relevant layer differs from that of the substrate, but also on the thickness of the relevant layer. This embodiment of the laser has a comparatively low emission wavelength owing to the material effect discussed in the preceding paragraph. The emission wavelength lies, for example, between 630 and 650 nm when this embodiment of the laser is formed in the GaAs/InGaP/InAlGaP material system.
A preferred embodiment of a laser according to the invention is characterized in that the first portion comprises at least one quantum well layer with a smaller compression stress and the second portion comprises at least one barrier layer with a greater tensile stress such that the resulting stress in the active layer is a tensile stress. Such a laser has a comparatively high emission wavelength. It lies, for example, between 650 and 700 nm for a laser in the GaAs/InGaP/InAlGaP material system comprising a quantum well layer of InGaP. Such a laser has a particularly low starting current thanks to the comparatively high emission wavelength. The use of cladding layers having the greatest possible bandgap here in fact implies that the confinement is better than if the emission wavelength were lower.
Preferably, the resulting tensile stress in the active layer of a laser according to the invention is smaller than or equal to approximately 30 nm. %. This means, for example, that the relative deviation of the lattice constant for a layer of 30 nm thickness compared with the substrate is less than -1%. It is avoided thereby that the resulting (tensile) stress leads to defects in the active layer with subsequent degradation of the luminescence.
In a favourable modification, the barrier layers comprise first barrier layers with a small thickness and a great stress and second barrier layers with a great thickness and a small stress. Such a distribution of the stress in the barrier layers over two kinds of barrier layers has the advantage that a great stress is possible while maintaining symmetry around the quantum well layers. This is particularly favourable for the preferred embodiment mentioned above in which the stress, i.e. tensile stress, in the barrier layers must be comparatively great.
A further favourable modification arises when the active layer comprises at least one quantum well layer with a thickness between 4 and 16 nm and at least two barrier layers with a thickness between 2 and 30 nm, the semiconductor material of one of the two portions of the active layer has a relative deviation of the lattice constant compared with the substrate of which the absolute value lies between 0.3 and 2%, and the semiconductor material of the other portion of the active layer has a relative deviation of the lattice constant compared with the substrate of which the absolute value lies between 0.15 and 1%. A symmetrical arrangement is thus possible, and thinner layers may have a comparatively great stress while thicker layers have a somewhat smaller stress. The stresses and thicknesses are so chosen, as noted above, that the product of layer thickness (d) and relative deviation of the lattice constant (Δa/a) is the same for the portions which compensate one another's stresses. Said product (d*Δa/a) is summed for each kind of stress if the kind of stress is distributed over several layers. The excess tensile stress, i.e. the result of the summation is preferably smaller than or equal to 30 nm. %.
In the preferred embodiment mentioned above, a very favourable result is obtained when the at least one quantum well layer has a thickness of approximately 8 nm, the at least two barrier layers have thicknesses between 8 and 30 nm, and the first semiconductor material has a relative deviation in its lattice constant compared with the substrate of approximately +1%, while the second semiconductor material has a relative deviation in its lattice constant compared with the substrate of between -1.0 and -0.5%.
A laser according to the invention may advantageously be manufactured in material systems such as the InP/InGaAsP material system and the GaAs/AlGaAs material system. In the latter case, a compression stress and a tensile stress may be realised through the addition of indium and phosphorus atoms, respectively. Preferably, the laser is realised in the GaAs/InGaP/InAlGaP material system. The substrate may comprise GaAs in that case, the quantum well layers InGaP, the barrier layers InAlGaP, and the cladding layers InAlGaP or InAlP. Lasers are created thereby with emission wavelengths below approximately 700 nm and with excellent properties.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained in more detail with reference to two embodiments and the accompanying drawing, in which
FIG. 1 shows a semiconductor diode laser according to the invention diagrammatically and in a cross-section taken perpendicularly to the longitudinal direction of the resonance cavity,
FIGS. 2 and 3 diagrammatically show a first and a second embodiment, respectively, of the active layer of the laser of FIG. 1, and
FIGS. 4 and 5 show the influence of the invention on the bandgap (E g ) as a function of the distance (S) to an end face for the first and the second embodiment, respectively.
The Figures are diagrammatic and not drawn to scale, the dimensions in the thickness direction being particularly exaggerated for greater clarity. Corresponding parts are generally given the same reference numerals in the various Figures.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a first and a second embodiment of a laser according to the invention diagrammatically and in a cross-section taken perpendicularly to the longitudinal direction of the resonance cavity. The laser comprises a semiconductor body 10 with a substrate 11 of a first, here the n-conductivity type, in this example consisting of monocrystalline gallium arsenide, provided with a connection conductor 9. On this body, a semiconductor layer structure is provided, in this example comprising a buffer layer 12 of n-AlGaAs, a first cladding layer 1 of n-InAlGaP, an active layer 2 of InGaP and InAlGaP, a second cladding layer 3 of p-InAlGaP, a third cladding layer 5 also of p-InAlGaP, a transition layer 6 of InGaP, and a contact layer 7 of p-GaAs. Between the second cladding layer 3 and the third cladding layer 5 there is a pn junction and in this case an intermediate layer 4 which acts inter alia as an etching stopper layer in the formation of the strip-shaped mesa 20 which comprises the third cladding layer 5 and the transition layer 6. A current blocking layer 15 is present here on either side of the mesa 20 and between the intermediate layer 4 and the contact layer 7. During operation, a strip-shaped active region arises within a resonance cavity below the mesa 20 in the active layer 2. Two end faces 30 of the semiconductor body 10, here acting as mirror surfaces and limiting the resonance cavity in longitudinal direction, are parallel to the plane of drawing. The laser in this example is of the so-called index-guided type. The electrical connection of the pn junction situated between the first and the second cladding layer 1, 3 is effected by means of connection conductors 8, 9 on the contact layer 7 and the substrate 1, respectively.
FIG. 2 shows the construction of the active layer 2 of a first example of the laser of FIG. 1. The active layer 2 comprises a single quantum well layer 2A which is surrounded by two barrier layers 2B. According to the invention, a portion of the active layer 2, here the quantum well layer 2A, has a compression stress while another portion of the active layer 2, here two barrier layers 2B, has a tensile stress which is effectively greater than the compression stress, so that the resultant net stress in the active layer 2 is a tensile stress. The stress situation in the active layer 2 necessary for the invention is achieved in this example as listed in the Table below. Δa/a therein is the relative difference in lattice constant compared with the substrate 11 and d is the thickness of the layer in question. The resultant tensile stress in the active layer 2 is: 2*(16)*(-0.5)+1*(8) *(+1)=-8 nm* %, the absolute value of which is smaller, in this case much smaller than 30 nm. %. This means that there is practically no risk of stress-induced defects occurring in the active layer 2. The stress relaxation in quantum well layer 2A and barrier layers 2B which occurs in the laser near the end faces 3 and the overcompensation of the compression stress cause a greater bandgap (E g ) near the end faces 30 in the active layer, so that the absorption of radiation generated in the active region decreases (strongly) near the end face 30. End face or mirror degradation in the laser according to the invention is substantially lower as a result of this than in the known laser, and the former has a considerably improved useful life. Thicknesses and compositions chosen for the two portions of the active layer 2 preferably lie in the domains mentioned in the introductory description. Lasers whose layers have properties lying within these domains yield the favourable results. The Table also contains relevant data on the other layers of the two embodiments of the laser, showing that in this example the active layer 2 also comprises two further barrier layers 2C which act as so-called separate cladding layers 2C and which in this example have the same lattice constant as the substrate 11.
______________________________________ Conc. d Δa/aLayer Semiconductor Type (at/cm.sup.3) (μm) (%)______________________________________11 GaAs N 2 × 10.sup.18 350 012 Al.sub.0.20 Ga.sub.0.80 As N 2 × 10.sup.18 0.1 0 1 In.sub.0.50 Al.sub.0.35 Ga.sub.0.15 P N 5 × 10.sup.17 1.4 0 2A In.sub.0.62 Ga.sub.0.38 P -- -- 0.008 +1.0 2B In.sub.0.42 Al.sub.0.23 Ga.sub.0.35 P -- -- 0.016 -0.5 2C In.sub.0.50 Al.sub.0.20 Ga.sub.0.30 P -- -- 0.030 0 3 In.sub.0.50 Al.sub.0.35 Ga.sub.0.15 P P 3 × 10.sup.17 0.3 0 4 In.sub.0.49 Ga.sub.0.51 P P 1 × 10.sup.18 0.05 0 5 In.sub.0.50 Al.sub.0.35 Ga.sub.0.15 P P 3 × 10.sup.17 1.1 0 6 In.sub.0.49 Ga.sub.0.51 P P 1 × 10.sup.18 0.01 0 7 GaAs P 2 × 10.sup.18 0.8 015 GaAs N 1 × 10.sup.18 0.8 0______________________________________
In FIG. 4, curve 42 represents the bandgap (E g ) of the active layer 2 as a function of the distance (S) to the end face 30 of the laser of this example. Curve 42 shows that the bandgap of the active layer 2 is greater, here by approximately 15 meV, between approximately 10 and 80 nm from the end face 30 than at a greater distance from the end face 30. This means that absorption of radiation generated in the laser in the region adjoining the end face 30 is considerably smaller than in a laser where the compression stress and tensile stress are mutually compensated. In that case, in fact, the bandgap gradient is as shown in curve 41. It should also be borne in mind here that absorption of the generated radiation depends exponentially on the bandgap (E g ). For comparison, finally, curve 40 shows the case where the active layer 2 has a compression stress, exclusively or as a net result, which yields an even worse situation than in the stress-compensated case of curve 41.
The width of the mesa 20 is 5 μm. The length and width of the semiconductor body 10 and the length of the mesa 20 are approximately 500 μm. The conductive layers 8, 9 are of usual thickness and composition. The emission wavelength of this embodiment of the laser realized in the InGaP/InAlGaP material system is approximately 680 nm. The laser is manufactured in a usual manner for the major part. Briefly, manufacture proceeds as follows. The layers 12 and 1 to 6 are provided on substrate 11 in a first growing process. The material compositions and thicknesses in accordance with the invention, here as listed in the Tables, are chosen for the active layer 2 in this case. Then the mesa 20 is formed by etching on both sides of a strip-shaped mask of SiO 2 down to the etching stopper layer 4. In a second epitaxy process, the current blocking layer 15 is provided on either side of the mesa 20, resulting in a substantially planar structure. Finally, after the SiO 2 mask has been removed, the contact layer 7 is provided over the structure in a third growing process. After two-sided metallization 8, 9 and cleaving in two directions, the lasers are ready for use.
FIG. 3 shows the construction of the active layer 2 of a second embodiment of a laser according to the invention having the structure of FIG. 1. The active layer 2 in this example comprises two quantum well layers 2A mutually separated and surrounded by three barrier layers 2B, of which the outermost layers are surrounded by two further barrier layers 2C which act as separate cladding layers. The other layers 12, 1, 3 to 7, 15 and the substrate 11 of the laser are the same as in the first embodiment of the laser. According to the invention, a portion of the active layer 2, here the quantum well layers 2A, has a compression stress while another portion of the active layer 2, here three barrier layers 2B and two further barrier layers 2C, has a tensile stress which is effectively greater than the compression stress, so that the resulting net stress in the active layer 2 is a tensile stress. In this example, the desired stress situation in the active layer 2 has been achieved as indicated in the Table below. The resulting tensile stress is: 3*(8)*(-1)+2*(24) *(-0.5)+2*(8)*(+1)=-32 nm* %, the absolute value of which is approximately 30 nm. %. In this example, the total tensile stress present is distributed over two kinds of barrier layers 2C, 2D. This has the advantage that a great tensile stress is possible while the symmetry around the quantum well layers 2A is maintained. Relaxation of the stress in quantum well layers 2A and barrier layers 2C, 2D occurs close to the end faces 30 also in this embodiment of the laser. Owing to the overcompensation of the compression stress, an increase in the bandgap occurs again near the end faces 30 in the active layer 2, so that the absorption of radiation generated in the active region is (strongly) reduced near the end face 30. The end face or mirror degradation in the laser according to the invention is thus much lower than in the known laser, and the former has a much improved useful life. The wavelength of the generated radiation in this embodiment of the laser is again approximately 680 nm. The stress in the barrier layers 2B, 2C is advantageously distributed in this embodiment. That is to say that the barrier layers 2B are thin and have a high tensile stress, while the barrier layers 2C are thick and have a lower compression stress, which renders it easier to obtain a symmetrical construction.
______________________________________ Conc. d Δa/aLayer Semiconductor Type (at/cm.sup.3) (μm) (%)______________________________________2A In.sub.0.62 Ga.sub.0.38 P -- -- 0.008 +1.02B In.sub.0.35 Al.sub.0.26 Ga.sub.0.39 P -- -- 0.008 -1.02C In.sub.0.42 Al.sub.0.23 Ga.sub.0.35 P -- -- 0.024 -0.5______________________________________
In FIG. 5, curve 53 represents the bandgap (E g ) of the active layer 2 as a function of the distance (S) to the end face 30 for this embodiment of the laser. Curve 53 shows that the bandgap of the active layer 2 is greater by a few tens of meV, here by approximately 25 meV, between approximately 10 and 80 nm from the end face 30 than at a greater distance from the end face 30. This means that the absorption of radiation generated in the laser is much lower in this region than in a laser in which the compression stress and tensile stress are mutually compensated. In the latter case, the bandgap has a gradient as shown with curve 51. Curve 50 shows the case in which the active layer 2 has a compression stress only, which leads to an even worse situation than in the stress-compensated case of curve 51. The influence of the outer barrier layers 2C is illustrated with curve 52. Curve 52 refers to the situation corresponding to the above Table, but with the two outermost barrier layers 2C omitted. In that case, too, the favourable effect according to the invention is present, but to approximately the same degree as in the first embodiment of the laser. Thanks to a net tensile stress which has approximately the maximum admissible value of 30 nm. %, the advantage of the invention in the present example is a maximum in the situation corresponding to curve 53.
The invention is not limited to the embodiments given, many modifications and variations being possible to those skilled in the art within the scope of the invention. Thus different semiconductor materials or different compositions of the chosen semiconductor materials may be used compared with those mentioned in the examples. This relates in particular to the use of the material systems InP/InGaAsP and GaAs/AlGaAs mentioned earlier. Furthermore, the invention is not limited to situations in which the quantum well layers and/or the barrier layers each have only one type of stress. Thus it is possible for quantum well layers with a compression stress and with a tensile stress to be present simultaneously. In that case the emission wavelength of both may sometimes be rendered equal through the use of the quantum effect, i.e. through adaptation of the thickness (ratio) of the quantum well layers.
It is also possible to replace the conductivity types all (simultaneously) with their opposites. Various techniques, such as MOVPE (=Metal Organic Vapour Phase Epitaxy), etc. may be used for providing the semiconductor layers.
The invention is furthermore not limited to the laser embodiment described here which is of the BR (=Buried Ridge) type. The invention may also be used for other types such as the BH (=Buried Hetero) type or the RW (=Ridge Waveguide) type, etc. | The invention relates to a laser with a multi quantum well active layer in which a portion of the quantum well and barrier layers is provided with a compression stress, while another portion is provided with an oppositely directed tensile stress. Said stresses are overcompensated such that the net stress is a tensile stress. Preferably, the laser comprises one or several quantum well layers with a compression stress and a number of barrier layers with an excess tensile stress. | 28,000 |
This application is a continuation-in-part of Ser. No. 883,769, filed Jul. 9, 1986, .Iadd.U.S. Pat. No. 4,797,087, .Iaddend.which is a continuation-in-part of application Ser. No. 755,831, filed Jul. 15, 1985, .Iadd.U.S. Pat. No. 4,642,047, .Iaddend.which is a continuation-in-part of application Ser. No. 642,141, filed Aug. 17, 1984, issued as U.S. Pat. No. 4,622,007; all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to hazardous waste disposal systems, and more particularly to an improved incineration system and method which results in the efficient destruction of liquid and solid wastes in an apparatus including a primary incineration combustion means, at least one afterburner and a flue gas treatment system.
A typical waste incineration system for the destruction and removal of hazardous wastes consists of a primary incineration combustion apparatus, an afterburner and a flue gas treatment system. Additionally, the incineration system may include:
a solid and/or liquid waste feed system;
a system for feeding an auxiliary fuel, usually in gaseous or liquid form;
a system for feeding oxidizer, usually air and sometimes oxygen or an oxygen enriched air;
a system for the evacuation of incombustible solid products of incineration, such as bottom ash;
a system of heat recovery from the hot exhaust combustion flue gases with generation of preheated combustion air of waste incineration units, hot water, steam and/or electricity;
a system for preparing, feeding, recycling and treating any water solutions produced for removal of gaseous and/or particulates in the flue gas treatment system;
a stack for the discharge of treated flue gases to the atmosphere;
a control system including flow, pressure and temperature transducers and controllers for controlling the flow of fuel and oxidizers, process temperatures and pressures at strategic locations in the system; and
a flue gas sampling system.
The primary incineration combustion apparatus for solid and liquid wastes and sludges may be embodied as rotary kilns, multiple hearth furnaces, fluidized bed furnaces, grate furnaces and other combustion apparatus. Liquid and semiliquid pumpable wastes can also be combusted in cyclonic reactors as well as in various burners during the initial thermal destruction step of incineration process.
The rotary kiln is the preferable embodiment of the primary incineration process due to its versatility. It is arranged as a cylindrical refractory lined vessel rotating about a slightly inclined axis. The residence time in the kiln varies from a fraction of a second to several seconds for gaseous materials and from several minutes to several hours for solid materials. Solid wastes can be charged in a kiln either continuously as in the case of shredded material or as a batch charge as in the case of containerized materials such as drums or bundles. Special loading devices are used for charging solid wastes while pumpable liquid wastes and sludges are typically introduced directly into the kiln. The combustible fraction of wastes is partially pyrolysed and oxidized in the kiln. An auxiliary fuel such as combustible liquid waste, oil, natural gas or propane is commonly used for preheating the kiln lining, for providing supplemental heating while combusting low caloric value wastes, and for insuring the combustion stability.
Although the design of other primary incineration combustion units differs from that of a rotary kiln, they typically accomplish the same functions and contain many of the same functional elements as the rotary kilns and exhibit much the same disadvantages as those discussed below for the kilns.
Afterburners are typically cylindrical refractory lined vessels equipped with an auxiliary burner which is fed with a liquid and/or gaseous fuel and an oxidizer. Combustible liquid wastes can be used instead of, or in addition to, the auxiliary fuel. Afterburners are used to insure combustion of organic vapors, soot and other combustible components remaining after the primary incineration process. The afterburners provide a high temperature, highly oxidizing atmosphere with sufficient residence time and mixing of combustible vapors with oxygen to insure the required degree of organics destruction.
The most typical unit for treatment of flue gases leaving the afterburner is a wet scrubber wherein the combustion gases are washed by water or water solutions. Soot and halogens are largely absorbed and sulfur dioxide and nitrogen oxides are partially removed in the scrubber. Some polar organics and organics which are adsorbed in the soot are also partially removed. An alkali is often added to the scrubbing water to increase the efficiency of scrubbing of halogens and sulfur dioxide. Electrostatic precipitators or dust baghouses for often used for removal of the particulates from flue gases.
Heat recovery units are often installed between thermal destruction and flue gas treatment units. Heat of hot combustion flue gases may be used to preheat the combustion air for the primary incinerator and/or afterburner.
Solid and liquid wastes typically contain organic and inorganic combustible constituents. A fraction of organics may be highly toxic, mutanogenic and teratogenic. This fraction of organics is usually called principle organic hydrocarbons (POHC). Many POHCs are very stable and require oxidation at elevated temperatures for their destruction. When wastes are charged into a kiln, a rapid volatilization and partial pyrolysis of organics, including POHCs and water, if any, occurs. The volatilized components of organics require an adequate quantity of oxygen for their oxidation. Fuel and oxygen are also needed to supply heat for vaporization of water and organics and for raising the temperature to required levels.
The appropriate firing rate and combustion air feed rate are selected to provide adequate temperatures and excess oxygen level for the incineration system to achieve the required destruction efficiency of the POHCs for a given type and quantity of wastes. This temperature and excess oxygen level will be maintained by the control system. Other nonhazardous organics present as well as the fuel as usually essentially oxidized when POHCs are oxidized in the primary incineration combustion apparatus; however, new intermediate products may be formed during the combustion process. These products include carbon microparticles, carbon monoxide and an array of organic compounds. Many of these organic compounds are a higher molecular weight polycyclic or polyaromatic organics such as dioxins, benz(a) pyrene, dibenz(a,c)anthracene, picene, dibenz(a,h)anthracene, 7, 12-dimethyl(a)anthracene, benz(b)fluortane, 9,10-dimethylanthracene. These higher molecular weight organics are often called products of incomplete combustion (PICs). PICs are often as hazardous as POHCs. A fraction of PICs becomes absorbed on carbon microparticles. The combined PICs and carbon particles represent soot. Accordingly, soot is also a hazardous product. Carbon monoxide is also a toxic constituent and only a limited quantity of it may be permitted for discharge into the atmosphere. Therefore, the waste incineration steps must insure the thermal destruction of carbon monoxide, soot and PICs in the gaseous phase. Such destruction should be provided prior to the discharge of the combustion gases from the afterburner.
Both the feed rate and the properties of wastes which are fed into the combustion system may vary. Extreme variations in the feed rate occur during the so called batch charge when a substantial quantity of wastes is rammed or otherwise introduced into the apparatus in a short period of time. Gradual variations in the feed rate are also possible for continuously charged waste streams. The operational objective of an incineration system is to maximize the amount of waste passing through the system while minimizing the amounts of discharged flue gases, POHCs, and PICs. Generally, the maximum allowable concentrations of pollutants in the flue gases are specified in the operating permit which is based on the current environmental requirements and regulations.
In order to achieve this operational objective high temperatures, sufficient retention time and high turbulence should be provided in both the primary incineration combustion apparatus and the afterburner. Typically, the kiln temperature ranges from 750° C. (1400° F.) to above 1100° C. (2500° F.). The residence time for gases in both the kiln and the afterburner ranges from a fraction of a second to several seconds. Turbulence in either the kiln or the afterburner is not defined quantitatively, however. It is usually assumed that mixing is sufficient to heat adequately all elementary streams of gases and to provide a sufficient contact between organics and oxygen molecules in the furnace. In order to insure the sufficient contact between organics and oxygen, an excess of combustion air in the range of 5% to 200% of stoichiometric is commonly used.
Temperature, retention time, level of excess air and turbulence in the primary incineration combustion apparatus and afterburner effect the destruction efficiency which may be maintained during the operation of a conventional incineration system. An increase in any of these parameters will enhance the destruction efficiency. Attempts to improve destruction efficiency by increasing one or more of the above parameters, however, has not proven to be effective utilizing currently available incineration systems because of a corresponding drop in one of the parameters as one of the others is increased. For example, a higher level of excess oxygen provided by an increase in the air feed results in a lower temperature and lower retention time of gases in the furnace. An increase of the temperature by raising the amount of auxiliary fuel results in increase of combustion product volume which reduces retention time.
The incompatible nature of these parameters in existing incineration systems has limited the capability of existing incineration systems to dynamically intensify the incineration process to overcome transient process malfunctions leading to process failures. Typical transient malfunctions resulting in incineration process failure modes are described below using the kiln as an example for the primary incineration apparatus.
When wastes are charged in large batches or when loading rates of liquids and sludges are rapidly increased, the quantity of oxygen present in the kiln and the amount of oxygen being fed into the kiln during the rapid vaporization stage typically is not sufficient for complete combustion to occur, resulting in an overcharging failure. Only a fraction of combustible constituents of wastes, including POHC, is completely oxidized, forming CO 2 and H 2 O. The remaining organics are partially pyrolyzed and oxidized, thus forming carbon microparticles, CO and PICs. Vaporized fractions of POHCs and of wastes together with carbon microparticles, CO and PICs formed are transferred in an increased amount into the afterburner, so that afterburner is also overloaded. Meeting the oxygen requirements during the overload period in the kiln by substantially increasing the level of continuous combustion air feed rate would result in a shortening of the retention time for volatilized and partially pyrolyzed products in the kiln and may degrade the flame stability. This problem is aggravated by the fact that the substantially excessive air feed brings along extra nitrogen which absorbs a portion of the heat generated in the kiln, thus reducing the heat available for the process and, correspondingly, the temperature level resulting in reduced destruction efficiency of organics.
When a portion of the waste charged into the kiln during a certain time period has lower caloric value than the expected design value, the kiln temperature can decline due to reduced heat release. This may lead to the formation of cold spots in the furnace when local temperatures decrease below the ignition point for some organics. The result is a low temperature failure mode with a substantial breakthrough of the original organics which cannot be destroyed at lower temperatures. A drastic increase in PIC formation may also occur due to quenching of pyrolytic products forming from the original wastes and fuel.
Other failure modes may occur as a result of poor atomization of liquid wastes and poor mixing of wastes with available oxidizers. Poor atomization of liquid wastes leads to increased size of droplets resulting in incomplete combustion while poor mixing may provide an opportunity for the volatilized wastes to short circuit the combustion process, avoiding adequate contact with an oxidizer. Both of these failure modes result in products of incomplete combustion being transferred to the afterburner.
Flameout failure modes predominantly occur at unfavorable aerodynamic conditions in the combustion zone. High velocities of gaseous products near the burner during low fire conditions, a deficiency of oxidizer, and excessive infiltration of cold ambient air in the combustion apparatus are typically events which cause flameout. Excessive increase in the ambient air moisture content and the high moisture of the wastes being charged may be other sources of low temperature or flameout failure.
Failure modes similar to those described above for the kiln may also occur in the afterburner. In addition, overcharging, low residence time, low temperature, poor mixing, the cold wall effect, flameout and poor atomization in the kiln will always result in an increased PICs loading rate on the afterburner, and subsequently, in a lower thermal destruction efficiency overall for existing incineration systems.
Conventional incineration systems are hindered in their ability to address failure modes because the kiln, the afterburner, if used, and the air pollution control system are designed to operate in steady state conditions ignoring the existence of transient process disturbances which result in failure modes. Existing incineration systems are also unable to anticipate transient operational changes of the several individual elements of the incineration system. For example, they are not capable of rapidly boosting temperatures and oxygen content in the afterburner to overcome failure modes in the primary combustion apparatus.
Several attempts have been made to improve thermal destruction efficiency by enriching combustion air in the primary incineration means with oxygen (see, for example, U.S. Pat. Nos. 4,520,746; 4,462,318 and 4,279,208). The advantage of oxygen use in incineration processes is based on the reduction in the volume of nitrogen introduced into the incineration process. This reduction in the volume of nitrogen decreases the amount of heat stored in the nitrogen molecules making additional heat available for waste destruction and for increasing the temperature in the kiln. In addition, the use of oxygen reduces the quantity of gases flowing through the kiln, thereby increasing the residence time and the efficiency of destruction of persistent organics.
The use of oxygen in the waste incineration processes helps to stabilize combustion and to eliminate the possibility of failures related to low temperature, insufficient residence time and the negative impacts of low caloric wastes. However, the steady flow of additional oxygen may be only marginally effective in cases of transient overcharging, poor atomization and poor mixing, which are the failure modes most prone to the breakthrough of POHCs and formation of PICs. Permanently maintaining an elevated oxygen feed rate can result in overheating of primary incineration combustion apparatus and in damage to the metal parts and refractories. Moreover, an increased oxygen feed results in added operational costs. Although the additional use of a permanent oxygen flow may improve the destruction efficiency of kilns and afterburners, it cannot solve the problems related to the transient changes such as those caused by batch charging, poor atomization and poor mixing. This also cannot help to optimize the destruction efficiency at a given capacity or to maximize the capacity of the facility at a given or required efficiency. Existing methods cannot reconcile the conflict among the desired factors of high temperature, retention time, turbulence, and oxygen level in furnaces.
There exists, therefore, a need for an incineration system and method which results in the efficient destruction of liquid and solid wastes.
Further, there exists a need for a system and method which solves the problems related to the transient changes such as those caused by batch charging, poor atomization and poor mixing.
Also, there exists a need for a system and method capable of identifying critical prefailure conditions of the process and providing optimum levels of fuel, oxygen and air to be fed into the system.
SUMMARY OF THE INVENTION
The present invention relates to a waste incineration system comprised of a primary incineration combustion means which preferably includes a kiln, an afterburner means, and a flue gas treatment means. Both the incineration means and the afterburner means may utilize at least two oxidizing gases having different oxygen concentrations, for example, oxygen and air or oxygen and oxygen enriched air. By varying the ratio of these oxidizers the amount of total oxygen and nitrogen delivered in either the primary incineration combustion means, the afterburner means, or both can be adjusted. In the course of this adjustment the required temperature, retention time, turbulence and oxygen supply level can all be provided simultaneously and without negative side effects.
Additional oxidizing agents can be optionally used. For example, water or steam may be introduced to reduce soot and NO x formation. Additionally, water can be used for the temperature control in either the primary incineration apparatus or in the afterburner. Ozonated oxygen or air may also be used as an initiator of chain reactions.
Dynamic variations in the rates of feed of these different oxidizing gases insures the optimization of the combustion process so that the quantity of oxygen and nitrogen and water supplied conforms with that required for complete combustion whenever fluctuations in the demand for oxygen for combustion of waste occurs. In particular, such fluctuations are related to charging of large batches or other transient events that may potentially reduce the efficiency of thermal waste destruction.
Improvements in incineration processes by the use of oxygen may be achieved with the use of traditional combustion apparatus such as oxy-fuel burners, oxygen enriched burners and oxygen lances. Further improvements can be accomplished by the separate introduction of two different oxidizing gases such as air and oxygen into the combustion tunnel of the burner, as previously described in U.S. Pat. No. 4,622,077 and U.S. Pat. .[.[number currently corresponding to allowed application Ser. No. 755,831].]. .Iadd.No. 4,642,047.Iaddend.. In accordance with these patents, the oxygen stream is introduced primarily as a high pressure, high velocity jet or jets directed through the hot core of the flame. The excess oxygen directed throughout the flame core has a substantially elevated temperature as compared with excess oxygen being introduced around flame pattern in a mixture with combustion air into a primary incineration combustion apparatus. Such hot oxygen has an increased ability to oxidize organics. Additionally, the axial introduction of a high velocity oxygen stream enveloped by fuel and/or fluid waste stream which in turn is enveloped by air or oxygen enriched air, insures a more effective mixing of combustible components of the fuel and/or of the waste stream inside the flame pattern, thus reducing NO x and PICs formations. The transport of oxidizer toward the fuel or liquid waste particles in the flame pattern is also intensified due to better conditions for mixing of oxygen with combustibles from both outside and inside the flame pattern.
Stable combustion under dynamically changing operational conditions may be provided by the use of a burner described in U.S. Pat. .[.application No. 883,769.]. .Iadd.No. 4,797,087.Iaddend.. This burner design provides a high temperature oxidizing gas being delivered for incineration purposes through a controllable flame pattern capable of uniform heating of the primary incineration combustion means and the afterburner means. This increased controllability reduces the possibility of cold spot formation or local overheating of the incineration system. Additionally, the high flame velocity of this burner is used to improve mixing and to reduce short circuiting.
The present invention also includes a dynamic control system containing transducers for measuring process variables such as temperature, pressure and flows of fuel, fluid waste, oxidizing gases and hot combustion products in order to identify critical prefailure conditions of the process based on signals received from the transducers and on such signals received by the process controller. The system prescribes the new "emergency" levels of fuel, oxygen and air to be fed into the primary incineration combustion means and the afterburner means to bring the process back to the desired mode of operation and to prevent process failure. Fuel, oxygen and air are supplied to the primary incineration combustion means by a gas train system containing the necessary valves and actuators communicating with the computerized control system to control fuel, oxygen and air flows according with the prescription of the process controller.
The present invention also relates to a method of waste incineration including the steps of identifying transient prefailure events and responding to such events by properly raising the ratio between the "emergency" amounts of oxygen and nitrogen being delivered into the afterburner means. An increase in the oxygen/nitrogen ratio immediately increases the temperature of the gaseous atmosphere of the afterburner vessel due to reduction of the ballast nitrogen flow. Also, a reduction in the nitrogen feed into the process results in an increase of the residence time for waste destruction and, therefore, in an improved destruction efficiency of the afterburner.
A further step in response to prefailure modes may be a rapid decrease of the flow of fuel being introduced in primary incineration means, without creating a problem with flame stability, to slow down the rate of volatilization in the primary incineration combustion means, to increase the quantity of oxygen available for the oxidation of the wastes and to further increase the retention time, simultaneously.
When two oxidizing gases are also utilized in the primary combustion incineration means, similar "emergency" changes in flow rates of these oxidizing gases may be implemented. If during an "emergency" operation, the kiln or afterburner temperatures rise for a prolonged period of time to a level above that allowable for the refractories, water or steam injection may be used for cooling purposes.
Mixing in the gaseous atmosphere and heat transfer in the afterburner means may be improved by tangentially feeding flue gases exhausted from the primary incineration combustion means into a vortex chamber of the afterburner vessel, thus eliminating short circuiting. Introduction of a high velocity flame in the afterburner may be arranged to create a venturi effect to move the entering stream of combustion products into the combustion chamber with less of a pressure drop. Alternatively, the flue gases may be fed into the vortex chamber axially, while a burner is fired into this chamber tangentially so that the hot exhaust gases from the primary combustion means are enveloped by and mixed with the hot oxidizing gases discharged from the burner.
The present method and apparatus are also capable of minimizing unplanned shutdowns of the incineration system and inappropriate transient releases of the POHCs and PICs to the atmosphere during shutdowns and transient surge conditions such as those caused by batch charging or unexpected changes in the caloric value of the waste as well as by other system malfunctions.
Other advantages of the invention will in part be obvious and in part appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a process flow diagram of an incineration system.
FIG. 2 is a longitudinal cross-sectional view of a burner mixer chamber used in the afterburner means.
FIG. 3 is a side cross-sectional view of a vortex chamber taken along lines 3--3 in FIG. 2.
FIG. 4 is a longitudinal cross-sectional view of an alternative burner mixer chamber used in the afterburner means.
FIG. 5 is a side cross-sectional view of a vortex chamber taken along line 5--5 in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention, comprising a primary incineration combustion means, an afterburner means and flue gas treatment system means, is now described with reference to the drawings in which like numbers indicate like parts throughout the views.
Apparatus
FIG. 1 shows a flow diagram including a primary incineration combustion vessel, or kiln 1, which is a part of the primary incineration combustion means 70, and a means for providing containment for combustion and destruction 2 connected to the kiln by a connecting duct 5. A fluid waste burner 3 is attached to kiln 1, preferably a watercooled burner as described in detail in U.S. Pat. .[.application Ser. No. 833,769.]. .Iadd.No. 4,797,087.Iaddend.. A means for feeding solid wastes 29 is attached to kiln 1. The burner 3 has a waste port 9 for the introduction of pumpable fluid wastes, a first gas port 6 for the introduction of a first oxidizing gas (for example, air), a second gas port 7 for the introduction of a second oxidizing gas having a different oxygen concentration from the first oxidizing gas (for example, oxygen), a fuel port 8 for the introduction of an auxiliary fuel, a water port 30 for the introduction of cooling water, and a cooling water discharge outlet 31. A collecting container 4 for ash residue is connected to kiln 1. A first flame supervising means 18 which determines the existence of a flame, such as an ultraviolet sensor, is built into the burner 3.
FIGS. 2 and 3 show a vortex mixing chamber 10 attached to the containment means 2 which receives hot flue gases from the kiln 1 by flue gas inlet 11. A first oxidizing gas, for example oxygen, is supplied through a first oxidizing gas inlet 13 to the fluid waste burner 26, and then into vortex mixing chamber 10. A second oxidizing gas having a different oxygen concentration from the first oxidizing gas, for example air, is supplied to the burner 26 through a second oxidizing gas inlet 12. Auxiliary fuel is supplied through an auxiliary fuel inlet 14. Pumpable fluid waste may be supplied in some cases through a liquid waste inlet 15. Cooling water for the liquid waste burner 26 is supplied through a cooling water inlet 16 and evacuated through a cooling water discharge outlet 17. A second flame supervising means 19 is used to identify the existence of the flame. The burner 26 is preferably designed as described in U.S. Pat. .[.application No. 883,769.]. .Iadd.No. 4,797,087 .Iaddend.to maintain a hot stable flame core during continuous incineration operation, to prevent flame failure and to minimize NO x formation.
FIGS. 4 and 5 show an alternative afterburner means which includes a vortex mixing chamber 101 with inlet 102 for flue gases fed from the primary combustion means 1 and a burner 103 which is similar in design to burner 26. Burner 103 is equipped with lines 104 and 105 for feeding primary and secondary oxidizing gases such as oxygen, oxygen enriched air or air, 106 for an auxiliary gaseous fuel and 107 for an auxiliary liquid fuel, and 108 and 109 for cooling water.
Referring again to FIG. 1, temperatures of combustion products exhausting from the kiln 1 are registered by a first thermocouple 20. Temperatures in the afterburner vessel 55 of containment means 2 are registered by a second thermocouple 21. The absolute pressure and the effluent flue gas flow rate from the kiln 1 are determined by first and second transducer 22 and 23, respectively, and the absolute pressure and the effluent flue gas flow rate from containment means 2 are monitored by third and fourth transducers 24 and 25, respectively.
A control system for detecting and adjusting to operational conditions in the apparatus is provided. The system includes a feed indicating means 33 for indication to a control means 34 of a batch charge approaching the feeding means 29. The feed indicating means 33 may be arranged, for example, as a limit switch which is energized when the batch charge passes its location. The control means 34 communicates with the feed indicating means 33. The control means 34 receives signals from thermocouples 20 and 21, electrical flow transducers 23 and 25, and pressure transducers 22 and 24. An optional smoke detection means 35 may be used to detect smoke in combustion products entering the flue duct 5. Such detection means 35 may include an ultraviolet flame detector or an electrical opacity sensor communicating with the control means 34. The control means 34 is also connected to operate a first air flow modulating means 47 on the first air line 80, a second air flow modulating means 51 on the second air line 81, a first oxygen flow modulating means 48 on the first oxygen line 82, a second oxygen flow modulating means 50 on the second oxygen line 83, a first auxiliary fuel flow modulating means 52 on the first auxiliary fuel line 84, a second fuel flow modulating means 49 on the second auxiliary fuel line 85, a first waste flow modulating means 36 on the first pumpable fluid waste line 86, and a second waste flow modulating means 37 on the second pumpable liquid waste line 87. The instant input flows to burner 3 are sensed for feedback control of the inputs by control means 34 as follows: air is measured by the first air flow metering means 38; oxygen is measured by the first oxygen flow metering means 39; auxiliary fuel is measured by the first auxiliary fuel flow metering means 41; and, pumpable wastes are measured by the first waste flow metering means 40. Similarly, for the second burner means 26, instant flow of air is measured by the second air flow metering means 45; oxygen is measured by the second oxygen flow metering means 44; auxiliary fuel is measured by the second auxiliary fuel flow metering means 43; and, pumpable wastes are measured by the second waste flow metering means 42.
The burner means 26 is fired into the interior of the vortex mixing chamber 10, shown in FIGS. 2 and 3, which is filled with hot flue gases being delivered from the kiln 1. The flue gases preferably enter tangentially to the interior 27 of the vortex mixing chamber 10, shown in FIGS. 2 and 3, thereby causing a rotating mixing movement. The flame of the fluid waste burner means 26, along with a controlled amount of excess oxygen, is directed through the burner combustion chamber 28 at high velocity, thereby creating a venturi effect for inspirating the kiln flue gases into the flame directed toward the afterburner vessel 55. This creates intensive mixing of the gaseous stream prior to entering a refractory lined afterburner vessel 55 of the containment means 2.
Referring now to FIGS. 1, 4 and 5, there is shown an alternative embodiment of the afterburner. This afterburner consists of a vortex mixing chamber 101 with inlet 102 for the flue gas transferred from the primary incineration means 1 and outlet 110 for transferring the hot gases in the afterburner vessel 55. The burner means 103 is tangentially attached to the vortex chamber 101. The burner means 26 has inlets 107, 104, 106 and 105 for feeding a combustible fluid (waste or fuel), a first oxidizer such as oxygen, an auxiliary fuel (when needed) and a second oxidizer, such as air, respectively.
Means for feeding additional amounts of oxygen 120 may also be provided. This means 120 allows oxygen to be fed directly into the vortex mixing chamber 101, if desired, rather than through input port 104. The vortex chamber 101 is attached to the afterburner vessel 55 by outlet 110 and is connected to the flue gas duct 5 by inlet 102. Alternatively, means 120 may be attached to the contracted section of the outlet 110. Additionally, a secondary burner similar to burner means 120 may be installed downstream of means 26. A further modification of afterburner shown in FIGS. 4 and 5 may include two or more consecutive rapid mix chambers similar to vortex chamber 101, having preferably burner means similar to means 103. These rapid mix chambers are communicating with each other by apertures allowing the flow of gases from the first rapid mix chamber into the second and following rapid mix chambers. Optionally, water or steam feeding means may be provided in either first, or second or all rapid mix chambers. Said rapid mix chambers may include afterburner vessels communicating with each mixing chamber to provide additional retention time.
Operation
Referring now to all of the figures, the operation of the system will be described. Solid waste may be continuously or batch charged into kiln 1 through feeder 29. At the same time pumpable fluid waste may be introduced for incineration through the waste port 9 into the fluid waste burner 3 and further with a flame into the kiln 1 interior.
For lower caloric value waste streams, auxiliary fuel may be introduced through auxiliary fuel port 8 into the burner 3 and further directed through the burner combustion chamber 28 towards the kiln 1 interior. A first oxidizing gas with low oxygen concentration (for example, air) enters the burner through first gas port 6 and is further directed through the burner combustion chamber 28 toward the kiln 1 interior. A second oxidizing gas with higher oxygen concentration (for example, oxygen) may be supplied from a liquid oxygen tank or from an on-site oxygen generation unit through second gas port 7 to fluid waste burner 3 and further through burner combustion chamber 28 toward kiln 1 interior.
To satisfy the required temperature in kiln 1 measured by thermocouple 20, the waste feeding rate, the auxiliary fuel flow and the first and second oxidizing gas flows to burner 3 and kiln 1 are maintained essentially constant during steady state operation. The kiln 1 temperature has to exceed sufficiently the temperature of volatilization of all organic components of the waste to a gaseous state during the solids retention time in the kiln 1. Additionally, the temperature should be above the ignition point of volatilized components originating from solid waste as well as combustible components formed during pyrolysis of pumpable waste and auxiliary fuel so that said volatilized combustion components undergo thermal destruction.
At the same time, the total amount of oxygen being delivered with oxidizing gases into the kiln 1 has to be kept high enough to insure its availability to completely combust auxiliary fuel and fluid waste, and to provide extra oxygen flow to destroy the bulk of combustible components being formed in the interior of the kiln 1.
Flue gases exhausted from the kiln 1 are directed into the first vortex mixing chamber 10 through flue gas inlet 11 and further throughout the interior 27 of the vortex mixing chamber 10 toward the interior of the afterburner vessel 55. At the same time, pumpable fluid wastes may be incinerated by introduction through liquid waste inlet 15 into combustion chamber 28 of the fluid waste burner 26 and further through the interior 27 of the vortex mixing chamber 10 toward the refractory lined vessel 55 of the containment means 2. Auxiliary fuel may be introduced when needed to insure flame stability and/or additional heat input to maintain the required afterburner temperature (for instance, as required by regulations), through auxiliary fuel inlet 14 into burner 26 then throughout burner combustion chamber 28 and further through the interior 27 of the mixing chamber 10 toward afterburner vessel 55. The first oxidizing gas with a higher oxygen content (for example, oxygen) than second oxidizing gas is directed into the burner 26 through the first oxidizing gas inlet 13, and further throughout combustion chamber 28, thus discharging hot oxidizing agent originated as auxiliary combustion products from the flame envelope of burner means 26 toward the interior 27 of vortex mixing chamber 10 and further toward afterburner vessel 55. A second oxidizing gas with low oxygen content (for example, air or oxygen enriched air) is directed into burner 26 through the second oxidizing gas inlet 12 and further throughout combustion chamber 28 thus discharging said hot oxidizing gas agent toward the interior 27 of the mixing chamber 10 and further toward afterburner vessel 55. At least 2% to 3% of residual oxygen content in the combustion gases leaving afterburner preferrably should be provided during steady-state operating conditions.
Referring now to FIGS. 4 and 5, an alternative embodiment of the vortex chamber will be operated as follows: The flue gases from the primary combustion means will be fed axially into the vortex mixing chamber 101 through inlet 102. The burner means 103 will be fed with a combustible fluid (waste or fuel), a first oxidizer such as oxygen, and a second oxidizer, such as air, or oxygen enriched air, through ports 107, 104 and 105, respectively. Auxiliary fuel may also be fed through port 106 when needed. The burner means 103 fires tangentially into mixing chamber 101 so that the hot auxiliary combustion product which may be, depending on operational mode, a hot oxidizing or reducing agent, originating as hot auxiliary combustion product from the flame envelope of burner means 103 mix with the flue gases fed from the primary combustion means 1 in the vortex chamber. Several operational modes of afterburner may be used. The selection of the operation mode depends on the composition of flue gases fed in the afterburner and environmental regulations.
When substantial quantities of POHCs, PICs, soot and CO are expected in the flue gases fed in the afterburner and NO x is of no concern, the burner means 26 is fired to produce a hot oxidizing auxiliary combustion product. Under this operational conditions, heat and oxygen are added to the flue gases in the afterburner, thus providing the required destruction of POHCs, PIC, soot and CO. In order to reduce NO x formation in the burner means 26, a fraction of oxidizing gas can be fed downstream of the hot flame zone at the burner means 26 by the use of the oxidizer injecting means 120.
When in addition to POHCs, PICs, soot and CO the concentration of NO x must also be controlled, the operation of the afterburner may be further improved as follows. The burner means 26 will be fired using fuel rich conditions to produce hot reducing auxiliary combustion products rich with CO and H 2 . Since CO and H 2 are selective reducing species for NO x , NO x will be reduced while oxygen in the flue gases will be consumed to a lesser extent. Simultaneously POHCs and PICs will undergo a further thermal destruction due to the additional heat provided with the hot reducing auxiliary combustion products generated in the burning means 26. By feeding additional oxidizing gas through the injecting means 120 downstream of the flame zone of the burner means 26, additional oxidative destruction of POHCs, PICs, soot and CO will be achieved to satisfy environmental regulations. A further improvement of this operating mode may be accomplished by the injection of a hot oxidizing auxiliary combustion product by the use of burner means similar to means 26 instead of or together with injecting a plain oxidizer by means 120. In this improvement additional heat is provided simultaneously with oxygen. A further improvement of this operating mode may include injection of water or steam into the burner means 26 thus increasing the CO and H 2 content in the hot reducing auxiliary combustion products.
When multiple consecutive rapid mix chambers are used, the chambers at the head of the afterburner can be fed with hot reducing auxiliary combustion products while the final stages will be fed with hot oxidizing auxiliary combustion product thus insuring NO x reduction and POHCs, PICs, soot and CO destruction.
Said hot auxiliary oxidizing combustion products have high temperatures and high momentum and provide high turbulence, extra heat to raise mix temperature and excess oxygen. As a result, rapid and uniform mixing occurs in chamber 101 and a final hot combustion product with at least 2% to 3% of residual oxygen is transferred through outlet 110 into afterburner vessel 55, wherein the required retention time is provided Such operation of afterburner insures accelerated burning of residual POHCs, CO, soot and gaseous PICs and provides higher destruction efficiency than that achievable with air above.
A negative pressure will be maintained in the kiln and in the afterburner in order to prevent gas leakage outside the system. An exhaust fan is used for creating the required negative pressure.
In the preferred embodiment and its operation, the ratio of air to oxygen or oxygen enriched air, the fuel feed rate and the oxygen excess level are selected for a particular composition and a particular feed rate of waste so that the required temperature, retention time, partial pressure of oxygen and turbulence in the afterburner and in the kiln are provided and the required destruction efficiency of POHCs is insured to comply with environmental standards.
The desired settings for temperature in the kiln and the afterburner, the maximum flow rates of combustion products from the kiln and the afterburner, and the safe level of negative pressure in the kiln and the afterburner vessel will be entered by the operator into the controller means 34.
Control means 34 will maintain the temperature of combustion product exhausted from the kiln according to a set point chosen by the operator. When temperature measured by thermocouple 20 drops below the desired set point, control means 34 will increase the amount of auxiliary fuel being delivered to the burner by raising the instant for setting for the auxiliary fuel supply line and accordingly on oxygen supply line so that the chosen oxygen excess level is provided until the temperature measured by thermocouple 20 has reached the desired set points chosen by the operator. Similar temperature control is provided for burner 10 of containment means 2.
At the same time, the control means 34 continuously compares the pressure measured by pressure transducer 22, with the pressure set point chosen by the operator as required to maintain a safe negative pressure condition within the kiln, insuring that any looseness in the kiln will result in a leakage of ambient air into the kiln rather than a leakage of combustion products from the kiln. Anytime the negative pressure measured by the pressure transducer 22 exceeds the safe set point chosen by the operator, the control means 34 will reduce the air flow set point and raise the oxygen flow set point in such fashion that each 4.76 volumes of air will be substituted by approximately 1 volume of oxygen fed in kiln 1 maintaining the total amount of the oxygen feed approximately constant until the negative pressure reaches the safe set point. Similar pressure regulation involving pressure transducer 24 is utilized in the afterburner.
To insure a maintenance of the desired retention time and to avoid additional air pollution volumes being produced in the kiln, the control means 34 continuously compares the allowed combustion product flow setting for the kiln discharge with the actual flow being measured by the flow transducer 23. When the actual flow exceeds the allowed set point chosen by the operator, the control means 34 reduces the air flow and increases the oxygen flow supplied to burner 1 in such a manner that the reduction in every 4.76 volumes of air flow will result in approximately a 1 volume increase in oxygen flow maintaining the total amount of the oxygen feed approximately constant until the combustion product flow reaches the allowed flow rate.
The control system 34, by means of thermocouples 20 and 21, will recognize an excessive increase in combustion product temperatures which result from the adjustments in pressures and flows and will reduce auxiliary fuel flow to bring the temperatures down to the desired levels. Simultaneously with the reduction of the auxiliary fuel flow, the oxygen flow will be reduced according to the approximately stoichiometric fuel/oxygen ratio.
Additionally, feed forward controls may be preferrably used for both the primary incineration combustion means and containment means 2 when solid wastes are batch charged. Prior to the feeding of a batch charge, the feed indicating means 33 located upstream of the loading chute of feeding means 29 transmits a signal to the controlling means 34 identifying that a charge is approaching loading chute 29. In response, the control means 34 changes air, oxygen and auxiliary fuel set points to a special "emergency" set of values, insuring the supply of additional excess oxygen during such transient loading conditions, and activates modulating means 47-52 so that the feeding of air is reduced and the feeding of oxygen is increased in both the kiln and the afterburner prior to loading of the incineration system, resulting in a rapid rise in oxygen concentration in the kiln and afterburner as well as the temperature in the afterburner. The emergency set of values should provide for maximum prestored oxygen mass in the primary combustion incineration means and afterburner while maintaining the flame stability, as well as the required temperatures and retention time of gases during the transient event. The excess mass of oxygen accumulated in the kiln 1 in anticipation of the approaching batch charge is utilized to provide sufficient oxidizer during the first stage of waste charge volatilization. Optionally, the auxiliary fuel feed and/or the liquid waste feed delivered to primary incineration combustion means may also be reduced while maintaining the temperature in the kiln under venting conditions substantially above the temperature of ignition of organics in the waste to be charged, thus leaving more oxygen in the kiln volume available for incineration of a batch of wastes, and increasing the retention time for gaseous products in the kiln.
When the batch charge enters the kiln 1, there exists a substantial prestored oxygen mass in the primary incineration combustion means as well as the afterburner and the temperature conditions necessary for the combustion of organics in said batch in the primary incineration combustion means and afterburner. The levels of oxygen, air and fuel feed will be returned to those corresponding to the nominal feeding rates when the destruction of volatilized organics created during the transient overload condition is complete. The duration of such "emergency" cycle can be predicted by experience and the timer of control means 34 will maintain the initial duration setting of such "emergency" transient air, auxiliary fuel and oxygen flows based upon this prediction maintaining maximum partial pressure of oxygen and temperature in afterburner. During such an "emergency" cycle, thermocouples 20 and 21 may indicate temperature levels beyond steady state opening conditions. However, the control means 34 will overrule these signals during an "emergency" cycle so that overheating for a short time period is allowed
After the "emergency" cycle ends, the control means 34 begins an "approaching cycle" which is designed to change gradually the auxiliary fuel flow and the oxygen flow towards a steady state ratio first in primary incineration combustion means and then in the afterburner. If during such cycle the smoke indicating means indicates smoke formation, the increase in the fuel flow will be discontinued but the oxygen flow will be raised again for a preset short time interval. After this time interval elapses, the "approaching cycle" will be initiated again. The control system will repeat the approaching cycle until the smoke is eliminated and the temperature and the level of excess oxygen in the kiln reach a normal level for steady operation. After such event the additional flow of oxygen being supplied to the afterburner to insure the complete combustion of any excess PICs during transient loading in the kiln will be discontinued and the afterburner will reach steady operational conditions. Proper temperature will be further maintained by thermocouples 20 and 21 and by control means 34.
Sensor means 20, 22, 23 and 35 located after the exit from kiln 1 and prior to containment means 2 will provide feedback control of the primary incineration combustion means and feed forward control of the afterburner means during the incineration process. These means supply electrical signals to control means 34 indicating the temperature, pressure or flow rate of gas leaving kiln 1 or the presence of excess smoke or flame. These signals are received and interpreted by control means 34, which in turn changes the oxygen, air and fuel flow into the kiln 1 and/or containment means 2.
Signals from thermocouples 20 and 21 are continuously compared with desired set points by the control means 34. A decrease or increase of the kiln 1 temperature beyond a desired set point triggers an increase or decrease, respectively, in the flow of auxiliary fuel by the use of the first fuel flow modulating means 52. The afterburner temperature is measured with thermocouple 21 and is compared by the control means 34 with a desired set point. A decrease or increase of the afterburner temperature beyond the desired set point triggers an increase or decrease, respectively, in the flow of auxiliary fuel by the use of the second fuel flow modulating means 49. An increase or decrease in the auxiliary fuel flow into the primary incineration combustion means 70 or the containment means 2 will be identified by control means 34 through communication with flow metering means 41 and 43. The control means 34 will also respond by adjusting the flow of oxygen to control the proper ratio between auxiliary fuel and oxidizer.
In order to prevent excess flue gas discharge from the incineration system, the control system will raise the flow of oxygen and reduce the flow of air based upon signals from the transducers 22, 23, 24, and 25 indicating that an excess amount of flue gases are being generated.
When the sensor means 35 detects excessive smoke or flame existing in the flue exhaust duct 5, indicating to the control means 34 a deficiency of oxygen in kiln 1, the control means 34 will activate first oxygen flow modulating means 48 to increase the oxygen supply and modulating means 52 and 36 to reduce auxiliary fuel flow and/or pumpable waste. When the second sensor means 65 detects excessive smoke or flame existing in the flue exhaust duct 32 indicating to the control means 34 a deficiency of oxygen in the containment means 2, the control means 34 will activate second oxygen flow modulating means 50 to increase the oxygen supply and modulating means 49 and 37 to reduce auxiliary fuel flow and/or pumpable waste.
Within the allowed magnitude of the batch charge and gradual fluctuations in the flow rate and composition of wastes, the process insures the required destruction efficiency of POHCs, prevents formation of PICs and minimizes formation of NO x due to the following features:
(a) The controlled oxygen to air ratio permits the change in the oxidizer flow in order to meet the oxygen demand and simultaneously to maintain the required temperature, retention time and turbulence. This eliminates such failure modes as overcharging or burning of wastes with low caloric value at temperatures below the required level. Additionally, the destruction and efficiency of POHCs, PICs and soot are increased, the negative effect of poor atomization of liquid wastes is minimized, and the possibility of a flame out failure is virtually eliminated;
(b) Uniform heating and intensive mixing due to the use of the burner means as described and due to rapid mixing of the hot oxidizing auxiliary combustion products with the flue gases, as presently described, eliminates cold spots and breakthrough of POHCs;
(c) The use of hot oxidizing and reducing auxiliary combustion products in combination with the hot oxidizing auxiliary combustion products in the afterburner further improves removal of NO x and destruction of POHCs, PICs and soot in the afterburner;
(d) The use of water or steam and ozone permits further optimization of either the oxidizing or reducing hot auxiliary combustion products which are used for NO x reduction and POHCs, PICs, sot and CO elimination;
(e) The use of rapid mix of the hot auxiliary combustion products with the flue gases in the afterburner provides uniform temperature and gaseous constituents distribution in the rapid mix chamber; and
(f) Rapid control of oxygen, air and fuel feed into the primary combustion means and after burner provide fast response to changes in the waste feed and composition. The feed-forward control of batch combustion in both the primary and the secondary combustion means allows the maximization of the size of the batch charge for a given system, while feedback control of the primary and feed-forward control of the secondary combustion means allows the maximization of the magnitude of the gradual changes in the waste feed. In either case the temperature, retention time and turbulence are maintained at required levels
A possible modification to the system is the conversion of a portion of the oxygen stream to ozone prior to its use as an exclusive oxidizer or in combination with air, oxygen or oxygen enriched air. Ozone can be most beneficially used as an oxidizer in situations where the need for additional heat input into the afterburner is insignificant. Ozone initiates chain reactions in the flame, thus resulting in faster and more complete destruction of POHC and reduction in the PIC formation.
A further modification is the use of water in line 90 as an additional oxidizing-reducing agent by its introduction into the combustion process in the primary incineration combination means and afterburner. Water will disassociate at high temperatures into hydrogen, oxygen and hydroxide, which are beneficial to the combustion process. These species prevent formation of soot and cyclic and aromatic hydrocarbons including halogenated and oxygenated compounds which are frequently PICs. The use of water is most advantageous when the caloric value of the wastes being incinerated in the primary incineration combustion means is high and/or the ratio of H:C is low. The hydrogen formed from water reacts with halogens which are often found in the POHCs forming HCl, HF, etc., thus making halogens mobilized and not available for the formation of halogenated PICs.
A further modification of the vortex mixing chamber is the use of co-current or counter-current feed of flue gases from the primary incineration chamber and the hot auxiliary combustion product generated in the afterburner burner.
In cases where further improvements of the destruction level of hazardous waste is needed, a second afterburner means may be utilized with an embodiment similar to those described above to provide an additional step of afterburning the hot gaseous products leaving the first afterburner means. A partial recycling of the gaseous products between the primary incineration combustion means and the afterburner, or between a first and second afterburner, may be utilized for further reduction of PICs and POHCs. Partial recycling of flue gases provides mixing of high and low concentrated portions of flue gases and equalization of fluctuations of POHC an PIC in the gaseous effluent from the system. Optionally, a reducing atmosphere may be maintained in the first afterburner and/or in recycled gases thus providing NO x reduction in the flue gases entering the final afterburner. An oxidizing atmosphere may be provided in the second afterburner.
Alternative probes, such as thermal pyrometers, combustible gas analyzers, oxygen analyzers and UV scanners, may be used to indicate to the control system the existence of prefailure conditions.
While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an amplification of one preferred embodiment thereof. | The invention relates to an afterburner apparatus and an incineration system and methods of waste destruction in primary incineration combustion means and afterburner means which both preferably utilize at least two different oxidizing gases. By varying the ratio of said oxidizing gases, the amount of total oxygen and nitrogen delivered in either means can be dynamically adjusted in accordance with the process requirements. Varying the flows of at least two oxydizing gases and auxiliary fuel in both the primary incinerator and afterburner makes it possible to operate the system under fluctuating waste loading conditions, by controlling temperature, partial pressure of oxygen and heat available for the process as a function of said ratio. | 57,839 |
TECHNICAL FIELD
[0001] The present disclosure relates to parking assist systems for vehicles.
BACKGROUND
[0002] When a vehicle is parked on a hill, a driver may angle the wheels in a certain direction to prevent the vehicle from rolling. For example, the front wheels of the vehicle may be angled away from the curb if the vehicle is facing uphill, toward the curb if the vehicle is facing downhill, or to the right if no curb is present.
SUMMARY
[0003] A parking assist system for a vehicle includes a controller configured to, in response to activation of the vehicle and data indicating that an inclination of the vehicle exceeds a first threshold and a steering angle of the vehicle exceeds a second threshold, adjust the steering angle to center wheels of the vehicle.
[0004] A vehicle includes a parking assist system configured to identify an inclination of the vehicle and an angle of wheels relative to a centerline of the vehicle, and a controller configured to, in response activation of the vehicle, the inclination exceeding a first threshold, and the angle exceeding a second threshold, adjust the angle to center the wheels relative to the centerline.
[0005] A control method for a parking assist system of a vehicle includes, in response to activation of the vehicle and data indicating a vehicle incline exceeding a first threshold and a steering angle exceeding a second threshold, adjusting by a controller the steering angle to center a set of wheels of the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic view of a vehicle parked on an inclined roadway; and
[0007] FIG. 2 is a control logic flow diagram for centering the wheels of the vehicle after vehicle activation.
DETAILED DESCRIPTION
[0008] Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
[0009] FIG. 1 depicts a schematic view of a vehicle 10 parked on an inclined roadway 12 . The vehicle 10 includes a steering system 14 having a steering wheel 16 , an accelerometer 17 , an EPAS motor 18 , and a steering angle sensor 20 in communication with a controller 22 . The steering angle sensor 20 may include a pinion angle sensor, a steering wheel angle sensor, or any other sensor that may be configured to determine an angle of vehicle wheels 32 . Further, the vehicle 10 includes a parking assist system 21 to communicate, using near field communication, between the controller 22 and an activation transceiver 24 . While preferred, any other communication system may allow communication between the controller 22 and the activation transceiver 24 , such as but not limited to, Bluetooth, WiFi, dedicated short range communication, or in-vehicle networks. The activation transceiver 24 may start, or ignite a vehicle engine to allow the vehicle 10 to propel forward or deactivate the vehicle and turn off a vehicle engine in order to park the vehicle 10 . The controller 22 may also be in communication with a vehicle vision system 26 including a camera 27 or an ultrasonic sensor 29 , as well as a navigation system 25 and a map 23 to detect the presence of a curb 28 . Any other vehicle vision sensors may be used to communicate the presence of the curb 28 to the controller 22 .
[0010] The inclined roadway 12 has an incline β. Incline β corresponds with a steering angle α. The steering angle α may be defined as an angle between the wheels 32 and a center 34 of the vehicle 10 . As incline β reaches a first threshold, the accelerometer 17 communicates that the incline β is above the first threshold to the controller 22 . The controller 22 uses the steering system 14 to account for the incline β of the roadway 12 . As by way of example, the steering system 14 uses the incline data from the controller 22 to activate the EPAS motor 18 to adjust the steering wheel 16 such that the steering angle α exceeds a second threshold. The steering system 14 may also be configured to adjust the steering angle α by angling the wheels 32 in vehicles without a steering wheel. The controller 22 may also use the accelerometer 17 to determine which direction the steering system 14 should adjust the wheels 32 . For example, FIG. 1 depicts a scenario in which a front 30 of the vehicle 10 faces downhill and the incline β exceeds the first threshold. When a front 30 of the vehicle 10 faces downhill, the controller 22 instructs the steering system 14 to adjust the vehicle wheels 32 toward the curb 28 to achieve the steering angle α. Angling the wheels 32 toward the curb 28 when the front 30 of the vehicle 10 faces downhill allows the curb 28 to act as a stop, preventing the vehicle 10 from rolling downhill. Downhill may be defined when the front 30 of the vehicle 10 faces toward a decline 23 of a slope 25 of the inclined roadway 12 .
[0011] While depicted in FIG. 1 , the controller 22 may use the accelerometer 17 to account for similar scenarios. For example, if the controller 22 , using the accelerometer 17 , determines a front 30 of the vehicle faces uphill while the incline β of the roadway 12 still exceeds the first threshold, the controller 22 instructs the steering system 14 to adjust the vehicle wheels 32 away from the curb 28 to achieve the steering angle α. Angling the wheels 32 away from the curb 28 when the front 30 of the vehicle 10 faces uphill allows the curb 28 to prevent the vehicle 10 from rolling down the roadway 12 . Uphill may be defined when the front 30 of the vehicle faces toward an incline (not shown) of the slope 25 of the inclined roadway 12 .
[0012] The controller 22 may angle the wheels 32 , using the steering system 14 as described above, when the activation transceiver 24 indicates the vehicle 10 is off and the steering angle sensor 20 indicates the wheels 32 are aligned with a center 34 of the vehicle 10 . This allows the steering system 14 to automatically adjust the wheels 32 to further park the vehicle 10 on the inclined roadway 12 .
[0013] The controller 22 is also configured to use the steering system 14 to align the wheels 32 with the center 34 of the vehicle 10 when the activation transceiver 24 indicates vehicle activation. For example, when the parking assist system 21 indicates to the controller 22 that the distance between the activation transceiver 24 and the parking assist system falls below a third threshold, the controller will instruct the steering system 14 to align the wheels 32 with the center 34 of the vehicle. The third threshold may preferably be when the activation transceiver 24 is within a cabin (not shown) of the vehicle 10 . However, the parking assist system 21 may also indicate that the activation transceiver 24 is within the third threshold at a predetermined distance from the parking assist system 21 . The predetermined distance may be based on the range of near field communication systems.
[0014] For example upon actuation of the activation transceiver 24 , the controller 22 receives input from the steering angle sensor 20 indicating that the wheels 32 have been angled at the steering angle α exceeding the second threshold and from the accelerometer 17 that the vehicle 10 is on the incline β exceeding the first threshold. The controller instructs the steering system 14 to actuate the EPAS motor 18 to turn the wheels 32 , based on the input from the steering angle sensor 20 , to align the wheels 32 with the center 34 of the vehicle 10 . Aligning the wheels 32 with the center 34 of the vehicle 10 prepares the vehicle 10 for road use. Further, the controller 22 may also instruct the steering system 14 to further adjust the steering angle α such that the wheels 32 are angled away from the curb 28 and toward the roadway 12 to prepare the vehicle 10 for road use. The parking assist system 21 may also be configured to send an input signal to the controller 22 indicating cancellation of the steering system 14 centering maneuver described above.
[0015] For example, if the incline β exceeds the first threshold and the steering angle α exceeds the second threshold and the activation transceiver 24 is within the third threshold of the parking assist system 21 and indicates vehicle activation, but an operator (not shown) indicates that aligning the wheels 32 with the center 34 of the vehicle 10 may not be ideal, the operator may apply a brake 36 for the vehicle 10 . Applying the brake 36 alerts the controller 22 that centering the wheels 32 may not be necessary and the controller 22 may likewise instruct the steering system 14 to maintain the wheels 32 at the steering angle α. Likewise, the operator may grab the steering wheel 16 to alert the controller 22 that centering the wheels may not be necessary.
[0016] Further, the steering system 14 may adjust the steering angle α to center the steering wheel 16 between vehicle activation and displacement of the brake 36 . This allows the parking assist system 21 to account for varying circumstances that may arise during operation of the vehicle 10 . Further, the controller 22 may also be configured to apply the brake 36 while the steering system 14 is aligning the wheels 32 with the center 34 of the vehicle. If the accelerometer 17 indicates that the incline β of the roadway 12 requires the brakes 36 be applied while the wheels 32 are centered, the controller 22 may likewise be configured to automatically apply the brakes 36 while the steering system 14 centers the wheels 32 .
[0017] The controller 22 may also be configured to activate an alert 38 of the pending centering of the wheels 32 by the steering system 14 . In at least one embodiment, the alert 38 may be an audible tone or dialect indicating that the steering system 14 is aligning the wheels 32 with the center 34 of the vehicle 10 . The alert 38 may also include a visual indication of the maneuver, or by providing haptic feedback indicating the maneuver. The alert 38 allows the operator the opportunity to abort aligning the wheels 32 with the center 34 of the vehicle 10 as described above. The alert 38 ensures that the operator is aware of the maneuver by the steering system 14 and may be able to control the vehicle 10 if needed.
[0018] FIG. 2 depicts control logic for the controller 22 to center the wheels 32 of the vehicle 10 . At 40 , the controller 22 determines if the activation transceiver is within range of the vehicle 10 or is sending data indicating vehicle activation. If at 40 the controller 22 does not receive data indicating vehicle activation from the activation transceiver, the control logic ends. If however at 40 the controller 22 does receive data indicating vehicle activation, the controller 22 uses the accelerometer to calculate the inclination of the roadway at 42 . The controller 22 uses the inclination data at 42 to determine if the vehicle inclination is greater than a first threshold at 44 . If the vehicle inclination is not greater than a first threshold at 44 , the control logic ends. If the controller 22 determines that the vehicle inclination is greater than the first threshold at 44 , the controller 22 may use the vision system, such as an ultrasonic sensor or camera to detect the presence of a curb 46 .
[0019] The controller 22 then receives input, using the steering angle sensor 20 , of the wheel angle at 48 . The controller 22 uses the input of the steering angle at 48 as well as the presence of the curb at 46 to determine if the steering angle is greater than the second threshold at 50 . If the curb is present at 46 and the steering angle has been adjusted at 48 to account for the curb, the controller 22 may then determine at 50 if the wheels 32 have been sufficiently angled toward the curb, exceeding the second threshold. If at 50 the controller determines that the steering angle does not exceed the second threshold and the wheels 32 do not need to be centered, the control logic ends. If however the controller 22 determines at 50 that the steering angle exceeds second threshold, the controller 22 determines at 52 whether centering the wheels 32 using the steering system 14 should be canceled. For example, at 52 the controller 22 will determine if a brake pedal has been depressed, as described above.
[0020] If at 52 the controller 22 determines that a brake pedal has been depressed, the controller 22 will activate the braking system at 54 . After activating the braking system at 54 the control logic ends. If, at 52 , the controller determines that a brake pedal has not been depressed, the controller 22 will adjust the steering angle, using the steering system 14 , to align the wheels 32 with the center of the vehicle 10 at 56 . While the controller 22 centers the wheels 32 with respect to the vehicle 10 , the controller 22 also will issue an alert of the centering at 58 . As stated above, issuing the alert of the centering at 58 further provides control and communication such that an occupant is aware of the adjustment at 56 . After the wheels 32 have been centered at 56 and the alert has been issued at 58 the control logic ends and the vehicle 10 is ready for travel.
[0021] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications. | A vehicle includes a parking assist system that identifies an inclination of the vehicle and an angle of wheels relative to a centerline of the vehicle. The vehicle also includes a controller that, in response activation of the vehicle, the inclination exceeding a first threshold, and the angle exceeding a second threshold, adjusts the angle to center the wheels relative to the centerline. | 16,302 |
STATEMENT OF THE PRIOR ART
In underwater operations, particularly those involving a diving bell or any similar apparatus, it is necessary to provide by means of cables and hoses (often termed "elements" or "Conduits") all means necessary to support and operate the bell. Furthermore, as a matter of safety it is necessary to provide a backup load bearing line capable of supporting the bell should the primary "down line" break. A conventional way of meeting the aforementioned requirements has been to wrap helically a load bearing member with any necessary elements and then joining same by hand taping them together. This procedure is ineffective because the cables as well as the load bearing member share the load of the bell upon breaking of the down line, thereby stretching and breaking the elements themselves. Moreover, frequent retaping has been required in order to secure the combination of the load bearing member and elements, thereby requiring unnecessary expenditure of time and money.
Another approach has been an attempt to unitize the elements within a protective jacket. Such attempts have been ineffective because once again all the elements are helically wound within the jacket and are subject to supporting the load of the bell upon fracture of the down line. Because these helically arranged elements are cabled under tension, upon release of that tension many of these elements are subject to axial contraction thereby causing "Z kinking," a phenomenon of metal wire wherein the load per unit caused by unloading the wire causes a point displacement resulting in a figure similar to a "Z." Past attempts at unitized marine umbilicals have not allowed for repair of the interior thereof.
Applicant is aware of U.S. Pat. No. 1,880,060 of Sept. 27, 1932 to Wanamaker disclosing a deep sea telephone, life line and diving cable having a centrally disposed wire rope stress member, a cushioning member entirely unlike that of the present invention, a yielding wrapping thereround, the presence of yielding spacer elements as well as the requirement for cables relatively smaller in size to that of the centered life line.
Applicant is also aware of U.S. Pat. Nos. 1,305,247 of June 3, 1919 to Beaver, 3,517,110 of June 23, 1970 to Morgan, 2,910,524 of Oct. 27, 1959 to Schaffhauser which disclose neither apparatus similar to that of the present invention nor propose to solve the problems resolved by the present invention.
SUMMARY OF INVENTION
The present invention relates to a unitized marine umbilical cable able to withstand the tensional impact resulting from a sudden tensional load placed upon the umbilical cable such as that caused by the break of the primary down line while at the same time supplying all necessary elements to, for example, a diving bell, for purposes of life support, television operation, electrical supply and the like. Moreover, the present invention relates to a unitized marine umbilical cable possessing the aforementioned capabilities while retaining sufficient flexibility for disposition around a reel, over a conveyor or sheave, as well as permitting easy repair or replacement of the internal elements thereof.
It is therefore a primary object of the present invention to provide a marine umbilical cable sufficient to withstand the tensional impact of a sinking diving bell and of continued support of the diving bell while reeling it to the surface.
Another object of the present invention is to have a unitized marine umbilical cable carrying not only a stress member but all necessary elements for operation and life support of the diving bell therein.
Yet another object of the present invention is the disposition of a high strength, highly resilient, low durometer elastomer material around the stress member thereby acting as a radial shock absorber against objects radially impacting the umbilical and tensional impact in the vertical part of the marine umbilical which is partially converted into radial impact at those points where the umbilical is substantially horizontal, to-wit, where the umbilical is disposed horizontally over a conveyor or sheave and circularly around a reel.
Still another object of the present invention is helically to dispose a combination of elements around the stress member whereby the stress member carries the entire impact and load of the diving bell thereby preventing the helically cabled elements from unwinding or breaking.
An even further object of the present invention is the extrusion of an exterior polyurethane jacket around the umbilical thereby facilitating easy and economic removal of the jacket for purposes of repair or replacement as necessary of one or more elements therein.
Still further objects of the invention will become apparent in the following specification, drawings, descriptions, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an environmental view depicting a surface support ship, an underwater diving bell, a primary down line supporting the bell from the surface ship, a marine umbilical cable tethering the diving bell to the surface ship and being slackened relative to the primary down line, a conveyor or sheave for guidingly facilitating the raising or lowering of the marine umbilical cable, a reel means for raising or lowering the umbilical cable, and a separate sheave and reel means for guiding and driving the primary down line not shown in the drawing.
FIG. 2 is an isometric view of the helical exterior embodiment of the invention irrespective of the particular type core.
FIG. 3 is a cross sectional view of FIG. 2 disclosing a diagrammatical representation of a wire rope center stress member, a surrounding low melt temperature high strength plastic jacket compression extruded onto the wire rope, an internal polyurethane jacket extruded onto the plastic jacket, a high strength, highly resilient, low durometer elastomer material compression extruded onto the internal polyurethane jacket, any number of conventional elements helically disposed around the core, a resilient fill material disposed within the internal interstices between the elements and the core, a polyurethane jacket tube extruded onto the exterior of the helically disposed elements and unfilled external interstices between the helically disposed elements and external polyurethane jacket which have been enlarged in the drawing for purposes of description only.
FIG. 4 is a diagrammatical representation of any flexible, high load bearing wire rope, this particular diagram showing by example a 6×36 Warrington Seale with independent wire rope center.
FIG. 5 represents an alternate stress member shown as an aramid fiber.
FIG. 6 is a cross sectional view of a marine umbilical cable having a stress member as shown in FIG. 5, an interior polyurethane jacket extruded onto the stress member, a high strength, highly resilient, low durometer elastomer material compression extruded onto the internal polyurethane jacket, helically disposed elements thereround, a resilient fill material in the internal interstices between the helical elements and the core, a substantially cylindrical exterior polyurethane jacket extruded onto the helically disposed elements and a conforming fill material disposed within the external interstices between the elements and the exterior polyurethane jacket.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the embodiments of the marine umbilical cable illustrated in the drawings and described in detail herein are directed for use primarily in maintaining while capable of supporting an underwater device such as but not limited to a diving bell, it is understood that the present device is equally suitable for any environment having a calling for a unitized umbilical cable supporting and maintaining any object or device requiring same.
Referring now to the drawings, reference character 4 represents a diving bell or any similar device requiring both physical support by tether means as well as life support. Reference character 2 depicts a surface ship floating on water level 3. Reference character 6 represents a primary down line supporting the bell 4 by tether means to surface ship 2 by passing the primary down line 6 over a conveyor or sheave 10 and thence onto and around reel means 12, the conveyor or sheave 10 and reel means 12 both being affixed to the ship 2, and being separate from the conveyor or sheave and reel means of the umbilical cable.
It should be noted that during normal operation the primary down line 6 supports the load of the bell 4 while the marine unbilical cable 8 connects the bell 4 to the ship 2 but remains unloaded. Upon breaking of the primary down line 6, the bell 4 will drop a certain distance necessary to take up the slack of the umbilical cable 8. Because of the dropping effect of the bell 4, umbilical cable 8 is first subjected to tensional impact along the vertical segment of the umbilical cable lying between the bell 4 and the sheave 10. Those skilled in the art will realize that a swelling sea raising the ship 2 relative to bell 4 will likewise cause tensional impact upon the umbilical 8 if the primary down line is broken. That part of the marine umbilical cable 8 disposed on and between the sheave 10 and the reel means 12 is substantially horizontal; therefore some of the impact and load produced by the falling bell 4 or the rising ship 2 on the umbilical cable 8 is radial as well as tensional on the upper portion of the sheave 10 as well as around the reel means 12. Consequently, any radial resiliency within the marine umbilical cable 8 and disposed upon the sheave 10 and the reel 12 tends to act as a radial shock absorber against the tensional impact of umbilical cable 8.
Similarly, a direct radial impact or load upon the umbilical 8 is cushioned by the resilient material 28, preferably a high strength, highly resilient, low durometer material, tending to prevent damage to the stress member 22 and elements 16.
FIG. 2 shows a particular mode of the marine umbilcal cable 8 having an exterior conforming to the helically cabled elements 16. FIG. 2 illustrates a core 14, one form of which is shown in FIG. 3 as comprising a wire rope stress member 22, a low melt temperature high strength plastic jacket 24 compression extruded onto wire rope stress member 22, an inner polyurethane jacket 26 extruded onto the jacketed stress member 22, 24 and a high strength, highly resilient, low durometer elastomer material 28 compression extruded onto the inner polyurethane jacket 26.
Another embodiment of the core 14 is shown in FIG. 6 as having an aramid fiber stress member 32, a polyurethane inner jacket 26 extruded onto stress member 32 and a high strength, highly reslient, low durometer elastomer material 28 compression extruded onto the inner jacket 26. It will be recognized by those skilled in the art that either embodiment of the core 14 is appropriate for a marine umbilical cable having a helical exterior 8' or cylindrical exterior 8.
Referring again to FIG. 6, the stress member 32 is laid axially to the cylindrical surface 8 of the marine umbilical. Because conventional elements 16 are helically cabled around the core 14, the stress member 32 is the shortest member per unit length of the marine umbilical 8 or 8' thereby being the first to assume any tensional load applied thereto; hence, the stress member 32, having sufficient load bearing characteristics for the particular tensional load to be applied, will not elongate sufficiently to cause elongation of the conventional elements 16, which are non-load bearing elements, or unwinding of the elements 16 and breakage thereof.
As previously noted, the inner polyurethane jacket 26 is extruded onto the stress member 32. The inner jacket 26 produces a transitional effect between stress member 32 which is substantially incompressible and the highly resilient, high strength, low durometer material 28. The inner jacket 26, tending to project the area of the stress member 22 or 32 bearing upon the high strength, highly resilient, low durometer elastomer 28, has reasonably high strength characteristics while at the same time possessing a noticeable degree of resiliency. The elastomer material 28, however, is a non-load bearing material which is highly resilient. Consequently, when radial loads are applied to the marine umbilical cable 8 or 8', the high strength elastomer 28 tends evenly to distribute that radial load. Resilient fill material 18 is injected as a high viscosity liquid during the cabling process into the internal interstices between the core 14 and conventional elements 16 and assists the elastomer material 28 in distributing a radial load applied to the marine umbilical 8 or 8'.
Turning now to FIG. 3, a preferred embodiment of the core 14 is shown as having a wire rope stress member 24. The particular wire rope used will vary according to the amount of load and impact expected to be applied to the umbilical 8 by the bell 4. A wire rope comprises an excellent stress member 22 in that it is both load bearing and flexible. One configuration of the wire rope 22 which is shown for purposes of illustration only, is a 6×36 Warrington Seale with independent wire rope center shown in FIG. 4. Interstices 33 as well as the individual wires comprising the wire rope stress member 22 generally come from the manufacturer with a lubricant thereupon which reduces galling of the wire rope 22 during repeated flexion thereof.
A low melt temperature high strength plastic jacket 24 of 0.005 inches minimum thickness is compression extruded onto the wire rope stress member 22, thereby inhibiting corrosion by salt water of the wire rope 22 and preventing bubbling of the inner jacket 26 by contact with a lubricant on wire rope 22.
Because the wire rope embodiment of stress member 22 is substantially less compressible than the stress member 32, the inner polyurethane jacket 26 even more importantly provides a transitional effect between the imcompressible stress member 22 and the highly resilient, high strength, low durometer elastomer 28. Because a wire rope stress member 22 has elongation characteristics of approximately one third of that of aramid fiber stress member 32, the cross sectional area of stress member 22 need be only approximately one third that of stress member 32. Consequently, because the inner polyurethane jacket is of approximate equal thickness for either embodiment of the core 14, preferably being at least 0.050 inches thick, the elastomer material 28 will vary according to the particular stress member utilized, thereby occupying a greater area of the core 14 when the wire rope stress member 22 is utilized and less of the core 14 when the aramid fiber stress member 32 is employed.
The external polyurethane jacket 20 is tube extruded as shown in FIGS. 2 and 3 onto the exterior of elements 16, and may be either tube or compression extruded as shown in FIG. 6. The embodiment shown in FIGS. 2 and 3 shows minute unfilled areas 30 in the external interstices between the surfaces of elements 16 and the external polyurethane jacket 20. It is understood that for purposes of representation only, the unfilled areas 30 are greatly enlarged in the drawings. These unfilled areas 30 must necessarily remain small in order to avoid undue stress on the jacket 20 caused by underwater pressures.
The jacket 20 may be economically removed for purposes of repair or replacement of the elements 16 and then a new jacket 20 extruded thereupon. An advantage of the helical configuration shown in FIGS. 2 and 3 of surface 8' is a reduction in the overall weight of the umbilical 8' resulting from the conforming of the jacket 20 approximately to the helices produced by the elements 16 as well as the unfilled external interstices 30. Furthermore, because all underwater lines are preferably black or of a substantially dark color in order to avoid attraction of sharks thereby prohibiting color coding, the rope configuration 8' is easily identifiable both onboard ship 2 where many lines may be in proximity to each other as well as underwater. Moreover, it is easier to grip the umbilical cable 8' than it is to grip the umbilical cable 8.
In some applications high radial loading upon the umbilical cable 8' disposed around the reel 12 or the sheave 10 may cause distortion of the helical configuration 8'. Consequently, it is more desirable to use a cylindrical embodiment 8 as shown in FIG. 6. Accordingly, a conforming fill material is disposed within the external interstices 36 between the elements 16 and the cylindrical polyurethane external jacket 34 thereby tending to support the elements 16 and to distribute radial loads applied to the umbilical 8. In any event, it will be recognized that the maximum effective diameter of the helical configuration 8' is equal to that of the cylindrical configuration 8. The cylindrical umbilical 8 remains easily and economically repairable in the manner described for configuration 8'.
Referring again to the core 14, those skilled in the art will easily recognize that the aramid fiber stress member 32 is non-corrosive and somewhat more elastic than the wire rope stress member 22, thereby necessitating less elastomer material 28 and thereby causing the diameter of the core 14 carrying the stress member 32 to be identical in diameter to the core 14 carrying stress member 22.
A preferred embodiment of the marine umbilical cable 8' comprises a wire rope center 22, a polyethylene jacket 24 of 0.005 inches or more in thickness compression extruded onto the wire rope stress member 22, a lubricant on and within wire rope 22, an inner-polyurethane jacket 26 compression extruded onto the polyethylene jacket, a high strength, highly resilient, low durometer elastomer 28 in the range of 2800-6000 P.S.I. tensile strength, 300-800% elongation and 50-80 durometer respectively an example of which is marketed under the trademark ROYALAR E-80 owned by Uniroyal, compression extruded onto the inner-polyurethane jacket 26, elements 16 helically cabled thereround, a resilient fill material located within internal interstices 18, and a polyurethane jacket 20 tube extruded around elements 16 without completely filling external interstices 30 and which is easily removable for economic repair of cable 8'.
An additional preferred embodiment is shown in FIG. 6. An aramid fiber stress member 32 marketed under the registered trademark of Kevlar owned by Du Pont is surrounded by a polyurethane jacket extruded thereupon. A high strength, highly resilient, low durometer elastomer 28 described above acts as a shock absorber against radial loading and is compression extruded onto the internal polyurethane jacket. The helically cabled elements 16 define internal interstices 18 carrying a resilient fill material. An external polyurethane jacket 34, being substantially cylindrical in shape, tangentially encircles the helically cabled elements 16 and the conforming fill material in the external interstices 36 tends to support the elements 16 and to distribute uniformly radial loading.
While the presently preferred embodiments of the invention have been given for the purposes of disclosure, changes may be made therein which are within the spirit of the invention as defined by the scope of the appended claims. | A unitized marine umbilical cable carrying any number or combination of conventional elements such as hoses and electrical cables. A center stress member disposed along the axis of the marine umbilical cable is capable of supporting an underwater device such as a diving bell should the primary down line break. Cylindrically surrounding the stress member is a compression extrusion of a high strength highly resilient elastomer around which are helically cabled various conventional elements. Within the interstices between the high strength elastomer and the helically cabled elements is a resilient fill material. The resilient fill material and high strength highly resilient, low durometer elastomer serve as a radial shock absorber against tensional impact upon the umbilical or radial forces thereupon. | 19,686 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 09/921,615, filed Aug. 3, 2001, pending, which is a continuation of application Ser. No. 09/495,534, filed Jan. 31, 2000, now U.S. Pat. No. 6,291,340, issued Sep. 18, 2001, which is a continuation of application Ser. No. 09/012,685, filed Jan. 23, 1998, now U.S. Pat. No. 6,081,034, issued Jun. 27, 2000, which is a continuation of application Ser. No. 08/509,708, filed Jul. 31, 1995, now U.S. Pat. No. 5,723,382, issued Mar. 3, 1998, which is a continuation-in-part of U.S. application Ser. 08/228,795, filed Apr. 15, 1994, now abandoned, which is a continuation of now abandoned U.S. application Ser. 07/898,059, filed Jun. 12, 1992.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to integrated circuit manufacturing technology and, more specifically, to structures for making low resistance contact through a dielectric layer to a diffusion region in an underlying silicon layer. The structures include an amorphous titanium nitride barrier layer that is deposited via chemical vapor deposition.
[0004] 2. State of the Art
[0005] The compound titanium nitride (TiN) has numerous potential applications because it is extremely hard, chemically inert (although it readily dissolves in hydrofluoric acid), an excellent conductor, possesses optical characteristics similar to those of gold, and has a melting point around 3000° C. This durable material has long been used to gild inexpensive jewelry and other art objects. However, during the last ten to twelve years, important uses have been found for TiN in the field of integrated circuit manufacturing. Not only is TiN unaffected by integrated circuit processing temperatures and most reagents, it also functions as an excellent barrier against diffusion of dopants between semiconductor layers. In addition, TiN also makes excellent ohmic contact with other conductive layers.
[0006] In a common application for integrated circuit manufacture, a contact opening is etched through an insulative layer down to a diffusion region to which electrical contact is to be made. Titanium metal is then sputtered over the wafer so that the exposed surface of the diffusion region is coated. The titanium metal is eventually converted to titanium silicide, thus providing an excellent conductive interface at the surface of the diffusion region. A titanium nitride barrier layer is then deposited, coating the walls and floor of the contact opening. Chemical vapor deposition of tungsten or polysilicon follows. In the case of tungsten, the titanium nitride layer provides greatly improved adhesion between the walls of the opening and the tungsten metal. In the case of the polysilicon, the titanium nitride layer acts as a barrier against dopant diffusion from the polysilicon layer into the diffusion region.
[0007] Titanium nitride films may be created using a variety of processes. Some of those processes are reactive sputtering of a titanium nitride target; annealing of an already deposited titanium layer in a nitrogen ambient; chemical vapor deposition at high temperature and at atmospheric pressure, using titanium tetrachloride, nitrogen and hydrogen as reactants; and chemical vapor deposition at low-temperature and at atmospheric pressure, using ammonia and Ti(NR 2 ) 4 compounds as precursors. Each of these processes has its associated problems.
[0008] Both reactive sputtering and nitrogen ambient annealing of deposited titanium result in films having poor step coverage, which are not useable in submicron processes. Chemical vapor deposition (CVD) processes have an important advantage in that conformal layers of any thickness may be deposited. This is especially advantageous in ultra-large-scale-integration circuits, where minimum feature widths may be smaller than 0.5 μm. Layers as thin as 10 Å may be readily produced using CVD. However, TiN coatings prepared using the high-temperature atmospheric pressure CVD (APCVD) process must be prepared at temperatures between 900-1000° C. The high temperatures involved in this process are incompatible with conventional integrated circuit manufacturing processes. Hence, depositions using the APCVD process are restricted to refractory substrates such as tungsten carbide. The low-temperature APCVD, on the other hand, though performed within a temperature range of 100-400° C. that is compatible with conventional integrated circuit manufacturing processes, is problematic because the precursor compounds (ammonia and Ti(NR 2 ) 4 ) react spontaneously in the gas phase. Consequently, special precursor delivery systems are required to keep the gases separated during delivery to the reaction chamber. In spite of special delivery systems, the highly spontaneous reaction makes full wafer coverage difficult to achieve. Even when achieved, the deposited films tend to lack uniform conformality, are generally characterized by poor step coverage, and tend to deposit on every surface within the reaction chamber, leading to particle problems.
[0009] U.S. Pat. No. 3,807,008, which issued in 1974, suggested that tetrakis dimethylamino titanium, tetrakis diethylamino titanium, or tetrakis diphenylamino titanium might be decomposed within a temperature range of 400-1,200° C. to form a coating on titanium-containing substrates. It appears that no experiments were performed to demonstrate the efficacy of the suggestion, nor were any process parameters specifically given. However, it appears that the suggested reaction was to be performed at atmospheric pressure.
[0010] In U.S. Pat. No. 5,178,911, issued to R. G. Gordon, et al., a chemical vapor deposition process is disclosed for creating thin, crystalline titanium nitride films using tetrakis-dimethylamido-titanium and ammonia as precursors.
[0011] In the J. Appl. Phys. 70(7) October 1991, pp 3,666-3,677, A. Katz and colleagues describe a rapid-thermal, low-pressure, chemical vapor deposition (RTLPCVD) process for depositing titanium nitride films, which, like those deposited by the process of Gordon, et al., are crystalline in structure.
BRIEF SUMMARY OF THE INVENTION
[0012] This invention constitutes a contact structure incorporating an amorphous titanium nitride barrier layer formed via low-pressure chemical vapor deposition (LPCVD) utilizing tetrakis-dialkylamido-titanium, Ti(NMe 2 ) 4 , as the precursor. Although the barrier layer compound is primarily amorphous titanium nitride, its stoichiometry is variable, and it may contain carbon impurities in amounts which are dependent on deposition and post-deposition conditions. The barrier layers so deposited demonstrate excellent step coverage, a high degree of conformality, and an acceptable level of resistivity. Because of their amorphous structure (i.e., having no definite crystalline structure), the titanium nitride layer acts as an exceptional barrier to the migration of ions or atoms from a metal layer on one side of the titanium carbonitride barrier layer to a semiconductor layer on the other side thereof, or as a barrier to the migration of dopants between two different semiconductor layers which are physically separated by the barrier layer.
[0013] The contact structure is fabricated by etching a contact opening through a dielectric layer down to a diffusion region to which electrical contact is to be made. Titanium metal is deposited over the surface of the wafer so that the exposed surface of the diffusion region is completely covered by a layer of the metal. Sputtering is the most commonly utilized method of titanium deposition. At least a portion of the titanium metal layer is eventually converted to titanium silicide, thus providing an excellent conductive interface at the surface of the diffusion region. A titanium nitride barrier layer is then deposited using a low-pressure chemical vapor deposition (LPCVD) process, coating the walls and floor of the contact opening. Chemical vapor deposition (CVD) of polycrystalline silicon, or of a metal, such as tungsten, follows, and proceeds until the contact opening is completely filled with either polycrystalline silicon or the metal. In the case of the polysilicon, which must be doped with N-type or P-type impurities to render it conductive, the titanium nitride layer acts as a barrier against dopant diffusion from the polysilicon layer into the diffusion region. In the case of CVD tungsten, the titanium nitride layer protects the junction from reactions with precursor gases during the CVD deposition process, provides greatly improved adhesion between the walls of the opening and the tungsten metal, and prevents the diffusion of tungsten atoms into the diffusion region.
[0014] Deposition of the titanium nitride barrier layer takes place in a low-pressure chamber (i.e. a chamber in which pressure has been reduced to less than 100 torr prior to deposition), and utilizes a metal-organic tetrakis-dialkylamido-titanium compound as the sole precursor. Any noble gas, as well as nitrogen or hydrogen, or a mixture of two or more of the foregoing may be used as a carrier for the precursor. The wafer is heated to a temperature within a range of 200-600° C. Precursor molecules which contact the heated wafer are pyrolyzed to form titanium nitride containing variable amounts of carbon impurities, which deposits as a highly conformal film on the wafer.
[0015] The carbon content of the barrier film may be minimized by utilizing tetrakis-dimethylamido-titanium, Ti(NMe 2 ) 4 , as the precursor, rather than compounds such as tetrakis-diethylamido-titanium or tetrakis-dibutylamido-titanium, which contain a higher percentage of carbon by weight. The carbon content of the barrier film may be further minimized by performing a rapid thermal anneal step in the presence of ammonia.
[0016] The basic deposition process may be enhanced to further reduce the carbon content of the deposited titanium nitride film by introducing one or more halogen gases, or one or more activated species (which may include halogen, NH 3 , or hydrogen radicals) into the deposition chamber. Halogen gases and activated species attack the alkyl-nitrogen bonds of the primary precursor and convert displaced alkyl groups into volatile compounds.
[0017] As heretofore stated, the titanium carbonitride films formed by the instant chemical vapor deposition process are principally amorphous compounds. Other processes currently in use for depositing titanium nitride-containing compounds as barrier layers within integrated circuits result in titanium nitride having crystalline structures. As atomic and ionic migration tends to occur at crystal grain boundaries, an amorphous film is a superior barrier to such migration.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0018] [0018]FIG. 1 is a block schematic diagram of a low-pressure chemical vapor deposition reactor system;
[0019] [0019]FIG. 2 is an X-ray spectrum (i.e., a plot of counts per second as a function of 2-theta);
[0020] [0020]FIG. 3 is a cross-sectional view of a contact opening having a narrow aspect ratio that has been etched through an insulative layer to an underlying silicon substrate, the insulative layer and the contact opening having been subjected to a blanket deposition of titanium metal;
[0021] [0021]FIG. 4 is a cross-sectional view of the contact opening of FIG. 3 following the deposition of an amorphous titanium nitride film;
[0022] [0022]FIG. 5 is a cross-sectional view of the contact opening of FIG. 4 following an anneal step; and
[0023] [0023]FIG. 6 is a cross-sectional view of the contact opening of FIG. 5 following the deposition of a conductive material layer.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The integrated circuit contact structure that is the focus of this disclosure is unique because of the use of a predominantly amorphous titanium or titanium carbonitride barrier layer therein. The layer is deposited using a low-pressure chemical vapor deposition (LPCVD) process that is the subject of previously filed U.S. patent applications as heretofore noted.
[0025] The LPCVD process for depositing highly conformal titanium nitride and titanium carbonitride barrier films will now be briefly described in reference to the low-pressure chemical vapor deposition reactor system depicted in FIG. 1. The deposition process takes place in a cold wall chamber 11 . A wafer 12 , on which the deposition will be performed, is mounted on a susceptor plate 13 , which is heated to a temperature within a range of 200-600° C. by a heat lamp array 14 . For the instant process, a carrier gas selected from a group consisting of the noble gases and nitrogen and hydrogen is bubbled through liquid tetrakis-dialkylamido-titanium 15 (the sole metal-organic precursor compound) in a bubbler apparatus 16 .
[0026] It should be noted that tetrakis-dialkylamido-titanium is a family of compounds, of which tetrakis-dimethylamido-titanium, tetrakis-diethylamido-titanium and tetrakis-dibutylamido-titanium have been synthesized. Because of its lower carbon content per unit of molecular weight, tetrakis-dimethylamido-titanium is the preferred precursor because it results in barrier films having lower carbon content. However, any of the three compounds or any combination of the three compounds will result in highly conformal barrier layers when pyrolyzed (decomposition by heating) in a CVD deposition chamber. These barrier layers are characterized by an amorphous structure, and by step coverage on vertical wall portions near the base of submicron contact openings having depth-to-width aspect ratios of 3:1 that range from 80-90 percent of the horizontal film thickness at the top of the opening.
[0027] Still referring to FIG. 1, the carrier gas, at least partially saturated with a vaporized precursor compound, is transported via a primary intake manifold 17 to a premix chamber 18 . Additional carrier gas may be optionally supplied to premix chamber 18 via supply tube 19 . Carrier gas, mixed with the precursor compound, is then ducted through a secondary intake manifold 20 to a shower head 21 , from which they enter the chamber 11 . The precursor compound, upon coming into contact with the heated wafer, pyrolyzes and deposits as a highly conformal titanium carbonitride film on the surface of the wafer 12 . The reaction products from the pyrolysis of the precursor compound are withdrawn from the chamber 11 via an exhaust manifold 22 . Incorporated in the exhaust manifold 22 are a pressure sensor 23 , a pressure switch 24 , a vacuum valve 25 , a pressure control valve 26 , a blower 27 , and a particulate filter 28 , which filters out solid reactants before the exhaust is vented to the atmosphere. During the deposition process, the pressure within chamber 11 is maintained at a pressure of less than 100 torr and at a pressure of less than 1 torr by pressure control components 23 , 24 , 25 , 26 , and 27 . The process parameters that are presently deemed to be optimum, or nearly so, are a carrier gas flow through secondary intake manifold 20 of 400 standard cubic centimeters per minute (scc/m), a deposition chamber temperature of 425° C., and a flow of carrier gas through bubbler apparatus 16 of 100 scc/m, with the liquid precursor material 15 being maintained at a constant temperature of approximately 40° C.
[0028] Thus, the carrier gas (or gases) and the vaporized precursor compound are then gradually admitted into the chamber until the desired pressure and gas composition is achieved. The reaction, therefore, takes place at a constant temperature, but with varying gas partial pressures during the initial phase of the process. This combination of process parameters is apparently responsible for the deposition of titanium carbonitride having a predominantly amorphous structure as the precursor compound undergoes thermal decomposition. The X-ray spectrum of FIG. 2 is indicative of such an amorphous structure. Both the peak at a 2-theta value of 36, which is characteristic of titanium nitride having a ( 111 ) crystal orientation, and the peak at a 2-theta value of 41, which is characteristic of titanium nitride having a ( 200 ) crystal orientation, are conspicuously absent from the spectrum. Such a spectrum indicates that there is virtually no crystalline titanium nitride in the analyzed film. Incidentally, the peak at a 2-theta value of 69 is representative of silicon.
[0029] Although the compound deposited on the wafer with this process may be referred to as titanium carbonitride (represented by the chemical formula TiC x N y ), the stoichiometry of the compound is variable, depending on the conditions under which it is deposited. The primary constituents of films deposited using the new process and tetrakis-dimethylamido-titanium as the precursor are titanium and nitrogen, with the ratio of nitrogen atoms to carbon atoms in the film falling within a range of 5:1 to 10:1. In addition, upon exposure to the atmosphere, the deposited films absorb oxygen. Thus the final film may be represented by the chemical formula TiC x N y O z . The carbon and oxygen impurities affect the characteristics of the film in at least two ways. Firstly, the barrier function of the film is enhanced. Secondly, the carbon and oxygen impurities dramatically raise the resistivity of the film. Sputtered titanium nitride has a bulk sheet resistivity of approximately 75 μohm-cm, while the titanium carbonitride films deposited through the CVD process disclosed herein have bulk sheet resistivities of 2,000 to 50,000 μohm-cm. In spite of this dramatic increase in bulk resistivity, the utility of such films as barrier layers is largely unaffected, due to the characteristic thinness of barrier layers used in integrated circuit manufacture. A simple analysis of the contact geometry for calculating various contributions to the overall resistance suggests that metal (e.g., tungsten) plug resistance and metal-to-silicon interface resistance play a much more significant role in overall contact resistance than does the barrier layer.
[0030] There are a number of ways by which the basic LPCVD process may be enhanced to minimize the carbon content of the deposited barrier film.
[0031] The simplest way is to perform a rapid thermal anneal step in the presence of ammonia. During such a step, much of the carbon in the deposited film is displaced by nitrogen atoms.
[0032] The basic deposition process may be enhanced to further reduce the carbon content of the deposited titanium nitride film by introducing an activated species into the deposition chamber. The activated species attacks the alkyl-nitrogen bonds of the primary precursor, and converts displaced alkyl groups into volatile compounds. The activated species, which may include halogen, NH 3 , or hydrogen radicals, or a combination thereof, are generated in the absence of the primary precursor at a location remote from the deposition chamber. Remote generation of the activated species is required because it is not desirable to employ a plasma CVD process, as Ti(NR 2 ) 4 is known to break down in plasma, resulting in large amounts of carbon in the deposited film. A high carbon content will elevate the bulk resistivity of the film to levels that are unacceptable for most integrated circuit applications. The primary precursor molecules and the activated species are mixed, preferably, just prior to being ducted into the deposition chamber. It is hypothesized that as soon as the mixing has occurred, the activated species begin to tear away the alkyl groups from the primary precursor molecules. Relatively uncontaminated titanium nitride deposits on the heated wafer surface.
[0033] Alternatively, the basic deposition process may be enhanced to lower the carbon content of the deposited titanium nitride films by introducing a halogen gas, such as F 2 , Cl 2 or Br 2 , into the deposition chamber. The halogen gas molecule attacks the alkyl-nitrogen bonds of the primary precursor compound molecule and converts the displaced alkyl groups into a volatile compound. The halogen gas is admitted to the deposition chamber in one of three ways. The first way is to admit halogen gas into the deposition chamber before the primary precursor compound is admitted. During this “pre-conditioning” step, the halogen gas becomes adsorbed on the chamber and wafer surfaces. The LPCVD deposition process is then performed without admitting additional halogen gas into the deposition chamber. As a first alternative, the halogen gas and vaporized primary precursor compound are admitted into the deposition chamber simultaneously. Ideally, the halogen gas and vaporized primary precursor compound are introduced into the chamber via a single shower head having separate ducts for both the halogen gas and the vaporized primary precursor compound. Maintaining the halogen gas separate from the primary precursor compound until it has entered the deposition chamber prevents the deposition of titanium nitride on the shower head. It is hypothesized that as soon as the mixing has occurred, the halogen molecules attack the primary precursor molecules and begin to tear away the alkyl groups therefrom. Relatively uncontaminated titanium nitride deposits on the heated wafer surface. As a second alternative, halogen gas is admitted into the chamber both before and during the introduction of the primary precursor compound.
[0034] As heretofore stated, the titanium nitride or titanium carbonitride films deposited by the described LPCVD process are predominantly amorphous compounds. Other processes currently in use for depositing titanium nitride-containing compounds as barrier layers within integrated circuits result in titanium nitride having crystalline structures. As atomic and ionic migration tends to occur at crystal grain boundaries, an amorphous film is a superior barrier to such migration.
[0035] Referring now to FIG. 3, which is but a tiny cross-sectional area of a silicon wafer undergoing an integrated circuit fabrication process, a contact opening 31 having a narrow aspect ratio has been etched through a borophosphosilicate glass (BPSG) layer 32 to a diffusion region 33 in an underlying silicon substrate 34 . A titanium metal layer 35 is then deposited over the surface of the wafer. Because titanium metal is normally deposited by sputtering, it deposits primarily on horizontal surfaces. Thus, the portions of the titanium metal layer 35 on the walls and at the bottom of the contact opening 31 are much thinner than the portion that is outside of the opening on horizontal surfaces. The portion of titanium metal layer 35 that covers diffusion region 33 at the bottom of contact opening 31 will be denoted 35 A. At least a portion of the titanium metal layer 35 A will be converted to titanium silicide in order to provide a low-resistance interface at the surface of the diffusion region.
[0036] Referring now to FIG. 4, a titanium nitride barrier layer 41 is then deposited utilizing the LPCVD process, coating the walls and floor of the contact opening 31 .
[0037] Referring now to FIG. 5, a high-temperature anneal step in an ambient gas such as nitrogen, argon, ammonia, or hydrogen is performed either after the deposition of the titanium metal layer 35 or after the deposition of the titanium nitride barrier layer 41 . Rapid thermal processing (RTP) and furnace annealing are two viable options for this step. During the anneal step, the titanium metal layer 35 A at the bottom of contact opening 31 is either partially or completely consumed by reaction with a portion of the upper surface of the diffusion region 33 to form a titanium silicide layer 51 . The titanium silicide layer 51 , which forms at the interface between the diffusion region 33 and titanium metal layer 35 A, greatly lowers contact resistance in the contact region.
[0038] Referring now to FIG. 6, a low-resistance conductive layer 62 of metal or heavily-doped polysilicon may be deposited on top of the titanium nitride barrier layer 41 . Tungsten or aluminum metal is commonly used for such applications. Copper or nickel, though more difficult to etch than aluminum or tungsten, may also be used.
[0039] Although only several embodiments of the inventive process have been disclosed herein, it will be obvious to those having ordinary skill in the art that modifications and changes may be made thereto without affecting the scope and spirit of the invention as claimed. | A contact structure incorporating an amorphous titanium nitride barrier layer formed via low-pressure chemical vapor deposition (LPCVD) utilizing tetrakis-dialkylamido-titanium, Ti(NMe 2 ) 4 , as the precursor. The contact structure is fabricated by etching a contact opening through an dielectric layer down to a diffusion region to which electrical contact is to be made. Titanium metal is deposited over the surface of the wafer so that the exposed surface of the diffusion region is completely covered by a layer of the metal. At least a portion of the titanium metal layer is eventually converted to titanium silicide, thus providing an excellent conductive interface at the surface of the diffusion region. A titanium nitride barrier layer is then deposited using the LPCVD process, coating the walls and floor of the contact opening. Chemical vapor deposition of polycrystalline silicon or of a metal follows. | 25,286 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 309,698, filed Nov. 27, 1972, abandoned, which is a continuation-in-part application of application Ser. No. 871,656, filed Nov. 14, 1969, abandoned, continuing application of Ser. No. 725,336 filed Apr. 30, 1968, abandoned, a continuation-in-part application of Ser. No. 504,949 filed Oct. 24, 1965, now Patent No. 3,380,779.
BACKGROUND OF THE INVENTION
A need exists for practicable means to counteract the tendency of a vehicle making a curve on a flat surface to lean outward and, if its speed is excessive, to slide or roll over or both due to centrifugal forces acting on the vehicle.
SUMMARY OF THE INVENTION
This invention relates to an improved wheel with a periphery adapted to expand or contract in response to forces acting parallel to its axle so that the tendency of a vehicle having such wheels on both sides to lean outward in making a curve is counteracted by expansion of the wheels farther from the center of the curve and by contraction of the wheel nearest the center. In addition, a means for absorbing lateral force on a vehicle within limits is provided in the wheel whereby the tendency of the vehicle to slide under such conditions is diminished.
Other objects, adaptabilities and capabilities will be appreciated as the description progresses, reference being had to the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary side view of one embodiment of the invention;
FIG. 2 is a sectional view, partly in elevation, taken on line II -- II of FIG. 1;
FIG. 3 is a schematic plan view of the embodiment shown in FIG. 1;
FIG. 4 is a schematic plan view similar to FIG. 3 showing a modification of the embodiment;
FIG. 5A and 5B are diagrams illustrating the effects of lateral forces on the wheel of the invention;
FIG. 6 is a representation in elevation of a further embodiment of the invention;
FIG. 7 is a diagram illustrating the application of lateral force on the embodiment shown in FIG. 6;
FIG. 8 is a fragmentary side view of a still further embodiment of the invention;
FIG. 9 is a sectional view, partly in elevation, taken on lines IX -- IX of FIG. 8;
FIG. 10 is a detail bottom view of a surface contacting member of the embodiment shown in FIGS. 8 and 9;
FIG. 10a, shows another embodiment of the surface contacting member;
FIG. 11 is a detail perspective view of a resilient bracket member of the embodiment shown in FIGS. 8 and 9;
FIG. 12 is a detail bottom view of a spoke guidance member in the embodiment shown in FIGS. 8 and 9;
FIG. 13 illustrates a removable resilient lug for tractors and the like;
FIG. 14 depicts the relationship between adjacent lugs as shown in FIG. 13 when attached to the wheel of a tractor; and
FIG. 15 shows a further embodiment of a lug similar to FIG. 13.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the embodiment shown in FIGS. 1 - 3, a wheel designated generally 10 is secured to an axle member 11 by means of bolts 12 extending through holes in the central portion 14 of wheel 10. A ring member 15 integral with central portion 14 extends around same and includes a limiting flange 16 on the inboard side and an outwardly biased flange 17 on the outboard side of wheel 10.
Secured on the outer periphery of the ring member 15 between flanges 16 and 17 is a securing portion 20 which is secured thereto by bolts, rivets or other suitable fastening means. Extending upwardly from the securing portion 20 is an inboard spoke portion 21 which joins, opposite the securing portion 20, a ground engaging portion 24. An outboard spoke portion 22 extends inwardly from ground engaging portion 24 and connects with a further securing portion 20 which connects with a still further inboard spoke portion 21 and so on until an endless member designated generally 25 comprised of successive portions 21--21--24--22 surrounds ring member 15.
The endless member 25 is composed of a resilient material such as, for example, spring steel which is sufficiently strong to support the vehicle involved. As will be noted from the drawings, the ground engaging members are disposed diagonally so as to overlap as seen from the side and present a smooth, uninterrupted ground contact. The spoke portions 21 and 22 include curves at 26 and 27 which tend to bend when the weight of the vehicle is borne by the associated spoke, and thus cushion and distribute the weight onto the adjacent spoke portions.
If desired, adjacent ground engaging portions 24 may be connected by resilient connecting members 30, as shown in FIG. 4, which are secured thereto by any suitable fastening means (not shown).
The spokes 21 all lie in the surface of an imaginary cone having an apex angle of about 150°, more or less, whereas, to increase stability of the wheels, the spokes 22 all lie in the surface of an imaginary cone having a slightly less apex angle -- say 145°, more or less.
FIG. 5A illustrates a vehicle having wheels 10a and 10b without the application of lateral forces. The axle member 11 is horizontal and angles a and b (one-half the aforesaid apex angles) are equal. Application of lateral force (such as centrifugal force) in the direction of arrow 31, as shown in FIG. 5B, increases the angle a to almost 90° and angle b is similarly decreased to about 60°. The periphery of wheel 10a is thus effectively increased and the periphery of wheel 10b is effectively decreased whereby the axle 11 is caused to slant downwardly into the force applied. From this, it will be understood that the disclosed structure tends to lean into, rather than away from, a curve. Any tendency of wheels 10 to "walk" away from lateral forces is compensated in part by the relatively increased wheel periphery which occurs in the outboard wheels and is minimized by provision of connecting members 30.
FIG. 6 shows an expansible wheel 40 which has a helical form and surrounds an axle 42. The spokes 41 are inclined increasingly outwardly from the center towards the sides as illustrated; the spokes 41 connecting the wheel 40 and the axle 42. The wheel 40 and spokes 41 are composed of a resilient material. Preferably, the wheel 40 is sinuous within the surface of an imaginary cylinder surrounding axle 42 so as to be capable of direct expansion or contraction. A vehicle 44, shown in dotdash lines, is carried on the axle 42 through supports 43.
When force is applied in direction 46, as shown in the diagram of FIG. 7, the angles c, away from the application of force, tend to increase whereas the angles d toward the application of force decrease and axle 42 is thus caused to lean in a direction to meet the application of force as illustrated.
Referring to FIGS. 8 and 9, a wheel designated generally 50 comprises an axle means 51 which includes openings 52 spaced about the wheel's axis of rotation to receive bolts extending therefrom for interconnection to the axle of a vehicle, in a well-known manner. A plurality of bolts 54 extend from axle means 51 about its axis of rotation to secure a hub cap or cover means 53. A plurality of spoke guidance means 55 are secured about the periphery of axle means 51 by bolts 56 or other suitable means. As seen in FIG. 9, each guidance means 55 is trapezoidal in configuration and includes elongated aperatures 57 on the bottom and circular aperatures 58 at top. A pair of parallel spoke members 60 are each received through a top and bottom aperture 58 and 57. The upper end of each spoke member 60 is threaded to receive nuts 61 and a resilient washer 62 may be received on each spoke member 60 between nut 61 and the top of guidance means 55. Within each guidance means 55, each spoke member 60 has a stop 64 rigidly attached thereto, the stop 64 having a configuration whereby it may pass through aperature 57. Between each stop 64 and the under side of the top of guidance means 55 is compression spring 65 surrounding each spoke member 60 in this area and, being in compression, urging each spoke member 60 outwardly relative to the axis of rotation of axle means 51. The strength of each spring 65 is such that it is only partly compressed when conveying its share of the weight of the vehicle involved in both loaded and unloaded condition and is almost fully compressed when it is subjected to a substantially greater force such as when the segment of wheel 50 involved encounters a rock or bump in the road.
Each spoke member 60 terminates in its outermost end with a ball 66 of a ball and socket joint 67 in a steel shoe plate 70. Secured to plate 70 by bolts 71 in recesses 72 is a rubber surface contacting member 74. The upper portion of plate 70 has secured thereto a resilient bracket member 75 by bolts 71. Bracket member 75 includes a pair of U-shaped parts 76 each having an opening 77 to receive snugly the lower end of a spoke member 60. The bracket member 75 is provided with resilience such that under unloaded conditions with the normal downward force due to the weight of the vehicle carried by wheels 50 a lateral force applied parallel to the axis of rotation of the vehicle 80 which is slightly or somewhat less than that required to cause member 74 to slide laterally on a wet flat concrete or asphalt surface changes the angle of spoke members 60 to that indicated by dot-dash lines 81 and an opposite like force changes the angle of spoke members 60 to that indicated by dot-dash lines 82, with the spoke members 60 being guided and limited in their movement by elongated aperatures 57. Rubber bumpers 84 secured in guidance means 55 adjacent to and slightly overlapping aperatures 57 protect the ends of aperatures 57 from undue wear and increase the resilient resistance against spoke members 60 to lateral forces as indicated above.
The plates 70 and surface contacting members 74 may be of an overlapping parallelogram configuration as shown in FIG. 10 or overlapping on both sides as shown in FIG. 10a which causes following action in successive spoke members 60 and avoids any tendency of the wheel to "walk" sidewise when the vehicle is subject to lateral force.
In operation, the springs 65 provide vertical cushioning of the vehicle to some extent and permits surface contacting members 74 to adjust to the inclination of the underlying surface within limits. In the event of lateral force vectors acting on the vehicle, such as occur when the vehicle turns, is on an incline, has a collision involving impact on one side, or the like, there is a certain lateral movement of the vehicle which takes place prior to lateral sliding by the surface contacting members 74 whereby the lateral force may, in effect, be absorbed and the sliding averted. Also, for reasons heretofore explained there is a tendency for a vehicle provided with wheels 50 50 to "lean" into a curve.
Referring to FIGS. 13 and 14, a lug 90 is bolted or otherwise secured to a steel tractor wheel 91 by a plurality of bolts 92, the lug 90 is curved so as to have a U-shaped configuration and has a rubber strip 94 bolted or otherwise secured to its opposite outward arm for contacting the ground. Strip 94 includes recesses 95 to receive the bolts 96. It will be noted from FIG. 14 that the lugs 90 are bolted to the wheel 91 so as to be biased relative to its normal directions of travel and with the strips 94 overlapping so there always will be at least one strip 94 contacting the ground. If desired, lug 90 and strip 94 can be divided as indicated by dot-dash lines 93 whereby it constitutes a plurality of lugs which act independently. FIG. 15 shows a lug 90a which is S-shaped, but otherwise similar to lug 90. The lugs 90 and 90a may be used with or in lieu of the lugs otherwise provided on a lugged steel tractor wheel or the like. If used with such lugs, then lugs 90 and 90a should extend beyond the existing lugs on the wheel. Preferably, lugs 90 and 90a are made of resilient steel. With such lugs, it is possible to travel on surfaced roads and highways which would be otherwise damaged. At the same time, the lugs 90 and 90a provide superior traction to pneumatic tractor tires under most conditions.
Although I have described preferred embodiments of my invention, it is to be understood that it is capable of other adaptions and modifications within the scope of the appended claims. | A wheel wherein the periphery comprises overlapping resilient members so that viewed from the side such members form a continuous circle about the wheel's axle; the spokes connecting such members with the axle extending within the surface of an imaginary cone having the same axis of the axis of rotation of the wheel; the individual peripheral members either not being connected or being connected in a manner that the periphery is, in effect, expansible and resiliently expands when force is applied parallel to the axle whereby the apex angle of the imaginary cone is enlarged. | 12,610 |
BACKGROUND OF INVENTION
This invention relates generally to methods for beneficiation of minerals, and more specifically, relates to a method for improving the brightness of kaolin clays through the use of synergistically related flotation and magnetic separation.
Naturally occurring kaolin clays frequently include discoloring contaminants in the forms of iron-based ("ferruginous") and titanium-based ("titaniferous") impurities. The quantities of the titaniferous discolorants are particularly significant in the case of the sedimentary kaolins of Georgia, where such impurities are commonly present as iron-stained anatase and rutile. In the case of various crude kaolin clays, it is accordingly often desired and indeed, frequently imperative, to refine the natural product in order to bring the brightness characteristics thereof to a level acceptable for paper coating and other applications. Various techniques have been used in the past to effect the removal of the aforementioned discolorants. Thus, for example, hydrosulfites have been widely used for converting at least part of the ferruginous discolorants to soluble forms, which may then be removed from the clays.
Among the most effective methods for removing titaniferous impurities, including, e.g., iron-stained anatase, are the well-known froth flotation techniques. According to such methods, an aqueous suspension or slurry of the clay is formed, the pH of the slurry is raised to an alkaline value, for example by the addition of ammonium hydroxide, and a collecting agent is added, as for example, oleic acid. The slurry is then conditioned by agitating same for a relatively sustained period. A frothing agent, such as pine oil, is then added to the conditioned slurry, after which air is passed through the slurry in a froth flotation cell to effect separation of the impurities.
The aforementioned flotation technology, however, becomes of decreasing effectiveness as one attempts to utilize same to remove smaller and smaller discolorant particles. The difficulty in this regard is that the flotation forces are insufficient with respect to such small particles to overcome drag forces; and hence, the particles cannot adequately respond to the flotation treatment.
Within recent years it has further been demonstrated that high intensity magnetic separation techniques may be utilized for removing certain of the aforementioned impurities, including titaniferous impurities, and certain ferruginous matter. Anatase, for example, and certain other paramagnetic minerals, have been found to respond to high intensity magnetic fields. Thus, for example, U.S. Pat. No. 3,471,011 to Joseph Iannicelli et al., discloses that clay slurries may be beneficiated by retention for a period of from about 30 seconds to 8 minutes in a magnetic field of 8,500 gauss or higher. Reference may also be made to U.S. Pat. No. 3,676,337, to Henry H. Kolm, disclosing a process for treating mineral slurries by passing same through a steel wool matrix in the presence of a background field of at least 12,000 gauss. Various apparatus, such as that disclosed in Marston, U.S. Pat. No. 3,627,678, may be utilized in carrying out the kolm processes. In this latter instance the slurry is thus passed through a canister, which contains a stainless steel or similar filamentary ferromagnetic matrix, while a high intensity magnetic field is impressed on the matrix by enveloping coils.
In certain further instances, as for example, in the teaching of U.S. Pat. No. 3,826,365, to V. Mercade, titaniferous impurities which are sought to be separated by a high-intensity magnetic field, are in advance of such separation, selectively flocculated. Somewhat similar phenomena are considered in Soviet Pat. No. 235,591 to Tikhanov, where several agents are used to selectively flocculate impurities in a slip of clay, which impurities are thereafter separated in a ferromagnetic filter including steel balls which have been previously rendered hydrophobic by treatment with a silicone compound.
All of the above magnetic separation methods, including those which employ differential flocculation, suffer from the limitation that particles with low magnetic susceptibility are not readily separated, despite the various technologies mentioned.
It may further be noted that in U.S. Pat. No. 3,974,067, to Alan J. Nott, which patent is assigned to the assignee of the present application, a method is disclosed for brightening a kaolin clay, wherein the clay as an aqueous dispersed slurry is subjected to a froth flotation treatment to remove titaniferous impurities, and the purified product from the froth flotation is thereupon subjected to magnetic separation by passing such product through a slurry-pervious ferromagnetic matrix positioned in a high intensity magnetic field. This method, while very effective compared to many prior art techniques, still retains certain of the limitations discussed in connection with flotation and conventional magnetic separation, i.e., small particle sized discolorants are floated only with difficulty, and particles of very low magnetic susceptibility cannot ultimately be removed by the magnetic separator stage of the process.
In a series of recent United States patents assigned to the assignee of the present application, a method has been disclosed for vastly increasing the effectiveness of magnetic separation methodology as same is applied to various minerals, including kaolin clays. In the techniques set forth in these patents, which include Nott et al U.S. Pat. Nos. 4,087,004, and 4,125,460, a dispersed aqueous slurry of the clay to be treated, is mixed with a finely divided magnetic particulate based upon magnetic ferrite particles. The slurry is thereupon passed through the aforementioned porous ferromagnetic matrix in the presence of an applied magnetic field, whereby contaminants seeded by the particulate are separated by the slurry. The said techniques are so effective that it is possible to obtain a high degree of brightening even with very low intensity applied fields. U.S. Pat. No. 4,125,460 indeed discloses achieving of fully acceptable brightening at field intensities as low as 0.5 kilogauss.
Further pertinent art is disclosed in Shubert, U.S. Pat. No. 3,926,789, which teaches the selective separation of minerals by use of ferrofluids. In particular the ferrofluid is used to selectively wet a mineral component sought to be separated from a mineral mixture. In consequence the selected component is rendered of increased magnetic susceptibility, and is able to respond and be captured in the magnetic separator through which the mineral mixture is then passed.
Despite the fact that very minute discolorant particles can often not be recovered by the method, for aforementioned magnetic seeding methodology as disclosed in the Nott et al U.S. Pat. Nos. 4,087,004 and 4,125,460 above mentioned, has been among the most effective techniques thus far found to remove titaniferous and feruginous discolorants. Certain practical difficulties, however, are presented by commercial scale use of the said seeding technology. A principal one of these is that use of the magnetic seeding materials tends to produce relatively rapid fouling and blinding of the porous ferromagnetic matrix.
In particular, the magnetic separating apparatus which are most commonly utilized in the kaolin and other minerals processing industries, and which are generally of the type disclosed in the aforementioned U.S. Pat. No. 3,676,337, employ, as already mentioned, a matrix comprising fine steel wool. The magnetic ferrites (such as ferroso-ferric oxide) which are used as the magnetic seed, are of course, removed at the steel wool matrix during passage of the seeded slurry through the said matrix. In the usual procedures for utilizing these magnetic separators, the matrix is periodically flushed with the magnetic field extinguished, i.e., in order to remove and flush the discolorant materials and magnetic seed which have become accumulated in the matrix. In conventional magnetic separation technology, these flushing operations are highly effective, and the said apparatus can operate for months without any requirement for completely disassembling the apparatus for removal for thorough cleaning or replacement of the steel wool.
Magnetic ferrite particles, as for example the aforementioned ferroso-ferric oxide, have, however, a degree of residual magnetism. In consequence they are not easily flushed from the steel wool matrix, i.e., flushed during the normal flushing operations which occur in situ. In consequence, fouling and blinding of the steel wool matrices can occur with rapidity, necessitating relatively frequent disassembling of the separator apparatus and replacement or separate cleaning of the fouled matrix.
It may further be pointed out that certain of the magnetic seeding compositions include liquid organics. These materials can similarly accumulate in the matrix and cause contamination and fouling of same. In addition, certain of the organics, as for example, fatty acids which can be present with various ferrofluids, even if such compounds do not excessively foul the matrix, remain in the beneficiated output from the separator. Where such output is a coating clay, the said compounds can add highly undesirable properties. Oleic acid, for example, will introduce an undesirable frothiness into the coating clay, which will render same relatively unsuitable for most coating applications.
In accordance with the foregoing, it may be regarded as an object of the present invention, to provide a method for magnetically beneficiating clays by utilizing as one aspect thereof, magnetic seeding, which method removes discoloring titaniferous and ferruginous discolorants, to enable brightness improvements previously unattainable through prior art techniques based upon flotation, magnetic separation, or prior known combinations of same.
It is a further object of the present invention, to provide a method for magnetically beneficiating kaolin clays, which is so highly effective in removing titaniferous and iron-containing discolorants, as to enable production of coating quality clays from crudes previously deemed too contaminated for such ultimate use.
It is a still further object of the present invention, to provide a method as aforementioned, which is based upon use of magnetic seeding materials, and which method may be practiced utilizing conventional porous matrix magnetic separators, without rapidly fouling or blinding the said matrices.
It is a yet further object of the invention, to provide a method for magnetically beneficiating kaolin clays, which method employs magnetic seeding materials which are produceable at low cost, which are highly stable and storeable, and which therefore, are admirably suitable for commercial scale operations.
SUMMARY OF INVENTION
Now in accordance with the present invention, the foregoing objects, and others as will become apparent in the course of the ensuing specification, are achieved in a method which synergistically integrates the processes of magnetic separation of seeded discolorants and froth flotation of clays, which processes were previously deemed distinct, so as to enable results previously unachievable by the individual processes, or by prior known combinations of same.
In accordance with the present invention, titaniferous and ferruginous discolorants are separated from a crude kaolin clay, by forming a dispersed aqueous slurry of the clay containing a deflocculant, and a fatty acid collecting agent. The slurry is thereupon conditioned in the presence of at least 0.25 lb/ton dry of the collecting agent (which more typically can be present as from about 1 to 4 lbs/ton of dry clay) to coat the discolorants with the collecting agent, and thereby render the discolorants hydrophobic. The slurry is thereupon seeded with a system of sub-micron sized magnetic ferrite seeding particles, the surfaces of which have been rendered hydrophobic, after which the seeded slurry is mixed to coalesce the hydrophobic-surfaced discolorants with the hydrophobic-surfaced seeding particles. The seeded slurry is thereupon subjected to a froth flotation to remove substantial quantities of the discolorants and seeding particles coalesced with same, and to remove excess seeding particles and excess collecting agent. Thereupon, the flotationbeneficiated slurry is subjected to a magnetic separation to remove further quantities of the discolorants and seeding particles associated therewith, and to remove seeding particles unassociated with the discolorants. The magnetic separation may be effected by passing the slurry through a porous ferromagnetic matrix whereat a field intensity of at least 0.5 kilogauss is maintained.
In a presently preferred embodiment of the invention, the magnetic seeding system may comprise magnetic ferrite particles in an aqueous phase, together with a fatty acid containing from 10 to 15 carbon atoms, the acid rendering the ferrite particles hydrophobic and serving to size-stabilize same.
The fatty acid should be present in the seeding system in concentrations of at least 6.7×10 -3 g-moles per lb. of magnetic ferrite expressed as Fe 3 O 4 , with a typical concentration of the said fatty acid being of the order of 3.8×10 -2 g-moles per lb. of the said ferrite. Because of its ready availability and low cost, dodecanoic acid is an especially attractive fatty acid for use in the foregoing seeding system.
In a further aspect of the invention, the seeding system may comprise magnetic ferrite particles in an organic liquid phase containing a fatty acid which will render the ferrite particle surfaces organophilac. The organic liquid in such a system may, for example, be kerosene or a similar hydrocarbon or hydrocarbon mixture and should be present in sufficient quantity to produce a fluid mixture of the ferrite particles and liquid. The fatty acid can be oleic acid, although numerous other fatty acids as are known in the art, can be utilized to render the ferrite surfaces organophilac--with sufficient of the acid being present to produce the desired surface characteristics. The above organic liquid phase can be present as a single phase, or as a component of an emulsion with water which is stable at ambient temperature. Where the latter, sufficient of the organic liquid should be present to produce the said stable emulsion.
The magnetic ferrite utilized in the seeding systems preferably comprises ferroso-ferric oxide particles, which may be prepared as described in the aforementioned U.S. Pat. Nos. 4,087,004, and 4,125,460. In the procedure set forth in said patents, a particulate of the said ferroso-ferric oxide is prepared as a product of aqueous coprecipitation of iron (III) with iron (II) salts, by an excess of a relatively strong base. For present purposes, the resulting precipitate may be extracted into the organic liquid/fatty acid phase or left in aqueous phase with addition of a stabilizing fatty acid such as the dodecanoic acid mentioned above. The precipitate can be washed or unwashed in either event.
In addition to the mentioned ferroso-ferric oxide, other finely divided ferrimagnetic materials may be used in the invention, including cubic ferrites such as NiFe 2 O 4 and CoFe 2 O 4 ; gamma-ferric oxide; and more generally, the magnetic ferrites represented by the general formula MO.Fe 2 O 3 , where M is a divalent metal ion such as Mn, Mi, Fe, Co, Mg, etc.
The magnetic seeding system is added to the clay slurry in quantities of at least 0.2 lbs. expressed as Fe 3 O 4 , per ton of dry clay, with from 1 to 2 lbs/ton dry clay being preferred. As excess ferrite seed is removed by flotation, as well as by magnetic separation, overdosing does not detrimentally affect the clay brightness. Thus although there is in principle no objection to higher dosage rates for the seed, economics dictate use of the smallest dose as will produce a desired product brightness.
The magnetic field to which the slurry is subjected during the magnetic separation step, may in practice of the invention be reduced to as low as 0.5 kilogauss--and yet provide brightening of the treated mineral to acceptacle levels. In general, retention times in the field are adjusted to the field intensities utilized and to the brightening required. Utilizing field intensities in a typical operational range of from about 5 to 10 kilogauss, typical retention times in practice of the present invention are of the order of 15 to 80 seconds. Within the limits of the technology (and of economics) higher fields may also be used with the invention, e.g., up to 60 kilogauss or higher.
While not all aspects of the mechanism of the present invention are fully understood, and while applicants are not bound by any particular hypothesis, it is presently believed that as a result of the conditioning of the clay slurry with the fatty acid collecting agent, and of the subsequent seeding with a system of sub-micron sized magnetic ferrite particles the surfaces of which have been rendered hydrophobic, the subsequent mixing effects a high degree of coalescence between hydrophic-surfaced discolorants and the hydrophobic-surfaced seeding particles. Futher, the common hydrophobicity of seed particles tends to coalesce excess seed particles with other excess seed particles. To be noted is that the phenomenom of this invention is fundamentally different from the spontaneous seed-discolorant association which occurs in the processes of the Nott et al patents. In the latter instances, the surfaces of the discolorants in the clay slurry are much more active, having not been coated with oleic or other fatty acids.
Thus, when the conditioned and seeded slurry is thereupon subjected to a froth flotation, not only are discolorants removed which would "normally" be removed by flotation, but in addition, some discolorant particles are removed which have become associated with seeding particles by coalescence, and futher, some seeding particles (which are floatable by virtue of their hydrophobic surface) are removed. A final element being removed is the excess fatty acid collecting agent, which would otherwise add highly undesirable properties to the clay slurry.
Hence, it will be evident that as a result of the steps thus far described, a hydrophobic coalescence has occurred, which coalescence has also produced discolorant-seed and seed-seed bodies, which are susceptible to removal by flotation and which have a high magnetic susceptability.
The flotation has removed particles which are ultimately sought to be separated, and which would otherwise create serious problems at the magnetic separator stage. In particular, the flotation has removed large quantities of discolorants, i.e., the larger discolorant particles and associated seed; and the flotation has removed excess seeding particles. All of these elements would otherwise be removed at the separator stage, whereat (especially the seed) would contribute to rapid fouling of the matrix.
The flotation has also removed the excess fatty acid collector, together with other floatable organics as may be present, thereby eliminating the fouling which such organics would otherwise cause at the separator stage.
Thereupon, in the final step of the instant process, the purified underflow from the flotation cell is provided to the magnetic separator, but the underflow as mentioned, is now free of many of those elements which would generate serious problems at the separator and otherwise impair the effective operation of same. Indeed, substantially what remains for removal at the magnetic field, are small discolorant particles, which have been coalesced with seed particles and perhaps with other discolorant particles to create entities of higher magnetic susceptibility than would otherwise be present. Accordingly, the magnetic separator can act with a new degree of efficiency, not only in that it is relieved of the burden of removing larger discolorant particles, the seed associated with such particles, and excess seed (all of which have already come out at the flotation and which would otherwise rapidly foul the magnetic matrix), but moreover, because of the enhanced magnetic susceptibility of the remaining discolorant particles.
Thus, it will be clear that the blunging and conditioning and flotation steps of the present method directly interact with and affect the subsequent magnetic separation step, to enable in totality, a synergistically integrated result which is not otherwise possible.
BRIEF DESCRIPTION OF DRAWINGS
In the drawings appended hereto:
FIG. 1 is a graph plotting titania content as a function of cumulative volumes of clay beneficiated in a magnetic separator, for clay samples processed by the present invention, and by the identical process excluding only the flotation step;
FIG. 2 is a graph plotting bleached clay product brightness for the samples processed as described for FIG. 1;
FIG. 3 is a graph plotting bleached clay product brightness as a function of applied magnetic field intensity, for clay samples beneficiated by the process of the present invention;
FIG. 4 is a graph plotting titania content for samples processed as described for FIG. 3;
FIG. 5 is a graph plotting bleached clay product brightness as a function of the magnetic ferrite seed dose rate; and
FIG. 6 is a graph plotting titania content for the samples processed as described for FIG. 5.
DESCRIPTION OF PREFERRED EMBODIMENTS
The manner in which the present invention is practiced is best understood by consideration of the Examples now to be set forth, which further, will render clear to those familiar with the present art, the striking improvements achieved by the practice of the present methodology.
In Examples I through IX, three soft, cream Georgia kaolin clay samples were subjected to various beneficiation procedures, including the procedures of the present invention. In particular, each of the clays A, B, and C, were initially blunged. In each instance, an aqueous alkaline dispersion of the crude clay was formed, (pH adjusted to about 7 to 10 with ammonium hydroxide). The blunging was effected in the presence of a small amount of a dispersant, such as sodium silicate--and in the case of clay C, in the presence of a polyacrylate available under the tradename "Dispex N-40" from Allied Colloids of Great Britain.
In all instances in this specification it will be understood that brightness values were obtained according to the specification established by TAPPI procedure T646 os-75. Bleached brightness values were obtained by subjecting the samples to a conventional reductive bleaching treatment with sodium hydrosulfite at an addition level of 5.6 lbs/ton. Finally the TiO 2 content was determined by means of X-ray flourescence. The resulting data for all of Examples I through IX are set forth in Table I hereinbelow.
EXAMPLE I
The present Example was intended to provide one of a series of control Examples to demonstrate (by comparison) the efficacy of the present invention. The blunged slurries were thus diluted to 18% solids (by weight), and were screened, and then bleached. The indicated brightness and TiO 2 values thus represent controls for crude clay samples of the clays A, B, and C, which have been blunged, diluted, and screened, but not in other respects beneficiated.
EXAMPLE II
In this Example, intended to provide further control data, the procedures described in connection with Example I were again followed, except at the conclusion of screening the slurry was classified in a Bird centrifuge to recover a fraction wherein 92% by weight of the particulate material had an E.S.D. (equivalent spherical diameter) less than 2 microns. The size characteristics just indicated, and particle size characteristics as same may hereinafter be discussed in this specification, are as determined by Sedigraph analysis ("Sedigraph" is a trademark for size analysis instruments manufactured by Micromeritics Instrument Corp. of Norcross, Ga.). Resulting brightness and TiO 2 content data (for the said fraction), is set forth in Table I.
EXAMPLE III
In this Example, the same procedure was used as described in Example II, except that following blunging, dilution to 18% solids, and screening, the slurry was subjected to a magnetic separation by being passed through a canister containing a steel wool matrix (7.5% packing) in an apparatus of the general type described in the aforementioned Marston U.S. Pat. No. 3,627,678. The average field intensity during such treatment was about 12 kilogauss, and the retention time in the field was approximately 51 seconds. The data yielded is again tabulated in Table I hereinbelow, and may be regarded as representative of beneficiation of a clay slurry by conventional (non-seeded) high intensity magnetic separation.
EXAMPLE IV
In this instance, samples were processed as in Example II, except that the samples were seeded using a magnetic particulate of the type described in the prior art, more specifically of the type described in the aforementioned Alan J. Nott et al patents, including U.S. Pat. No. 4,087,004. This particulate thus comprised a synthesized ferroso-ferric oxide prepared by coprecipitating iron (III) and iron (II) ions from an aqueous solution in a desired molar ratio by contacting with an excess of a relatively strong base, i.e., ammonium hydroxide. The mode of preparation of such particulate is described in Example II of the aforementioned U.S. Pat. No. 4,087,004. This prior art aqueous particulate was utilized with the clay samples as taught in said U.S. Pat. No. 4,087,004. Ferroso-ferric oxide was added at the rate of 1.2 lbs/ton of dry clay. Thereupon the slurry was mixed to facilitate seeding, the seeded slurry was diluted to 18% solids and then passed through the magnetic separator under conditions identical to Example III. It was then classified to provide a 92% by weight less than 2 micron ESD fraction, which was subjected to the aforementioned testing procedures to determine bleached clay product brightness, and TiO 2 content. The data set forth in Table I, shows that quite excellent improvements in brightness, and reduction in titania content can be achieved by the procedure of this Example.
EXAMPLE V
It will be appreciated that thus far, all of the Examples set forth, specifically Examples I through IV, have utilized prior art techniques, and hence may all be regarded as control Examples, i.e., for providing comparative data for evaluating the present invention. In the instant Example, a procedure was utilized which is similar to that described in connection with Example IV, except in this instance the system of magnetic ferrite seeding particles was prepared by first utilizing the preparative procedures described in Example IV, i.e., by the same procedures as are referenced in the Nott et al U.S. Pat. No. 4,087,004 (see Example II of that patent). The aqueous magnetic particulate which results from the Nott et al procedure was, however (in correspondence to one aspect of the present invention), subjected to the further important step of particle size stabilization, by mixing the said magnetic particulate with approximately 0.017 lbs. of dodecanoic acid per lb. of ferroso-ferric oxide.
It may be pointed out in this connection that the use of dodecanoic acid, as well as of other fatty acids having carbon chain length of from about 10 to 15 carbon atoms, in connection with aqueous magnetic fluids, is not in its broadest sense first taught herein. Rather, reference may be made to the article, "Preparation of Dilution-Stable Aqueous Magnetic Fluids", by S. E. Khalafalla and George W. Reimers, appearing in IEEE TRANSACTIONS ON MAGNETICS VOL. MAG-16, No. 2, March, 1980. This article describes the use of dodecanoic acid and other fatty acids as mentioned, to produce an aqueous magnetic fluid which is stable toward dilution with water. It is, however, pointedly observed herein, that the said article considers exclusively "ferrofluids", i.e., homogeneous, completely stable magnetic fluids. In the present Example, i.e., in the magnetic ferrite particulate system used in this Example, the system is not a ferrofluid, as the system is actually not dispersed or peptized; indeed, the system above described is non-homogeneous, and upon standing, settles out into two components, one a relatively dark-colored phase including the ferroso-ferric oxide, and the other a clear aqueous phase. However, the dodecanoic acid, in any event, size stabilizes the magnetic ferrite particles, which is a most important aspect of the present process. In the process of the invention, the said dodecanoic acid or other fatty acid in the indicated carbon chain length, should be present in concentration of at least 6.7×10- 3 g-moles/lb of magnetic ferrite expressed as Fe 3 O 4 , with a typical concentration of the fatty acid being of the order of 3.8×10- 2 g-moles/lb. of the said ferrite (expressed as Fe 3 O 4 ). The 6.7×10- 3 figure translates to about 0.003 lbs. of dodecanoic acid. It may be noted that much greater quantities of the fatty acid can be utilized in the seeding system as same will be removed during flotation; but in consideration of economics it is desirable to use the minimum quantity of fatty acid as is effective. It is also of interest to note that the quantities of fatty acid used in the present seeding system are far below the range which is recommended for use in the compositions taught in the aforementiond Reimers and Khalafalla article. Of further interest for purposes of the present invention, is that the described aqueous seeding systems are found to be stable for use over sustained periods; e.g., after a month's storage, they are found to perform just as well in the process of the invention (such as in Example IX below).
In the instant Example, and following the addition of the said seeding system, the resultant slurry was diluted once again to 18% solids by weight, screened, subjected to magnetic separation as aforementioned, and thereupon classified to produce for testing a fraction of clay, including 92% by weight of particles which are less than 2 microns ESD. The resulting data is again set forth in Table I hereinbelow. The data is of interest, in part in showing that this type of seeding system, when used in the prior art Nott et al process (of Example IV) is actually less effective than the seeding materials described in Nott et al (which are used in the above Example IV). Part of the explanation for this is thought to be that the dodecanoic acid has passivitated the surfaces of the magnetic ferrite particles, and thereby reduced the tendency to spontaneous seeding which occurs with the prior art particulates.
EXAMPLE VI
In the present Example (a further control), the procedure utilized differed from that described in Example V, in that persuant to a key aspect of the invention, the crude clay was blunged and then conditioned in the presence of a conventional fatty acid collecting agent i.e., oleic acid. The subsequent processing was identical to that described in connection with Example V. In studying the results set forth in Table I, it is seen that the bleached clay product brightness has been increased considerably by the present procedure, and of considerable further interest is the lowering of titania content. While it will be appreciated that a flotation step has not been utilized in the present Example, the cited improvements in brightness and titania levels tends to support the hypothesized mechanism of the present invention, i.e., as being one wherein hydrophobic coalescence occurs, facilitating removal of the coalesced materials by subsequent separation processes, which in this instance, includes only magnetic separation.
EXAMPLE VII
In this Example, the groups of clays A, B, and C, were subjected to a further control procedure, in this instance to conventional benefication by froth flotation. Such procedure is described as one aspect of Nott U.S. Pat. No. 3,974,067. In particular, in such sequence, the crude clay samples were blunged and conditioned in the presence of oleic acid as a collecting agent. The blunged and conditioned slurry, after addition of a frothing agent, was then subjected to a conventional treatment in a froth flotation cell, after which the beneficiated underflow was classified in a centrifuge to yield a 92% by weight less than 2 micron ESD fraction, which was subjected to the tests for brightness and titania content, as previously discussed. The resulting data is set forth in Table I, from which it will be seen that bleached clay product brightness and titania levels are not as good as those achieved with the seeding and magnetic separation processes called for in Examples IV, V, and VI.
EXAMPLE VIII
In this Example, which again constitutes a further control, for comparing and evaluating the results yielded by the present invention, the same series of clay specimens, i.e., of groups A, B, and C, were subjected to the combined flotation and magnetic separation procedure of the prior art, as same is disclosed in the Alan J. Nott U.S. Pat. No. 3,974,067, which has previously been referenced. The flotation procedure was as disclosed in Example VII; and following flotation the beneficiated output from the flotation cells were subjected to subsequent treatment in a high intensity magnetic field. The flotation-beneficiated slurry samples, after being diluted, as appropriate to include about 30% solids content, were passed through the magnetic separator of the aforementioned Marston type, wherein an approximate field intensity of about 15.5 kilogauss was maintained at the steel wool matrix. The flow rate of the slurry during the magnetic treatment was such that retention time in the magnetic field was approximately 1.2 minutes. The samples emerging from the magnetic separator were flocculated, bleached, and dewatered to yield test samples. The result of the said processes are once again set forth in Table I, from which it will be seen that very excellent brightness improvements were achieved, and titania levels were reduced well below those yielded by the flotation alone procedure of Example VII.
EXAMPLE IX
In the present Example, the process of the present invention was utilized to beneficiate the clay samples of groups A, B, and C. Thus, in the procedure utilized in this Example, the samples were first blunged together with oleic acid, as in Examples VI, VII, and VIII. A seeding system of the type described in Examples V and VI, which comprised ferroso-ferric oxide particles in an aqueous phase, together with 0.017 lbs. dodecanoic acid per lb. of ferroso-ferric oxide, was thereupon added to the blunged and conditioned clay slurry samples. The said seeding system was added to the slurries in quantities to yield 1.2 lb. expressed as Fe 3 O 4 per ton of dry clay. Following this, the resulting seeded slurry was further mixed to coalesce the hydrophobic-surfaced discolorants with the hydrophobic-surfaced seeding particles. The resulting seeded slurries were then subjected to froth flotation as described in connection with Examples VII and VIII; and thereupon the beneficiated underflow was subjected to a magnetic separation by passing same through the aforementioned Marston-type separator utilizing a field intensity of about 12 kG and retention time of 51 seconds.
Thereupon, 92% less than 2 micron fractions of the beneficiated slurry samples were evaluated for bleached product brightness and titania content. The results are set forth in Table I, from whence it will be seen that brightnesses have been achieved well exceeding those obtained in any of the procedures described in the preceding Examples. Further, it will be seen that a remarkable reduction in titania content has been achieved. Clearly the results exceed all expectations yielded by the prior art procedures.
TABLE I__________________________________________________________________________CLAY A CLAY B CLAY CBleached Clay Bleached Clay Bleached ClayExampleProduct Brightness %TiO.sub.2 Example Product Brightness %TiO.sub.2 Example Product Brightness %TiO.sub.2__________________________________________________________________________I 83.5 3.24 I 84.7 1.4 I 85.7 1.47II 83.5 3.24 II 84.8 1.4 II 86.8 1.28III 85.7 2.67 III 88.7 1.28 III 89.8 .90IV 88.0 1.47 IV 91.0 .52 IV 91.9 .33V 86.8 2.16 V 90.6 .71 V 91.7 .43VI 87.1 1.78 VI 91.2 .52 VI 92.3 .33VII 85.6 2.41 VII 88.7 .75 VII 88.3 .90VIII 87.4 2.03 VIII 90.4 .58 VIII 90.2 .58IX 90.7 .84 IX 91.7 .39 IX 92.4 .20__________________________________________________________________________
EXAMPLE X
A most important and significant aspect of the present invention as previously discussed herein, is the fact that where the present process is utilized, the matrix material of the magnetic separator (which material commonly comprises steel wool as aforementioned) is not rapidly fouled and blinded, as occurs in prior art beneficiation of clays utilizing magnetic seeding techniques.
In the present Example, this aspect of the invention was illustrated by subjecting clay samples which consisted of approximately 50% by weight of the aforementioned clay A, and 50% by weight of the aforementioned clay C, to two types of beneficiation, namely to beneficiation sequences corresponding to those set forth in Example VI and in Example IX. Example IX, of course, is in accordance with the present invention, and constitutes a preferred mode of operation persuant to same. The procedure in Example VI is similar to that of Example IX, with the important distinction that no flotation step is utilized. In each instance, the beneficiated clay slurries were passed through a magnetic separator of the Marston type at flow rates of approximately 800 ml/min, and at a field intensity of 12 kilogauss. The initial crude samples had a titania content of 2.35% by weight. The canister volumes in each instance were such that retention time in the field was approximately 51 seconds.
Utilizing the two procedures, specimens of the output from the magnetic separator were examined for titania content after a specified number of canister volumes had been successively processed. Thus, it was possible by this procedure to determine how the efficiency of the magnetic separator was being effected by the cumulative processing of samples. The results yielded are set forth in the graph of FIG. 1, from whence it will be apparent that by use of the process of the present invention, the titania content is not only reduced to far lower levels than by following a similar sequence but without the use of the synergistically related flotation step; but further, it will be evident that in the sequence of seeding and magnetic separation without the intermediate flotation, the magnetic separator rapidly loses its ability to remove the titania, this being a consequence of fouling of the matrix. On the contrary, however, and using the process of the present invention, it will be clear that the efficiency of removal remains at its extremely high level for a very extended period. Indeed, the efficiency remains fairly close to a constant value to the end of the graph, where 60 canister volumes have been cumulatively processed.
EXAMPLE XI
In the present Example, the same procedure as was described in connection with Example X was utilized, except in this instance, bleached brightnesses were determined as a function of cumulative flow through the canister of the magnetic separating apparatus. The results yielded by this procedure are set forth in the graph of FIG. 2, which is similar in nature to FIG. 1, except that bleached clay product brightnesses are plotted as ordinates against number of canister volumes which have been processed up to the abscissa at which the ordinate is plotted. Examination of the comparative curve (at lower left) for the data yielded by a procedure using a sequence which is substantially identical to the present invention, but which does not employ the intermediate flotation step following the blunging and conditioning with oleic acid and seeding, shows a rapid fouling of the matrix, whereby there is a rapid drop off in the brightness level of the processed clay samples. In marked contrast, the process of the present invention, which yields the results shown in the uppermost curve, shows but a very slow drop-off in brightness as the canister volumes are processed. The curve is indeed seen to be close to flat.
EXAMPLE XII
In order to demonstrate the effect of magnetic field intensity levels upon the process of the present invention, a group of samples of clay C were first beneficiated by prior art flotation, as in Example VII, and by the combined flotation and magnetic separation (at 12 kG) technique of Example VIII. These respectively yielded bleached product brightnesses of 88.3 and 90.2, which served as control values. Further such samples, were then subjected to the seeded flotation and magnetic separation process of the present invention, using the procedure set forth in Example IX. The quantity of the aqueous seeding system was such as to provide ferrite concentration of 1 lb. Fe 3 O 4 equivalent per ton of dry clay, and the seeding system was otherwise identical to that utilized in Example IX. Flow rate through the magnetic separator during the magnetic separation step was 800 ml/min. corresponding to a residence time of 0.85 minutes (51 seconds) in the magnetic field. The said procedure was carried out utilizing a a sequence of clay samples which were processed at different field intensities at the magnetic separator. The beneficiated samples were then processed to determine bleached clay product brightness, and the resulting data is plotted in the graph of FIG. 3, which specifically plots bleached clay product brightnesses as a function of magnetic field intensity. From this it will be seen that even at the lowest intensity utilized, i.e., approximately 0.64 kilogauss, the process of the invention has yielded a bleached clay product brightness of approximately 91.8, which is very remarkable, especially considering that conventional flotation (normally regarded as a very efficient process) has yielded a brightness of 88.3 and even combined conventional flotation and magnetic separation, a brightness of 90.2. Further to be noted, is that there is remarkably little variation in the bleached brightness over the range of magnetic intensity studied.
EXAMPLE XIII
In this Example, samples of clay C were subjected to the process of the invention as described in Example XII, and were then analyzed to determine the titania content thereof as a function of the applied magnetic field at the separator. The conventional flotation process in this instance, i.e., the conventional procedure of Example VII, had yielded an average titania content of 0.90% by weight for the samples. The results yielded by practice of the present invention are set forth in the graph of FIG. 4, which plots percentage titania (by weight) as a function of the intensity of the said field. It will be evident that the titania content has been remarkably reduced, especially in comparison to what is normally considered a very effective process in its own right, i.e., conventional flotation. It will also be seen that even at very low field values of approximately 0.6 kilogauss, the the process of the invention is still remarkably effective.
EXAMPLE XIV
In this Example, the process of the present invention as exemplified by the procedure of Example IX, was carried out with a series of clay B samples, utilizing, however, various dosage levels for the aqueous magnetic seeding system. In order to again provide a control, the samples were subjected to a conventional flotation procedure as exemplified by the process described in Example VII. This yielded a bleached clay product brightness of 85.7. The samples were then subjected to the process of the invention utilizing a field intensity at the magnetic separator of 12 kG, and a 0.85 minutes residence time in the magnetic field. Bleached clay product brightnesses were determined as a function of concentration of the ferrite seed in the clay slurry. The results are set forth in the graph of FIG. 5, which represents bleached clay product brightness as a function of lbs/ton of dry clay of the ferrite expressed as Fe 3 O 4 . The depicted range for the curve is seen to run from about 0.27 lb/ton to 1.35 lb/ton-- the curve is seen to be virtually flat over this range. The flattening out of the curve illustrates that there is little advantage in operating with seed concentrations exceeding the 1 to 2 lbs/ton previously mentioned.
EXAMPLE XV
In this Example the same procedures as were described in connection with Example XIII were followed, for the purposes, however, of determining the effect of concentration of the magnetic ferrite added by the seeding system upon titania content in the beneficiated samples. Again, for control purposes, evaluation of titania content was made of similar clay B samples which had been subjected to a conventional flotation treatment as described in connection with Example VII. This yielded a titania content of 0.75% by weight.
FIG. 6 plots the percentage of titania in the beneficiated samples for various dosage levels yielded in the slurry from addition of the seeding system. The abscissa values are identical to those in FIG. 4. To be noted again, is that the process of the invention is highly efficient over the entire range of data plotted, although the curve is not as flat as that of FIG. 5, suggesting that greater quantities of titania are removed at the somewhat higher seed concentrations.
EXAMPLE XVI
In this Example, the seeding system utilized was of the type set forth in Example IX, i.e., it constituted a system of magnetic ferrite particles in an aqueous phase together with a fatty acid containing from 10 to 15 carbon atoms. The objective of the Example was to demonstrate the effect of the fatty acid concentration on the bleached clay product brightnesses. In order to provide controls, a sample of clay A, was initially subjected to a conventional beneficiation by flotation as in the procedure of Example VII. This yielded a bleached clay product brightness of 85.6. Similar clay A samples were then subjected to the combined conventional flotation and magnetic separation treatment as in Example VIII. This yielded a bleached clay product brightness of 87.4. Thereupon, further samples of clay A were subjected to the process of the invention as in Example IX, with the fatty acid utilized in the seeding system being dodecanoic acid. The bleached brightnesses yielded in consequence of this procedure are set forth in Table II below.
TABLE II______________________________________Dodecanoic Acid Concentration Bleached Clayin lbs/lb of Magnetic Ferrite Product Brightness______________________________________.0025 87.9.005 88.1.01 88.5.0125 89.3.046 89.4.072 89.5.144 89.5______________________________________
It is seen from the above Table that good results are yielded even with the fatty acid at the minimum tabularized concentration. In many representative applications of the process, the dodecanoic acid will be present in the seeding system at about 0.017 lbs/lb of the ferrite. It can be seen from the Table II, that at such level approximately the maximum brightness has been reached; i.e., as the quantity of dodecanoic acid is raised beyond this level, there is little further advantage to be gained in brightness improvements.
EXAMPLE XVII
In this Example, the procedure of the invention, i.e., as in Example IX utilizing a sequence of blunging and conditioning with a fatty acid collecting agent, followed by seeding, flotation, and magnetic separation, was again followed; except in this instance the seeding system utilized was not the aqueous system described in connection with Example IX. Rather, the seeding system of the present Example was prepared by first forming a ferroso-ferric oxide precipitate as in Example II of the Nott et al. U.S. Pat. No. 4,087,004, which material was admixed with a mixture of kerosene and oleic acid. This yielded a thick, creamy emulsion. The emulsion was added to clay slurry samples formed from a further soft cream Georia kaolin at an identical processing point as in the procedure of Example IX, and the seeding system was added in sufficient quantity to give the same concentration of magnetic ferrite with relationship to the dry clay in the slurry. Following flotation and classification, the samples were evaluated for brightness. This yielded a value of 91.3. Corresponding control brightnesses were determined for the same samples of clay when beneficiated by flotation alone, as in Example VII, and for the combined flotation and magnetic separation treatment as in Example VIII. This provided respective control brightnesses of 88.7 and 89.7.
EXAMPLE XVIII
The same procedure as described in connection with Example XVII was repeated, except in this instance, the seeding system, while initially prepared as in Example XVII, was admixed with more water and with sulfuric acid, in order to break the emulsion, and was thereupon heated to facilitate such breaking. This led to a separation into two layers, with the resulting system being used by first mixing the system so as to intermix the layers, and then adding the intermixed product to yield the desired concentrations of magnetic ferrite as aforesaid. It was found that bleached clay product brightnesses yielded were substantially identical to those found in Example XIX.
While the present invention has been particularly set forth in terms of specific embodiments thereof, it will be understood in view of the instant disclosure, that numerous variations upon the invention yet reside within the scope of the present teaching. Accordingly the invention is to be broadly construed, and limited only by the scope and spirit of the claims now appended hereto. | A method is disclosed for separating titaniferous and ferruginous discolorants from a crude kaolin clay. A dispersed aqueous slurry of the clay is formed containing a deflocculant and a fatty acid collecting agent, and the slurry is conditioned to coat the discolorants with the collecting agent to thereby render the discolorants hydrophobic. A system of sub-micron sized magnetic ferrite seeding particles, the surfaces of which have been rendered hydrophobic, is thereupon added to the slurry. The seeded slurry is mixed to coalesce the hydrophobic-surfaced discolorants with the hydrophobic-surfaced seeding particles, and the slurry is then subjected to a froth flotation, which removes substantial quantities of the discolorants and seeding particles coalesced therewith, and also removes excess seeding particles and excess collecting agent. The flotation-beneficiated slurry is then subjected to a magnetic separation by passing the slurry through a porous ferromagnetic matrix positioned in a magnetic field, having an intensity of at least 0.5 kilogauss, to remove further quantities of the discolorants and seeding particles associated therewith, and to remove seeding particles unassociated with said discolorants. | 51,582 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 62/163,724, filed on May 19, 2015, entitled “ILLUMINATOR”, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The subject invention relates to an optical device for generating illumination that appears to emanate from a location different from the actual light source. Such an optical device is useful for a variety of photographic or video capture situations where it is impractical or impossible to place an actual physical light source where needed.
BACKGROUND OF THE INVENTION
[0003] Most photographic or video capture situations require some form of illumination. The desired illumination could be supplied, for example, by a flash connected to a camera. However, in many situations, providing the needed illumination can be a challenge.
[0004] One such situation relates to a display system developed by the assignee herein for the creation of an augmented reality for a user. In such a system, the user would be provided with a head mounted device that includes a window for viewing the outside world. The window would have the capability to generate image information and project that image information into the eyes of the user. In such a system, images of simulated objects could be generated and added to the real world scene. A more detailed description of this type of window is provided below.
[0005] There is interest in adding certain functionality to such head mounted displays. For example, there is interest in including a camera for monitoring the gaze direction of the user. Knowing where the user is looking at any moment has many benefits. For example, knowledge of a person's gaze can be used to control the display system. Knowledge of gaze direction can be used as a selection tool to control a mouse pointer, or its analog. Knowledge of gaze direction can be used to select objects in the field of view. Capturing gaze information with a camera can be improved by providing a source to illuminate the eye.
[0006] Another feature of interest in head mounted displays is the possibility of identifying the user through biometric measurements, such as iris recognition. An iris recognition system will include a camera for capturing an image of the iris. The process of capturing iris information can be improved if a source of illumination is provided.
[0007] The illumination device of the subject invention has some similarities to the structure of the window used by the assignee herein to create augmented reality. Although the embodiment of the subject invention will be discussed in this context, it should be understood that the invention is not limited to augmented reality systems but, in fact, could be used in any situation that requires illumination, particularly where it is desired to create a virtual illumination source.
[0008] The subject device includes a planar waveguide having a structure similar to that proposed for use in augmented reality. A description of a device for creating an augmented reality can be found in U.S. Patent Publication No. 2015/001677, published Jan. 15, 2015, the disclosure of which is incorporated herein by reference.
[0009] As described in the latter publication and illustrated in FIG. 1 herein, the optical system 100 can include a primary waveguide apparatus 102 that includes a planar waveguide 1 . The planar waveguide is provided with one or more diffractive optical elements (DOEs) 2 for controlling the total internal reflection of the light within the planar waveguide. The optical system further includes an optical coupler system 104 and a control system 106 .
[0010] As best illustrated in FIG. 2 , the primary planar waveguide 1 has a first end 108 a and a second end 108 b , the second end 108 b opposed to the first end 108 a along a length 110 of the primary planar waveguide 1 . The primary planar waveguide 1 has a first face 112 a and a second face 112 b , at least the first and the second faces 112 a , 112 b (collectively, 112 ) forming a partially internally reflective optical path (illustrated by arrow 114 a and broken line arrow 114 b , collectively, 114 ) along at least a portion of the length 110 of the primary planar waveguide 1 . The primary planar waveguide 1 may take a variety of forms which provide for substantially total internal reflection (TIR) for light striking the faces 112 at less than a defined critical angle. The planar waveguides 1 may, for example, take the form of a pane or plane of glass, fused silica, acrylic, or polycarbonate.
[0011] The DOE 2 (illustrated in FIGS. 1 and 2 by dash-dot double line) may take a large variety of forms which interrupt the TIR optical path 114 , providing a plurality of optical paths (illustrated by arrows 116 a and broken line arrows 116 b , collectively, 116 ) between an interior 118 and an exterior 120 of the planar waveguide 1 extending along at least a portion of the length 110 of the planar waveguide 1 . The DOE 2 may advantageously combine the phase functions of a linear diffraction grating with that of a circular or radial symmetric zone plate, allowing positioning of apparent objects and a focus plane for apparent objects. The DOE may be formed on the surface of the waveguide or in the interior thereof.
[0012] With reference to FIG. 1 , the optical coupler subsystem 104 optically couples light to the waveguide apparatus 102 . Alternatively, the light may be coupled directly into the edge of the waveguide 108 b if the coupler is not used. As illustrated in FIG. 1 , the optical coupler subsystem may include an optical element 5 , for instance a reflective surface, mirror, dichroic mirror or prism to optically couple light into an edge 122 of the primary planar waveguide 1 . The light can also be coupled into the waveguide apparatus through either the front or back faces 112 . The optical coupler subsystem 104 may additionally or alternatively include a collimation element 6 that collimates light.
[0013] The control subsystem 106 includes one or more light sources and drive electronics that generate image data which may be encoded in the form of light that is spatially and/or temporally varying. As noted above, a collimation element 6 may collimate the light, and the collimated light is optically coupled into one or more primary planar waveguides 1 (only one primary waveguide is illustrated in FIGS. 1 and 2 ).
[0014] As illustrated in FIG. 2 , the light propagates along the primary planar waveguide with at least some reflections or “bounces” resulting from the TIR propagation. It is noted that some implementations may employ one or more reflectors in the internal optical path, for instance thin-films, dielectric coatings, metalized coatings, etc., which may facilitate reflection. Light that propagates along the length 110 of the waveguide 1 intersects with the DOE 2 at various positions along the length 110 . The DOE 2 may be incorporated within the primary planar waveguide 1 or abutting or adjacent one or more of the faces 112 of the primary planar waveguide 1 . The DOE 2 accomplishes at least two functions. The DOE 2 shifts an angle of the light, causing a portion of the light to escape TIR, and emerge from the interior 118 to the exterior 120 via one or more faces 112 of the primary planar waveguide 1 . The DOE 2 can also be configured to direct the out-coupled light rays to control the virtual location of an object at the desired apparent viewing distance. Thus, someone looking through a face 112 a of the primary planar waveguide 1 can see the virtual light source as if from a specific viewing distance.
[0015] As will be discussed below, the subject illuminator can be configured using the DOE and waveguide technology discussed above.
BRIEF SUMMARY OF THE INVENTION
[0016] An optical device is disclosed for generating illumination that appears to emanate from a location different from the actual light source. The device includes a waveguide having opposed first and second planar faces. A light source is positioned to direct light into the waveguide. A diffractive optical element (DOE) is formed across the waveguide. The DOE distributes the light entering the waveguide via total internal reflection and couples the light out of the surface of said first face.
[0017] In one embodiment, the DOE is configured to collimate the outgoing light, so as to emulate the light field of a source positioned at an infinite distance from the waveguide. In another embodiment, the DOE is configured to diverge the outgoing light, so as to emulate a light field of a source that is a predetermined distance from the waveguide. In a preferred embodiment, the light source generates a narrow bandwidth of radiation in the infrared region of the spectrum.
[0018] For instance, the DOE may be configured such that light rays exit said first face perpendicular thereto, or such that light rays exit said first face in a manner to create a virtual source in space opposite the second face; or such that light rays exit said first face in a manner to create at least two virtual sources in space opposite the second face.
[0019] Additionally, the light source may generate infrared radiation. The second face may be provided with a coating reflective for infrared radiation.
[0020] The light from the light source may be directed into the waveguide via the first face thereof and/or via the second face thereof. In another embodiment, the light source from the light source may be directed into the waveguide via an edge of the waveguide. In such an embodiment, the illuminator may include a second waveguide extending along the edge of the first waveguide. The second waveguide may receive the radiation from the light source and distribute the light along an axis of the first waveguide parallel to the edge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a schematic diagram showing an optical system including a waveguide apparatus, a subsystem to couple light to or from the waveguide apparatus, and a control subsystem, according to one illustrated embodiment.
[0022] FIG. 2 is an elevational view showing a waveguide apparatus including a planar waveguide and at least one diffractive optical element positioned within the planar waveguide, illustrating a number of optical paths including totally internally reflective optical paths and optical paths between an exterior and an interior of the planar waveguide, according to one illustrated embodiment.
[0023] FIG. 3 is a schematic diagram showing an illuminator formed in accordance with a first embodiment of the subject invention where the virtual light source is at infinity.
[0024] FIG. 4 is a schematic diagram showing an illuminator formed in accordance with a second embodiment of the subject invention where the virtual light source is a point in space some finite distance from the waveguide.
[0025] FIG. 5 is a schematic diagram showing an illuminator formed in accordance with a third embodiment of the subject invention which includes a distribution waveguide.
DETAILED DESCRIPTION OF THE INVENTION
[0026] FIG. 3 illustrates a first embodiment of an illumination device 10 made in accordance with the subject invention. The device may be used in a wide variety of applications that require illumination. The device may be particularly useful with head mounted displays for implementing features such as gaze tracking or iris identification.
[0027] Device 10 includes a planar waveguide 20 . One or more diffractive optical elements (DOEs) 22 are formed in the waveguide. The DOE can be formed on a surface of the waveguide or be embedded within the waveguide.
[0028] A light source 24 is provided for generating optical radiation for illumination. A wide variety of light sources could be used. In the preferred embodiment, the light source generates a single wavelength or a narrow band of wavelengths. In one example, the light source 24 is a light emitting diode (LED). The light output of the LED is directed into the waveguide. The light can be directed into either side of the waveguide or along the edge thereof. The light then propagates throughout the waveguide by total internal reflections.
[0029] The DOE is arranged to out couple the light at various points along the surface of the waveguide. In the embodiment of FIG. 3 , the light rays coupled out are substantially perpendicular to the surface of the waveguide. This approach emulates the situation where the light source would be located at an infinite distance from the waveguide and the light is substantially collimated.
[0030] FIG. 4 illustrates a device 10 b in accordance with a second embodiment of the invention. In the FIG. 4 embodiment, the DOE 22 a of waveguide 20 a is arranged to create diverging rays to emulate the effect of a point source 30 located a particular distance from the opposite side of the waveguide. The particular location of the virtual light source is controlled by configuring the DOE.
[0031] The DOE can be arranged to place the virtual light source in any location, from quite close to the waveguide to quite far away. The choice will depend on providing the best illumination for the particular application. For example, if the illumination of the eye is used to capture images of the iris, it may be better to move the virtual source farther away from the waveguide to create a more uniform illumination.
[0032] For augmented reality applications, it is preferable that the light source emits illumination in the infrared spectrum so that the radiation is not visible to the user. In this way, the illuminator would not interfere with the real world or computer generated images reaching the user. Using infrared illumination is particular useful for iris recognition as a much higher level of detail of the iris is available in this wavelength range.
[0033] In a system using an infrared source, it may be preferable to provide a coating that reflects infrared radiation on the side 32 ( 32 a ) of the waveguide (opposite the transmission side). An infrared coating would minimize any losses due to light leakage on that side. The infrared coating would not interfere with the transmission of visible light from the real world, through the waveguide and into the eyes of the user.
[0034] The embodiment of FIG. 4 shows how the DOE can be configured to emulate light coming from a single point source. It is within the scope of the subject invention to configure the DOE to create diverging light rays that emulate light emanating from two or more virtual light sources. This could be achieved by allocating some fraction of the pixels of the DOE to one virtual source and another fraction of the DOE pixels to another virtual source. Of course, one could achieve a similar result by using two waveguides 30 a . The two waveguides would be aligned parallel to each other. Each waveguide 30 a would be configured to emulate a point light source at a different location.
[0035] Various pupil tracking systems are configured to require multiple light sources to generate multiple reflections from the eye. It is envisioned that an embodiment of the subject invention which can generate multiple virtual point source could be used to implement these type of pupil tracking systems.
[0036] FIG. 5 is a diagram of a system 10 c that includes a planar waveguide 50 having a DOE 52 . System 10 c further includes a second waveguide 56 aligned with an edge of waveguide 50 . Second waveguide 56 includes a DOE 58 . Light source 54 directs light into the second waveguide. The light spreads across the second waveguide 56 via total internal reflection. The light exits second waveguide 56 and enters waveguide 50 . In this embodiment, waveguide 56 acts to distribute light along the axis thereof (vertical axis of FIG. 5 ). Waveguide 50 then distributes the light along the horizontal axis of FIG. 5 . The use of the second waveguide may improve coupling efficiency.
[0037] While the subject invention has been described with reference to some preferred embodiments, various changes and modifications could be made therein by one skilled in the art, without varying from the scope and spirit of the subject invention as defined by the appended claims. | An optical device is disclosed for generating illumination that appears to emanate from a location different from the actual light source. The device includes a waveguide having opposed first and second planar faces. A light source is positioned to direct light into the waveguide. A diffractive optical element (DOE) is formed across the waveguide. The DOE distributes the light entering the waveguide via total internal reflection and couples the light out of the surface of said first face. | 17,110 |
FIELD OF THE INVENTION
The present invention relates generally to computer networks, and particularly to methods and systems for prioritizing the setting up of Virtual Private Network (VPN) connections over communication networks.
BACKGROUND OF THE INVENTION
Many organizations use Virtual Private Networks (VPNs) to connect users and remote sites securely to their corporate network. VPNs over Internet Protocol (IP) networks often use the IP security (IPsec) protocol suite, which provides a set of cryptographically-based security services. The IPsec architecture is described by Kent and Atkinson in “Security Architecture for the Internet Protocol,” published as Request for Comments 2401 by the Internet Engineering Task Force (IETF RFC 2401), November 1998, which is incorporated herein by reference.
Internet key exchange (IKE) is a sub-protocol of IPsec that authenticates each peer in an IPsec transaction, negotiates security policy and handles the exchange of encryption keys. IKE is described by Harkins and Carrel in “The Internet Key Exchange,” IETF RFC 2409, November 1998, which is incorporated herein by reference.
The Internet Security Association and Key Management Protocol (ISAKMP) is a protocol that is part of IKE. ISAKMP defines procedures and packet formats for establishing, negotiating, modifying and deleting security associations (SA) between peers. ISAKMP is defined by Maughan, et al., in “Internet Security Association and Key Management Protocol (ISAKMP),” IETF RFC 2408, November 1998, which is incorporated herein by reference.
The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram that schematically illustrates a computer network, in accordance with an embodiment of the present invention; and
FIG. 2 is a flow chart that schematically illustrates a method for prioritizing VPN tunnel setup requests, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
System Description
FIG. 1 is a block diagram that schematically illustrates a computer network 20 , in accordance with an embodiment of the present invention. Network 20 comprises multiple remote clients 24 and remote sites 28 that connect to a corporate network 32 via a wide-area network (WAN) 36 , such as the Internet. Corporate network 32 typically belongs to an organization having employees and/or customers that need to remotely connect to the organizational network. Remote clients 24 may comprise, for example, employees working from home and traveling users connecting to the network from hotel rooms or via wireless hotspots. Remote sites 28 may comprise, for example, branch offices located away from the corporate headquarters and customers or suppliers that are granted access to certain services of the corporate network. In some embodiments typical of remote branch offices, remote site 28 comprises a number of personal computers or work-stations 37 connected by a local area network (LAN) 38 . LAN 38 is connected to WAN 36 using a router 39 . (In the description that follows, remote clients and remote sites are collectively referred to as “clients” for the sake of simplicity.)
In many applications it is desirable to maintain a high level of information security when communicating over WAN 36 . For this purpose, clients 24 and sites 28 are connected to network 32 using Virtual Private Network (VPN) connections, also referred to as VPN tunnels. Each client establishes a secure VPN tunnel to corporate network 32 via a VPN aggregator 40 . In particular, aggregator 40 prioritizes the setting up of VPN tunnels for different client types based on predefined client profiles, as will be explained in detail below. In some embodiments, aggregator 40 may prioritize and set up VPN tunnels for any or all of the clients of network 32 .
Some exemplary VPN aggregators that can use the prioritization methods described herein are the VPN 3000 series concentrators produced by Cisco Systems, Inc. (San Jose, Calif.).
Each VPN tunnel generally uses a secure communication protocol between the client and the VPN aggregator. The protocol typically uses mutually-agreed encryption keys to encrypt and decrypt the information being transferred. In some embodiments, networks 32 and comprise Internet Protocol (IP) networks that communicate by exchanging IP packets. In these embodiments, the exchange of packets within and between these networks is performed in accordance with the IPsec and IKE protocols, as defined and described in the IETF RFCs cited above.
The network configuration shown in FIG. 1 is an exemplary configuration chosen purely for the sake of conceptual clarity. In general, network 20 may comprise any number of remote clients and/or remote sites. Remote clients and sites may be connected to WAN 36 using any suitable wired or wireless links. Aggregator 40 may comprise any network element, which may serve as the gateway connecting corporate network 32 to WAN 36 , or may be part of any other suitable configuration that connects the two networks. Corporate network 32 may comprise a private network or be implemented as part of a shared public network whose services are provided by a service provider.
Although the embodiments described herein mainly relate to a “responder mode” in which the clients initiate the setting up of VPN tunnels with network 32 , the methods and systems described herein can be used, mutatis mutandis , in an “initiator mode” in which aggregator 40 initiates the setting up of the VPN tunnels.
Aggregator 40 comprises an aggregation processor 44 , which performs the various functions associated with setting up and managing the VPN tunnels, and a network interface 48 , for communicating with WAN 36 and with the different components of corporate network 32 . Typically, processor 44 of aggregator 40 comprises a general-purpose computer, which is programmed in software to carry out the functions described herein. The software may be downloaded to the computer in electronic form, over a network, for example, or it may alternatively be supplied to the computer on tangible media, such as CD-ROM. Further alternatively, processor 44 may be implemented using a combination of hardware and software elements. The processor may be a standalone unit, or it may alternatively be integrated with other computing platforms of corporate network 32 .
Typically, a newly-joining client sends an IKE request packet to the VPN aggregator, requesting to set up a VPN connection (tunnel) to network 32 . The VPN aggregator receives the request packet and performs a tunnel setup process that authenticates the client and exchanges encryption keys. In many cases, the IKE process of setting up a VPN tunnel for a newly-joining client is a long and computation-intensive process that consumes a significant amount of time and computation resources in aggregator 40 . The length and complexity of this process are partly due to the algebraic calculations associated with generating the encryption keys. In some cases, aggregator 40 may need to communicate with other nodes in network 32 in order to authenticate a particular client, which further lengthens the tunnel setup process.
In some applications, aggregator 40 supports many thousands of clients simultaneously. In peak periods (such as at the beginning of a working day), several hundred clients may request to set up VPN tunnels every second. Due to the finite resources of the aggregator, some of these clients may experience a noticeable delay in setting up their VPN tunnels. An extreme scenario occurs when parts of the network, or aggregator 40 itself, recover from a communication failure that affects a large number of clients. When the network recovers, thousands of clients may request to set up VPN tunnels simultaneously. In such a scenario, some of these clients may suffer significant delays of up to several minutes in establishing their VPN connections. Clearly, such delays may be considered a prohibitive and intolerable quality of service (QoS) flaw by some clients and applications.
Some VPN applications use a Call Admission Control (CAC) mechanism, which limits the rate of tunnel setup request packets being processed in order to protect the resources of the aggregator. Typically, when the aggregator resource utilization exceeds a predetermined threshold, the CAC process prevents subsequent request packets from being processed. For example, in some embodiments the CAC process measures the aggregator processor utilization (i.e., the percentage of CPU resources used). If the processor utilization crosses a predetermined threshold, the CAC process rejects subsequent request packets. Because of the computational complexity of the tunnel setup process, the CAC process often gives higher priority to requests whose processing has already begun and may reject new requests.
In view of the long setup delays that may be experienced by clients, it is sometimes desirable to assign priorities to the setup request packets based on a classification of the clients. For example, in some networks it is desirable to give remote sites (e.g., branch offices) priority over individual remote clients. As another example, some remote clients may be classified as senior employees or as premium customers that are offered higher service quality. In other cases, it is desirable to give higher priority to VPN tunnels that use voice services or to tunnels used for network control. Request packets from clients having higher priority should be handled first by the aggregator, thereby shortening the connection delay for these clients.
Existing QoS mechanisms, such as the Modular QoS Command line interface (MQC) provided by Cisco Systems, Inc. (San Jose, Calif.), are generally unsuitable for prioritizing IKE request packets. Since the majority of IKE-related information is encrypted, such QoS mechanisms are generally unable to process and prioritize IKE packets.
Prioritization Method Description
In order to provide a faster connection time and an overall better QoS to selected client types, embodiments of the present invention provide methods and systems for prioritizing the setting-up of VPN tunnels based on client profiles.
FIG. 2 is a flow chart that schematically illustrates a method for prioritizing VPN tunnel setup requests, carried out by VPN aggregator 40 in accordance with an embodiment of the present invention. The method begins with an operator, such as a system administrator, defining a configuration of two or more client profiles, at a profile definition step 60 . Each client profile defines the client's association with certain predetermined client categories. A client category may comprise, for example, branch offices or other remote sites. Other client categories may comprise, for example, senior employees or premium customers. In general, the configuration of client profiles is arranged so that every client is associated with no more than a single profile.
As part of the profile definition, each client category is assigned a priority level. Typically, the priority level is represented as a number selected from a predetermined range.
In some VPN applications, the VPN aggregator maintains a set of ISAKMP profiles as part of the ISAKMP process. The ISAKMP profiles are used, for example, for identity matching, certificate filtering, authentication, authorization and virtual routing and forwarding (VRF). In some embodiments of the present invention, the ISAKMP profiles are adapted to serve as client profiles for prioritizing the VPN tunnel setup requests. For this purpose, an additional “priority” command is added to the ISAKMP profile. The following code shows an exemplary configuration comprising three adapted ISAKMP profiles:
crypto isakmp profile cisco
vrf cisco match identity group cisco-vpncluster match identity user JohnChambers
priority 1
match identity group cisco-engineers
priority 2
match identity group cisco-sales
priority 3
match certificate group cisco-ca keying cisco-keyring client authentication list cisco-client isakmp authorization list global-aaa priority 1
crypto isakmp profile company-A
vrf cmp-A match identity group cmp-A-vpncluster match certificate group cmp-A-ca keying cmp-A-keyring client authentication list cmp-A-client isakmp authorization list global-aaa priority 2
crypto isakmp profile company-B
vrf cmp-B match identity group cmp-B-vpncluster match certificate group cmp-B-ca keying cmp-B-keyring client authentication list amp-B-client isakmp authorization list global-aaa priority 2
Each ISAKMP profile comprises one or more “match identity” commands, identifying client categories such as client groups or individual clients. In some embodiments, when a “priority” command is added below a certain “match identity” command, the aggregator assigns the priority level specified in this command to this category. When a single “priority” command is added to the entire ISAKMP profile, this priority level applies to all “match identity” commands in this profile. (See, for example, the “company-A” and “company-B” profiles above.)
Having defined the client profiles, the profiles are provided to aggregator 40 . In some embodiments, the configuration of client profiles can be modified and updated whenever necessary during operation.
Aggregator 40 receives IKE VPN tunnel setup request packets (referred to as request packets for brevity) from clients of corporate network 32 , at a request reception step 62 . According to the IKE protocol, each request packet comprises an identification (ID) payload, which identifies the client sending the packet.
Aggregator 40 matches each VPN request packet with one of the client profiles, at a matching step 64 . In some embodiments, the aggregator extracts the ID payload from the request packet and attempts to match it against the different “match identity” commands in the ISAKMP profiles. If a matching “match identity” command is found, the aggregator reads the priority level assigned to this category from the client profile and assigns the priority level to the request packet. In some embodiments, if a match is not found, the request packet is assigned a default priority level, such as the lowest priority level. Alternatively, the request packet may be dropped.
Aggregator 40 prioritizes the request packets, at a prioritization step 66 . In some embodiments, aggregator uses the priority levels assigned to each request packet at step 64 above to prioritize the handling of the packets. Typically, request packets having the same priority level are handled on a “first come, first served” basis, although any other criterion can be used for this purpose.
In some embodiments, aggregator 40 operates a prioritized Call Admission Control (CAC) mechanism responsively to the assigned priorities, at a CAC operation step 68 . For example, the CAC mechanism may operate several queues, each queue associated with a particular priority level. After assigning priorities to the request packets, the aggregator adds each request packet to the queue associated with the priority of this packet. The queues are then served, typically giving more weight to queues associated with higher priority levels. Any suitable scheduling method known in the art, such as Modified Deficit Round Robin (MDRR), can be used for this purpose. As noted above, the CAC mechanism is used to protect the aggregator resources, typically by rejecting pending request packets when the aggregator utilization exceeds a predetermined threshold. However, when using the CAC mechanism described above, high priority requests are served first and are unlikely to be rejected.
Aggregator 40 sets up VPN tunnels according to the prioritized order of the request packets, at a tunnel setup step 70 . The method then returns to request reception step 62 above for receiving subsequent request packets.
In some embodiments, aggregator 40 may assign priorities to clients responsively to measured traffic characteristics of the clients. For example, the aggregator may measure the volume of traffic (e.g. the average packet rate) originating from each client and assign a higher priority to high traffic clients. As another example, the aggregator may identify service types used by clients, and give a higher priority to clients who frequently use a certain service type (e.g. voice). Any other suitable traffic characteristic or combination of characteristics can be used for this purpose. The measurement of the traffic characteristics and the assignment of priorities based on these characteristics may be performed during a learning period and/or during normal operation of the network. The process may be fully-automated or may involve a human operator, for example for verifying the automated assignments, for reviewing measured characteristics or for manually assigning priorities to automatically measured traffic characteristics.
Although the embodiments described herein relate mainly to prioritizing IKE VPN tunnel setup requests, the principles of the present invention can also be used in other tunnel-based protocols that use aggregators, such as PPP, L2TP, SSH and SSL.
It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art. | A method for communication includes predefining two or more client profiles applicable to clients of a communication network. Virtual Private Network (VPN) connections are initiated between at least two of the clients and the network. At least two of the clients are matched with respective profiles selected from the two or more predefined client profiles. Priorities are assigned to packets exchanged between the at least two of the clients and the network responsively to the profiles. The VPN connections are set up for the at least two of the clients responsively to the priorities. | 18,416 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. patent application Ser. No. 62/025,910, which was filed on Jul. 17, 2014, and is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] This disclosure relates to implementations of a method to use eugenol to treat blisters.
BACKGROUND
[0003] U.S. Pat. No. 8,273,719 disclose that it is known that the eugenol is generally used as an analgesic agent for toothache and others, and further has a blood flow promotion effect or demelanizing effect when applied to a surface topical site. The '719 patent discloses an antiwrinkle agent comprising an eugenyl glycoside.
[0004] U.S. Pat. No. 6,313,329 discloses that clove bud oil has long been used as a herbal remedy. The '329 patent discloses that the oil is distilled from the dried-flower buds. The '329 patent discloses that the oil is used in many natural-based toothpastes. The '329 patent discloses that the oil is also a strong insect repellent and useful as a moth repellent. The '329 patent discloses that clove bud oil is a strong antiseptic, anti-spasmodic. The '329 patent discloses that clove bud is also anti viral, anti fungal and healing. The '329 patent discloses that the oil comes from the buds of cloves. The '329 patent discloses that the oil has been used traditionally to remedy skin infections and to reduce digestive upsets. The '329 patent discloses that the oil is also used to kill intestinal parasites and to aid in childbirth. The '329 patent discloses that a tea that is made from cloves is often used to relieve nausea. The '329 patent discloses that the bud oil also has been used for the symptoms above for diarrhea, hernias, bad breath and bronchitis. The '329 patent discloses that the oil can be used to reduce acne, athlete's foot, and pain from burns. The '329 patent discloses that the oil is a very effective insect repellent and will relieve the pain of most toothaches, ulcers and wounds. The '329 patent discloses that the vapors of the oil have beneficial effects on arthritis, rheumatism and most sprains.
DETAILED DESCRIPTION
[0005] A method to use eugenol to treat blisters is provided. In some implementations, the composition may be comprised of 85% or about 85% of eugenol by weight. In some implementations, the composition may be comprised of less than 85% or more than 85% eugenol by weight. In some implementations, the composition may be comprised of 85% or about 85% of eugenol by volume. In some implementations, the composition may be comprised of less than 85% or more than 85% eugenol by volume.
[0006] In some implementations, the composition may be comprised of 85% or about 85% of clove oil by weight. In some implementations, the composition may be comprised of less than 85% or more than 85% clove oil by weight. In some implementations, the composition may be comprised of 85% or about 85% of clove oil by volume. In some implementations, the composition may be comprised of less than 85% or more than 85% clove oil by volume.
[0007] In some implementations, the composition may be comprised of 15% or about 15% of sesame oil by weight. In some implementations, the composition may be comprised of less than 15% or more than 15% sesame oil by weight. In some implementations, the composition may be comprised of 15% or about 15% of sesame oil by volume. In some implementations, the composition may be comprised of less than 15% or more than 15% sesame oil by volume.
[0008] In some implementations, eugenol is a phenylpropene. In some implementations, eugenol is a member of the phenylpropanoids class of chemical compounds. In some implementations, eugenol may be extracted from essential oils. In some implementations, eugenol may be extracted from clove oil, nutmeg, cinnamon, basil, and/or bay leaf.
[0009] In some implementations, the composition containing eugenol, and in some implementation sesame oil, may be a paste. In some implementations, the composition containing eugenol, and in some implementation sesame oil, may be a liquid. In some implementations, the composition containing eugenol, and in some implementation sesame oil, may be a gel.
[0010] In some implementations, a composition comprising eugenol, and in some implementation sesame oil, may be applied topically to the epidermis of a patient. In some implementations, a composition comprising eugenol, and in some implementation sesame oil, may be applied to a blister which has formed on the epidermis of a patient. In this way, the eugenol, and in some implementation sesame oil, may cause the blister to heal faster than a blister that has not had eugenol applied thereto. In some implementations, the composition comprising eugenol, and in some implementation sesame oil, may be applied topically to the epidermis of a patient to help treat shingles, psoriasis, acne, eczema, irritations from bug bits, bee stings, poison oak, and other skin irritations, rashes, and blisters.
[0011] Table 1 shows an example implementation of the composition comprised of eugenol and sesame oil according to the present disclosure. The composition may be comprised of the following ingredients:
[0000]
TABLE 1
Components
Quantity
Clove Oil
4.92 ml
Sesame Oil
1.08 ml
[0012] The above composition was used on various skin condition including shingles, acne, eczema, irritations from bug bits, bee stings, poison oak, and other skin irritations, rashes, and blisters. Subjects found the composition eased pain and dried up blisters. The sesame oil helped moisturize the skin and dilute the eugenol.
[0013] Reference throughout this specification to “an embodiment” or “implementation” or words of similar import means that a particular described feature, structure, or characteristic is included in at least one embodiment of the present invention. Thus, the phrase “in some implementations” or a phrase of similar import in various places throughout this specification does not necessarily refer to the same embodiment.
[0014] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.
[0015] The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the above description, numerous specific details are provided for a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that embodiments of the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations may not be shown or described in detail.
[0016] While operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. | Implementations of a method for treating an affected area of an epidermis having a blister or rash caused by shingles, psoriasis, acne, eczema, bug bits, bee stings, and poison oak comprising applying topically to the affected area of an epidermis a composition comprises eugenol and sesame oil. | 8,160 |
FIELD
Embodiments of the present invention relate in general to the field of information technology.
BACKGROUND
Over the last few years, information technology (IT) organizations have increasingly adopted standards and best practices to ensure efficient IT service delivery. In this context, the IT Infrastructure Library (ITIL) has been rapidly adopted as the de facto standard. ITIL defines a set of standard processes for the management of IT service delivery organized in processes for Service Delivery (Service Level Management, Capacity Management, Availability Management, IT Continuity Management and Financial Management) and Service Support (Release Management, Configuration Management, Incident Management, Problem Management and Change Management). The service support processes, such as Configuration Management, Incident Management, and Configuration Management are some of the more common processes IT organizations have implemented to bring their service to an acceptable level for their businesses.
The implementation of ITIL processes has yielded significant results to IT organizations by defining interfaces between service providers and consumers; by clarifying the IT organizational structures, roles, and responsibilities; and by designing internal processes for the management of IT operations. IT Service Management (ITSM) is a process-based practice intended to align the delivery of IT services with the needs of the enterprise, while emphasizing benefits to customers. ITSM focuses on delivering and supporting IT services that are appropriate to the business requirements of the organization, and it achieves this by leveraging ITIL-based best practices that promote business effectiveness and efficiency. Thus, the focus of ITSM is on defining and implementing business processes and interactions there between to achieve desired results. IT services are typically built around the processes. For example, in a manufacturing application, the ITSM may provide services built around a build-to-order manufacturing process scenario. The ITSM architecture generally provides services that are capable of being directly instantiated. With a focus on processes, presenting and packaging an organization's IT needs may be a challenge in an ITSM environment.
SUMMARY
Various embodiments of methods, systems, and computer program products for computer executable services are discussed herein. In one embodiment, a method comprises determining available hardware, determining computer executable services based in part on the available hardware, displaying a catalog of the computer executable services, receiving a selection of at least one service of the computer executable services, and instantiating the at least one service on the at least one server. The available hardware comprises at least one server.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates an example structure of a model for IT services, according to an embodiment.
FIG. 1B describes a state transition diagram for a two-phase model instantiation process, according to an embodiment.
FIG. 2A illustrates an architecture for a runtime environment described with reference to FIG. 1A , according to an embodiment.
FIG. 2B illustrates a block diagram of a configure-to-order system to implement an architecture described with reference to FIG. 2A , according to an embodiment.
FIGS. 3A , 3 B, and 3 C illustrate in a tabular form an example list of service operations supported by an architecture described with reference to FIGS. 2A and 2B , according to an embodiment.
FIG. 4 is a flow chart of a method for managing IT services, according to an embodiment.
FIG. 5 illustrates a block diagram of an active enclosure, according to an embodiment.
FIG. 6 illustrates an architecture for an active enclosure with a master-slave relationship, according to an embodiment.
FIG. 7 illustrates a block diagram of a management component of an active enclosure, according to an embodiment.
FIG. 8 is a flow chart of a method for managing IT services of an active enclosure, according to an embodiment.
DESCRIPTION OF EMBODIMENTS
Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings. While the embodiments of the present invention will be described in conjunction with the various embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, embodiments of the present invention are intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the appended claims. Furthermore, in the following description of various embodiments of the present invention, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the embodiments of the present invention.
The following terminology may be useful in understanding embodiments of the present disclosure. It is to be understood that the terminology described herein is for the purpose of description and should not be regarded as limiting.
Architecture—A blueprint or basic infrastructure designed to provide one or more functions. An architecture used in an IT environment may typically include hardware, software and services building blocks that are designed to work with each other to deliver core functions and extensible functions. The core functions are typically a portion of the architecture, e.g., an operating system, which may not be modifiable by the user. The extensible functions are typically a portion of the architecture that has been explicitly designed to be customized and extended by the user as a part of the implementation process. For example, services oriented architecture (SOA) is a type of an architecture used for addressing the need for structuring IT services that lowers cost and enhances reusability.
Model—A model can be a representation of the characteristics and behavior of a system, element, solution, or service. A model as described herein captures the design of a particular IT system, element, solution, or service. The model can be a declarative specification of the structural, functional, non-functional, and runtime characteristics of the IT system, element, solution, or service. The instantiation of a model creates a model instance. Unlike object oriented (OO) theory, in which an instance object can be a slot space, the model instance can be a design space that may be capable of accommodating refinement.
IT artifact—An IT artifact refers to a tangible attribute or property of an IT system. Examples of an IT artifact may include hardware, software, documentation, source code, test apparatus, project plans, educational and marketing material, and similar others. The IT artifact may be available for external or internal use.
Separation of concerns—A technique for addressing different issues of a problem individually, thereby making it possible to concentrate on each issue separately. Applying this principle may result in a decrease in the complexity by dividing the problem into different smaller issues; support division of efforts and separation of responsibilities; and improve the modularity of IT systems or artifacts.
Service—Utility or benefit provided by a provider to a consumer. The provider and the consumer may vary by application and may include an enterprise, a business unit, a business process, an application, a third party, an individual, and similar others. Enterprise services may be provided in the course of conducting the enterprise business. IT services generally refer to any application that enables the enterprise to provide utility or benefit by adding functionality to the IT infrastructure.
Service Model—A service model can be the representation of a service within a SOA. It defines the externally visible description, behavior, state, and operations available from a service to other services. As described herein, instantiation of a service model can be conducted in two phases—a binding phase and a grounding phase. The binding phase can be responsible for resolving dependencies between models. The grounding phase can be responsible for materializing the instances, e.g., by creating an IT artifact corresponding to the specification defined in the service model instance.
Meta Model—A meta model (or metamodel) can be a description of a set of building blocks, constructs and rules that define the model itself.
System—One or more interdependent elements, components, modules, or devices that co-operate to perform one or more predefined functions.
Configuration—Describes a set up of elements, components, modules, devices, and/or a system, and refers to a process for setting, defining, or selecting hardware and/or software properties, parameters, or attributes associated with the elements, components, modules, devices, and/or the system.
Applicants recognize that it would be desirable to provide a services architecture that would include tools and techniques to initially design, reuse, maintain, and refine services during their entire lifecycle, thereby ensuring alignment between IT services and IT infrastructure. That is, it would be desired to provide IT service lifecycle management tools and techniques that would promote the development, capture, and subsequent reuse and refinement of reliable and scalable services. Applicants further recognize that it would be desirable that the separation of concerns between the artifacts managed by the services be based on roles, e.g., a designer or developer and an end user of services. Therefore, a need exists to provide improved tools and techniques to be used in the automation of IT services lifecycle management.
Embodiments of systems and methods disclosed herein provide an architecture that is capable of designing and delivering IT services that are entered as a configure-to-order compared to a build-to-order provided by traditional ITSM services. An analogy may be made between a builder that is capable of building standard model homes that are orderable as a build-to-order home and an architect designed home that is capable of building a customized home in accordance with user specifications and that is orderable as a configure-to-order home. New features or functions of the configure-to-order home that were not included in the standard build-to-order home may be cataloged (with known price and delivery) and offered as re-usable features or functions that may be combined with existing model homes.
A Model for Information Technology (IT) Services
FIG. 1A illustrates an example structure of a model 100 , according to an embodiment. The model 100 captures the design of a particular IT element or solution, e.g., IT services captured as a service model. As described earlier, a service model can be the representation of a service within a SOA. It defines the externally visible description, behavior, state, and operations available from a service to other services. The model 100 includes one or more models 110 , 112 and 114 capable of being instantiated in a runtime environment 120 to generate corresponding model instances 130 , 132 and 134 and corresponding IT artifacts 140 , 142 , 144 and 146 generated in an IT infrastructure 150 . Thus, the instantiation of a model results in a generation of a virtual runtime object, e.g., the model instance, and also results in a generation of a real, tangible IT artifact in the IT infrastructure 150 . The IT infrastructure 150 may be a data center that includes hardware, software, communications, applications, services and similar other components to provide IT functions. The runtime environment 120 includes services that process the models 110 , 112 and 114 .
The model 100 can be a declarative specification of the structural, functional, non-functional, and runtime characteristics of an IT system. That is, the model 100 may use declarative programs that may include expressions, relationships, or statements of truth. The declarative programs may not include variables. Closely equivalent to the concept of a class in Object Oriented (OO) theory, the model 100 supports the principles of encapsulation and hiding of implementation detail. As in OO, the model 100 also supports recursive composition. Also as in OO theory, in which a class instantiation results in an object, the instantiation of a model results in the creation of a model instance. However, unlike OO, in which an instance object is a slot space, the model instance, e.g., each of model instances 130 , 132 and 134 , can be a design space that can accommodate refinement. In addition, as described earlier, a corresponding IT artifact becomes associated with the model. In the depicted embodiment, the bi-instantiation process for the models 110 , 112 and 114 is desirable to not only create a virtual runtime object that represents that particular instance of the model but in addition also generate an IT component or system in the real, tangible, IT Infrastructure 150 . A relationship between a model instance, e.g., one of the model instances 130 , 132 and 134 , and an IT artifact, one of the IT artifacts 140 , 142 , 144 and 146 , is therefore homomorphic. That is, one represents the other and a change in one is reflected in the other. Additional description of the two-phase instantiation process for a model is described with reference to FIG. 1B .
Referring back to FIG. 1A , in order to support initial design, reuse, maintain, and refinement during the entire lifecycle of the models, the model 100 supports the following example properties (among others): refinement, variability, polymorphism, composability, import, association, constructors, operations, deployment, monitors, declarative modeling language, and best practice. Recursive composability enables a designer to depend on and leverage existing designs in order to define or create new ones, which in turn are available to others to reuse. Refinement allows the instantiation process to be multi-step, thereby allowing for a greater flexibility in the model design. Encapsulation (also referred to as information hiding), use of clear boundary between the visibility into the internal design of a model and its publicly available characteristics, supports inter-model dependencies that allow changes to the internal specification without requiring changes in the model user. Characterization enables the expressing the outward nature of the model in terms that are directly relevant to the consumer of the model instead of in terms relevant to the implementer. Variation enables capturing variations in a single model. A model may be defined under several variations of its characteristics to reflect specific changes to the underlining design. Capturing these variations in a single model avoids combinatorial explosion of models and supports better model reuse. Declaration enables definition of models using declarative specifications. The models are defined in terms of their association to underlying design instead of as process steps for instantiation using programming code. Use of statements of truth to define the models reduce errors due to interpretation or avoid use of languages have meaning only during execution in the intended environment.
The models 110 , 112 and 114 can be defined by a meta model, thereby enabling the models 110 , 112 and 114 to be translated into other modeling languages. Thus, model 100 enables easy translation of user-defined models to other forms (both model-oriented and script-oriented forms) thereby enhancing its flexibility. In addition, model 100 provides the tools and techniques for the replacement of one modeling language with other modeling languages and for the coexistence of multiple structural modeling languages. As described herein, a meta model is a model that further explains or describes a set of related models. Specifically, the meta model includes an explicit description (of constructs and rules) of how a domain-specific model is built.
The model 100 may be specified by using various modeling languages including, among others, a unified modeling language (UML), the Resource Description Framework (RDF), Extensible Markup Language (XML) Schema, XML Metadata Interchange (XMI), and Java languages or a combination thereof. The RDF may include extensions such as RDF schema and languages such as the RDF Ontology Web Language (RDF/OWL).
The concept of refinement, which may be an example of an extensible feature of the model 100 , allows a smooth multi-valued transition from a model to a model instance. Whereas classic modeling approaches [OO, CIM, SML, UML] are based on a single value slot mechanism for instance creation, refinement can be based on a linked list approach that enables multi-slot capabilities for model elements. In addition, substitution can be supported, similar to XML schema. A refinable object or a refinable model element is any object/element that extends a refinable construct. The refinable construct carries metadata including: 1) allowRefinement: a Boolean attribute that can be used to stop the refinement process, 2) timestamp: a timestamp that record the time at which the refinement occurred, and 3) tag: a tag that records extra information such as purpose of the refinement or similar other.
FIG. 1B illustrates a state transition diagram for a two-phase model instantiation process, according to an embodiment. The instantiation of a model, e.g., any one of the models 110 , 112 and 114 , can be conducted in two phases: a binding phase 160 and a grounding phase 170 . In an example, non-depicted embodiment, the binding phase 160 may be implemented in a binding phase engine and a grounding phase 170 may be implemented in a grounding phase engine. In the binding phase 160 inter-model dependencies, e.g., made by a model to other models, can be resolved. An output of the binding phase 160 is a bound model instance 162 . Model instances 130 , 132 , and 134 are examples of the bound model instance 162 . The binding phase 160 may be viewed to provide a dynamic linking between model instances. Dependencies to other models can be abstract, refined or very specific and the binding phase 160 resolves these types of model references by reusing existing instances or creating new instances. The binding phase can be inherently recursive in that the binding of a dependent model can itself trigger a binding of its dependencies.
In the grounding phase 170 , the bound model instance 162 can be materialized to generate a bound and grounded model instance 172 . The materializing includes creating an IT artifact corresponding to the specification defined in the model instances. This can be achieved by recursively traversing the instance tree and creating, when appropriate, the corresponding artifacts in the IT infrastructure. IT artifacts 140 , 142 , 144 and 146 are examples of a bound and grounded model instance 172 .
An Architecture for a Runtime Environment
FIG. 2A illustrates an architecture 200 for a runtime environment 120 described with reference to FIG. 1A , according to an embodiment. The architecture 200 can be deployed to provide e-commerce for IT services. That is, the architecture 200 may be deployed as a configure-to-order business system in which a set of predefined models of IT systems are offered to customers (may include internal or external users, clients and similar others). FIG. 2B illustrates a block diagram of a configure-to-order system 202 to implement an architecture 200 described with reference to FIG. 2A , according to an embodiment.
Referring to FIGS. 2A and 2B , the predefined models are for IT services. It is understood that the models may be expressed for other aspects of IT within an enterprise. The architecture 200 includes a design service 210 operable to generate models 110 , 112 and 114 . The design service 210 may include design tools 212 and techniques (such as declarative programming) available to a designer or an architect of IT services to manage the lifecycle of the models from initial design to cataloging to refinement. In a particular embodiment, the design service 210 can be operable to capture declarative specifications of services as a service model.
A catalog service 240 can be operable to store a plurality of service offerings 242 . The plurality of service offerings 242 are models of services that are cataloged and are orderable by a customer. The catalog service 240 communicates with the design service 210 to access one or more service models that are new and not been previously cataloged. The service models may include modifications or refinements made to existing models included in the plurality of service offerings 242 . The one or more service models generated by the design service 210 are combined into the plurality of service offerings 242 to provide a catalog of orderable services 244 .
End users may access the features of the configure-to-order system 202 through the catalog service 240 and an Order Processing Service (OPS) 250 to browse, search, select, configure, and order the type of service model to be created and ordered or the type of changes desired to an existing model. In order to simplify the user interface, the catalog service 240 may filter model information provided to the user. That is, complex details about the model and its methods and properties, which may be provided to a designer or an architect, may be hidden from the user, thereby simplifying the user interface. For example, complex details of a blade server model having several processors arranged as a cluster may be presented to the user as a normal, high, and non-stop availability selection. Included in the information provided to the user is price and delivery associated with the order. In a particular embodiment, at least one orderable service 246 can be selectable from the catalog of orderable services 244 for placing an order. The selection may be performed by one of a user and an application program. In a particular embodiment, the OPS 250 can include a set of intermediate services for performing validation 252 , approval 254 and billing 256 of the end user order.
An order instantiation service 260 is coupled to receive the order (that has been validated and approved) for the at least one orderable service 246 from the OPS 250 . Specifically, upon validation and approval of the order by the OPS 250 , a request resolution service 258 can be triggered to initiate further processing of the order by the order instantiation service 260 . The order instantiation service 260 can be operable to instantiate the at least one orderable service 246 , thereby generating an instantiated ordered service 262 . The order instantiation service 260 includes a configuration management service (CMS) 220 operable to perform the binding phase 160 and generate the instantiated ordered service 262 . The CMS 220 includes tools and techniques for implementing the binding phase 160 of the two-phase instantiation process as well the management of the model instances, e.g., model instances 130 , 132 and 134 . The CMS 220 generates a service instance corresponding to each order.
An order fulfillment service 270 can be operable to fulfill the order in accordance with the instantiated ordered service 262 . The order fulfillment service 270 can include a request for change (RFC) scheduling 272 and a RFC execution service 274 for the sequencing of the various orders in the runtime environment 120 . The order fulfillment service 270 includes a creation and configuration service (CCS) 230 operable to perform the grounding phase 170 of instantiated ordered service 262 . The CCS 230 includes tools and techniques for the implementation of the grounding phase 170 , which includes creation of IT artifacts (such as artifacts 140 , 142 , 144 and 146 ) in the IT infrastructure 150 .
The connection between the runtime environment 120 and the IT infrastructure 150 can be performed through an actuator service 280 . The actuator service 280 may include two layers, a generic actuator 282 and a custom actuator 284 . In an embodiment, more than one generic actuators and more than one custom actuators may be included. The generic actuator 282 can be operable to dispatch instances to the custom actuator 284 . For example, a server model may be configured to define deployment and provisioning information related to a Rapid Deployment Pack (RDP) deployer. A deployment request can be triggered from the CCS 230 to a generic installer included in the generic actuator 282 , which in turn will search for a specialized deployer that can handle RDP deployment information. This technique enables a loose coupling between the runtime environment 120 and the IT infrastructure 150 and offers a high level of customization. That is, the architecture 200 provides IT service lifecycle management tools and techniques that promote the development, capture, and subsequent reuse and refinement of reliable and scalable services. In addition, the architecture 200 further provides the separation of concerns between the artifacts managed by the services be based on roles, e.g., a designer or developer (e.g., user of the design service 210 ) and an end user of services (e.g., user of the catalog service 240 ).
In a particular embodiment, the architecture 200 is scalable to be deployed in applications having varying scope and complexity starting from a blade server to a large scale, enterprise-wide IT service. In an example non-depicted embodiment, SmartRack can be an example name of an application of the architecture 200 that combines hardware, management software, and applications to provide customers with a unique, systematic experience to IT conceptualization, delivery, and consumption. This can be accomplished by both shipping the management software embedded with the hardware and by providing a systematic way of modeling applications that can be deployed. Once a SmartRack is powered on, the main point of user contact can be the catalog service. Service offerings can be presented to the user along with their available configuration options, each of which are characterized in terms of the resulting service's attributes, the cost, and time to build. Service offerings may be dynamically generated views based on a set of rich models, stored in the design service, that weave together the structural, functional, non functional, and runtime characteristics of a service using a set of best practices. In a typical deployment, SmartRacks may be configured with pre-populated foundation models. Other models may be either purchased and downloaded from Hewlett Packard Development Company, L.P. (HP) or 3rd parties, or developed in house by customers. Once the appropriate service offering is selected and ordered, it can be sent to the management services that will process it and ground (materialize) it using a set of installer services. If specified in the model, once grounded, the various elements of the model are automatically monitored by monitoring service(s). SmartRacks may be deployed in stand alone mode when a customer only desired one rack of blades. In addition, through its built-in federation capability, several SmartRacks can be combined together providing a unified management experience for the customer. Lastly, SmartRack, through its open SOA architecture and service proxy technology, can support the substitution of its services by external services allowing SmartRacks to reuse existing management software assets of the enterprise, and, allow more than one SmartRacks to be combined so that they are both managed through one user interface (instead of each being independent).
In an example, non-depicted embodiment, the architecture 200 can be a scaled up to a full enterprise architecture that puts services as the key economic principle of value transfer between business (or enterprise) and IT. IT may provide “IT-consumed services” to operate itself (tools and techniques to improve internal productivity). These are things like service desk technologies, change management systems, blades, facility services, networks, employees, legal services. These services can be thought of as the tooling of IT, and together they can be used to create the IT deliverable, the “IT-delivered service.” IT-delivered services can be created by IT for use by the business. Examples might include a consumer credit check service, employee expense reporting service, new employee set up service, a QA lab rental service, a private network and similar others. The IT delivered services can be delivered as an economic unit of value to the business. In other words, they are designed, constructed and delivered in a way such that the lines of business see its value, and are willing and able to purchase them. In fact, the IT-delivered service transforms into to a business-consumed service at the moment of payment. This payment can be indicative of the value as perceived the consumer, which in this case is the line of business. The IT-delivered services in and of themselves render IT as a service provider.
IT services provided to a business may be defined starting with a name (e.g. sales forecasting service), followed by a description (e.g. daily worldwide sales pipeline report and analysis for senior sales management). Every service may need additional artifacts and descriptors that are associated with the ongoing integrity of the service. These may include the service level agreements (SLAs) so that IT and the business are aligned around performance and availability, a logical and physical view of the configuration items that underpin the service, a view of dependant services, documentation, a continuity plan, knowledge entries, subscriber entitlements, and security and access provisions. The IT services may be defined by defining a service-line category structure. Just like consumer goods providers have product line categories, so do IT services. They may include employee services, application services, network services, others. Similar to consumer products, IT services may be established with a price, value and business outcome for each service. In order to qualify as an IT-delivered service, it is desirable that there is an associated, measurable business outcome. The IT services can be made available through a customer catalog service by developing a consistent way to articulate both a public characterization (business-facing) and private implementation (IT-facing). Service components can be reused whenever possible. Consistent design criteria for both the public and private facing aspects of the service can directly impact the process automation effort required to instantiate, monitor and manage the service throughout its lifecycle. Service visibility and integrity can be maintained at all levels including management stakeholders like the service desk, problem managers, change managers, application owners, IT finance managers, business relationship managers are able to view and manage activities around the service definition in a consistent way. When scaling up to the enterprise-wide architecture, IT provided services are defined as models and the services of the runtime environment are the embodiments of the IT consumed services.
Example Services Supported by the Architecture 200
FIGS. 3A , 3 B, and 3 C illustrate in a tabular form an example list of service operations supported by the architecture 200 described with reference to FIGS. 2A and 2B , according to an embodiment. In accordance with the principles of Service Oriented Architecture (SOA), components in the architecture 200 are conceived as services, that is, independent units of functionality with well specified interfaces and data models. The list of services may be described to perform a generic service (for aggregating data across data services), a data service (for the management of lifecycle of specific data models), a computational service (for the execution of business logic) or a combination thereof. An activation service 302 can be a generic actuator with responsibility to dispatch service activation requests to an appropriate custom activator. An approval service 304 (computational service) can be responsible for approving or not approving a received order. An authentication service 306 (data and computational service) can be responsible for the management of users, roles and access rights as well as granting authorizations. A billing service 308 (computational service) can be responsible for setting up charge back mechanism and proper billing for received orders.
A catalog service 312 (computational service) can be responsible for the generation of a service offerings. A configuration management service 314 (data service) can be responsible carrying out a binding phase of the instantiation process and for the management of the lifecycle of instances. A creation configuration service 316 (data service) can be responsible for carrying out a grounding phase of the instantiation process. A design service 318 (data service) can be responsible for the management of the lifecycle of models.
A discovery service 322 (computational service) can be a generic actuator responsible for triggering the discovery of assets in the infrastructure. To fulfill its responsibility, discovery service 322 can connect to custom discovery services. An incident service 324 (data service) can be responsible for the management of the lifecycle of incidents or events. An installer service 326 can be a generic actuator responsible to dispatch service installation requests to the appropriate custom activator. A logging service 328 (data service) can be responsible for the lifecycle management of log messages.
A monitoring service 332 can be a generic actuator which has the responsibility to dispatch service monitoring requests to the appropriate custom activator. An offering availability estimation service 334 (computational service) can be responsible for the generation of service offering availability and pricing. An order processing service 336 (data service) can be responsible for the management of the lifecycle of orders. A package model design service 338 (data service) can be responsible for the lifecycle management of a package model.
A policy service 342 (data and computational service) can be a generic service and has the responsibility of dispatching policy evaluation requests to the appropriate specific policy services. A request resolution service 344 (computational service) can be responsible for initiation of the instantiation process of models. A request for change (RFC) execution service 346 (data service) can be responsible for the management of the lifecycle of RFCs in the platform. A RFC scheduling service 348 (computational service) can be responsible for finding optimal schedules for RFC in the platform.
A session service 352 (data service) can be responsible for the management of the lifecycle of sessions. The create method generates a new session in the open state associated with a new, unique SessionKey. Changes to the session state, such as closing the session can be done through the update method. A validation service 354 (computational service) can be responsible for the validation of an order.
A change catalog service 356 can be responsible for the management of changes to the catalog, such as changes due to new features, software updates, hardware availability, etc. The consumer management service 358 can be responsible for providing an interface for consumers and manages retrieving service offerings, ordering services, retrieving changes, making order changes, establishing logins, and the like. The provider management service 360 can be responsible for providing an interface for providers, thus allowing management of users and profiles, designs, designs supported, pricing, and the like. In various embodiments, the consumer management service 358 and/or the provider management service 360 coordinates with the session service 352 to provide an interface for users.
FIG. 4 is a flow chart of a method for managing IT services, according to an embodiment. In a particular embodiment, the method may be used to manage the model 100 described with reference to FIGS. 1A and 1B . In an embodiment, the method may be used to manage IT services provided by the architecture 200 deployable in an e-commerce environment. At step 410 , declarative specifications of the services are captured as a service models. At step 420 the service models can be combined into a plurality of service offerings to provide a catalog of orderable services. At step 430 , an order can be received for at least one orderable service selectable from the catalog of orderable services. At step 440 , the at least one orderable service can be instantiated, thereby generating an instantiated ordered service. At step 450 , the order can be fulfilled in accordance with the instantiated ordered service.
It is understood, that various steps described above may be added, omitted, combined, altered, or performed in different orders. For example, a step may be added to refine the service models. At step 460 , the service models can be refined, the refining including a multi-step transition from the service models to a refined service model instance.
FIG. 5 illustrates a block diagram of an active enclosure 500 , according to an embodiment. The active enclosure 500 is a computer system and includes dedicated resources 510 , and may be coupled to one or more blade and hardware resources 520 . The dedicated resources 510 include a processor 530 coupled to a memory 540 . The memory 540 is operable to store program instructions 550 that are executable by the processor 530 to perform one or more functions. It should be understood that the term “computer system” is intended to encompass any device having a processor that is capable of executing program instructions from a memory medium. In a particular embodiment, the various functions, processes, methods, and operations described herein may be implemented using the active enclosure 500 . For example, the model 100 , the architecture 200 , the configure-to-order system 202 and similar others may be implemented using the active enclosure 500 .
Components of the active enclosure 500 comprise a server 560 . In some embodiments, the server 560 includes the dedicated resources 510 . In other embodiments, the server 560 includes the dedicated resources 510 and some hardware resources 520 .
The various functions, processes, methods, and operations performed or executed by the active enclosure 500 can be implemented as the program instructions 550 (also referred to as software or simply programs) that are executable by the processor 530 and various types of computer processors, controllers, central processing units, microprocessors, digital signal processors, state machines, programmable logic arrays, and the like. In an example, non-depicted embodiment, the active enclosure 500 may be networked (using wired or wireless networks) with other active enclosures and/or computer systems.
In various embodiments the program instructions 550 may be implemented in various ways, including procedure-based techniques, component-based techniques, object-oriented techniques, rule-based techniques, among others. The program instructions 550 can be stored on the memory 540 or any computer-readable medium for use by or in connection with any computer-related system or method. A computer-readable medium is an electronic, magnetic, optical, or other physical device or means that can contain or store a computer program for use by or in connection with a computer-related system, method, process, or procedure. Programs can be embodied in a computer-readable medium for use by or in connection with an instruction execution system, device, component, element, or apparatus, such as a system based on a computer processor, or other system that can fetch instructions from an instruction memory or storage of any appropriate type. A computer-readable medium can be any structure, device, component, product, or other means that can store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
The dedicated resources 510 include hardware used for automated management of the dedicated resources 510 and/or the blade and hardware resources 520 . In some embodiments, the automated management includes management of resources external to the active enclosure 500 , as discussed further herein and in FIG. 6 .
The blade and hardware resources 520 are computer systems, computer components, and/or computer hardware, such as storage arrays, network switches, and the like. In some embodiments, the active enclosure 500 does not include blade and hardware resources 520 . In other embodiments, the active enclosure 500 includes one or more blade and hardware resources 520 including one or more computer systems. Hardware within the blade and hardware resources 520 may be coupled to each other, the dedicated resources 510 , and/or networked to other computer systems. In some embodiments, one or more program instructions are executed via the blade and hardware resources 520 .
In one embodiment, active enclosure 500 provides a turn key system that combines/integrates generic management software with hardware, wherein the management software acts as a runtime environment for the management of the hardware resources. Also, in various embodiments, the active enclosure 500 is self sufficient and may be configured to run independently of other software. In some embodiments, the active enclosure 500 is an open architecture in which management services may be substituted by other services running outside the active enclosure 500 .
FIG. 6 illustrates an architecture 600 for an active enclosure with a master-slave relationship, according to an embodiment. The architecture 600 includes an active enclosure 500 coupled to an active enclosure slave 620 . The active enclosure 500 includes a management component 610 . As discussed herein, through federation, one or more active enclosures, such as the active enclosure 500 , may be networked together and via the management component 610 coordinated one or more services operating on several computer systems. In various embodiments, federation may be performed via a master-slave pattern in which one active enclosure operates as a master and one or more other active enclosures operate as slaves, subordinate to the master. Using a master-slave relationship allows for coordination and/or collaboration of services, hardware and/or other software resources between several active enclosures. Federation allows easy, dynamic and scalable systems. In various embodiments, different services may be instantiated on the master server and/or on one or more different slaves.
FIG. 7 illustrates a block diagram 700 of a management component 610 of an active enclosure, according to an embodiment. In embodiments of block diagram 700 , the management component 610 includes a provider management service 360 , a consumer management service 358 , a design service 318 , an authentication service 306 , an offering availability estimation service 334 , a configuration management service 314 , an authentication service 306 , a catalog service 312 , an order processing service 336 , a change catalog service 356 , a request resolution service 344 , an approval service 304 , a billing service 308 , an RFC scheduling service 348 , a creation configuration service 316 , a monitoring service 332 , an activation service 302 , and an installer service 326 . In other embodiments, the management component 610 includes a combination of fewer, more and/or different services, such as a discovery service 322 , an incident service 324 , a logging service 328 , a policy service 342 , a session service 352 , like services and other services.
In various embodiments, the active enclosure 500 has one or more services that have a management interface, such as the provider management service 360 and consumer management service 358 . In some embodiments, the active enclosure 500 has several management interfaces and may be selected and/or determined by user privileges. For example, an administrator management interface may be accessed by an administer using an administrator management service, not depicted. The provider management service 360 is coupled to several other services, such as the design service 318 , the authentication service 306 , and the offering availability estimation service 334 . Similarly, the consumer management service 358 is coupled to several other services, such as the authentication service 306 , the catalog service 312 , the order processing service 336 , and the change catalog service 356 . In some embodiments, management services are standardized and commoditized which may lower overall development costs, provide guidelines for developers, and increase active enclosure value and usefulness.
The arrows depicted within the management component 610 show a flow direction of information. For example, the design service 318 requests information from and provides information to the offering availability estimation service 334 . In various embodiments, the information flow may be unidirectional and/or bi-directional.
FIG. 8 is a flow chart of a method for managing IT services of an active enclosure, according to an embodiment. In a particular embodiment, the method may be used to instantiate services offered by the active enclosure 500 with reference to FIG. 5 . In an embodiment, the method may be used to manage IT services provided by the architecture 200 deployable in an e-commerce environment. At step 810 , available hardware is determined, such as hardware from dedicated resources 510 and/or blade and hardware resources 520 . In various embodiments, the available hardware includes at least one server. The available hardware may be hardware currently available and/or hardware designed to be available. For example, if particular hardware is being used for another purpose, it may be determined that this particular hardware is not available at this time. In some embodiments, a hardware discovery service, such as discovery service 322 , is used to discover and to determine available hardware. Available hardware may be within the active enclosure, within a different active enclosure of the services performing the discovering, and/or outside an active enclosure. In various embodiments, the available hardware is supplied and/or modified via user input.
At step 820 , computer executable services are determined. The services are determined based in part on the available hardware, the hardware performance, and/or the services accessible by the active enclosure 500 . For example, if a service and/or a service level requires an aggregate and/or average computer performance, and the available hardware is insufficient for the service, the service will be determined as unavailable, that is, the service will not be displayed as an offering. Some computer performance characteristics include response time, throughput (the rate of processing), utilization rates, and availability. Some computer performance metrics may include availability, response time, channel capacity, latency, completion time, service time, bandwidth, throughput, relative efficiency, scalability, performance per watt, and speed up. In parallel computing, speedup refers to how much a parallel algorithm is faster than a corresponding sequential algorithm.
At step 830 , a catalog of the computer executable services are displayed. The displayed services may be dependent on a user interface, a user's permission level, and/or the determined hardware. Similar services may be displayed or grouped together for easier selection. Different levels and/or performance of the same or similar service levels may also be displayed. In some embodiments, the catalog displays granulation of services, such as different levels of security and/or performance levels. For example, a user is presented with a high level and medium level of security.
In various embodiments, the catalog display is dynamic. For example, if a user selects a service and only one particular operating system functions well with that service, previously presented operating systems may be removed as to narrow the selection of appropriate operating systems. In some embodiments, the management component 610 determines an operating system based in part on a selected service. In various embodiments, a display of computer executable services is dynamic as resources are allocated for selected services. For example, if ten high performance web servers are selected and the available hardware near full capacity, then some other services that would require more than a capacity of the available hardware is no longer displayed.
At step 840 , the active enclosure 500 receives a selection of a service of the computer executable services. In various embodiments, a selection may be a bundle of services and/or performance levels, for example, a high performance database may be bundled with an operating system. In some embodiments, the catalog options are dynamic and may change depending on a user's selection. For example, if a user selects a database with high performance, some options previously presented may be removed, as the combination of the selected service may not be optimal with the removed services. In some embodiments, the selectable services may change dynamically via communications between the consumer management service 358 , the catalog service 312 , the change catalog service 356 , and the offering availability estimation service 334 . In various embodiments, the received selection may be a selection of the declarative specification.
At step 850 , the selected service is instantiated. The service may be instantiated on the active enclosure 500 , on a slave active enclosure, such as active enclosure slave 620 , another computer, and/or a combination of computers, as in the case where multiple computers are used. The service is instantiated from a service model. The service model includes the selected service. In various embodiments, the service model includes one or more other service models containing multiple service selections. The service model may be saved and/or stored for later use. In various embodiments, a previous selection of services may be dynamically modified, increased, and/or decreased at any time. For example, if a user wished to downgrade from a high power web service to a medium power web server, the service model may be changed. Thereby, further instantiation of the service model may generate different end points on different resources. In some embodiments, management software allocates resources and end points for multiple service models upon instantiation.
In various embodiments, the management component 610 transfers data over the Internet to generate the service model. Data transferred may include a security key, a license, updates, and/or a full service application. In some embodiments, the management component 610 transfers data over the Internet to instantiate the service model. In various embodiments, service models capture a key value of a vendor, which allows new models to be added at run time without any changes to management software to deploy new services on hardware resources.
It is understood, that various steps described above may be added, omitted, combined, altered, or performed in different orders. For example, a step may be added to refine the service model, and then instantiate the service model. Additionally, at step 840 , the offered services can be refined, the refining including a multi-step transition from the service models to a refined service model instance.
The foregoing descriptions of example embodiments have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the teaching to the precise forms disclosed. Although the subject matter has been described in a language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. | A method comprises determining available hardware, determining computer executable services based in part on the available hardware, displaying a catalog of the computer executable services, receiving a selection of at least one service of the computer executable services, and instantiating the at least one service on the at least one server. The available hardware comprises at least one server. | 53,970 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a signal recording apparatus and method, a signal reproducing apparatus and method, a medium, and an information assembly.
2. Description of the Related Art
As the high efficient encoding system employing the VLC (Variable Length Coding) or DCT (Discrete Cosine Transform), the DVCPRO (trade name, defined in SMPTE314M as the compression method) or the MPEG (Moving Picture Experts Group) compression is provided, but the details of these compression methods are different. For example, in order to convert a DVCPRO bit stream into an MPEG bit stream, it was necessary that the DVCPRO bit stream is once uncompressed to restore the image data, which is then MPEG compressed again.
However, with the above method, since the DVCPRO bit stream is once uncompressed to restore the image data, which is then MPEG compressed again, the video signal is compressed twice, resulting in a problem that the image quality is degraded inevitably.
On the contrary, the present inventor proposed a conversion method which is able to convert a bit stream subjected to the DVCPRO compression to an MPEG bit stream, only by employing the bit stream conversion (refer to Japanese Patent Laid-Open No. 2000-165879). However, the present inventor found a problem that the number of quantization steps may be sometimes extended to implement a compression method which is capable of such bit stream conversion, in which case the conventional compression method can not be employed.
SUMMARY OF THE INVENTION
In view of the above-mentioned problems, it is an object of the invention to provide a signal recording apparatus and method which can implement a compression method capable of expanding the number of quantization steps, a signal reproducing apparatus and method which can reproduce a signal compressed in accordance with the compression method, a medium, and an information assembly.
One aspect of the present invention is a signal recording apparatus, comprising:
quantization means of quantizing a signal employing a quantization step;
quantization information creating means of creating plural pieces of quantization information to specify said quantization step;
encoding means of generating an encoded signal from said quantized signal; and
recording means of recording a compressed signal having data containing said plural pieces of quantization information and said encoded signal.
Another aspect of the present invention is the signal recording apparatus wherein said quantization step is a product of a basic quantization step and a multiplier factor to be combined with said basic quantization step, and
said data is a quantization number for specifying said basic quantization step and the multiplier factor information for specifying said multiplier factor to be combined with said basic quantization step.
Still another aspect of the present invention is the signal recording apparatus wherein said quantization step is uniform in a macro block comprised of DCT blocks,
said quantization number is recorded for each said macro block, and
said multiplier factor information is recorded for each said DTC block.
Yet another aspect of the present invention is the signal recording apparatus further comprising range conversion means of range converting said quantized signal using a range conversion multiplier factor which is represented as the power of 2,
wherein said data had the information regarding said range conversion multiplier factor.
Still yet another aspect of the present invention is the signal recording apparatus wherein said quantization step is a product of a basic quantization step and a multiplier factor to be combined with said basic quantization step, and
said plural pieces of quantization information are a quatization number for specifying said basic quantization step and the multiplier factor information for specifying said multiplier factor to be combined with said basic quantization step,
wherein the information involving the range conversion multiplier factor means the overall multiplier factor information consisting of the information regarding the range conversion multiplier factor and the information on the basis of said multiplier factor information.
A further aspect of the present invention is the signal recording apparatus wherein the multiplier factor to be combined with said basic quantization step is the power of 2, said multiplier factor information being the power exponent,
and said overall multiplier factor information is a sum of its power exponent and the power exponent of the range conversion multiplier factor represented as the power of 2.
A still further aspect of the present invention is the signal recording apparatus wherein said quantization step is uniform in a macro block comprised of DCT blocks,
said quantization number is recorded for each said macro block, and
said sum is recorded for each said DTC block.
A yet further aspect of the present invention is the signal recording apparatus wherein said signal has 12 bits,
said range converted signal has 9 bits, and
said overall multiplier factor information had 2 bits or less.
A still yet further aspect of the present invention is a signal recording method, comprising the steps of:
quantizing a signal employing a quatization step;
creating plural pieces of quantization information to specify said quantization step;
generating an encoded signal from said quantized signal; and
recording a compressed signal having data containing said plural pieces of quantization information and said encoded signal.
A further aspect of the present invention is a signal reproducing apparatus, comprising:
reproduction means of reproducing the data containing plural pieces of quantization information for specifying a quantization step used in quantizing the signal and an encoded signal to be generated from said quantized signal from a compressed signal recorded as a signal having the data and said encoded signal;
quantization step configuration means of configuring a quantization step on the basis of plural pieces of said reproduced quantiztion information; and
inverse quantization means of making the inverse quantization in accordance with said configured quantization step on the basis of said reproduced encoded signal.
An additional aspect of the present invention is the signal reproducing apparatus wherein said quantized signal is range converted using a range conversion multiplier factor which is represented as the power of 2, and
said data has the information regarding said range conversion multiplier factor,
said signal reproducing apparatus comprising inverse range conversion means of making the inverse range conversion on the basis of said encoded signal and the information regarding said range conversion multiplier factor,
said inverse quantization in accordance with said configured quantization step being effected for said signal which has undergone the inverse range conversion on the basis of said encoded signal.
A still additional aspect of the present invention is the signal reproducing apparatus wherein said quantization step used in quantizing the signal is a product of a basic quantization step and a multiplier factor to be combined with said basic quantization step, and
said plural pieces of quantization information is a quantization number for specifying said basic quantization step and the multiplier factor information for specifying said multiplier factor to be combined with said basic quantization step,
wherein the information involving said range conversion multiplier factor means the overall multiplier factor information consisting of the information regarding its range conversion multiplier factor and the information of the basis of said multiplier factor information.
A yet additional aspect of the present invention is the signal reproducing apparatus wherein the multiplier factor to be combined with said basic quantization step is the power of 2, said multiplier factor information being the power exponent, and
said overall multiplier factor information is a sum of its power exponent and the power exponent of the range conversion multiplier factor represented as said power of 2.
A still yet additional aspect of the present invention is the signal reproducing apparatus wherein said quantization step used in quantizing said signal is uniform in a macro block composed of DCT blocks,
said quantization number is recorded for each said macro block, and
said sum is recorded for each said DTC block.
A supplementary aspect of the present invention is the signal reproducing apparatus wherein said quantization step configured is a product of a not greater value among the minimum value of the sums recorded for said DCT blocks within said macro block and the maximum value which the multiplier factor information for specifying the multiplier factor to be combined with the basic quantization step can take, and a quantization number recorded for each said macro block.
A still supplementary aspect of the present invention is a signal reproducing method, comprising the steps of:
reproducing the data containing plural pieces of quantization information for specifying a quantization step used in quantizing a signal and an encoded signal to be generated from said quantized signal from a compressed signal recorded as a signal having the data and said encoded signal;
configuring the quantization step on the basis of plural pieces of said quantization information reproduced; and
making the inverse quantization in accordance with said configured quantization step on the basis of said reproduced encoded signal.
A yet supplementary aspect of the present invention is a medium for carrying a program and/or the data for enabling a computer to execute all or some functions provided for means in whole or part of the invention wherein said medium can be processed by said computer.
A still yet supplementary aspect of the present invention is a medium for carrying a program and/or the data for enabling a computer to execute all or some operations provided for steps in whole or part of the invention wherein said medium can be processed by said computer.
Another aspect of the present invention is an information assembly which is a program and/or the data for enabling a computer to execute all or some functions provided for means in whole or part of the invention.
Still another aspect of the present invention is an information assembly which is a program and/or the data for enabling a computer to execute all or some operations provided for steps in whole or part of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory view for explaining an embodiment of the present invention;
FIG. 2 is a table for effecting a quantization step conversion in the embodiment of the invention (two tables are provided on account of space consideration);
FIG. 3 is a table for effecting a basic quantization number conversion in the embodiment of the invention;
FIG. 4 is a table for effecting a multiplier factor conversion in the embodiment of the invention;
FIG. 5 is a block diagram for explaining an embodiment 2 of the invention;
FIG. 6 is an explanatory view for explaining an embodiment 3 of the invention;
FIG. 7A is an explanatory view for explaining an input signal which is to be D-range converted in the embodiment of the invention.
FIG. 7B is an explanatory view for explaining an output signal which has been D-range converted in the embodiment of the invention;
FIG. 8 is a block diagram for explaining an embodiment 4 of the invention;
FIG. 9 is an explanatory view for explaining an embodiment 5 of the invention; and
FIG. 10 is a block diagram for explaining an embodiment 6 of the invention.
DESCRIPTION OF SYMBOLS
501 , 801 Input terminal
502 , 802 Blocking unit
503 , 803 Orthogonal transformation unit
504 , 804 Quantizer
505 , 806 Variable length encoder
506 , 807 Quantization step converter
507 , 809 Formatter
508 , 810 Recorder
509 , 811 , 1011 Magnetic tape
805 D-range converter
808 Adder
1001 Output terminal
1002 Inverse blocking unit
1003 Inverse orthogonal transformation unit
1004 Inverse quantizer
1005 D-range expander
1006 Variable length decoder
1007 Quantization step creating unit
1008 Minimum multiplier factor information detector
1009 Inverse formatter
1010 Reproducer
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present inventor proposed a conversion method which is able to convert a bit stream subjected to the DVCPRO compression to an MPEG bit stream, for example, only by employing the bit stream conversion, as described before (refer to Japanese Patent Laid-Open No. 11-264521). To implement the compression method capable of such bit stream conversion, it is often required to increase the number of quantization steps or the effective number of bits for the AC component after quantization. However, if they are simply increased, the data cannot be recorded in accordance with the conventional compression method.
Thus, the present inventor invented a new compression method capable of bit stream conversion as previously described, and a new reproduction method for reproducing a signal compressed in accordance with such compression method. These compression and reproduction methods will be described below with reference to the drawings.
(Embodiment 1)
Referring now to FIGS. 1 to 4 , a video signal recording method according to an embodiment 1 of the invention will be described below. FIG. 1 is an explanatory view for explaining the video signal recording method according to the embodiment 1. In this embodiment, it is assumed that the number of quantization steps that allows for the recording is 15 kinds, as represented in terms of four bits, and the number of quantization steps for use in the quantization is 31 kinds, as represented in terms of five bits.
As shown in FIG. 1 , an input signal is quantized, and a quantized signal and a quantization step used in the quantization, are output as the data. Normally, the quantized signal is variable length encoded and recorded together with the quantization step used, but because a greater number of quantization steps are used in this embodiment, they can not recorded directly. Therefore, the number of steps is reduced from 31 kinds to 15 kinds, employing the following method.
That is, the quantization step used in the quantization is divided into a basic quantization step and a multiplier factor, employing a table as shown in FIG. 2 (two tables are provided on account of space consideration). For example, if the quantization step used is 72, the basic quantization step is 18 and the multiplier factor is 4.
Then, the basic quantization step is converted into the quantization number, employing a table as shown in FIG. 3 , and the multiplier factor is converted into the multiplier factor information, employing a table-as shown in FIG. 4 . In the above example, the quantization step 18 and the multiplier factor 4 are converted into the quantization number 10 and the multiplier factor information 2 , respectively.
The quantization number and the multiplier factor information as obtained in this way are recorded together with the data obtained by variable length encoding the quantized signal.
Note that the location for recording the multiplier factor information as shown in the embodiment 1 is arbitrary. For example, it may be a location for recording the class information in a unit of DCT block in the DVCPRO compression, which is unnecessary to implement a compression method for creating a DVCPRO bit stream which can be bit stream converted into an MPEG bit stream, as explained in this embodiment (in this case, the multiplier factor itself may be recorded instead of the multiplier factor information). Of course, in the previous case, the location for recording the quantization number of MPEG bit stream may be, for example, the location at which the quantization number of the original MPEG bit stream has been recorded. In this way, the number of quantization steps can be extended by recording the quantization number corresponding to the basic quantization step for determining the quantization step and the multiplier factor information indicating the multiplier factor.
Note that if the multiplier factor information is recorded in a unit of DCT block, it is possible to limit the range of an error within a DCT block where the error has occurred, even when the error has occurred in the multiplier factor information recorded.
If the quantization step is divisible, as described above, the information required for the quantization is increased by the amount of multiplier factor (e.g., if each of 31 quantization steps is represented in terms of four bits, 4×31=124 bits are required in the embodiment 1, but the quantization step is divided as above described, 4×15(basic quantization step)+4×3(multiplier factor)=72 bits are only required). Accordingly, in the case where a quantization table containing the elements of quantization steps is defined, it is possible to suppress the increasing amount of information.
The quantization step, the basic quantization step, the multiplier factor, the quantization number, and the multiplier factor information as employed in the embodiment 1 and shown in FIGS. 2 to 4 are only illustrative. In brief, the quantization step for use may be a multiplication of the basic quantization step and the multiplier factor.
If the quantization step used in the quantization is converted into the quantization number and multiplier factor information which are recordable, as described above, the number of quantization steps for use in the quantization can be extended.
(Embodiment 2)
Referring now to FIG. 5 , the configuration of a video signal recording apparatus in an embodiment 2 will be described below. FIG. 5 is a block diagram for explaining the configuration of the video signal recording apparatus in the embodiment 2. In this embodiment, it is assumed that the recordable number of quantization steps is 15 kinds as represented in terms of four bits, and the number of quantization steps for use in the quantization is 31 kinds as represented in terms of five bits.
In FIG. 5 , reference numeral 501 denotes an input terminal for inputting a video signal, reference numeral 502 denotes a blocking unit for dividing the input signal into blocks, reference numeral 503 denotes an orthogonal transformation unit for making the discrete cosine transform of the input video signal, reference numeral 504 denotes a quantizer for quantizing the video signal which has undergone the discrete cosine transform, reference numeral 505 denotes a variable length encoder for variable length encoding the quantized video signal, reference numeral 506 denotes a quantization step converter for converting the quantization step used in the quantization, reference numeral 507 denotes a formatter for transforming the input signal into the recordable data format, reference numeral 508 denotes a recorder for recording the input signal, and reference numeral 509 denotes a magnetic tape.
The quantizer 504 corresponds to quantization means of the invention; the quantization step converter 506 corresponds to quantization information creating means of the invention; variable length encoder 505 corresponds to encoding means of the invention; and means comprising the formatter 507 and the recorder 508 corresponds to recording means of the invention.
Referring to FIG. 5 again, the operation of the video signal recording apparatus in this embodiment 2 will be described below.
The blocking unit 502 divides a video signal input via the input terminal 501 into DCT blocks, and builds up a macro block by collecting a plurality of DCT blocks. The orthogonal transformation unit 503 performs the discrete cosine transform for the DCT blocks within the macro block for output to the quantizer 504 .
The quantizer 504 quantizes an alternating current component of a DCT block having undergone the discrete cosine transform within the macro block, which is an input signal, employing any quantization step among 31 kinds of quantization steps as shown in FIG. 2 , and outputs the quantized signal to the variable length encoder 505 and the quantization step used to the quantization step converter 506 , respectively.
The quantization step converter 506 obtains the quantization number and the multiplier factor information from the input quantization step, employing the method as explained in the embodiment 1, and outputs them to the formatter 507 . Also, the variable length encoder 505 applies the variable length coding to the alternating current component of the input signal for output to the formatter 507 .
The formatter 507 converts the direct current component of the input DCT block within the macro block which has undergone the discrete cosine transform, the alternating current component which is variable length encoded, the quantization number, and the multiplier factor information into the data format for recording and outputs them to the recorder 508 .
The recorder 508 records the input signal on the magnetic tape 509 .
As described above, the quantization step converter 506 converts the quantization step used in the quantization into the quantization number and the multiplier factor information which are recordable. In this way, the quantization step for use in the quantization can be extended. Also, by recording the multiplier factor information in a unit of DCT block, as previously described, it is possible to limit the range of an error within a DCT block where the error has occurred, even when the error has occurred in the recorded multiplier factor information.
In the embodiment 2, the location at which the multiplier factor information is recorded is also arbitrary. The multiplier factor itself may be recorded. The quantization step, the basic quantization step, the multiplier factor, the quantization number, and the multiplier factor information are only illustrative, as in the embodiment 1, and may take different values.
The extension in this embodiment 2 is effective not only to the magnetic tape, but also to the data on the digital interface, which is output to the formatter 507 .
(Embodiment 3)
Referring now to FIGS. 6 and 7 , a video signal recording method according to an embodiment 3 of the invention will be described below. FIG. 6 is an explanatory view for explaining the video signal recording method according to the embodiment 3. In this embodiment, it is assumed that the recordable number of quantization steps is 15 kinds as represented in terms of four bits, and the number of quantization steps for use in the quantization is 31 kinds as represented in terms of five bits. It is also assumed that the bit precision of the AC component capable of variable length coding is nine bits, and the output of quantization is twelve bits.
In FIG. 6 , an input signal is quantized, and the quantized signal, and the quantization step used in the quantization are output as the data. In this embodiment 3, the quantization step used can not be recorded directly owing to the same reason as in the embodiment 1.
Therefore, the number of quantization steps is reduced from 31 kinds to 15 kinds, with reference to FIGS. 2 and 3 , owing to the same method as in the embodiment 1. In this embodiment 3, to record in combination with the multiplier factor taking place in making a D-range (dynamic range) transformation as will be described later, the multiplier factor introduced to record the quantization step is represented by 2 to the C-th power (the multiplier factor in FIG. 2 is already set to 2 to the C-th power and may be used directly). Herein, when the quantization step of FIG. 2 is used, the value of C takes three kinds, 0, 1 and 2.
The D-range conversion will be described below. In this embodiment 3, the bit precision of the AC component capable of variable length coding is nine bits, and the quantized output is twelve bits, as previously described.
An input signal with an effective bit number of twelve bits has an effective bit number of twelve bits after being quantized. However, since the effective bit number which can be treated with the variable length coding in this embodiment is nine bits, it is required that the effective number bit of the quantized input signal is reduced from twelve bits to nine bits.
Thus, the D-range conversion in a unit of DCT block will be performed employing an explanatory view of FIG. 7 . FIG. 7A is an explanatory view of the input signal which will undergo the D-range conversion, and FIG. 7B is an explanatory view of an output signal which has undergone the D-range conversion.
That is, for the quantized input signal, the D-range (absolute value excluding the sine bits (see FIG. 7 )) within each DCT block is first calculated, and the input signal of twelve bits is transformed into the data of nine bits and the multiplier factor by deleting upper bits and lower bits, depending on this value of D-range, as shown in FIG. 7 .
Herein, the value of 2 to the Z-th power is produced as the multiplier factor, in proportion to the number of bits in deleted lower bits. Note that the Z value takes four kinds, 0, 1, 2 and 3 in the conversion from twelve bits to nine bits in this embodiment.
Thus, the overall multiplier factor information in the embodiment 3 is obtained by adding this Z and an power exponent (coefficient) C of a multiplier factor represented as the power of 2 as explained in the embodiment 1. As shown in FIG. 2 , the value of C is equal to 1 or 2 when the quantization step is 10 or greater (see FIG. 2 ). At this time, since it can be considered that the effective bit number of the quantized input signal is within nine bits, the value of Z is always equal to zero (see FIG. 7 ) , and the overall multiplier factor information which is a sum of Z and C is either 1 or 2. As shown in FIG. 2 , when the quantization-step is 8 or less, the value of C is always zero, whereas the overall multiplier factor information which is a sum of Z and C is equal to 0, 1, 2 or 3 in this case (because the value of Z is 3 at maximum, when the quantization step is 1; the value of Z is 2 at maximum, when the quantization step is 2; the value of Z is 1 at maximum, when the quantization step is 4; and the value of Z is always zero, when the quantization step is 8). In effect, the overall multiplier factor information is 0, 1, 2 or 3, and can be represented in terms of within two bits.
Accordingly, by introducing the MPEG compression, for example, the overall multiplier factor information can be recorded in two bits of the class information in a unit of DCT block which is not employed in the DVCPRO compression as explained in this embodiment (refer to Japanese Patent Laid-Open No. 11-264521). For example, the quantization number as represented (see FIG. 3 ) by any number of 1 to 15 can be recorded in four bits where the quantization number of the DVCPRO compression is recorded, and the quantization number corresponding to the basic quantization step for determining the quantization step and the overall multiplier factor information indicating the multiplier factor is recorded, whereby the number of quantization steps and the effective bit number of the AC component after quantization can be extended in the same recording format as that of the DVCPRO compression as explained in this embodiment.
In this way, the overall multiplier factor information and the quantization number are recorded together with the data obtained by variable length coding the video signal which has been D-range converted. In this embodiment, since the D-range conversion is performed in a unit of DCT block, the overall multiplier factor information is also recorded in a unit of DCT block.
As described above, the quantization step used in the quantization is converted into the quantization number and the multiplier factor which are recordable. Further, the quantized signal is converted into the data with a smaller effective bit number and the multiplier factor by the D-range conversion, and the overall multiplier factor information obtained by adding these two kinds of multiplier factors is recorded, whereby changes of the number of quantization step used in the quantization and the dynamic range of the quantized data can be made.
In this embodiment, the D-range extension is performed in a unit of DCT block, but may be made in a unit of macro block. In this case, the overall multiplier factor information is recorded in a unit of DCT block, whereby it is possible to limit the range of an error within a DCT block where the error has occurred, even if the error has occurred in the overall multiplier factor information recorded.
In the embodiment 3, the location at which the overall multiplier factor information is recorded is also arbitrary. The multiplier factor (i.e., 2 to the power of the overall multiplier factor information) itself may be recorded. The quantization step, the basic quantization step, the multiplier factor, the quantization number, and the overall multiplier factor information are only illustrative, as in the embodiment 1, and may take different values. In effect, the quantization step used may be a multiplication of the basic quantization step and the multiplier factor.
(Embodiment 4)
Referring now to FIG. 8 , the configuration of a video signal recording apparatus in an embodiment 4 will be described below. FIG. 8 is a block diagram for explaining the configuration of the video signal recording apparatus in the embodiment 4. In this embodiment, it is assumed that the recordable number of quantization steps is 15 kinds as represented in terms of four bits, and the number of quantization steps for use in the quantization is 31 kinds as represented in terms of five bits. The bit precision of the AC component capable of variable length coding is nine bits, and the output of quantization is twelve bits.
In FIG. 8 , reference numeral 801 denotes an input terminal for inputting a video signal, reference numeral 802 denotes a blocking unit for dividing the input signal into blocks, reference numeral 803 denotes an orthogonal transformation unit for making the discrete cosine transform of an input video signal, reference numeral 804 denotes a quantizer for quantizing the video signal which has undergone the discrete cosine transform, reference numeral 805 denotes a D-range converter for making the D-range conversion for the quantized signal, reference numeral 806 denotes a variable length encoder for variable length coding the video signal which has been D-range converted, reference numeral 807 denotes a quantization step converter for converting the quantization step used in the quantization, reference numeral 808 denotes an adder for adding the signal produced by the quantization step conversion and the signal produced by the D-range conversion, reference numeral 809 denotes a formatter for converting the input signal into the recordable data format, reference numeral 810 denotes a recorder for recording the input signal, and reference numeral 811 denotes a magnetic tape.
The quantizer 804 corresponds to quantization means of the invention; the D-range converter 805 corresponds to the range converting means of the invention; means comprising the quantization step converter 807 and the adder 808 corresponds to quantization information creating means of the invention; variable length encoder 806 corresponds to encoding means of the invention; and means comprising the formatter 809 and the recorder 810 corresponds to recording means of the invention.
Referring to FIG. 8 again, the operation of the video signal recording apparatus in this embodiment 4 will be described below.
The blocking unit 802 divides a video signal input via the input terminal 801 into DCT blocks, and builds up a macro block by collecting a plurality of DCT blocks. The orthogonal transformation unit 803 performs the discrete cosine transform for the DCT blocks within the macro block, and outputs the transformed DCT blocks to the quantizer 804 .
The quantizer 804 quantizes an alternating current component of DCT blocks having undergone the discrete cosine transform within the macro block, which is the input signal, employing any quantization step among 31 kinds of quantization steps as shown in FIG. 2 , and outputs the quantized signal to the D-range converter 805 and the quantization step used to the quantization step converter 807 , respectively.
The quantization step converter 807 calculates the quantization number and the power exponent (coefficient) C of the multiplier factor as represented in the C-th power of 2 from the input quantization step, employing the method explained in the embodiment 3, and outputs the quantization number to the formatter 809 , and the value of C to the adder 808 , respectively.
The D-range converter 805 converts an alternating current component of the input signal for output to the variable length encoder 806 , employing a method as explained in the embodiment 3, and calculates the value of the power exponent (coefficient) Z of the multiplier factor for output to the adder 808 .
The adder 808 calculates a sum of C and Z which are input, and outputs the sum to the formatter 809 . Also, the variable length encoder 806 applies the variable length coding to the alternating current component of the input signal which has undergone the D-range conversion and outputs the encoded alternating current component to the formatter 809 .
The formatter 809 transforms the direct current component of input DCT block within the macro block which has undergone the discrete cosine transform, the alternating current component which has undergone the variable length coding, the quantization number, and the multiplier factor information into the data format for recording and outputs them to the recorder 810 .
The recorder 810 records the input signal on the magnetic tape 811 . Note that the multiplier factor information is recorded in accordance with the unit used in the D-range extension in this embodiment.
As described above, the quantization step converter 807 transforms the quantization step used in the quantization into the quantization number and the multiplier factor which are recordable. Further, the D-range converter 805 converts the quantized signal into the data with a smaller effective bit number and the multiplier factor by the D-range conversion. The adder 808 creates the overall multiplier factor information obtained by adding these two kinds of multiplier factors. In this way, changes of the number of quantization step used in the quantization and the dynamic range of the quantized data can be made.
In this embodiment 4, the D-range extension is performed in a unit of DCT block, but may be made in a unit of macro block. In this case, the overall multiplier factor information is recorded in a unit of DCT block, whereby it is possible to limit the range of an error within a DCT block where the error has occurred, even if the error has occurred in the overall multiplier factor information recorded.
In the embodiment 4, the location at which the overall multiplier factor information is recorded is also arbitrary. The multiplier factor (i.e., 2 to the power of the overall multiplier factor information) itself may be recorded. The quantization step, the basic quantization step, the multiplier factor, the quantization number, and the overall multiplier factor information are only illustrative, as in the embodiment 3, and may take different values.
The extension in this embodiment 4 is effective not only to the magnetic tape, but also to the data on the digital interface, which is output to the formatter 809 .
(Embodiment 5)
Referring to FIG. 9 , a video signal reproducing method according to an embodiment 5 will be described below. FIG. 9 is an explanatory view for explaining the video signal reproducing method according to the embodiment 5.
This embodiment 5 involves a new video signal reproducing method for reproducing the signal recorded by quantizing each DCT block within a macro block in the same quantization step, employing the video signal recording method as explained in the embodiments 3 and 4. This signal inversely formatted (reproduced) is composed of a variable length encoded signal, the overall multiplier factor information and the quantization number, as will be described later in the embodiment 6.
Thus, among the minimum value of the overall multiplier factor information C+Z and the maximum value which the multiplier factor information C for specifying the multiplier factor to be combined with the basic quantization step can take, a not greater value M is obtained within the macro block, and the D-range extension and the quantization step configuration are effected, as described below.
That is, the variable length encoded signal is decoded in variable length, and the D-range extension is performed, employing a value subtracted by the value M. Herein, supposing that the effective bit number of the signal decoded in variable length is Y bits, the effective bit number of the signal D-range extended is equal to Y bits×(2 to the (overall multiplier factor information−M)-th power)=X bits.
The quantization number is converted into the basic quantization step with reference to a table of FIG. 3 , and the quantization step is configured, employing the value M (i.e., the product of the basic quantization step and the M-th power of 2 is the quantization step) Of course, the inverse quantization of the signal of X bits D-range extended is performed, employing this quantization step.
The inversely quantized signal is subjected to the inverse discrete cosine transform and the inverse blocking, and output as a reproduced signal, as will be described later in the embodiment 6.
As described above, it is possible to reproduce a signal compressed in accordance with a new compression method capable of extending the number of quantization steps.
The reproducing operation with the new video signal reproducing method has been thus described. In the following, explanation will be given of the reason of employing the not greater value M among the minimum value of the overall multiplier factor information and the maximum value which the multiplier factor information for specifying the multiplier factor to be combined with the basic quantization step can take will be described below in connection with an instance of transforming the DVCPRO bit stream into the MPEG bit stream (refer to Japanese Patent Laid-Open No. 11-264521). The overall multiplier factor information is recorded as a sum of the D-range conversion information and the quantization step, as already described in the embodiment 3.
For example, in recording the signal, the overall multiplier factor information is 1 in the cases where in the macro block, (1) the quantization step is 7 (hence C=0) and the exponent (coefficient) Z in the D-range transform is 1, and (2) the quantization step is 14 (hence C=1) (automatically Z=0).
In this embodiment 5, the inverse quantization is made, employing the quantization step of 14 in either case (because the minimum value of the overall multiplier factor is one in either case). On the contrary, a method can be conceived in which the overall multiplier factor information itself (i.e., one) is used to make the D-range extension, and the basic quantization step (i.e., 7) is directly used as the quantization step, unlike this embodiment. Of course, it is possible to employ any of the method of this embodiment and the above method to obtain the same reproduced signal.
Herein, a case will be considered in which the inversely quantized signal as described above is stream transformed into the MPEG stream, without applying the inverse discrete cosine transform and the inverse blocking. Since the variable length coding of MPEG is applied at this time, the code amount can be reduced with the smaller value of AC component in the DCT block. Accordingly, if the reproduced signal is identical, the quantization step should be a greater value, and it is beneficial to make use of a not greater value among the minimum value of the overall multiplier factor information C+Z and the maximum value (herein, 2) which the multiplier factor information C for specifying the multiplier factor to be combined with the basic quantization step can take. This is the reason for using a not greater value M among the minimum value of the overall multiplier factor information and the maximum value which the multiplier factor information for specifying the multiplier factor to be combined with the basic quantization step can take in this embodiment.
As described above, a not greater value M among the minimum value of the overall multiplier factor information and the maximum value which the multiplier factor information for specifying the multiplier factor to be combined with the basic quantization step can take is obtained, and by reflecting its result, the quantization step is configured to be larger, whereby the code amount after the MPEG transcode can be reduced.
(Embodiment 6)
Referring to FIG. 10 , the configuration of a video signal reproducing apparatus will be described below. FIG. 10 is a block diagram for explaining the configuration of the video signal reproducing apparatus according to the embodiment 6. In this embodiment 6, the video signal recording method as explained in the embodiments 3 and 4 is employed to quantize each DCT block within a macro block by using the same quantization step to reproduce a signal.
In FIG. 10 , reference numeral 1011 denotes a magnetic tape on which the signal is recorded, reference numeral 1010 denotes a reproducer for reproducing a signal from the magnetic tape, reference numeral 1009 denotes an inverse formatter for inversely formatting the required information from the reproduced signal, reference numeral 1008 denotes a minimum multiplier factor information detector for detecting a minimum value of the overall multiplier factor information that has been input, reference numeral 1007 denotes a quantization step creating unit for creating the quantization step from an input signal, reference numeral 1006 denotes a variable length decoder for variable length decoding the input signal, reference numeral 1005 denotes a D-range extender for extending the D-range of the input signal, reference numeral 1004 denotes an inverse quantizer for inversely quantizing the input signal, reference numeral 1003 denotes an orthogonal transformer for making the inverse discrete cosine transform of the input signal, reference numeral 1002 denotes an inverse blocking unit for unblocking the input signal, and reference numeral 1001 denotes an output terminal for outputting the reproduced signal.
The inverse quantizer 1004 corresponds to inverse quantizing means of the invention; the D-range expander 805 corresponds to inverse range converting means of the invention; means comprising the quantization step creating unit 1007 and the minimum multiplier factor information detector 1008 corresponds to quantization step constructing means of the invention; and means comprising the inverse formatter 1009 and the reproducer 1010 corresponds to reproducing means of the invention.
Referring now to FIG. 10 again, the operation of the video signal reproducing apparatus in the embodiment 6 will be described below.
The reproducer 1010 reproduces the information from the magnetic tape 1011 , and outputs the reproduced information to the inverse formatter 1009 . The inverse formatter 1009 makes the inverse formatting to reproduce the direct current component, the alternating current component that is variable length encoded, the quantization number, and the overall multiplier factor information from the information reproduced by the reproducer 1010 .
The minimum multiplier factor information detector 1008 detects the minimum value of the overall multiplier factor information, employing the method as described in the embodiment 5, and outputs a not greater value among the minimum value of the overall multiplier factor information C+Z and the maximum value which the multiplier factor information C for specifying the multiplier factor to be combined with the basic quantization step can take to the D-range expander 1005 and the quantization step creating unit 1007 .
The quantization step creating unit 1007 constructs the quantization step, employing the method as described in the embodiment 5, and outputs the constructed quantization step to the inverse quantizer 1004 .
On the other hand, the variable length decoder 1006 variable length decodes the reproduced alternating current component for output to the D-range expander 1005 . Also, the D-range expander 1005 D-range extends the alternating current component input from the variable length decoder 1006 , employing the method as described in the embodiment 5, for output to the inverse quantizer 1004 .
The inverse quantizer 1004 inversely quantizes the alternating current component which is D-range extended by the D-range expander 1005 , using the quantization step input from the quantization step creating unit 1007 , and outputs this to the inverse orthogonal transformer 1003 .
The inverse orthogonal transformer 1003 makes the inverse discrete cosine transform of the alternating current component input from the inverse quantizer 1004 and the direct current component reproduced by the inverse formatter 1009 and input through the same path as the alternating current component, for output to the inverse blocking unit 1002 .
The inverse blocking unit 1002 unblocks a blocked signal, and outputs the reproduced signal to the output terminal 1001 .
As described above, the minimum multiplier factor information detector 1008 calculates the minimum value of the overall multiplier factor information, and the quantization step creating unit 1007 constructs the quantization step to be greater by reflecting the result. In this way, the code amount after the MPEG transcode can be reduced. In this embodiment, the signal can be decoded without obtaining the minimum value of the overall multiplier factor information. Since the minimum value multiplier factor detector 1008 can be dispensed with in such case of decoding, the configuration of the video signal reproducing apparatus can be simplified.
In the embodiments 1 to 4, the recordable number of quantization steps is 15 kinds as represented in terms of four bits, the number of quantization steps for use in the quantization is 31 kinds as represented in terms of five bits. In the embodiments 3 and 4, the bit precision of the AC component capable of variable length coding is nine bits, and the output of quantization is twelve bits. However, those values are adopted for explanation of the specific example, and the present invention is not limited thereto.
While the multiplier factor to be combined with the basic quantization step of the invention is the power of 2 in the above embodiments, the invention is not limited thereto but may take arbitrary number for such multiplier factor.
In the above embodiment, the overall multiplier factor information is a sum of the power exponent of the multiplier factor to be combined with the basic quantization step which is the power of 2, and the power exponent of the range conversion multiplier factor. However, the invention is not limited thereto, but the overall multiplier factor information may be a pair of the multiplier factor to be combined with the basic quantization step which is not the power of 2 and the range conversion multiplier factor itself, for example.
The quantization step used in the quantization of the signal according to the invention is uniform in the macro block composed of DCT blocks in the above embodiments, but may be different in each DCT block within the macro block, for example.
The quantized signal of the invention is range converted in the above embodiments, but may not be range converted, unless required. In the reproduction of such signal, the inverse range conversion is not necessary to perform, and the signal reproducing apparatus of the invention may not have the inverse range converting means.
A medium for carrying a program and/or the data for enabling a computer to execute all or some functions provided for means in whole or part of the above embodiments is produced, and may be used to enable the computer to perform the above operation in accordance with the read program and/or the data.
An information assembly for carrying a program and/or the data for enabling a computer to execute all or some functions provided for means in whole or part of the above embodiments is produced, and may be used to enable the computer to perform the above operation in accordance with the read program and/or the data structure.
Herein, the data involves the data structure, the data format, and the kind of data. Also, the medium involves the recording medium such as ROM, the transmission medium for the Internet, and the transmission medium for light, radio wave and sound wave. Also, the carrying medium involves the recording medium for recording the program and/or the data, and the transmission medium for transmitting the program and/or the data, for example. To be processable by the computer means to be readable by the computer in the case of the recording medium such as ROM, or to be handleable by the computer as a result of transmitting the program and/or the data in the case of the transmission medium. Also, the information assembly involves the software such as the program and/or the data, for example.
As will be apparent from the above description, the video signal recording method of the invention comprises quantizing an input video signal employing L (L≦M×N) kinds of quantization steps among M×N kinds of quantization steps of which the values are determined by the multiplication of M kinds (M≧1) of basic quantization steps and N kinds (N≧1) of multiplier factors, wherein the quantized signal is variable length encoded, the quantization number corresponding to the basic quantization step for determining the quantization step used in the quantization, the multiplier factor information corresponding to the multiplier factor, and the variable length encoded signal are recorded. Thereby, the number of quantization steps can be extended in the same recording format as employed in the DVCPRO compression.
The video signal recording apparatus of the invention comprises block division means of dividing an input video signal into DCT blocks and constructing a macro block from a plurality of DCT blocks, discrete cosine transform means of discrete cosine transforming each DCT block within the macro block, quantization means of quantizing an alternating current component of DCT block which has undergone the discrete cosine transform employing L (L≦M×N) kinds of quantization steps among MXN kinds of quantization steps of which the values are determined by the multiplication of M kinds (M≧1) of basic quantization steps and N kinds (N≧1) of multiplier factors, quantization information determination means of determining the quantization number corresponding to the basic quantization step and the multiplier factor information corresponding to the multiplier factor for determining the quantization step used in the quantization means, variable length coding means of variable length coding the alternating current signal quantized, and recording means of recording the direct current component of DCT block which has undergone the discrete cosine transform, the alternating current signal which is variable length encoded, the quantization number, and the multiplier factor information. Thereby, this video signal recording apparatus can exhibit the same effect as obtained with the video signal recording method of the invention, as described above.
The video signal recording method of the invention comprises quantizing an input video signal employing L (L≦M×N) kinds of quantization steps among M×N kinds of quantization steps of which the values are determined by the multiplication of M kinds (M≧1) of basic quantization steps and N kinds of multiplier factors as represented by 2 to the K-th (K=0, 1, 2, . . . ) power, range converting the quantized signal of X bits into Y (Y<X) bits×(2 to the Z-th power (Z=0, 1, 2, . . . )), variable length coding a Y-bit signal within the range converted signal, and recording the quantization number corresponding to the basic quantization step for determining the quantization step used in the quantization, the overall multiplier factor information corresponding to the sum of the exponent K of multiplier factor and Z obtained in the range conversion, and the variable length encoded signal. Thereby, the effective bit number of the AC component after quantization can be extended.
The video signal recording apparatus of the invention comprises block division means of dividing an input video signal into DCT blocks and constructing a macro block from a plurality of DCT blocks, discrete cosine transform means of discrete cosine transforming each DCT block within the macro block, quantization means of quantizing an alternating current component of DCT block which has undergone the discrete cosine transform employing L (L≦M×N) kinds of quantization steps among M×N kinds of quantization steps of which the values are determined by the multiplication of M kinds (M≧1) of basic quantization steps and N kinds of multiplier factors as represented by 2 to the K-th (K=0, 1, 2, . . . ) power to create a quantized alternating current signal having an effective bit number of X bits, range conversion means of converting the quantized alternating current signal of Xbits into Y (Y<X) bits×(2 to the Z-th (Z=0, 1, 2, . . . )), quantization information determination means of determining the quantization number corresponding to the basic quantization step for determining the quantization step used in the quantization and the exponent K of multiplier factor, multiplier factor determination means of determining the overall multiplier factor information by calculating the sum of K and Z, variable length coding means of variable length coding a Y-bit signal within the quantized alternating current signal which has undergone the range conversion, and recording means of recording the direct current component of DCT block which has undergone the discrete cosine transform, the quantized alternating current signal which is variable length encoded, the quantization number, and the overall multiplier factor information. Thereby, this video signal recording apparatus can exhibit the same effect as obtained with the video signal recording method of the invention, as described above.
A video signal reproducing method of the invention for reproducing a video signal recorded in accordance with the video signal recording method of the invention comprises reproducing the variable length encoded signal recorded, the quantization number and the overall multiplier factor information, and making the inverse quantization by variable length decoding the variable length encoded signal, employing the quantization step which is obtained by multiplying the basic quantization step corresponding to the quantization number by (2 to the P-th power) with the coefficient P corresponding to the overall multiplier factor information. Thereby, the signal recorded in accordance with the video signal recording method of the invention can be reproduced. Further, by using the minimum value of the overall multiplier factor information, the signal can be decoded with the reduced code amount transformed into the MPEG bit stream.
A video signal reproducing apparatus of the invention, which for example reproduces a video signal recorded by the video signal recording apparatus of the invention, comprises reproduction means of reproducing the direct current component recorded in a unit of macro block composed of a plurality of DCT blocks, the alternating current component which is variable length encoded, the quantization number and the overall multiplier factor information, variable length decoding means of variable length decoding the alternating current component which is variable length encoded to create an alternating current signal, quantization step determining means of determining the quantization step by calculating the basic quantization step corresponding to the quantization number and the exponent P corresponding to the overall multiplier factor information and multiplying the basic quantization step by (2 to the P-th power), and inverse quantization means of inversely quantizing the alternating current component with the quantization step. Thereby, the video signal reproducing apparatus of the invention can exhibit the same effect as obtained with the video signal reproducing method of the invention.
As described above, the present invention can provide a signal recording apparatus, a signal recording method, a signal reproducing apparatus, a signal reproducing method, a medium, and an information assembly, which are capable of changing a compression method with less degradation of data than conventionally.
As will be clear from the above description, the present invention has the advantage of implementing the compression method which is capable of extending the number of quantization steps. | A signal recording apparatus includes a quantizer for quantizing a signal employing a quantization step. The apparatus further includes a quantization information creator for creating plural pieces of quantization information to specify the quantization step, an encoder for generating an encoded signal from the quantized signal, and a recorder for recording a compressed signal having data containing the plural pieces of quantization information and the encoded signal. | 58,916 |
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to high speed communications, in particular, to an interface device between a transmitting device and a receiving device of a transmission system, wherein the transmitting device is capable of automatic compensation of cross-talk effects in the interface device by using information stored in an integrated circuit attached to that interface device. .
The present invention is particularly applicable to interfaces to logic and memory devices, to test equipment for testing semiconductor devices and to high speed communications.
2. Background of the Invention
It shall be appreciated that the invention can be applied to a wide variety of fields, though examples and background information, without limitation to the scope of the invention, represent automated semiconductor testing. Test equipment is typically used to determine whether a device under test (“DUT”) follows a set of timing specifications. Accordingly, timing accuracy plays a vital role in the design of test equipment because a discrepancy in the timing accuracy can result in an incorrect classification of a DUT.
A typical test equipment comprises a tester and a device interface board (DIB) connected thereto. A test socket adapted to receive a DUT is mounted on the interface board. A plurality of transmission lines such as coaxial cables or strip lines are provided which join contacts of the test socket and junctions of the interface board with the testing device. The tester and the interface board are interconnected by urging pin electrodes provided on one of them against planar electrodes provided on the other, by pressing planar electrodes provided on both of them against each other, or by engaging connectors provided on both of them with each other. A device to be tested is mounted on the test socket.
A signal generator in the tester generates a test signal of logical levels at specified timings, based on a pattern and a timing signal. The test signal is converted by a driver in the tester into a signal voltage of a predetermined level such as the ECL or TTL level, which is supplied from the tester to pins of the DUT via the transmission lines of the interface board. Then, the resulting DUT output response signals are provided via the transmission lines to the tester, wherein they are compared by a comparator with a reference voltage for the decision of their logical level. Each logical signal based on the decision is compared by a logical comparator with an expected value pattern contained in the data pattern, and the output from the logical comparator is used to determine whether the DUT is good or bad.
In this instance, it is necessary that the timing for sending out the test signal and the timing for fetching the DUT output response signal in the tester be determined taking into account not only the relative delay times between respective circuits in the tester corresponding to the pins of the DUT or delays in the transmission lines but also crosstalk or crosstalk artifacts times of the transmission lines of the interface board which are connected to the pins of the DUT.
The following methods have been proposed to adjust the test signal send-out timing and the DUT output response signal acquisition timing.
According to one of these methods, the transmission lines are made equal in length to make the above-mentioned delay times in the interface board constant, and in the tester, the above-said timing is corrected using data on the constant time. This method suffers from differences between the physical length—all wires are normally the same actual length, and the electrical length for a given pattern. According to another method, the actual lengths of the transmission lines and the delay times are measured, the measured data are stored in a memory provided in the tester and the above-said timing is adjusted using the data read out of the memory. This method tries to adjust delay times by measuring the electrical length of isolated traces. In practice, the electrical length is influenced heavily by crosstalk, so the electrical length during measurement is not an accurate representation of the electrical length in service.
According to still another method, such as described in U.S. Pat. No. 5,225,775, the DUT connection board is equipped with a nonvolatile storage for storing data on the delay times in the transmission line on the connection board corresponding to each terminal of the device under test, and the tester main body unit is so constructed as to adjust the test signal send-out timing and the device output response signal acquisition timing based on the data read out of the storage. Storing the actual topography and topography dependent parameters in a serial presence detect (SPD) memory and adjusting a control signal accordingly is known also from U.S. Pat. No. 6,321,282. This suffers the same problems as previously mentioned, i.e. the electrical length during isolated test differs from that in service due to the neglect of the crosstalk coefficients.
According to U.S. Pat. No. 5,225,775, a calibration procedure is performed by selecting one of a plurality of transmission lines on the connection board and measuring a time required for a signal to pass via this connection board, while all the other transmission lines are silent. Thus, cross-talk from adjacent lines is not taken into account.
As the speeds at which electronic devices operate have increased dramatically and it is not uncommon for these memory devices to run at frequencies at or greater than 100 MHz, the above mentioned methods fails to provide an adequate accuracy of timings. To test at such high frequencies, tester systems include a clock running at or above the maximum frequency at which devices can be tested. As clock frequencies increase, factors such as transmission line crosstalk or crosstalk artifacts such as uneven transmission line performance become significant. To compensate for such variations, some tester systems, such as production-oriented automatic test equipment (ATE) testers, use very high frequency (some as high as 1 GHz) to provide very fine resolutions. However, in these systems crosstalk in signal paths can influence greatly the accuracy of calibration.
Still one more problem arises when the number of testing signals required to test a semiconductor device increases and it becomes more and more complicated technically to compensate timing errors for individual signals in each separate transmission line.
The similar problems arise in high speed communications where it is required to reduce artifacts introduced into a communication channel from the limited and non-linear characteristics of the channel, such as by reflections not being absorbed efficiently or cross-talk between the transmission lines.
BRIEF SUMMARY OF THE INVENTION
Generally, the present invention is directed to an interface device, such as between a transmitter and a receiver in a communication channel, or such as an interface board for a tester system, provided with a means to compensate for uneven transmission line performance, e.g. caused by crosstalk or crosstalk artifacts using stored data on transmission characteristics.
According to one aspect of the invention, an interface device is provided for connecting a transmitting device having a first plurality of terminals and deriving a plurality of signals of a predetermined data pattern, the signals being arranged in groups, and a receiving device having a second plurality of terminals for receiving said signals;
the interface device having, respectively, input connectors connectable to said transmitter's terminals and output connectors connectable to said receiver's terminals, the inputs and outputs being interconnected by transmission lines within said interface device, the transmission lines being arranged in groups corresponding to said groups of signals; and
a storage for storing data on interconnections between said first plurality and second plurality of terminals and data on timing errors caused by crosstalk in each said group of transmission lines, measured with respect to a reference signal and relating to a specific data pattern, for each of said stored interconnection;
wherein the transmitting device is capable of compensating for timing errors in said groups of transmission lines using data read from said memory storage.
In another aspect, a test system is provided incorporating the interface device according to the invention.
In still another aspect, a method of compensation of timing errors in transmission lines is provided comprising the steps of:
transmitting via transmission lines a plurality of signals of a predetermined data pattern to be applied to a semiconductor device, the signals being driven in groups; comparing the output response of a group of signals with a reference signal level; storing in a non-volatile memory data on timing errors in said transmission lines relating to specific data patterns, for each separate group of signals; and compensating for timing errors in said transmission lines for each said group of signals using said data read from said nonvolatile memory.
In still another aspect, a method of testing semiconductor devices employing the above method of compensation is provided.
In FIG. 5 , a typical interface device 52 according to the invention is shown having a plurality of transmission lines within the device (not shown), input connectors 57 for connecting to a tester head, a DUT socket 55 with output connectors 51 for connecting to a DUT and a storage 54 for storing data on interconnections and correction coefficients for compensating for timing errors caused by crosstalk in transmission lines.
According to the present invention, a tester interface such as a DUT interface board (DIB) is equipped with a means for storing the results of measurements of transmission line behavior caused by the combination of crosstalk or crosstalk artifacts and physical manufacturing tolerances or impedance errors in signal paths in a test head and interface board. The timing errors are measured for a group of signals and compensated by applying correction coefficients to a whole group of signals which provides increasing greatly the effectiveness of compensation and reduces time consuming calibration operations. In testers, the information is used to enable accurate calibration of timings of signals associated with a DUT.
In the testing equipment of the above construction according to the present invention, the length of the transmission lines on the interface board corresponding to the respective groups of terminals of the DUT are all known precisely from PCB design software. This software enables the DIB card to be designed so as to completely eliminate inaccuracy caused by errors in trace lengths. What remains are manufacturing errors and crosstalk. While manufacturing errors may be measured at the production stage and the resulting correction coefficients may be stored in a memory storage mounted on a DIB, the effect of crosstalk is still the key source of inaccuracy left which depends on particular data pattern. Measurements of crosstalk and compensation thereof automatically equilibrates variations in manufacturing impedance due to fluctuations in PCB manufacturing process such as fluctuations in thickness, dielectric constants and other technology and material parameters which may be revealed to different extent during usage.
According to the present invention, the data on crosstalk and crosstalk artifacts is stored together with the information about interconnections required for a certain type of the DUT. The data on interconnections is stored in a storage device attached to the DIB and is retrieved automatically when the test is started. As the crosstalk and crosstalk artifacts depend on particular interconnection scheme, the measurements are conducted not only for each test pattern, but for each card interconnection. This is useful as the variety of DUT form factors requires many different DIB cards to be used in connection with each different DUT type. Though the interconnections for different DUT types are different, to unify the DIB card treatment by software, it is very convenient to store the information about DIB card interconnections comprising crosstalk information, in DIB card itself. A more detailed description of the DIB card of the present invention is presented in Attachment A.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a testing device according to the invention;
FIG. 2 is a block diagram illustrating example equipment for measurement of crosstalk in transmission lines of a DIB according to the present invention;
FIG. 3 is a flowchart of the method of compensating crosstalk in test results;
FIG. 4 a is a diagram explaining the influence of crosstalk in the transmission lines of the interface board;
FIG. 4 b is a graph illustrating a calibration procedure in relation to reference signal, wherein the calibration is performed at a rising edge of a clock signal;
FIG. 4 c is a graph illustrating a calibration procedure in relation to reference signal, wherein the calibration is performed at a falling edge of a clock signal;
FIG. 5 is a plan view of an example embodiment of the device interface board.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be further described in detail with reference to the accompanying drawings illustrating an example embodiment of the device interface board for an IC tester. However, it shall be appreciated that the present invention is not limited to ATE and may be equally employed by a specialist in the art to communication equipment.
As shown in FIG. 1 , the DUT testing device is provided with a tester 1 and a device interface board (DIB) 2 . The tester includes a clock generator 11 , a pattern generator 12 , timing control circuits 13 , drivers 14 , receivers 15 and fault comparator 16 for storing the data for cycles containing differences between data provided by pattern generator 12 and DUT 3 . Delays 4 , 5 , 6 are used to provide compensation for timing errors in transmission lines within interface device 2 . The tester is controlled by a computer 18 through interface 17 . The controlling computer may be external as well as an internal computer may be provided.
The clock generator 11 generates, based on an internal operation clock CLK, a clock signal to be applied to the drivers 14 , receivers 15 and DUT 3 through timing control circuits 13 . Timing control 13 comprises a means to control the crosstalk or crosstalk artifacts in output signals from drivers 14 and crosstalk or crosstalk artifacts in receivers' 15 clock signals. The pattern generator 12 operates in synchronization with the system clock CLK from the clock generator 11 to generate patterns to be provided via timing control 13 to the terminal pins of the DUT 3 .
The DIB 2 comprises a storage 4 , such as non-volatile memory, e.g. flash memory, for storing data on timing errors caused by crosstalk or crosstalk artifacts in transmission lines in the board 2 corresponding to each terminal of the DUT to make corrections to the results of tests based on the data read out from the storage 4 . The storage memory shall be of a type allowing to read/write data after each calibration procedure and store them when the device is switched off.
The fault comparator 16 compares the obtained signal from the DUT with the expected value from the pattern generator 12 to produce test results which are downloaded by the computer 18 through interface 17 for further processing by a computer software. The said software uses the crosstalk or crosstalk artifacts data stored in the storage 4 for compensating timing errors in final results for a current data pattern. The same data may be used to manage the timing control circuitry 13 to compensate effects of crosstalk for each particular pattern by adding these data to values which shall define crosstalk or crosstalk artifacts in drivers 14 .
The above test system may be essentially the same as disclosed, for example, in U.S. application Ser. No. 60/209,613 “Test systems for protocol memories” filed on 6 Jun. 2000, or PCT/RU01/00234 filed on Jun. 06, 2001, the specification of which applications is incorporated herein by reference.
As shown in FIG. 2 , on the interface device 22 which is in this example a device interface board (DIB) there is mounted the DUT socket 25 and the transmission lines 26 are provided within the DIB 22 which connect contacts of the socket 25 to the junctions between the DIB 22 and the tester 21 .
The lengths of the transmission lines 26 are the same. Though the transmission lines are separated as a rule by insulation material, they have mutual capacitance and inductance caused by magnetic and electric fields having areas of intersections of force lines as illustrated in FIG. 4 . This cross-talk influence is exacerbated in synchronous systems wherein all the signals are synchronized, i.e. they change state at one and the same time. These effects cause a part of the signal to penetrate from one transmission line into another. As a result, a moment when the signal crosses the threshold at the output of transmission line depends on signals in other transmission lines, i.e. it depends on a particular data pattern. Thus, one of the important features of the present invention is that the timing errors caused by crosstalk effects are measured when the tester is running a test pattern to provide compensation of the timing error caused by this particular combination of signals. The knowledge of the influence of the signal crosstalk for each data pattern provides a basis for crosstalk compensation for each data pattern. Another important feature is that the timing errors are measured for a group of signals and the compensation coefficients are applied to these groups also to adjust the position of this group in whole with respect to a reference signal.
To the contrary, according to a method as described in U.S. Pat. No. 5,225,775, the measurements of the delay times and storing of the measured data into the storage are performed on the stage when the interface device has been fabricated, i.e. with no regard to a particular test pattern, also, the possibility of correcting these data during the exploitation of the interface device in a particular application is neither proposed, nor surmised.
Moreover, according to the known method, the delay times are stored for each transmission line and correction is applied to each signal. However, in practice, in high speed transmission of signals, it has been discovered that the skew between signals within one group is relatively low comparing to the skew between different groups of signals. Thus, it is assumed in the present invention that the timing skew of individual signals within one group is less than the skew of the group of signals in whole. For example, the group skew equal to ±250 ps means that the individual signal skew is lower than ±250 ps.
FIG. 2 illustrates a method according to which the aforementioned timing errors caused by crosstalk in the transmission lines of the interface device are measured and the measured data is stored in the storage on the interface device.
The interface device 22 comprises socket 25 , which can be for example, a DIMM socket. During the calibration, no DUT is mounted on the interface device. Instead, preferably, a crosstalk card 27 is installed in DUT socket 25 . Generally, the crosstalk card is a PCB having no electronic components mounted thereon and comprising contact points 28 which correspond to contact points of a real DUT (e.g. a DIMM) and which are made connectable to oscilloscope probes 29 . To provide maximum accuracy of measurements, the crosstalk card preferably has transmission lines of minimum electrical length and the test points arranged closely to the ground point.
However, in a general case, the use of this card is not necessary, while the probes may be connected directly to interface device 22 close to the DUT socket, or another suitable device may be used for this purpose.
A tester, such as a conventional tester for testing synchronous memory, e.g. BT72 manufactured by Acuid Corporation Limited (Guernsey), comprising a tester head 21 and a tester main body (not shown in FIG. 2 ), is powered on, and the selected data pattern is running. The tester shall be fully in operation and the tester head's flash memory (SPD, serial presence detect) and an interface device 22 shall be initialized with start-up values. At this stage the SPD Reader/Writer software tool is used to initialize the tester head's SPD. The next step is initialization of an SPD installed on the interface device 22 .
The SPD installed on the interface device, or DIB (device interface board), is generally designed so that it comprises at least three arrays of data that is read by the tester and provided to the controlling computer. In the first array, the number and type of the connector of the DIB is stored. In the second array, a table is stored relating to interconnection of contacts of the DUT and test signals. In the third array, correction coefficients are stored that are written to this memory during production and bears information on timing errors in transmission lines, measured during calibration. These correction coefficients are further adjusted according to the invention for crosstalk timing errors.
To obtain the required accuracy of measurements, an oscilloscope 20 is used, which may be a calibrated 1 GHz bandwidth, 4 GS/s sample, or better version digital oscilloscope having at least two active probes having input capacitance not more than 1 pF, for example, TDS794 manufactured by Tektronix Inc. (OR). One probe of the oscilloscope is connected to the crosstalk card 27 at a point CK 0 providing a signal used for triggering the scope, preferably, a clock signal. The second probe of the oscilloscope is connected sequentially to each of the other signal lines.
The signals are grouped in accordance with its functionality, so that, for example, data signals are arranged in separate groups, clock signals are arranged in other separate group, DQ (bi-directional data) signals are arranged in another groups. An example of typical signal grouping is shown in Appendix B.
The crosstalk timing error of a selected group of signals is measured with respect to the reference clock signal CK 0 . Another clock signal CK 1 is used to trigger the scope. Note that, for timing error measurement, all signals are observed on test points of crosstalk card 27 . Both rising and falling edges of a signal being measured are to be considered. To observe them simultaneously, the scope shall be configured so as to accumulate waveforms with reasonable persistence and triggered from a clock signal.
Timing error measurements are performed whilst the system is running a special crosstalk test. This test is running continuously to generate transitions on all signals to be checked. To achieve the best possible precision and resolution, the scope should have only one channel activated when taking measurements. This will ensure that the total sample rate is not divided between several channels but fully assigned to the channel which is used for measurements. The other channel is only used to trigger the scope. For a DDR memory, differential signals are used for measurements.
Before skew measurements, a clock signal delay is measured to provide high accuracy in subsequent calculations.
For initial tuning, a trigger channel connected to CK 1 is enabled and trigger level is adjusted, for example, to 1.4 for SDR memory, or 1.25V for a DDR type memory. When the expected rising edge of the clock is observed, the other channel is connected to CK 0 . This channel is selected as a reference signal for crosstalk measurements. A rising edge of the signal CK 0 is selected close to the edge of CK 1 , and then, the first channel (CK 1 ) is disabled.
If the timing error is measured at 1.4V level, the vertical position of the displayed signal shall be adjusted accordingly, so that the scope's central horizontal line would correspond to the 1.4V level. To measure time intervals, vertical cursors are enabled. The first cursor is set to the point where the center of the clock edge crosses the 1.4V level. Then, the second cursor is selected for measurements, while the position of the first one remains constant, as illustrated in FIG. 4 b and FIG. 4 c , where example diagrams are shown for SDR memory. It shall be mentioned that one and the same scope channel is used for both the reference and measured signals.
The measuring probe is disconnected from CK 0 and connected to a signal that is chosen for timing error measurement. Using the second vertical cursor, two crosstalk measurements are made on each signal, to define the leftmost (T left ) and rightmost (T right ) timing error caused by crosstalk in transmission line. The leftmost timing error is measured at the leftmost point where signal traces cross the selected level on the scope's screen. The rightmost timing error is measured at the rightmost point where signal traces cross 1.4V level on the scope's screen.
The individual signal timing error is a signed value. For points on the left of the reference cursor (read: of the Clock edge) the timing error has a negative value. For points on the right of the first cursor the timing error has a positive value.
The procedure of crosstalk adjustment is iterative, and several iterations of full measurement may be preferably needed.
According to the embodiment of the invention where all fast output signals on the header are driven by multi-bit registers, and each register has its own delay vernier, such as described in PCT/RU99/00194 filed on Oct. 06, 1999, the signals are grouped so that the signals controlled by a selected vernier form one group, and signals controlled by different verniers, form different groups. The skew measurements are performed for groups of signals instead of performing measurements for each individual signal, thereby, the accuracy of measurements is increased and the time consuming measurement operations are reduced.
According to another embodiment, signals are grouped with respect to pin cards, so that the signals relating to a selected pin card form one group. Other criteria may be chosen to group the signals and obtain the advantages mentioned above.
At the first stage, the crosstalk timing error is adjusted in each group of signals. In a first iteration, in each group only a signal having leftmost timing error and a signal having rightmost timing error are considered. The average of these two values is calculated as T update , as shown below.
The update T update to the propagation time for a given group is an additional delay value required to make the leftmost and the rightmost timing error symmetrical with respect to the reference clock. The update value is calculated as follows:
T update =( T left +T right )/2,
where
T left is a minimum left crosstalk timing error value among all the individual signal timing errors measured for signals of the given group;
T right is a maximum right crosstalk timing error value among all the individual signal timing errors measured for all signals of the given group.
The T update is passed on to the SPD card and used further by vernier to shift this group of signals so that the group is centered at this average value at the next step of iterations. Preferably, when the leftmost and the rightmost deviation from the reference are counted in each group, further iterations are performed using only these measurements, and T update values for groups are calculated for all iterations except the final one. The final measurement must be complete to ensure the maximum timing error requirement is met on all signals.
To facilitate the calibration, a special update table may be used with pre-calculated results. The table contains minimum and maximum timing error values entered during current iteration to the table for each group. Update values are calculated for each group in the bottom row of the table and shall be entered in to the respective group tables. As the update values are used in further calculations, they can be adjusted directly in the respective cells of the group tables.
The method of the invention is further illustrated with reference to FIG. 3 .
First, the memory storage that is mounted on the DIB, is initialized, i.e. some initial values shall be written in the memory, for example, zero update values. Second, the calibration procedure is running. The signal crosstalk artifact, such as delay, is measured as has been described in details above. Next step is measuring timing error with respect to the reference clock for fast DUT signals which are most likely to produce minimum and maximum timing error.
An example table providing typical DUT signals, which produce minimum and maximum skew in each Delay Vernier Group is shown below. This example is valid for SYNBASED baseboards and HDRDIMMG header boards.
Delay Vernier Group
Minimum Skew
Maximum Skew
7
DQ10, DQ36
DQ8, DQ38
8
DQ37
DQ39
11
DQ48
DQ60
12
DQ49
DQ63
10
BA1
A4
9
CB0
CB6
13
DQMB1
DQMB7
14
WE
CKE1
15
S2
S0
Once the reference line is selected and the position of the reference signal is fixed on the scope, a crosstalk timing error is calculated as defined by time difference between the position of the measured signal and the position of the reference signal, to obtain thus the relative values in respect to the selected reference. If the crosstalk timing error for these signals is within the desired range, e.g. within ±250 ps for the DDR memory, then, measurements are considered to be completed and the values are stored, otherwise, compensation coefficients are updated and the iterative procedure is continued as has been explained above.
The obtained relative data at the end of the measuring procedure is stored in the flash memory 4 for further usage by the controlling computer software as described above in detail.
As shown in a flow chart in FIG. 3 , the above procedure, as has been mentioned already, has an iterative character because the resulting crosstalk artifacts changes each time when a new compensation values applied and is performed sequentially until the crosstalk timing errors are minimized for a predetermined range when a single time control element, e.g. a vernier, is used to control several signals, or, eliminated, if each signal has a separate time control element.
The flow chart in FIG. 3 can be further modified by adding a step of reading interconnection data or in other way within the scope of the invention as shall be evident for a specialist in the art.
Another example embodiment of the procedure of the invention with respect to DDR memory is illustrated in the Attachment B.
It shall be appreciated also that other embodiments and modifications of the present invention are possible within the scope of the present invention. Thus, the invention may be applied to compensating timing errors in communication systems that can serve to increase the bandwidth of signal transmission. It can be applied to reduce timing dispersion of a signal in cases when signals are transmitted via an optical cable and in various other applications. | The present invention relates to high speed communications, in particular, to an interface device between a transmitting device and a receiving device of a transmission system, wherein the transmitting device is capable of automatic compensation of cross-talk timing errors in the interface device, for a group of signals, by using information stored in a storage attached to that interface device. Preferably, the data stored in said storage comprises data on interconnections between said first and second plurality of terminals and data on crosstalk timing errors in said transmission lines relating to a specific data pattern, for each of said stored interconnection. | 33,107 |
BACKGROUND OF THE INVENTION
The present invention relates broadly to methods and apparatus for controlling yarn package winders and, more specifically, to a method and apparatus for controlling such a winder to effect the relative positioning of the yarn strand during consecutive winds.
Surface winding of natural rubber yarn, spandex, or other elastomeric yarns is a difficult process with unique problems caused by the ability of the yarn to stretch. If the yarn stretches too much during winding, the wound yarn will be under internal tension and such poorly wound yarn can destroy the core about which it is wound or, in the case of rubber yarn, fuse together internally within the package thereby becoming unusable. A typical tension control technique for surface winding rubber yarn concerns the increase or decrease of the speed of the drum driving the yarn package. Since the yarn is under some tension when being wound, increasing the speed can increase the amount of tension experienced by the yarn.
One way the situation wherein the yarn is wound too tightly can become manifest is in the appearance of the wound yarn package itself. Since the yarn is being wound on a traverse, the traverse arm makes one complete cycle for a predetermined number of yarn package or spindle revolutions. The ratio of spindle revolutions to strokes of the traverse is known as the wind ratio. If the wind ratio remains constant throughout the winding process, the resultant process is known as a "precision wind."
As may be appreciated, varying this ratio can affect the pattern formed by the yarn when wound on a core. Typically, the proper appearance of a wound package appears in FIG. 3 wherein the yarn remains as individual strands tracing an individual path. Problems can arise when the yarn appears as in FIG. 4. There, the yarn no longer experiences individual yarn trajectories and ribbons can be formed. These ribbons are repetitive patterns in the wind resulting in a side-by-side closely adjacent parallel orientation of yarn. Due to the stretchability of the yarn and the aforesaid increased tension, packages wound with ribbons can experience localized internal stresses which can damage or destroy the yarn package. Therefore, when winding elastomeric yarn it is desirable to avoid creating ribbons on the package.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a method and apparatus for the elimination of parallel, side-by-side orientation of yarn winding on a yarn package.
It is another object of the present invention to provide such a device and method for prediction of the approach or occurrence of ribbon patterns and to responsively alter winding parameters in response thereto.
It is another object of the present invention to use the wind ratio to predict the upcoming occurrence or approach of ribbons and to correct for the ribbons before they are formed.
As was previously stated, the wind ratio, namely, the revolutions of the spindle to the strokes of the traverse, can be useful in predicting the formation of ribbons or repetitive patterns on the surface of a random wind where the ratio W is constantly changing from its maximum value starting with the empty yarn tube to its minimum value with a maximum diameter of the finished package. Between these limits, whenever twice the ratio passes through any value that can be represented by a rational fraction, a repetitive pattern will be formed on the surface of the package. Since one stroke of the traverse represents one half traverse cycle, multiplying the wind ratio by two accounts for one complete cycle of traverse operation and repetitive patterns must be a multiple of complete traverse cycles. The computation may be simplified by multiplying the ratio (2W) by a factor which must be an integer. The integer factor will provide a simple way to rationalize the fractions into integers so that, if 2WN in equals any integer, a ribbon will be forming. This information may be used to predict the approach of ribbons and, if such an approach occurs, the speed of the traverse may be altered to prevent ribbon formation.
To that end, the present invention provides a method and apparatus to control the winding pattern on a yarn package for traverse winder used for winding elastomeric yarn to prevent repetitive orientation of individual yarn tracks on the package with method comprising the steps of providing an arrangement for monitoring the operation of a yarn package spindle; providing an arrangement for monitoring the operation of a traverse arm associated with a traverse winder; providing an assembly for predicting the occurrence of repetitive patterns of yarn; and providing an arrangement for adjusting the relative speed of the yarn package spindle to prevent the occurrence of the repetitive patterns of yarn. The method further includes the steps of monitoring the operation of the yarn package spindle, monitoring the operation of the traverse arm, predicting the occurrence of a repetitive pattern of yarn strands; and adjusting the relative speed of the yarn package spindle to prevent the occurrence of the repetitive patterns of yarn. It is preferred that the step for monitoring the operation of a yarn package as well as the means to accomplish that step include an arrangement for counting the number of revolutions experienced by the yarn package spindle. Further, the step of providing an arrangement for monitoring the operation of a traverse arm associated with the traverse winder includes providing an assembly for determining the occurrence of a complete traversing movement of the traverse arm associated with the traverse winder, defining a traverse cycle. It is preferred that the step of providing an arrangement for predicting the occurrence of repetitive patterns of yarn includes providing an arrangement for determining a ratio with the ratio being the number of revolutions experienced by the yarn package spindle per traverse cycle to determine a wind ratio and providing an assembly for predicting when the wind ratio will be a rational fraction. Further, the step of providing an assembly for adjusting the relative speed of the yarn package spindle and the traverse arm includes providing an arrangement for changing the speed of the traverse arm. Finally, the previously discussed steps are performed using the apparatus above described. It is further preferred that the wind ratio be doubled and the result multiplied by a predetermined factor with that factor being an integer to determine a derived wind ratio and the method includes providing an arrangement for predicting when the derived wind ratio will be an integer. It is preferred that the step of adjusting the relative speed of the yarn spindle and traverse arm be performed responsive to a determination that the derived wind ratio is approaching an integer.
It is preferred that the apparatus for determining the occurrence of a complete traversing movement of the traverse arm include providing a pulse generator for producing pulses associated with traversing movement. It is further preferred that the assembly for counting the number of revolutions experienced by the yarn package spindle includes providing a pulse counter that has a resolution of at least 0.001 revolution and the assembly for predicting when the wind ratio will be a rational fraction, or the derived wind ratio an integer, includes providing an electrical circuit formed as a comparator with the comparator receiving an input from the yarn package spindle pulse counter and the traverse pulse counter and the method further includes the steps of comparing the pulse counter value to a predetermined baseline value of less than zero to determine a wind ratio factor responsive to the presence of the traverse pulse and when the factor equals zero changing the relative speed of the yarn package spindle and the traverse arm using the arrangement for doing so to prevent repetitive patterns in the yarn.
By the above, the present invention provides a method and apparatus for controlling the appearance of repetitive patterns in a surface wound yarn package of elastomeric yarn.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a yarn winder for winding elastomeric yarn;
FIG. 2 is an elevational view of a traverse winder;
FIG. 3A is an elevational view of a properly wound yarn package illustrating the relationship of individually wound portions of the strand;
FIG. 3B is a detailed view of the surface of the yarn package illustrated in FIG. 3A;
FIG. 4A is an elevational view of a yarn package improperly wound revealing the repetitive patterns on the yarn surface;
FIG. 4B is a detailed view of the surface of the yarn package illustrated in 4A; and
FIG. 5 is a block diagram of the apparatus for predicting the occurrence of repetitive patterns in the yarn wind.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings and, more particularly, to FIG. 1, a winder is illustrated generally at 10 and is configured for multiple traverse winding of individual yarn strands of natural rubber, spandex or other elastomeric yarns. The winder 10 includes several discrete systems mounted on a skeletal frame 12. While the remainder of the present invention will be described relative to the use of natural rubber yarn, it will be appreciated that the principles involved herein are equally applicable to spandex or other elastomeric yarns.
Natural rubber yarn is shipped as a fused tape of individual strands providing a flat, ribbon-like elongate strand 15 of several individual strands fused in a side-by-side relationship. The strand 15 is loosely coiled into a box 11 for shipment and is withdrawn from the box 11 by the winder 10. In that regard, the winder includes a support 14 for yarn leaving the box 11 and, from the support 14, the yarn goes through a stretcher 16 and a tractor/distribution mechanism 18 for ultimate winding on any one of a bank of 24 traverse mechanisms 22. A microcomputer 46 is provided for overall control of the winder 10.
A traverse mechanism 22 is illustrated in FIG. 2. There, a yarn package 28 is illustrated wound on a core 26 which is mounted to a spindle 24 which is in turn mounted to the frame 12 using journals 30. A pulse counter 25 is shown as a box associated with the spindle 24. At this point it should be noted that the present invention uses no esoteric or complex electronic gear to perform its function. Pulse generators, frequency counters, comparator circuits, and switching are all well within the skill of those skilled in the art of control systems. Therefore, the electronics are provided in diagrammatic form for clarity. Since the traverse mechanism 22 represents a surface drive system, a drive roll 32 is rotatably mounted to the frame 12 and is motor driven. The outer surface of the drive roll 32 frictionally contacts the outer surface of the yarn package 28 to drive the yarn package in a yarn take-up manner. A capstan 34 is rotatably mounted to a bracket 35 which is mounted to the frame 12. The capstan 34 provides a debarkation point for maintaining constant tension on the yarn strand 15 as it is being wound. A traverse arm 36 having an eyelet 36' formed in the distal end thereof is caused to oscillate in a traversing manner to guide the yarn 15 onto the package 28. The traverse arm 36 is mounted to a traversing mechanism 37 which is shown in diagrammatic form in FIG. 2 with a portion of the frame 12 broken open to reveal the traverse mechanism. A motor 38 drives a chain mechanism 39 which drives the traverse arm 36. A pulse generator 40 is attached to the motor arm for generating electronic pulses corresponding to the motor's armature rotation. This is one of many possible systems for generating a predetermined number of electrical pulses per traversing cycle.
Since it is known that if 2WN equals any integer, a repetitive pattern or ribbon will occur. Therefore, if it could be predicted when such an integer value would occur, the relative speed of the traverse arm movement and yarn package rotational speed could be adjusted to prevent the integer value of the derived wind ratio from occurring. Looking now at FIG. 5, a block diagram of the electronics required to accomplish the anticipation and avoidance of repetitive patterns is illustrated. The spindle 24 is fitted with a pulse generator 25 which produces, for example, 1,000 pulses per revolution. The pulses from this pulse generator 25 are fed into a countermodule so that the accumulated count will represent spindle revolutions with great accuracy, preferably to three decimal places. A similar pulse generator 41 is coupled to the traverse mechanism 37. This pulse generator 41 produces, for example, 250 pulses per revolution and, if the traverse driving mechanism requires two revolutions per stroke and two strokes per cycle, each 1,000 pulses represents one traverse cycle. These pulses are fed to a counter which will produce a trigger pulse every 1,000 counts. Essentially, a trigger pulse is produced for every traverse cycle. The trigger pulse is fed into the counter keeping track of the spindle revolutions. Upon triggering, the three least significant digits, or the fractional portion, of each sample count will be isolated and compared to a predetermined limit with the limit being set at slightly less than zero, i.e., 0.90 to 0.98. If the difference between the fractional portion of the spindle count and the predetermined limit is zero, then an integer value of the wind ratio is approaching. Consider that, if the wind ratio is an integer, the least three significant digits in the pulse count will also be zero and that means the repetitive pattern is occurring. If the least three significant digits are found to be approaching zero, as determined by the comparison or subtraction circuit, then the least three significant digits are approaching zero; therefore, the wind ratio is approaching zero, and therefore the repetitive pattern is approaching. As a result of this comparison, a signal or trigger pulse can be generated in the speed control circuit to slightly increase the speed, i.e., on the order of one percent to prevent the occurrence of the repetitive pattern.
As can be seen in FIG. 3, a proper random wind of a yarn package 40 offers a pattern 42 where individual winds or individual strand segments defined by circumventions of the yarn package are laid in a random manner, thereby randomly distributing the tension throughout the package and reducing the tendency of the winds to fuse together. As seen in FIG. 4, an improperly wound package 44 includes a series of repetitive patterns 46 seen as closely adjacent parallelly oriented winds. As previously stated, these repetitive patterns can have a detrimental effect on the resultant yarn package.
By the above, the present invention provides a method and apparatus for automatically predicting the occurrence of repetitive patterns of yarn strand segment on a yarn package and providing the necessary operational correction to avoid the patterns' ocurrence.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well asmany variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof. | An apparatus for controlling the winding pattern on a yarn package for traverse winder used for winding elastomeric yarn to prevent repetitive patterns of individual yarn segments on the package includes an apparatus for monitoring the operation of a yarn package spindle, an apparatus for monitoring the operation of a traverse arm associated with a winder, an arrangement for predicting the occurrence of repetitive patterns of yarn strands, and an arrangement for adjusting the relative speed of the yarn package spindle and the traverse arm to prevent the occurrence of thusly predicted repetitive patterns. | 16,486 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of United Kingdom Patent Application No. 0504810.3 filed Mar. 9, 2005.
FIELD OF THE INVENTION
The present invention relates to methods, apparatus and computer programs for consolidating updates to replicated data.
BACKGROUND OF THE INVENTION
A known server in a distributed system can maintain a cache of resources locally to provide independence from centralised infrastructure and/or performance benefits of avoiding network communications. Applications executing on that server make updates to the resources, generally being unaware of the existence of the local cache. If these updates are transactional, then the locks and log entries used to maintain the transactionality will also only have scope local to the server.
At some point it will be appropriate to reconcile the updates made locally with some master state held in a central server. At this point it May be discovered that the state of the updated resources has been changed since the last time the cache was reconciled. Either direct updates on the server may have taken place, or another peer distributed server may have successfully reconciled some changes to the same resources. Since the basis on which the applications made their updates to the cache are now invalid (or at least questionable) it would not be appropriate to reflect those updates in the master state.
In a replicated messaging system using optimistic locks, several applications acting on different replicas may attempt to consume the same message. These actions may be asynchronous. This will be resolved when an arbitrating server ultimately commits one of the optimistic transactions and rolls back all of the others.
U.S. Published Patent Application 2003/0149709 to Banks discloses enabling one or many replicas of a data resource to be updated independently of a master copy of the data resource, and then each replica to be separately consolidated with the master copy. If a data update is applied ‘optimistically’ to a local replica and conflicts with updates applied to the master copy (since the last consolidation with that replica), then the local update will not be applied to the master copy. All updates are treated the same and rolled back together.
Transactions in such a server fail due to contention when they try to consume or update data that no longer exists. This arises in cases where the updated data is shared between updaters—i.e. accessible to several of them. One of the reasons for failing is that one update, although not conflicting with a prior update, is dependent on a conflicting update.
A system holding a local cache may keep any records which are part of an optimistic transaction locked until the optimistic transaction is committed in the master server. This prevents any other applications running against that local cache from making changes dependent on the optimistic data. So once a cache has been updated, no more updates can be made until the optimistic transaction involving that message has been committed in the master server.
SUMMARY OF THE INVENTION
In one aspect of the present invention there is provided a method for managing updates to a replicated data resource, including the steps of: in response to a first update and one or more dependent updates applied to a first replica of the data resource at a first data processing system, and comparing the updates with a master copy of the data resource held at a second data processing system. For the updates which do not conflict with the master copy, the non-conflicting updates are applied to the master copy; and for the updates which conflict with the master copy due to other updates applied to the master copy, the method includes sending to the first data processing system an instruction to back out the conflicting updates from the first replica and to replace them in the first replica with the corresponding other updates applied to the master copy.
The appropriate time to reconcile the local updates with the master could be after every transaction on the server owning the cache. This would give rise to the behaviour similar to the technique of optimistic locking. However, in a distributed system where less frequent reconciliation is appropriate, it is not desirable to hold exclusive locks on updated resources until the reconciliation occurs. It is proposed that other transactions in the distributed server are allowed to execute and a composite reconciliation is performed following the execution of a set of transactions. Multiple transactions in the period between reconciliations may update the same cached resource. As the time between reconciliations increases, so will the number of updates that are at risk of failing to reconcile.
It is recognised that the set of transactional updates arising from a set of unreconciled transactions can be captured as a history in the distributed server that owns the cache. The set of transactional updates will have a number of dependencies with it—a second transaction may make a further update to a resource updated from the reconciled state by a first transaction.
During reconciliation, each transaction in the history is replayed against the master state. As each of the transactions originally performed on the distributed server against the cache is replayed it may encounter an initial state in the master that does not match that which was in the cache at the equivalent point. That transaction against the master state should be rolled-back, and any subsequent transaction in the history that depends upon state updated by that transaction should not be replayed, and also needs correcting in the cache from which the history is being replayed. This management of the replayed transactions must be robust even in the event of the rollback—the failure must assuredly provoke the corrective action.
The effect of this behaviour will be to propagate as many of the transactions as possible from the distributed server cache to the master state as possible. Depending on the likely contention for the same resource in the master state by applications executing in multiple distributed servers maintaining caches, the overall yield of successful transactions will vary with less contention leading to higher yield, and frequent reconciliation leading to less contention.
It can be observed that the replay of history from a set of transactions is somewhat similar to the process of forward recovery of a point in time backup of a database using a log. This invention assumes that multiple histories (logs) can be replayed, potentially concurrently, to bring the master state up to date.
This solution allows a chain of optimistic transactions. Optimistic transactions progress on the assumption that prior optimistic transactions commit. The chain of transactions can be arbitrarily long; however, long chains increase the probability of ultimate failure. The transactions may have arbitrary dependencies on the prior transactions. Chains of optimistic transactions may branch into multiple chains. Chains of optimistic transactions may also join together.
Applications running optimistic transactions against a replica of the messages record the history of their processing. When a communications connection is made with the master arbitrating server the optimistic transaction history is replayed against the master data store. If no conflicting updates are detected, i.e. there were no clashes of the optimistic locks, then the optimistic transaction becomes the ultimate transaction which commits, as an ACID transaction.
Optimistic transactions are replayed in the master server in the same order that they were generated against a particular replica, therefore they will only ultimately commit if an optimistic transaction they depend on has already committed.
An application can update a message in a local cache so long as no other application is in the process of updating that message. In other words it can make an update so long as no other application has updated that message as part of any uncommitted optimistic transaction run against that cache.
Once an optimistic update has been made in the local cache and optimistically committed, then further optimistic updates are allowed by applications as part of other optimistic transactions. Optimistic transactions are replayed in the master server in the same order that they were optimistically committed in each cache. If the master server detects that an optimistic transaction makes a conflicting update, then it is rejected, causing the optimistic transaction to be undone. All other optimistic transactions which also depend on the same conflicting change are also rolled back.
Some restrictions apply if a resource manager is joined using a classic ACID transaction with an optimistic transaction running against a local cache. For example, the transaction branch in the resource manager must be prepared before the optimistic transaction is sent to the master server and data modified in the resource manager as part of the transaction branch must remain locked until the outcome is received from the master server.
The solution should respect the following basic test case: two disconnected local caches, A and B, each share data replicated off a master server, with ‘cs’ being a shared replicated message.
Optimistic transaction 1 A on A: consume ‘cs’ and produce ‘pa’ Optimistic transaction 2 A on A: consume ‘pa’ and produce ‘paa’ Optimistic transaction 3 A on A: consume ‘paa’ and produce ‘paaa’ Optimistic transaction 1 B on B: consume ‘cs’
B connects to the master server and replicates before A—its optimistic transaction 1 B succeeds and commits. When A replicates, it should have failures reported for all 3 of its optimistic transactions. The tree can be persisted efficiently by keeping a transaction ID pair against each data resource element to indicate when it was produced and when (if) it was consumed. The tree can otherwise be kept in memory as a tree structure to allow fast deletes. In this case, before B connects and replicates, client A's data table would look like:
Client A:
Resource
Transaction Produced
Transaction Consumed
cs
0
1A
pa
1A
2A
paa
2A
3A
paaa
4A
Transactions applied on cached data, whose master copy is shared between independent applications, are not able to progress if they depend on changes made by prior transactions on the same items of data. This is because conflicting changes may have been made to the equivalent items of data in a separate cache and these changes may take priority. One known solution is to lock the cached data changed by the prior transaction until it has been successfully played back against the master copy. This delays the dependent transactions.
A solution relates to a sequence of two (or more) transactions operating on a cached data set, which depend on each other because they operate on (at least one) same items of data from the data set. The transactions are saved until the master copy of the data becomes available at which point they are played back against it. This continues until one of the played back transactions fails because another completely independent transaction, which operated on the same items of data but against a separate cached copy and originating from another independent application, was successfully played back on the master copy at an earlier moment in time. At this point, all subsequent transactions which depended on the failing one are rolled back on the cached copy (with appropriate failure reports generated) and activity resumes from there. This invention therefore allows “chained” (optimistic) transactions applied to cached data to progress by recording their dependencies so they can be undone when required.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described in more detail, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a schematic representation of a network in which the present invention may be implemented;
FIG. 2 is an example user view of seat availability within an aircraft within an airline reservation system implementing the present invention;
FIG. 3 is an example user view according to FIG. 2 after multiple transactions on replica 110 and consolidation between replica 120 and master copy 100 of a database reflecting seat reservations;
FIG. 4 is an example user view according to FIG. 2 and FIG. 3 after consolidation between replica 110 and master copy 100 ; and
FIG. 5 is a schematic flow diagram showing the sequence of steps of a method implementing the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following terms are used in this description. ‘Consumption’ means deletion of a message. An update is achieved by consumption of one message and production of another. The terms ‘consumption’ and ‘update’ are used interchangeably. ‘Asynchronous’ means that client transactions are made to their local cache as if it were the master data—therefore not needing to block for confirmation that their transaction was really successful. ‘Shared data’ means that the local cache or replica is a copy of data that is logically on offer to multiple consumers. ‘Optimistic transaction’ means the initial optimistic processing of the messages—operations are grouped and persisted in a transactional manner. ‘Ultimate transaction’ means the definitive step that records the ultimate result of an optimistic transaction's success.
As shown in FIG. 1 , a plurality of client data processing systems 10 are each running an application program 60 and a database manager program 20 and each hold a replica 30 of a database 40 . Each client system 10 is connectable to a server data processing system 50 which is also running a database manager program 20 and holds a master copy 35 of the database 40 . The present invention is applicable to any network of data processing systems in which the client systems are capable of running the database manager program to maintain their local replica of the database, but is particularly suited to applications in which a number of replicas are updated on mobile devices or desktop workstations before being consolidated with the master copy held on a back-end server computer. The invention is especially useful in environments in which either a large number of client systems may need to concurrently apply local updates to the database, or a number of the client systems rely on wireless communications to connect to the server computer and so cannot rely on permanent availability of connections.
An implementation of the present invention will now be described using the illustrative example of an airline reservation application in which users (such as travel agents and airline employees) working at a number of client workstations each need to be able to process their customers' requests to book seats on an airline.
The reservation application 60 sees each table of the local replica database as if it is the only copy, and as if only that application is accessing it. For illustration, the table could be a simple hash table of data and an index. Hidden from the application's view within a consolidation process 70 of the database manager 20 is some more state information.
For each element in the table, the following information can be held and sent as part of an update consolidation request (as will be described further below):
protected Object underlyingObject;
// The application object being contained.
protected Object oldUnderlyingObject;
// The before image, in case we back out.
protected Object key;
// The object identifier key.
protected long unitOfWorkIdentifier = 0;
// Unit of work for an update.
protected long tableSequenceNumber = 0;
// Server/Master sequence number of last
table update
// we received.
protected long sequenceNumber = 0;
// Sequence number of last object update we
made,
// incremented by 1.
int state;
// The current state of the managedObject.
// The lifecycle of the object.
static final int stateError = 0;
// A state error has occurred.
static final int stateConstructed = 1;
// Not yet part of a transaction.
static final int stateAdded = 2;
// Added.
static final int stateReplaced = 3;
// Replaced.
static final int stateDeleted = 4;
// Deleted.
The use of the protected Object oldUnderlyingObject (the before image), sequence numbers and consolidation processing will be described later.
For the table as a whole, the following information is also held and sent in update consolidation requests:
protected long highestTableSequenceNumber = 0; // The highest
tableSequenceNumber in the entire table.
// This may be higher than any recorded in our
version of the table
// because our update may have been the latest;
it also allows the
// master to detect that this is a repeat update.
The user's view of seat availability for the airline is as shown in FIG. 2 , with each specific seat being a separately identifiable data element of the database and being separately reservable. FIG. 2 shows three views of the data resource—the master copy 100 as updated at the server, a first replica 110 and a second replica 120 .
A first set of data elements 130 corresponding to seats in an aircraft have been updated and the replicas 110 , 120 of the data resource have each been consolidated with the master copy 100 so that the reservation is now reflected in each of the replicas. Subsequent to that consolidation, further updates are made concurrently to replica 110 and replica 120 . A first update 140 to replica 110 indicates a desire to reserve four seats in rows 3 and 4 . The replica 110 entry is not locked. However, for the nested updates involving modified entries are recorded as being dependent on the updates that modified them. All local updates are in-doubt (uncommitted) until the server has successfully applied itself and returned a confirmation of success.
An update 150 of replica 120 indicates a desire to reserve four seats in rows 2 and 3 , but the user of the client system of replica 110 has concurrently attempted to reserve two of these four seats. Replica 120 is optimistically updated concurrently with replica 110 . Again the updated elements within replica 120 are not locked and are available for further (dependent) updates. Which of these replicas 110 , 120 has its local updates successfully applied to the master copy 100 of the database depends on which client system is first to notify the server system of its desire for consolidation.
Let us assume that the client system maintaining replica 120 is the first to request consolidation 170 . Note that replica 110 still has local update 140 which has not been consolidated with other replicas, and which are now inconsistent with the master copy of the data. Since there is no consolidation processing currently in progress and there is no conflict between updates applied to the master copy and updates applied to replica 120 since their last consolidation, the updates will be successfully applied 170 to bring the replica 120 and the master copy 100 into a consistent state, see 160 and 160 ′ as shown in FIG. 3 . After consolidation between the master copy and replica 120 , further updates may be applied to the replica 120 or the master copy 100 , and further updates may also be optimistically applied to replica 110 .
Let us assume that two further updates 190 and 195 are applied to replica 110 as represented in FIG. 3 . Update 190 amends update 140 by cancelling a passenger from a window seat, therefore update 190 is dependent on update 140 . Update 195 assigns two unallocated window seats to two new passengers, therefore update 195 is not dependent on any previous update.
The client system maintaining replica 110 now attempts to consolidate 180 with the master copy 100 of the data. The results are shown in FIG. 4 . Update 140 now conflicts with the consolidated update 160 ′ to the master copy and it is not applied. Furthermore transaction 190 which does not conflict with transaction 160 ′ is not applied because it does depend on conflicting update 140 . However update 195 is applied to master copy 100 at 195 ′ because it does not conflict with any other update and does not depend on any update which conflicts. Updates 140 and 190 are backed out. The updating application running at the client system is notified, either by a return value to a synchronous consolidation request or, in the preferred embodiment, by an asynchronous callback to an asynchronous consolidation request. The local update is backed out by reinstating (temporarily) the “before update” image of the data.
Then the “before update” image is overwritten with the latest updates to the master copy 100 . The result of this is shown in FIG. 4 . In this example, all copies of the data are now consistent, with conflicting client updates not having been allowed to change the master copy. This has been achieved without complex programmatic conflict resolution processing at any of the systems in the network.
Note that at no point during this process has either of the client replica 110 or 120 been prevented from applying updates to any element of data.
Thus each travel agent and the airline has a copy of the seat reservations, and two or more agents may ‘optimistically’ update their own view of the data to attempt to reserve the same seat. Initially, these updates are not committed. On subsequent consolidation, one agent sees a successful consolidation with their updates committed, whereas the others see a failure of some updates due to the first agent now holding the seat. Neither agent needs a connection to the airline's copy of the database table in order to request the reservation, but the reservation will only be processed locally until the update is consolidated with the airline's copy.
It should be noted that the present invention does not require synchronization of all replicas at any one time (although this could be implemented using conventional techniques if global syncpoints are required for other reasons), and does not require the master copy to immediately reflect the very latest updates performed at client systems.
Instead, the invention allows each replica to be updated independently of each other and independently of the master copy, but for the update transactions to be held in doubt until they are subsequently consolidated with the latest version of the master copy of the data. Sufficient information is held for backing out conflicting updates (sequence number and the local replica's incremental changes—see above) and dependent updates, preferably without reliance on database logs. Any non-conflicting and nondependent updates are applied to the respective one of the local replica or master copy of the database, and any conflicting and dependent updates result in a back-out at the client. This backout is achieved by reinstating the image of the relevant database elements and then overwriting the relevant database elements at the client using the corresponding data from the server.
By handling each update as a separate transaction, only a small number of local replica updates have to be backed out in most cases, although it is preferred that all updates entered between consolidation points will be identifiable as a set in case they are deemed interdependent by the user or updating application program. In one embodiment of the invention, a set of updates to data elements (such as booking seats in an aircraft for a group) can be applied together as a single transaction or explicitly flagged as an interdependent set of transactions, so that if one update cannot be applied to the server's master copy of the data then they will be backed out as a set at the client.
A degree of short term inconsistency between replicas of the data resource has been accepted to achieve improved concurrency and availability of data, with optimistic updating of local replicas of the data and a backout processing. All updates are eventually applied to all replicas of the data unless they conflicted with updates applied to the master copy or are dependent, and problematic data conflicts are avoided by the decision to accept the master copy's validity in the case of conflicts.
A specific implementation will now be described in more detail with reference to FIG. 5 . As described above, updates can be applied to a local replica of a database without requiring continuous access to the master copy of the database held on a server, without requiring all replicas to be concurrently locked for synchronization, and without complex programmatic conflict resolution processing.
The client updates (step 500 ) elements in the local database replica as part of a local transaction. When updates are applied locally, the database manager program 20 updates the relevant rows and columns of the database 40 as one or more local transactions in response to user input via the local application program 60 .
The client records (step 505 ) dependencies of this transaction. The database manager program 20 is free to update the local modified rows again, however all updates that depend upon a prior, non-consolidated update are recorded as being dependent upon their prior update. When local updates are completed, the client records each update against elements in the replica. Each dependent update is recorded in a dependency table that identifies the depending update and the dependent update.
The client initiates consolidation (step 510 ) at the consolidation point. The client consolidates the updates performed on the local copy and any updates performed on the master copy of the database held at the server. This involves the local database manager program 20 sending an asynchronous request message to the server system 50 holding the master copy 35 of the database. The database manager program 20 running on the server 50 receives these requests and places them in a FIFO queue for serialization.
The request includes: a unique unit of work identifier for the request; the highest sequence number in the table (in order to determine which updates the replica has not yet applied); and, for each changed data element, the new state of each changed data element (i.e. added, deleted, replaced); the new data (if any); and the sequence number for the version of the master copy on which the update is based.
The client thread continues (step 530 ) and possibly terminates.
The server attempts (step 540 ) to apply the same updates to the master copy of the data in a server side transaction. When ready to process a next consolidation request, a consolidation manager process 70 within the database manager 20 of server computer 50 processes this information within the request to identify which rows of the database tables have been updated since the last consolidation with this replica. This is managed by comparing a replica database table row's sequence number with the sequence number of the corresponding row in the master copy.
The sequence number is incremented in the master copy of the database whenever the respective row of the master copy's database is updated, and this sequence number is copied to the corresponding row in a replica when that replica is consolidated with the master copy. Hence, the database table rows of the master copy always retain a sequence number which can be checked against the database rows of a local replica to determine a match. If they match, then that row of the master copy of the database has not been updated since it was consolidated with this local replica, and so any updates applied to that row of the local replica can be safely applied to the master copy at consolidation time. In that case, a set of one or more server side transactions applies to the master copy the updates defined in the request message and the transactions are committed 250 .
If they do not match, then that row has been updated in the master copy, and in that case the server side update transaction is backed out 250 . All dependent updates are not applied and marked as failed. This is notified to the client side and the in-doubt client-side transaction which applied the conflicting update is also backed out 260 along with all dependent updates. Next, the updates which had been applied to the master copy before consolidation (including those which led to the mismatch) are applied to the local replica.
The server response includes: a list of transaction results; a list of rows to insert; a list a rows to delete; and a new sequence number for the new version of the master copy.
No conflicting and no dependent updates are committed, the server commits 550 non-conflicting and nondependent updates. Hence, if the database rows updated in the local copy are different from the rows updated in the server-based master copy, all updates are successful. Whereas, if conflicts are identified when consolidation is attempted, all conflicting local updates since the last consolidation point are backed out and the relevant database table rows of the local replica are overwritten using the updates applied to the corresponding rows of the master copy of the database.
The server backs out (step 555 ) all conflicting and dependent updates.
A separate client thread can either commit (step 560 ) or back out the client side transactions, according to the result on the server.
If required, notification procedure is executed (step 570 ) in a separate client thread to deliver notification of the result of the consolidation.
The programming construct implemented by the present invention may be called a “Consolidation Point”—a place in the logic of a program where updates to a copy of a resource are to be merged with another copy. Although the preferred embodiment described above includes synchronous processing for the database merge operation, this could be completed asynchronously in alternative implementations.
The resource in question could be a database table, or a queue, or generally any data where a copy is held locally for update. The result of the merge is reported back to the program as success or failure of the merge. If the merge succeeds, the updated values persist in both copies of the resource. If the merge fails, perhaps due to some conflicting update in the merge processing, then the local copy of the resource elements is updated to be the same as the remote server copy. Thus, in the event of the merge processing failing because there are conflicting updates, the resource elements will be returned to a known consistent state. No elements are ever locked during these updates which reduces delay between operations. Failing updates will automatically trigger the failure of all the dependent updates as the server is aware of the dependencies and does not even attempt to apply them.
The invention applies to situations in which there are two copies of a table, or many copies.
The “Consolidation Points” define a section of program logic where either all of the changes to elements in the local copy within the scope of a single transaction are merged, or none of them are merged.
This programming construct is similar in concept to a “Synchronisation Point” in distributed transaction processing, however instead of fixing a place in the logic of the program where updates to resource managers commit or back out, this fixes a place in the logic of the program where a set of updates to a table are merged with another copy of the table, the merge either succeeds or fails. A “Consolidation Point” and the “Synchronisation Point” could be one and the same place in the program logic.
In preferred implementations, the state of the tables is well defined and easy to program to. It is either the state before or after all of the updates are applied, and if the merge of the two resources fails then the updates that were not applied are also well defined. Furthermore the updates to the replica can be coordinated with transactional resources by executing the prepare phase of a two phase commit where the entity performing the consolidation is also of the two phase commit coordinator.
In many conventional solutions, a replication error is reported in an error log. This has three significant disadvantages: it is not easily accessible to the program logic; the precise scope of the failure is not defined, in fact in most cases some of the updates are applied; and the updates cannot easily be coordinated with other updates.
Additional embodiments and variations of the embodiments described herein in detail will be clear to persons skilled in the art, without departing from the described inventive concepts. For example, the embodiments described above include submitting a request for consolidation which request includes all of the required information for identifying data conflicts, whereas alternative embodiments may include an asynchronous request for consolidation followed by the server establishing a synchronous communication channel with the client system for exchanging information and identifying conflicts.
In another implementation, some applications may require an automatic retry of one or more of the data element updates that are within a failed encompassing update transaction. If the application or the local replica's database manager program is notified of which data element update resulted in a conflict with the master copy, it will be possible to retry all or a subset of the other data element updates. This may be done as a set of separate transactions or as a single transaction which encompasses all of the failed transaction's data element updates except the one which caused the failure.
The present invention may be realized in hardware, software, or a combination of hardware and software. The present invention may be realized in a centralized fashion in one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software may be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.
The present invention also may be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form.
This invention may be embodied in other forms without departing from the spirit or essential attributes thereof. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope of the invention. | A sequence of processing transactions operating on a cached data set, which depend on each other because they operate on the same items of data from the data set. The transactions are saved until the master copy of the data becomes available. The transactions are played back against the master copy until one of the played back transactions fails because another transaction which operated on the same items of data but against a separate cached copy and originating from another application, was successfully played back on the master copy at an earlier time. At this point, all subsequent transactions which depended on the failing transaction are rolled back on the cached copy (with appropriate failure reports generated) and activity resumes from there. “Chained” (optimistic) transactions can therefore be applied to cached data and can be allowed to progress by recording their dependencies so they can be undone when required. | 38,604 |
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application is also related to co-pending applications, application Ser. No. 11/761,968, filed on Jun. 12, 2007, entitled: Methods and Apparatus for Determining Network Risk Based upon Incomplete Network Configuration Data, application Ser. No. 11/761,977, filed on Jun. 12, 2007, entitled: Methods and Apparatus for Prioritization or Remediation Techniques for Network Security Risks, and application Ser. No. 11/761,982, filed on Jun. 12, 2007, entitled: Adaptive Risk Analysis Methods and Apparatus. The present application and co-pending applications claim benefit of priority under 35 U.S.C. 119(e) of U.S. provisional Application Nos. 60/804,552, filed on Jun. 12, 2006, 60/813,603 filed Jun. 12, 2006, and 60/804,930, filed Jun. 15, 2006. The above applications are hereby incorporated by reference for all purposes.
BACKGROUND OF THE INVENTION
The present invention relates to methods and apparatus for network analysis. More specifically, the present invention relates to methods and apparatus for determining vulnerability of a network (e.g. hosts, applications, data) to threats. Still more specifically, various embodiments of the present invention determination of vulnerabilities, prioritization of vulnerabilities of a network, visualization of vulnerabilities of a network to threats based upon incomplete configuration data (including vulnerabilities of hosts) of network devices. In various embodiments of the present invention, reference to a network and network configuration data includes not only network hardware and software, but also includes application host servers, and any other device forming part of a network, as well as software operating thereon.
Determination of threats to a network has been described in application Ser. No. 11/335,052 filed on Jan. 18, 2006, and herein by incorporated by reference for all purposes. In that application, one of the named inventors of the present application described determining a software model of the network based upon configuration data of “network devices” in the network. The “network devices” included routers, firewalls, host application servers, and other devices in the network. Based upon the software model, the previous application described determining potentially harmful traffic paths in the network by simulating the software model.
The inventors of the present application explicitly consider and address the problems of what happens if some or all configuration data (and host vulnerabilities) from the network, e.g. firewall, router, one or more host application servers, or the like, are incomplete, i.e. unavailable, not gathered, or the like. Problems such as how to determine threats based on incomplete data, how to prioritize threats that are determined based on incomplete data, how to provide visualization of threats determined based upon incomplete data, and the like are considered by the inventors.
The inventors of the present invention have determined that it would be advantageous to be provide such information to users such as network administrators even in cases where configuration data (and host vulnerabilities) from one or more host application servers is unavailable, incomplete, not gathered, or the like.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to methods and apparatus for network security risk management. In various embodiments, network security risk management includes quantitizing security risk based upon incomplete network data; prioritizing between remediation actions; identifying changes in security risk based upon changes to the network, new threats, and the like; visualization of network security risks; and the like.
The inventors introduce the concept of “confidence” or “vulnerability certainty” to network analysis as one basis for prioritizing discovered threats or vulnerabilities. In various embodiments, “confidence” is typically based upon how much information may be known about one or more host servers. Such information may include the presence of a host server, network addresses associated with a host server, ports monitored by a host server, applications monitoring ports on the host server, versions of operating systems on the host server, versions of applications on the host server, vulnerability data of applications and operating systems, and the like. Unlike previous systems, embodiments of the present invention can operate with less than complete configuration information of the network e.g. host servers, or the like.
In various embodiments of the present invention, “harm probability,” “vulnerability exploitablility,” or “exposure” are associated with a threat or vulnerability. A “security risk” value or score is determined from the exposure and a “business value” or “asset value” associated with one or more host servers. The security risk score is considered when prioritizing the remediation of threats (vulnerabilities). Additionally, each host server may be associated with a confidence factor (vulnerability certainty), as discussed above.
In various embodiments, when determining threat paths within a network topology, the exposed risk and confidence factor are used to prioritize threats (prioritize the remediation of vulnerabilities). The quantization of security metrics, such as exposed risk, confidence factors, and the like, based upon incomplete network configuration data is herein termed “adaptive risk.” In some embodiments risk is evaluated as a (risk, confidence) number pair.
In some embodiments, adaptive risk=exposed risk*confidence factor. For example, a first host server has a high exposed risk (e.g. 90), a high confidence factor (0.90), and an adaptive risk of 81, and a second host server that has a high exposed risk 80 but a lower confidence factor (0.5), and an adaptive risk of 40. In such an example, the first host server may be prioritized as having a potential vulnerability that should be addressed before the potential vulnerability of the second host server. As another example, a first host server has a low exposed risk (e.g. 45), a high confidence factor (e.g. 0.9), and an adaptive risk of 40.5, and a second host server that has a low exposed risk (e.g. 50), a low confidence factor (e.g. 0.50), and an adaptive risk of 23. In such an example, again the potential vulnerability of the first host server may be prioritized over the potential vulnerability of the second host server based upon the adaptive risks. In other embodiments, with different weights or different combinations of the exposed risk and confidence factors, a different prioritization that shown above may be determined. In some general cases, the least “dangerous” or vulnerable situation for the network is where a host server has a low exposed risk and a high confidence factor; the most “dangerous” or vulnerable situation for the network is where a host server has a high exposed risk and a high confidence factor; and other weightings are in between these situations.
According to one aspect of the invention, methods for a computer system including a display are described. A technique includes determining a plurality of security metrics associated with a plurality of servers within a network, and displaying a tree map on the display representing at least a portion of the network. In various embodiments, the tree map comprises a plurality of shapes associated with servers from the plurality of servers, and a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metric associated with the servers. In various embodiments, an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers.
According to another aspect of the invention, a computer system is disclosed. One system includes a processor configured to determine a plurality of security metrics associated with a plurality of servers within a network, and a memory configured to store the plurality of security metrics. An apparatus includes a display for displaying a tree map on the display representing at least a portion of the network, wherein the tree map comprises a plurality of shapes associated with servers from the plurality of servers, wherein a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metric associated with the servers, and herein an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers.
According to other aspects, a computer program product including computer-system executable-code resident on a tangible media is described. A computer program product may include code that directs the computer system to determine a plurality of security metrics associated with a plurality of servers within a network. A computer program product may also include code that directs the computer system to display a tree map on the display representing at least a portion of the network, wherein the tree map comprises a plurality of shapes associated with servers from the plurality of servers, wherein a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metric associated with the servers, and wherein an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers. The tangible media may include optical media, magnetic media, semiconductor media, or the like.
According to other aspects, a graphical user interface for a computer system including a display is disclosed. A GUI includes a first portion configured to display a tree map on the display representing at least a portion of the network including a plurality of servers, wherein the portion of the network is associated with a plurality of security metrics, wherein the tree map comprises a plurality of shapes associated with servers from the plurality of servers, wherein a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metrics associated with the servers, and wherein an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers. A GUI may also include a second portion configured to display a textual display of security metrics from the plurality of security metrics.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to more fully understand the present invention, reference is made to the accompanying drawings. Understanding that these drawings are not to be considered limitations in the scope of the invention, the presently described embodiments and the presently understood best mode of the invention are described with additional detail through use of the accompanying drawings.
FIG. 1 is a block diagram of typical computer system according to an embodiment of the present invention;
FIG. 2 illustrates an example of an embodiment of the present invention;
FIGS. 3A and B illustrate a diagram of a flow chart according to one embodiment of the present invention;
FIGS. 4A-B illustrates screen shots according to embodiments of the present invention; and
FIGS. 5A-C illustrates additional screen shots according to other embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram of typical computer system 100 according to an embodiment of the present invention. In various embodiments, computer system 100 is an analysis server that performs the vulnerability analyses and prioritization described below.
In the present embodiment, computer system 100 typically includes a monitor 110 , computer 120 , a keyboard 130 , a user input device 140 , computer interfaces 150 , and the like.
In the present embodiment, user input device 140 is typically embodied as a computer mouse, a trackball, a track pad, a joystick, wireless remote, drawing tablet, and the like. User input device 140 typically allows a user to select objects, icons, text and the like that appear on the monitor 110 via a command such as a click of a button or the like.
Embodiments of computer interfaces 150 typically include an Ethernet card, a modem (telephone, satellite, cable, ISDN), (asynchronous) digital subscriber line (DSL) unit, FireWire interface, USB interface, and the like. For example, computer interfaces 150 may be coupled to a computer network, to a FireWire bus, or the like. In other embodiments, computer interfaces 150 may be physically integrated on the motherboard of computer 120 or the like.
In various embodiments, computer 120 typically includes familiar computer components such as a processor 160 , and memory storage devices, such as a random access memory (RAM) 170 , disk drives 180 , and system bus 190 interconnecting the above components.
In one embodiment, computer 120 includes one or more Xeon microprocessors from Intel. Further, in the present embodiment, computer 120 typically includes a UNIX-based operating system.
RAM 170 and disk drive 180 are examples of tangible media configured to store data such as configuration files, network topologies, vulnerability databases, embodiments of the present invention, including executable computer code configured to prioritize network vulnerabilities, or the like. Other types of tangible media include floppy disks, removable hard disks, optical storage media such as CD-ROMS, DVDs and bar codes, semiconductor memories such as flash memories, read-only-memories (ROMS), battery-backed volatile memories, networked storage devices, and the like.
In the present embodiment, computer system 100 may also include software that enables communications over a network such as the HTTP, TCP/IP, RTP/RTSP protocols, and the like. In alternative embodiments of the present invention, other communications software and transfer protocols may also be used, for example IPX, UDP or the like.
FIG. 1 representative of a computer system capable of embodying the present invention. It will be readily apparent to one of ordinary skill in the art that many other hardware and software configurations are suitable for use with the present invention. For example, the computer may be a desktop, portable, rack-mounted or tablet configuration. Additionally, the computer may be a series of networked computers. Further, the use of other micro processors are contemplated, such as Xeon™, Pentium™, Core™ microprocessors; Turion64™ or Athlon64™ microprocessors from Advanced Micro Devices, Inc; and the like.
Further, many types of operating systems are contemplated, such as Windows®, WindowsXP®, WindowsNT®, or the like from Microsoft Corporation, Solaris from Sun Microsystems, LINUX, UNIX, and the like. In still other embodiments, the techniques described above may be implemented upon one or more chips, an auxiliary processing board (e.g. graphics processor unit), or the like.
FIG. 2 illustrates an example of an embodiment of the present invention. In FIG. 2 , a network 200 is modeled including network infrastructure devices 210 , 220 and 230 . Also shown are host server locations 240 , 250 , 260 , and 270 . A server 280 and an analysis server are also illustrated.
In various embodiments of the present invention, network infrastructure devices 210 - 230 are typically devices such as network routers, firewalls, data bridges, or the like. Network infrastructure devices 210 - 230 are typically used to route traffic within a network. Accordingly, in other embodiments, network infrastructure devices 210 - 230 may be embodied in many forms, such as wireless routers, load balancing systems, or the like. In various embodiments, the configurations of network infrastructure devices 210 - 230 are typically specified by a system administrator. In some embodiments, the configurations may take the form of a configuration file. Some network infrastructure devices 210 - 230 may have default configurations which can be modified via the system administrator loading a new configuration file. Conversely, configuration files may be downloaded from network infrastructure devices 210 - 230 for analysis by a system administrator.
In various embodiments, host server locations 240 - 270 are locations where host application servers may be located. As will be described below, host server locations 240 - 270 are locations within network 200 where host server machines are predicted to be located, based upon configuration files of network infrastructure devices 210 - 230 .
As will be described below, server 280 is a location from which a system administrator will initially launch one or more attacks from. The location of server 280 may is arbitrary and may represent any server within network 200 or a server outside network 200 (e.g. the internet). In various embodiments, the attack may be any type of network threat such as a virus, a worm, a Denial of Service attack, key logger, spyware, or the like. Such threats are commonly profiled in publicly available threat or vulnerability reference libraries compiled by Computer Associates, McAfee, Cisco, the National Vulnerability Database, or the like.
Additionally, in FIG. 2 , an analysis server 290 is illustrated. In various embodiments, analysis server 290 is coupled to network infrastructure devices 210 - 230 and may be coupled to host server locations 240 - 270 .
FIGS. 3A and B illustrate a diagram of a flow chart according to one embodiment of the present invention. Description of the embodiment of FIG. 3 is made with respect to the diagram in FIG. 2 .
Initially, analysis server 290 requests configuration data (e.g. configuration files) from network infrastructure devices 210 - 230 , step 300 . This process may be initiated by a user, or automatically, upon a schedule or an event. Next, configuration data from network infrastructure devices 210 - 230 is received by analysis server 290 , step 310 . In various embodiments, a library of threats (e.g. a threat reference library) is also referenced. In other embodiments, such data may have previously been collected, and thus retrieved in these steps.
In various embodiments, based upon the configuration data of network infrastructure devices 210 - 230 , a network topology may be determined, step 320 . In other words, based upon the network traffic patterns allowed by network infrastructure devices 210 - 230 , the flow of data within network 200 may be determined.
Additionally, based upon the configuration data, host server locations 240 - 270 are determined, step 330 . In the example in FIG. 2 , it can be determined that network infrastructure device 210 is coupled to outside of network 200 , to host location 240 and 260 , network infrastructure device 220 is coupled to host locations 240 and 250 , and network infrastructure device 230 is coupled to host locations 260 and 270 .
It should be noted that in various embodiments, the identification of host locations does not imply that an actual host server is present at these host locations. Instead, as above, the host locations are typically identified based upon the configuration data of network infrastructure devices, or the like.
In various embodiments, data about host locations 240 - 270 may be retrieved, step 340 . For instance, data about host locations 240 - 270 may include whether a host machine is actually present at host locations 240 - 270 . In various embodiments, the presence of host machines may be indicated by a user via a questionnaire, via a network discovery module, via an asset management system, via a network netflow or sniffer device, patch management system, or the like. As another example, data may include system maintenance practices, a vulnerability management system, or the like of the user. For instance, data may include how often does the user push out software patches, software policy (e.g. only Microsoft products), software licenses, service plans, and the like. Similar to the above, such data may be indicated by a user via a questionnaire, via a policy file, or the like.
Additionally, in various embodiments, if a host machine is present, specific configuration data may also be received from host machines (e.g. host servers), step 350 . For instance, partial or complete hardware and software configurations of host servers may be returned. As examples, the specific configuration data may include and indication of network addresses (e.g. IP addresses) associated with the host servers, which ports, if any are monitored by the host servers, which applications (including operating system) are running on the host servers and monitoring the ports, which versions of the applications are running, and the like. In various embodiments, other similar types of information may also be determined. This data may be indicated by a user via a questionnaire, via querying of a host machine, or the like.
In various embodiments of the present invention, various levels of configuration information regarding a host server location may be determined, for example, the existence of a host server at the host server location, the existence of specific applications of a host server at the host server location, ports monitored on a host server at the host server location, confirmation of vulnerabilities of a host server at the host server location, identification of software patches applied to a host server at the host server location, potential vulnerabilities, confirmed vulnerabilities, and the like. In various embodiments, the amount of this configuration information known about a server is translated into a “coverage factor score” (CFS). For example, if 40 of 100 pieces of data regarding a host server are known, the CFS may be 0.4, and integer, or the like. In various embodiments, if a CFS is below a specified level, for example 10%, too many presumptions (90%) to the configuration of the host server have to be made for a given host server. Accordingly, the security risk score for the host may be ignored when considering remediation, quantization of risk, or the like.
In various embodiments, the knowledge, or lack of knowledge of the above information are used to determine a confidence factor (vulnerability certainty) of host servers. In various embodiments of the present invention, a confidence factor is then associated with each of host server locations 240 - 270 , step 360 . The confidence factor may be determined based upon how much is known or confirmed about a host server at the specific host server location, as discussed above.
As an example, if a host server 510 is present at host server location 260 , and the full software configuration is known and entered, host server location 260 may be associated with a high confidence factor (e.g. 0.90 in a 0 to 1 scale). Further in this example, if it is unknown whether a host server is present at host server location 270 , host server location 270 may be associated with an initial confidence factor that is low (e.g. 0.10 from 0 to 1). In various embodiments of the present invention, since host server location 270 is “downstream” from host server location 260 , the confidence factor for host server location 270 is also based upon the confidence factor of host server location 260 . In one example, if the confidence factors are multiplied, the confidence factor for host server location 270 is equal to 0.09 (0.09=0.90×0.10). In other embodiments, other types of combination, including weighted combinations are contemplated.
Continuing the example, if a host server 520 is present at host server location 240 , but nothing more about host server 520 is entered, host server location 240 may be associated with a lower confidence factor (e.g. 0.25 from 0 to 1). Further in this example, if it is unknown whether a host server is present at host server location 250 , host server location 250 may be associated with an initial confidence factor that is low (e.g. 0.10 from 0 to 1). Again, since host server location 250 is “downstream” from host server location 240 , the confidence factor for host server location 250 is also based upon the confidence factor of host server location 240 . In one example, the confidence factors are multiplied, the confidence factor for host server location 250 is equal to 0.025 (0.025=0.25×0.10). Again, in other embodiments, other types of combination, including weighted combinations are contemplated.
Next, a first host server location is selected, step 370 . In various embodiments, host server locations are prioritized based upon closeness to server 280 , the original attack source.
Next, a vulnerability profile for the host server location is determined, step 380 . In various embodiments, the vulnerability profile is determined by the type of network traffic pattern that is allowed to flow to the host server. Further, the vulnerability profile is determined by the data about the host application server determined in step 340 , for example if a host server is present or not, and the like. Still further, the vulnerability profile is determined by any configuration data associated with the host application server determined in step 350 , or lack thereof.
As an example, referring to FIG. 2 , the type of network traffic allowed from network infrastructure device 210 to host server location 260 may be TCP data. Further, in this example, host server 510 is known to be present at host server location 260 . Still further, in this example, host server 510 is known to run an Apache HTTP server, and the like. Accordingly, the vulnerability profile for host server location 260 is determined from these types of data: TCP traffic, Apache HTTP server.
As another example, the type of network traffic allowed from network infrastructure device 210 to host server location 240 may also be TCP data. In this example, host server 520 is known to be present at host server location 240 , however, no other configuration details regarding the configuration of host server 520 is known. In various embodiments, when configuration data is missing, it is assumed that host server 520 includes virtually all possible combinations of software, etc. In this simple example, it is assumed host server 520 runs an Apache HTTP server, a Microsoft Web server, or the like. It should be understood that many other types of configuration data may also be assumed, for example, many different versions of software (e.g. Oracle 9i and 11i databases, Microsoft SQL server 2000, 2005; or the like). In some embodiments, the range of applications assumed and the versions assumed can be limited by the user. In sum, in this example, because nothing is known about host server 520 , various embodiments assume a wide range of data within the vulnerability profile.
In embodiments of the present invention, based upon the vulnerability profile, one or more threats from the library of vulnerabilities (threats), discussed above, are identified, along with their mode of attack, step 390 . This step may also be referred to as determining reachability of threats or vulnerabilities to the host server location. In various embodiments, the reachability also refers to leapfroggable vulnerabilities.
In various embodiments of the present invention, the reachability data is incorporated into a threat map. In such embodiments, the threat map may be generated and displayed to a user as a directed graph having nodes representing subnets, and a root node representing a threat server. The reachability of the threat server to the host server location, discussed above, is reflected by the paths between the host server location and the threat server. In addition, in various embodiments, in the threat map, each node is associated with a known or presumed vulnerability of a host server location or subnet. For example, if nine out of ten pieces of configuration data are known for a host server, a worse-case presumption is made for the tenth piece of data. As an example, if version 1.0 of an application is vulnerable to an attack, but version 1.1 of an application in a host server is not vulnerable, and the specific version for a host server has not been determined, a presumption is made that the version of the application is 1.0.
Following this step, a “harm probability” or “vulnerability certainty” is determined for the threats that are reachable, step 400 . In various embodiments, harm probability may be determined based upon the harm probability specified for these threats (e.g. parameters or attributes of the threats). These attributes can typically be determined from the library of vulnerabilities. For instance, for threats that are relatively easy to implement, a harm probability may be high (e.g. 0.5 on a 0-1.0 scale; and for threats that are very difficult to implement (e.g. requires many events to occur), a harm probability or attribute may be low (e.g. 0.1 on a 0 to 1.0) scale. In additional embodiments, a severity of harm may also be determined from the threats that are reachable. For example, the severity may be low, if the threat can perform a ping, however, the severity may be very high, if the threat can get root access.
In various embodiments, as is discussed, the vulnerability certainty value for a host server may depend upon the amount of configuration data known about the host server or conversely, the amount of presumption of configuration data that is required (e.g. the coverage factor score). In various embodiments, the vulnerability certainty value is also determined in response to how vulnerable the host server is to a given vulnerability, given vulnerability attributes versus known configuration data of the host server. As an example, the coverage factor score may indicate that all configuration data of a host server is known, but given that configuration, the host server is not vulnerable to a threat. In such a case, the vulnerability certainty may be low. As another example, the coverage factor score may indicate that only half of the configuration data of a host server location is known, and presuming additional configuration data, the host is vulnerable to a threat. In such a case, the vulnerability certainty may be medium. As yet another example, the coverage factor score may indicate that almost all of the configuration data of a host server location is known, and presuming additional configuration data, the host is vulnerable to a threat. In such a case, the vulnerability certainty may be high.
In embodiments where more than one vulnerability may reach a target host server location, the harm probabilities of the vulnerabilities may be combined. For instance if threat A has a harm probability of 0.5 and threat B has a harm probability of 0.5, a combined harm probability for the host server location may be 0.75, for example. In various embodiments, many ways of combining multiple harm probabilities are also contemplated. In some embodiments, the severity of multiple threats reaching a target host server location may simply be the highest severity of the multiple threats, or a combination.
In the example in FIG. 2 , for host server 510 , the vulnerability profile includes TCP traffic and an Apache server. In this step, only a very difficult to exploit vulnerabilities from the library of vulnerabilities is identified that uses TCP as a protocol to attack Apache servers. In this example, the harm probability may be 0.1 from a range of 0 to 1.0 for example. Additionally, in this example, the attack may simply crash the host server 510 , the severity may be 0.5 from a range of 0 to 1.0.
In the case of host server 510 , the vulnerability profile includes TCP and a large number of assumed applications and versions. In this step, many easy to exploit vulnerabilities from the library of vulnerabilities are identified that use TCP as a protocol to attack applications such as: Oracle 9i and 11i databases, Microsoft SQL server 2000, 2005; or the like. In this example, the combination of the harm probabilities may be high, for example 0.9 from a range of 0 to 1.0, for example. In this example, the reachable vulnerability with the highest severity can obtain root access, accordingly, the severity may be 0.9 from a range of 0 to 1.0.
In various embodiments of the present invention, the process may be repeated for other host server locations that may be reachable by threats or vulnerabilities. In some embodiments, multiple threats may be used to penetrate a network via “leapfrogging” host servers. More specifically, host server locations can become a source of a threat within a network. In various embodiments, a leapfrogging analysis may repeat until the confidence factors decreases below a given threshold.
As an example, as discussed above, host server 520 is assumed to have many vulnerabilities able to reach it from server 280 . Further, at least one such reachable vulnerability provides root access. Accordingly, host server 520 may then serve as a source of attack within the rest of network 200 .
In this example, using the steps described above, it is first determined that a host server 530 is present at host server location 250 . However, not much else is known about host server 530 . Accordingly, similar to host server 520 , the harm probabilities may be 0.9 and the severity may be 0.9. An initial confidence factor may be 0.25, similar to host server 520 . However, since an attack on host server 530 depends upon an attack on host server 520 , in various embodiments, the initial confidence factor may be combined with the confidence factor of host server 520 . For example the confidence factor for host server 530 may be the product of the two confidence factors, e.g. 0.06, or any other combination of the confidence factors. In light of this, if a sophisticated attack on a network relies upon successive control of many servers, for example, smaller confidence factors are determined for servers further down the attack chain. As discussed, the process may continue until the confidence factors drop below a defined threshold. In other embodiments, the process may continue until any other factor is satisfied. For example, until a given percentage (e.g. 75%, 100%) of the host server locations have been analyzed, until a given number (e.g. 100) vulnerable host server locations have been identified, or the like.
In some embodiments of the present invention, after the process above, harm probabilities, severities, and confidence values for each host server location in a network can be determined. Typically, after this process is run upon a network, multiple host server locations may be associated with a high harm probability and a high severity.
In various embodiments, a “security risk score” (SRS) may be determined for host servers based upon business value of the host server and upon threat likelihood. In various embodiments, threat likelihood is determined based upon a number of factors such as, reachability of the threat to the host server; how recent or novel the vulnerability is (including vulnerability of the underlying components, dependency of the vulnerability, patches available, and the like); the severity of the vulnerability; difficulty of the vulnerability, and the like.
Accordingly, vulnerabilities of the host server locations can be prioritized, step 410 , and graphically displayed to the user, step 420 (as will be described further below). In some embodiments of the present invention, the SRS, described above is a metric used in prioritizing or highlighting the vulnerabilities, and/or the remediation actions.
In various embodiments, to help the user prioritize, a number of other factors may be provided about the host server locations/host servers. In one embodiment, an “asset value” or “business value” may be assigned to a host server. For example, a host server with confidential client data may be assigned a high asset value (initially by the user), and a host server with web graphics data may be assigned a lower asset value, e.g. 20 from 0 to 100. In some embodiments, the harm probability may be combined with the asset value to obtain an “exposed risk.” In one example, the exposed risk is simply the product of the two.
In the example in FIG. 2 , the asset value of host server 510 is 90, and the harm probability 0.1, thus the exposed risk is computed to be 9; and the asset value of host server 520 is 50 and the harm probability is 0.9, thus the exposed risk is computed 40 . Thus, according to one embodiment, host server 520 would be prioritized before host server 510 .
In various embodiments, if the associated confidence value is low for particular “reachable threats,” the user may enter additional configuration data about the host server locations, step 430 . Accordingly, in response to the prioritization, the user may obtain more information, to make a more informed decision about the network. As an example, for a first server location the exposed risk is 60 and a first confidence factor is 0.90 and for a second server location the exposed risk is 80 and a second confidence factor is 0.50. In such an example, the second server location may be prioritized before the first server location. As the second confidence factor is low (0.50), a first course of action may be the user determining more about the configuration of the host server location. For example, the second confidence factor may be a result of not knowing or not entering the list of applications running on a host server located at the host server location. In response, the user may run a software inventory of the host server, and enter that data into embodiments of the present invention. When the system is re-run with this additional information, the exposed risk of the second server location may drop, for example to 20, and the second confidence factor may rise, for example to 0.95. This process above may then be repeated until the user is satisfied with the level of confidence for some or all of the host server locations.
In various embodiments, a user may otherwise begin patching/fixing the vulnerabilities for the prioritized host application locations, step 440 . As is known, the user may install a patched version of one or more applications on a host server, the user may close ports on the host server, the user may change application software on the host server, or the like. Additionally, in various embodiments, this process may include patching or changing the configuration of particular network infrastructure devices.
In various embodiments, the process allows the user to supplement the system with additional configuration data or making changes to network infrastructure devices or host servers to address the prioritized vulnerabilities (e.g. install a firewall or filtering device, changing rules or policies, or the like.) The process above may be repeated to allow the user to address the next prioritized vulnerability, or the like. As discussed previously, the priority may be based upon a combination of many factors including value of data stored on a host server, an “exposed risk” (harm probability*value), whether the vulnerability is exploitable (e.g. root access), what level of data access is provided, and the like.
FIGS. 4A-B illustrates screen shots according to embodiments of the present invention. More specifically, FIGS. 4A-B illustrate exemplary graphical user interfaces that allow a user to view threats within a network, as referred to in step 420 , above.
FIG. 4A illustrates a threat graph (threat map) 500 of a portion of a network. In this example, the link risk distribution illustrates a plots harm potential (risk) versus number of servers. As is illustrated, the average harm potential for the network is 0.32. As is also illustrated, any number of ways to graphically illustrate data are enabled by this GUI. As shown, harm potential (probability) is illustrated by a red cylinder. In this example, the diameter of the red cylinder represents the harm potential, the diameter of the gray cylinder represents the asset value, and the greater the respective diameters, the greater the harm/value. For instance “widget supplier” servers have a large gray cylinder, and a red cylinder filling up the same cylinder, accordingly, this visually indicates that the widget supplier servers are very valuable and very vulnerable. In another example, the “Seattle Engr” servers are valuable, but is not as vulnerable to threats. As yet another example, the “customer service” servers are not very valuable and not very vulnerable.
In the example in FIG. 4A , links are shown connecting servers in the portion of the network. In various embodiments of the present invention, the thickness and/or color of the links may represent the confidence value of the source server. For example, if confidence in the configuration of a source server is high, a connecting line may be heavy, and if confidence in the configuration is low, the connecting line may be thinner.
In the present example, a link between “sfcorp-inside” server to “seattle engr” server has been highlighted and detailed in text below the image. As illustrated, many types of data may be presented to a user, for example, the source IP addresses, harm probabilities (“Prob.”) of different vulnerabilities on the source host servers, the attack mechanism (“Port”), the target host IP address, harm probability (“Prob.”) of the different vulnerabilities on the target host servers, “A/P/C” vulnerabilities, discussed below, severity of the vulnerability, impact of the vulnerability, discussed below, whether a patch is available for the vulnerability, and the like.
In various embodiments; A/P/C summarizes the vulnerability in response to what is known about the host configuration. A represents assumed harm, P represents presumed harm, and C represents Confirmed harm. In this example, the less that is known about a host server, the higher the Assumed harm, and the more that is known about the host server, the lower the Assumed harm. However, the more that is known about the host server, the presumed or confirmed harms may be higher or lower, with respect to a given vulnerability. In the example, for source host at IP address 192.168.0.101, the assumed harm may be identified specifically by identifier, such as A:2002-1000. Additionally, the harm may be identified by class, for example for engr — 03 server, the A/P/C counts are 1/0/0, respectively.
In various embodiments the type of impact are “CIAS.” As is known, C stands for the ability to reach confidential data (e.g. break-in), I stands for the ability to affect the integrity of the server (e.g. delete data), and A stands for the ability to affect the availability of the server (e.g. crash).
FIG. 4B illustrates a case where more information of “Engineering subnet” is displayed to the user. As is shown, another field that may be displayed to the user is an “exploitable” field. In various embodiments, this represents whether a threat may obtain root access to the target server. In cases where a threat is exploitable, the target server may serve as a basis for additional attacks within the server.
Additionally, shown in FIG. 4B is a histogram of harm probabilities of servers within the engineering subnet. As can be seen, the median harm probability is 0.5, and many servers within the subnet have harm probabilities in the range of 0.80 to 0.90. This histogram reports that many host servers are vulnerable to threats, and is not a desirable situation. To a user, it would indicate that corrective action for those servers is required.
In additional embodiments of the present invention, the above process may be run on the network before and after a change to the network, and the changes in vulnerabilities may be highlighted or detailed. For example, after the system is run a first time, the user enters additional data about a host server, and the system is run again. Based upon the additional data, the user may either see the new vulnerability state of the network, or the delta, the change in vulnerability state of the network. As an example, the user can see that the new information decreases the harm probability of the host server and other servers. As another example, based upon a first run of the system, the user sees that a host server is vulnerable, and decides to patch the host server. Running the system again, the user may see the effect of the patch is that the host server harm probability is lowered, but the harm probability of three other servers greatly increases. In such a case, the user may decide to push out the patch, and to also install an additional firewall in front of the three servers; alternatively, the user may decide any other way to address the vulnerability.
In other cases, other types of changes include changes to the network, new vulnerabilities discovered, and the like. These effect of these changes may also be reflected as a change in network vulnerabilities. For example, the user may update the given “value” of an asset, a new set of worms may be discovered, a new network infrastructure device is added to the network, a new application is added “upstream” from a vulnerable host server location, a certain amount of time has passed (e.g. one week, one month) or the like.
Embodiments of the present invention provide visualization of network-wide risk analysis in the form of a graphical user interface with customizable at-a-glance views of the network. In various embodiments, the nodes of the network that have the highest probability of exposure to known vulnerabilities may be indicated in red, for example. Other configurations of the GUI enable the user to quickly ascertain whether any server in a network is exposed to specific threats.
FIGS. 5A-C illustrates additional screen shots according to other embodiments of the present invention. More specifically, FIGS. 5A-C illustrate exemplary graphical user interfaces that allow a user to view threats within a network, as referred to in step 420 , above. As can be seen in FIGS. 5A-C , the inventor has adapted the concept of “tree maps” to the visualization of network vulnerabilities. As is known with “tree maps” portions of data that are of interest to a user may be magnified, while other portions are less magnified. For example, a first icon within the tree maps may be larger than a second icon indicating importance of a server represented by the first icon over a server represented by the second icon.
In various embodiments of the present invention, “importance” may depend upon the criteria specified by the user. For example, the user could specify importance as servers having the highest security risk score, servers having the highest business value, servers having the greatest increase in security risk score over a given time period, servers having the highest vulnerability certainty, deltas of the above values, and the like. Other criteria and combinations thereof are contemplated. In the example in FIG. 5B , the sizes of the nodes within the tree maps are determined in response to “Asset Value” of the nodes.
In some embodiments, the shape of the icons may be different. For example, more important icons may be shaped as a letter “X,” or skull-and-bones, or the like, and less important icons may be shaped as the letter “O,” a check-mark, or the like. In other embodiments, the color and steadiness of the icons may also reflect the above factors. As an example, an important icon may be red in color and/or blink (the rate of blinking may also depend upon the importance, as defined by the user specified criteria), whereas a less important icon may be yellow or green in color and/or be steady.
The examples in FIGS. 5 A-B may illustrate the affect of network changes between two different time periods, the affect of proposed changes to a network, the current or proposed vulnerabilities of the network or the like. For example, the change in vulnerability of the network before and after a patch, update, or the like, has been pushed out, giving the user feedback as to the new vulnerability state of the actual network, or the predicted vulnerability state of the network. Interestingly, because the change in vulnerabilities of the network can be visualized, the user can determine why a patch, update, or the like affects the network in the way indicated. For example, upgrading software to another version may open a host server up to a new set of vulnerabilities.
In this example, FIGS. 5A-C represents changes or proposed changes with respect to time. Such GUIs may allow the user to spot trends in security over time. Additionally, such GUIs may also allow the user to see the result of specific changes in the network. For example, an original risk tree map can be determined, a new network component can be added to the network (e.g. a firewall), and a new tree map can be determined. In such an example, the user may compare the original tree map to the new tree map to see the effect of the new network component. For example, at-a-glance, the user can see that certain nodes are now blue in color, indicating that the security risk score, for example, has improved and the network is more secure. In other embodiments, a network change may result in network security deteriorating. This may be reflected, at-a-glance, to the user, by certain nodes in the tree map being red in color.
The graph at left represents the change in harm probability with respect to count. In this graph, a positive (e.g. +0.60) number represents increase in harm probability, and is typically undesirable, and a negative number (e.g. −0.35) represents a decrease in harm probability, and is desirable. As can be seen, the yellow portion of the graph shows that that the vulnerability of the network has increased. In various embodiments, this may occur when new viruses, worms, or the like are released. In this example, in the main section, subnets are color-coded according to change in harm probability. Further, relative sizes of the boxes are used to represent asset value (value) of the host servers. With this GUI, the user may quickly focus upon those host servers that are most likely affected by either a change in network configuration, or the like.
In the example in FIG. 5C , a GUI is shown that illustrates remediation prioritization to a user. In this example, the sizes of the nodes in the tree map are determined by business value, and may be organized by user-selected criteria. For example, the tree map is organized by primary capability then by subnet. In this GUI, a lighter red color indicates vulnerabilities that are suggesl lted to be mitigated first. For example, the light red color indicates a higher security risk score (a higher security risk).
In various embodiments of the present invention, the GUI may display user-selected tree maps, as illustrated in FIG. 5A , or highly-user-customized tree-maps, as illustrated in FIG. 5B . As illustrated in the embodiments in FIGS. 5A-B , GUIs may also provide textual representations of information displayed. In these examples, the GUIs illustrate a “histogram” of data: server population count versus a user defined metric. For example, in FIG. 5A , the histogram represents the server population count versus trends in risk (over a defined time). In this GUI, at a glance, the user can see if whether the network security is improving (a positive value) or is getting worse (a negative value). In FIG. 5C , the histogram represents node count versus security risk score.
In various embodiments, in addition to the default information displayed to the user, the user may drill-down by selecting a node within the tree map. In response, more detailed information regarding the configuration of the subnet, server, or the like may be presented to the user. An example of this is illustrated in FIG. 5C , with the pop-up window on top of the tree map.
Further embodiments can be envisioned to one of ordinary skill in the art after reading this disclosure. In other embodiments, combinations or sub-combinations of the above disclosed invention can be advantageously made. The block diagrams of the architecture and graphical user interfaces are grouped for ease of understanding. However it should be understood that combinations of blocks, additions of new blocks, re-arrangement of blocks, and the like are contemplated in alternative embodiments of the present invention.
The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims. | A method for a computer system including a display includes determining a plurality of security metrics associated with a plurality of servers within a network, displaying a tree map on the display representing at least a portion of the network, wherein the tree map comprises a plurality of shapes associated with servers from the plurality of servers, wherein a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metric associated with the servers, and wherein an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers. | 53,886 |
This is a continuation of application Ser. No. 037,790, filed May 10, 1079, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to inductive low pressure radio frequency plasma reactions, and in particular to a plasma process for the deposition of glassy material onto a solid surface.
The inductive radio frequency plasma has been known for many years. The essential feature of the inductive discharge is that the power is introduced into the gas phase by inductive coupling and hence the conductor paths in the gas form closed paths within the container. This provides a hot intense plasma and has the advantage that no internal electrodes are required nor are there the problems with large potential drops, as can occur with capacitive coupling, at the walls of the containing vessel.
The term `radio frequency` as used herein is understood to include microwave frequencies.
An inductive discharge, or H-discharge, is produced by the magnetic field (H) of the exciting coil, unlike a capacitive discharge or E-discharge which is relatively diffused and is produced by electrostatic fields. It has been found that the H & E discharges become indistinguishable as the wavelength of the exciting radiation becomes comparable with the dimension of the discharge.
At low pressures the discharge tends to be most intense at the walls of a containing tube. At higher pressure 500 Torr the discharge becomes more restricted to the center of the tube.
The use of H-discharges for chemical processing has been limited previously to the atmospheric plasma torch. This device is essentially a high power H-discharge which is generally operated in argon to ease power requirements and at 3-10 MHz. Such a plasma torch has been used in the past to produce ultra-pure silica. The reactants were introduced into the tail flame of the plasma, as oxygen and silicon tetrachloride in high concentration tend to extinguish the plasma. Silica produced by such a torch was in the form of sub-micron spheres which had to be collected and sintered to form clear glass. While such an arrangement has proved effective for performing many chemical reactions it does not lend itself readily to the production e.g. of optical fiber preforms, in which it is preferred to deposit material directly as a glassy layer so as to avoid an intermediate sintering process.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a method of depositing a glass or its precursor by a radio frequency induced chemical vapor reaction using an inductively sustained plasma fed with gas at a pressure within the range 0.1 to 50 Torr, wherein the plasma discharge is such that its largest dimension is significantly less than the free space wavelength of the radio frequency employed to sustain the plasma, the plasma pressure and energy density being such that the deposit is non-porous.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a schematic diagram indicating the operating regimes of various types of plasma;
FIG. 2 is a schematic diagram of an inductive plasma deposition arrangement;
FIG. 3 indicates the plasma configuration obtained in the arrangement of FIG. 2;
FIG. 4 shows an alternative deposition arrangement;
FIG. 5 shows a further type of deposition arrangement; and
FIG. 6 shows an alternative arrangement employing a radio-frequency concentrator.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, it can be seen that the various defined types of plasma appear with various combinations of gas pressure and input power. Thus the conventional E-discharge is achieved at relatively low pressures and low power. The H-discharge, however, occurs at intermediate pressures e.g. between 0.1 and 50 Torr and requires medium to high input power for its maintenance. The various forms of plasma are discussed in greater detail by G.I. Babat, J. Inst. Elec. Eng. 94 27-37 (June 1947).
Referring to FIG. 2, there is shown an arrangement for the deposition of a solid material on the inner surface of an insulating, e.g. glass or silica, tube 11. The tube 11 is evacuated via a pump 12 coupled to a pressure gauge 13 and is supplied with reactant gases via valves 14. Thus, for example, if silica is to be deposited on the inner surface of a silica tube in the manufacture of optical fiber preforms, th reactant gases may be silicon tetrachloride (SiC1 4 ) and oxygen together with an inert carrier gas such as argon.
Radio frequency power is supplied to the tube 11 via a coil 15 coupled via a flexible RF feeder 10 and a loading coil 16 to a generator 17.
A grounded electrode 18 is provided at one end of the tube downstream from the coil 15 as it has been found that this aids the initiation of an inductive plasma within the coil 15 and causes any capacitive discharge to be confined downstream of the coil. It is essential that the lower potential or grounded end of the coil 15 faces the incoming gas flow to the system.
It has been found for example that, using a 2 inch silica tube, the mimimum power required to strike and sustain an inductive plasma at a frequency of 3 MHz is from 4 to 6 kW. However, as it is preferable to have an ample power reserve a 24 kW generator may be employed. Matching of the generator to the plasma is provided by adjustment of the loading coil 16 and, as will be apparent to those skilled in the art, by the particular design of the coil 15 surrounding the tube. In this respect it should be noted that, when an inductive plasma on H-discharge is struck within the tube, the parallel inductance effect of the plasma on the coil 15 reduces the effective inductance of that coil causing the generator frequency to rise. This is opposite to the effect observed with capacitors of E-discharge where striking of the plasma cause the generator frequency to fall.
Referring to FIG. 3, the plasma 31 is struck with the tube 11 evacuated to the desired pressure in the range 0.1 to 50 Torr by increasing the generator power until electrical breakdown of the gas occurs. The inductive plasma may then be sustained at a somewhat lower power level. As shown in FIG. 3, the plasma 31 is displaced from the center of the coil 15 by the gas flow along the direction of the arrow A forming a broad front 32 against the gas flow and having an extended tail portion 33. Solid material 34, e.g. silica, is deposited on the tube from the plasma forming a ring of material adjacent the front 32 of the plasma 31. Thus, by moving the coil 15 along the tube 11, or by moving the tube within the coil, a contiguous layer of material may be deposited along the inner surface of the tube. The generator power may be so controlled that, while maintaining the inductive plasma, the solid material 34 is deposited directly in a glassy condition without fusion of the silica tube 11 and without the need to sinter the deposited material. Relative movement of the coil 15 and the tube 11 prevent overheating and subsequent collapse of any one portion of the tube 11.
The technique is particularly advantageous for the manufacture of silica optical fiber preforms by the coated tube method. The various layers of doped and/or undoped silica may be deposited on the inner surfce of a silica tube without fusion of the tube and subsequent loss of tube geometry. The coated tube may then be collapsed into a preform tube and drawn into optical fiber in the normal way.
In a deposition process using the apparatus of FIG. 2, silica in glassy form may be deposited over a 40 cm length of 20 mm diameter silica tube by admitting 200 cc/min oxygen bubbled through silicon tetrachloride liquid at 20° C. and admitting an additional 200 cc/min of oxygen into the tube at a pressure of 7.0 Torr. Conveniently the work coil 16 may comprise a two layer coil, 5 turns on the first layer wound on a 3 cm former, and 3 turns on the second layer. The turns may be insulated with glass sleeving and the two layers separated e.g. with a silica tube. The inductive plasma may be maintained at 2.9 MHz at a power level sufficient to heat the tube to about 1000° C., the coil being reciprocated along the tube at a rate of 5 secs. per pass. This provides a deposition rate of glassy silica on the tube of 16 g/hour. Dopants commonly employed in the production of optical fibers may of course be included in the plasma to vary the refractive index of the deposited material.
It has been found that, using the arrangement of FIGS. 2 and 3, by adjusting the generator output and, if necessary, by local heating of the deposition tube an inductive plasma may be struck and conveniently confined to the region of the work coil at pressure up to 20 Torr. At pressures up to 50 Torr the tube diameter should be increased, i.e. above 20 mm, to improve matching and facilitate maintenance of the plasma.
FIG. 4 shows an inductive plasma deposition arrangement for the plasma deposition of material by a tube-in-tube process in which a tube 41 on which material is to be deposited rests or is supported in an outer tube 42. This technique, when applied to the coating of a silica tube e.g. for optical fiber production, has the advantage that the tube 41 may be maintained at a temperature approaching its softening point without the risk of collapse due to the relatively low pressure of the plasma. It is found with this arrangement that the plasma confines itself to the inside of the tube 41 and that deposition takes place therefore only on the inside of this tube. By this means the temperature of the inner tube may be raised to 1300° C. without risk of distortion.
FIG. 5 shows a modification of the arrangement of FIG. 4 in which provision is made for the treatment of a plurality of tubes 51 by a semi-continuous tube-in-tube process. The tubes 51 to be treated are stacked in a vacuum tight storage chamber 52 communicating with a tube 53 in which the tubes 51 are to be treated. Reactant gases are supplied to the system via an inlet 54 into the storage chamber 52. To effect inductive plasma deposition, the bottom tube 51 of the stack is pushed e.g. by a piston (not shown) into the tube 53 and plasma coated with the desired material, e.g. silica or doped silica, as previously described. When coating has been completed the next tube 51 of the stack is pushed into the tube 51 ejecting the previously coated tube 51 into a further storage chamber 55. The process is then continued until all the tubes 51 have been treated.
In the arrangement of FIG. 6, a current concentrator or RF transformer 61 is employed to localize and intensify the H-discharge. Hitherto it has not been possible to apply such a current concentrator, to plasma systems operating at atmospheric pressures.
Such a transformer can be employed to effectively isolate the high voltage associated with the primary coil 15 from the plasma region and also provide a step down--high current path which can be used to stabilize and concentrate the plasma to the required deposition zone. The concentrator, which should be water cooled, comprises a conductive, e.g. copper, hollow cylinder provided with a longitudinal slot 62 and closed at one end by a plate 63 provided with a keyhole slot 64 communicating with the slot 62. The discharge tube is placed in the keyhole slot 64 around which an intense RF current is induced by the surrounding work coil (not shown). As the concentrator is isolated from the generator it may be grounded thus eliminating any stray capacitive discharges or maintained at any desired potential. Other forms of concentrator known to those skilled in the art may of course be used.
The following examples illustrate the invention:
EXAMPLE 1
A silica deposition tube of 21 mm internal diameter was mounted in a vacuum pumped flow system of the type shown in FIG. 2. The tube was pumped by a rotary vacuum pump through a liquid nitrogen cold trap, the tubing between pump and deposition tube being designed to give a high flow conductance.
A coil was constructed from two layers of 1/4" copper tube wound with five turns on the inside layer and three turns on the outside. The coil was insulated with glass fiber sleeving and isolation between the two layers was achieved by means of a silica tube.
The coil was placed over the silica tube and connected by means of flexible water cooled leads to the tank circuit of a 35 kW RF generator. Provision was made for reciprocation of the coil along 50 cm of the silica tube.
As stray capacitor effects resulting from discharge from high RF voltage parts of the coil were found to promote sooty deposition incorporated in the glassy deposit, the coil was arranged with the grounded end on the inside of the coil and facing the incoming gas stream. Stray discharges were then more or less confined to the downstream end where no unreacted silicon tetrachloride existed.
The silica tube was pumped down to less than 0.01 Torr. With the pump operating 200 sccm of O 2 was admitted causing the pressure in the tube to rise to 2 Torr. The voltage to the oscillating valve was then increased briefly to 3 kv when an intense white plasma appeared within the tube confined to the coil region.
The frequency before the plasma appeared was 4.54 MHz and on appearance of the plasma this increased to 4.62 MHz as the inductance of the coil was reduced by the inductive plasma.
The voltage to the valve was then adjusted until the tube temperature rose to 1100° C.
Silicon tetrachloride was then admitted by bubbling oxygen through the liquid at 22° C. at a rate of 300 sccm causing the pressure to rise to 3 Torr. After one hour the tube was removed and it was found by weighing that 16 g of silica had been deposited in a glassy form.
EXAMPLE II
A coil and concentrator of the type shown in FIG. 6 were used. A ten turn coil was wound as before (Ex. 1) on an internal diameter of 55 mm. A water cooled copper concentrator was inserted and grounding provided to it by means of a switch. Note that in some applications the concentrator may be maintained at any chosen RF potential with respect to earth.
The coil and concentrator were connected to the tank circuit of the generator. The voltage on the valve was increased as before until an H-discharge appeared in the region of concentrator field. The voltage was then adjusted to give a tube temperature of 1200° C. The concentrator was then grounded and all trace of stray capacitive discharges disappeared.
Silicon tetrachloride and germanium tetrachloride were admitted in the usual way to cause a layer of doped SiO 2 /GeO 2 to be deposited on the tube.
While we have described above the principles of our invention in connection with specific apparatus it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the accompanying claims. | The vitreous material, e.g. silica, is deposited on the inner surface of the tube from a hot, intense, inductive plasma, which plasma is formed by utilization of wavelengths substantially longer than the diameter of the plasma. The process may be employed in the production of preform tubes or step or graded index optical fiber manufacture by gradually varying the contents of the vapor introduced into the plasma. | 15,260 |
FIELD OF THE INVENTION
This invention is directed to a medical device and a method of treating mammals, especially humans, to alleviate the symptoms, including pain, of several conditions and symptoms, including hemorrhoids, vaginal inflammation and/or yeast infections, and open, draining wounds or incisions.
BACKGROUND OF THE INVENTION
Prior to the invention disclosed herein, conditions such as hemorrhoids have been treated with topical applications, or suppositories. One of the leading medicaments is phenylephrine (rectal). However, while the relief provided by this medicament is only temporary, it can be contra-indicated if the patient has high blood pressure and/or heart disease, thyroid disease, diabetes, and can lead to side effects, such as skin problems, including acne. Hemorrhoids have also been treated surgically, but of course, that is a much more involved and expensive method of treatment, which many patients are reluctant to undergo. Hemorrhoids may exist in several forms, including external, thrombosed, prolapsed internal, internal or combined (internal and external).
Thus, there exists a need for temporary treatment and relief of the symptoms of hemorrhoids, without the contra-indications and side effects of phenylephrine (rectal) or the more invasive, expensive surgical treatment.
SUMMARY OF THE INVENTION
In one aspect, the invention provides a medical device that can be used by the consumer who may have one or more of high blood pressure or heart disease, diabetes, thyroid disease or for the relief of tissue inflammation. On the other hand, the medical device of the invention will not cause side effects, such as acne.
In yet other embodiments of the invention, there is provided a method of treating hemorrhoids, vaginal inflammation and/or yeast infections and draining open wounds or incisions.
According to one embodiment of the invention, a low cost tubular element, having high heat capacity, which has been chilled, as by refrigeration or other mechanism (e.g., ice bath), can be inserted into the anal canal and/or rectum, vagina, or an open wound or incision of the patient. The chilling effect will bring temporary relief of the symptoms of hemorrhoids, such as the itching, burning sensations, in a non-chemical manner. Thus, there is no likelihood of the inducement of side effects or the contra-indications for patients as those for phenylephrine (rectal) noted above. For use in the treatment of inflammation in the vagina or in draining wounds or incisions, the cooling effect will provide temporary relief of these symptoms/conditions as well.
The method of use of the medical device includes the chilling (by refrigeration, ice-bath, or otherwise) of the medical device, formed of the high heat capacity materials, and insertion/placement of the chilled medical device into the affected area.
These and other embodiments of the invention will become apparent when read in light of the following detailed description of the preferred embodiments in conjunction with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of typical hemorrhoids;
FIG. 2 is a schematic representation of the medical device of the invention in its most basic form;
FIG. 3 is a schematic representation of a medical device of the invention in another embodiment;
FIG. 4 is a schematic representation of the medical device of the invention with a bail or string to aid in removal of the device after use;
FIG. 5 is a further schematic representation of the medical device of the invention having a cross-sectional configuration which is triangular;
FIG. 6 is a schematic representation of a medical device of the invention having at least one protuberance, which could contain an aperture in the form of an eye, to retain the bail or string to assist in removal of the medical device after use;
FIG. 7 is a further variant having a groove at the proximal (nearer the external) end of the medical device when inserted for use to attach a bail or string to aid in removal of the device;
FIG. 8 is a still further variant of the shape of the medical device having flared proximal and distal edges;
FIG. 9 is a still further variant of the medical device of the invention, having an overall frusto-conical shape, but with numerous protuberances and surface striations.
FIG. 10 is a still further variant in which the medical device has a rectangular cross-sectional shape with an aperture therethrough;
FIG. 11 is a schematic representation of a medical device of the invention having at least one protuberance, which could be in the form of a hook, to retain the bail or string to assist in removal of the medical device after use; and,
FIG. 12 is a schematic representation of a further embodiment of the invention having a generally cross-sectional shape of a rectangle with curved corners, and further containing surface striations on its external surface, wherein this embodiment further contains a notch facilitating the attachment of a bail or string to aid in removal of the medical device after use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates various forms of hemorrhoids in the human patient. As can be seen from FIG. 2 , the medical device 2 , in its simplest form can take the shape of a cylindrical tube, have a generally cylindrical outer surface 4 , with an aperture therein. The aperture could be a throughbore 6 , but it is to be understood that the aperture may be drilled or bored through a mass of material, after forming the device, or formed from a combination of boring and broaching, such that non-circular apertures could be formed, or it could be created in other variations, such as elliptical during forming of the material by extrusion, molding and other shaping techniques. Thus, while the term “throughbore” is used to describe the aperture, it should be expressly understood that as used throughout the specification and claims, both circular, flat-sided, and non-circular cross-sections of the aperture are encompassed by the term “throughbore”. The throughbore 6 is most conveniently placed along the center axis of the device 2 as seen in FIG. 2 , but such placement is not essential and it may occupy a position other than that of a central axis of the device 2 as seen in FIG. 2 .
FIG. 3 illustrates a second embodiment of the medical device in which device 12 has a general frusto-conical shaped outer surface 14 with a flared end 15 . As in FIG. 2 , a throughbore 16 is most conveniently placed along the center axis of the device 12 , but such is not essential as noted above.
FIG. 4 illustrates a third variant of the medical device 22 of the invention having an aperture having an opening 27 in an end face thereof, with the other end of the opening 28 existing in a lateral surface thereof to accommodate a string 29 (or plastic-coated fine wire or high strength plastic, such as dental floss) to aid in removal of the device 22 after use. As with the embodiments of FIGS. 2 and 3 , it has a throughbore 26 .
FIG. 5 is a further variation of the medical device 32 of the invention having an external surface 34 of a shape such that a cross-section thereof is triangular. As with the embodiments of FIGS. 2-4 , it has a throughbore 36 .
FIG. 6 illustrates a further embodiment of the medical device 42 , which includes a protuberance 47 on an outer surface of the device 42 . The protuberance 47 preferably takes the form of a notch therein, or has an aperture 48 therein. The purpose of the aperture 48 (or notch) is to secure a bail 45 , such as a string, plastic coated fine wire, or similar material, such as the plastic used for dental floss, as an aid for removing the used device 42 .
FIG. 7 is a further variant of the medical device 52 having a groove 53 at the proximal end of the device 52 . The purpose of groove 53 is to secure a bail 54 to aid in removal of the device 52 after use.
FIG. 8 is a still further variant of the shape of device 62 having flared proximal 64 and distal 66 edges, which may, in some patients, be more comfortable to retain in position while the chilled device 62 engages in heat transfer with the hemorrhoids. The embodiments of FIGS. 6-8 all have throughbores.
The throughbores in FIGS. 6, 7 and 8 are respectively numbered as 46 , 56 and 65 in these figures.
FIG. 9 is a still further variant of the medical device 72 of the invention, having an overall frusto-conical shape, but with numerous protuberances 75 - 78 and surface striations 79 . As with the other embodiments, the device 72 has a throughbore 73 . Although the surface striations are introduced with this embodiment, it is to be understood that the surface striations may appear in any of the embodiments disclosed herein, even though omitted from some drawing figures for purposes of clarity. The spacing of these surface striations is schematic, and they may take various forms such as being spaced 1/64 of an inch apart. Alternatively the surface striations can be 1/32; 3/64; 1/16; 5/64; 6/64; 7/64; ⅛; 9/64, etc. inches, or other increments, apart. The spacing of the surface striations may also be irregular, such that different spacing exists between adjacent striations. It is also to be understood that the striations may be formed as embossments or bumps (as in FIG. 9 ) or as grooves (as in FIG. 12 ). The purpose of these surface striations, which may be in the form of bumps, embossments, grooves or a roughened surface, is to assist with retention of the device in the body of the user or as a carrier for external ointments added thereon.
FIG. 10 is a still further variant in which the medical device 82 has a generally rectangular cross-sectional shape with rounded edges and is provided with a throughbore 86 .
FIG. 11 is a schematic representation of a medical device 92 of the invention having at least one protuberance, which could be in the form of a hook 95 , to retain the bail or string (not shown) to assist in removal of the medical device after use. As with the other devices, device 92 has a throughbore 96 .
FIG. 12 is a schematic representation of a still further embodiment of the invention, where the medical device 102 of the invention has a generally rectangular cross-sectional shape with rounded corners. A notch 105 is provided along one rounded edge of the device to receive a bail, string, plastic coated fine wire, or other element, such as dental floss to aid in removal of the device 102 from the user. Similar to other embodiments of the invention, the device 102 contains a throughbore 106 . A series of intersecting surface striations 108 covers at least opposed portions, but preferably all portions of outer surface of device 102 . As described above, the spacing between surface striations is shown schematically in the drawings but can be selected from the group consisting of 1/64; 1/32; 3/64; 1/16; 5/64; 6/64; 7/64; ⅛; 9/64, etc, inches, or other increments, apart. In this embodiment of the invention, the outer surface of the body 102 has surface striations, cross-hatching or roughened surface 108 . The purpose of the modified surface 108 on device 102 can accommodate various surface agents, such as lubricants, local anesthetics, antibiotics, astringents, or medically active substances, such as vinegar (for treating yeast infections).
In addition to the cylindric, frusto-conical, flared, triangular shapes illustrated herein, the shapes can be generally rectangular with rounded edges, or irregular in shape.
The dimensions of the outer diameter and length of the invention will vary according to the specific method of treatment but typically may be as small as ½ inch outer diameter and 2-7 inches in length.
In the most preferred use, the medical device of the invention is chilled (by refrigeration, ice bath or other techniques) to lower the temperature of the medical device. As heretofore described, the medical device is preferably formed from a high heat capacity material. Suitable material include artificial materials comprising a combination of hardened calcium carbonate/sodium carbonate materials, such as described in my previous U.S. Pat. Nos. 6,264,740 and 6,913,645 (each incorporated by reference in its entirety); natural materials, such as stone and jade; ceramics; rubbers; geo-polymers (such as described in U.S. Pat. No. 8,202,362, hereby incorporated by reference in its entirety); some composites of plastics/fillers; plastics/metal and metals and alloys. Geo-polymers are known to be based on inorganic materials. Cements are called geopolymeric cement because it contains geopolymer minerals, consisting of alkaline aluminosilicates, best known under the name of poly(sialate), poly(sialate-siloxo) and/or poly(sialate-disiloxo). The hardened calcium carbonate/sodium carbonate materials with a high sodium carbonate component have the advantage of breaking down in sewer/septic systems, and therefore are considered to be a preferred material for this invention.
In order to obtain the maximum effective time of use, the chilling should be to or at 32° F. (0° C.), or slightly above. Temperatures below the freezing point of water might induce thermal damage to the tissues surrounding the medical device of the invention and therefore should be avoided.
Chilling could be effective by placing a plurality of devices in a container having a fluid therein to simultaneously chill a plurality of the medical devices of the invention. The fluid can be vinegar, alcohol, wine, brine, an ice bath, witch hazel, and mixtures thereof, or other suitable liquid which does not freeze at the freezing point of water. Once properly chilled, a single device is selected and inserted, either by the patient or a medical practitioner, to provide immediate relief from the symptoms/conditions mentioned herein.
Alternatively, the medical devices of the invention could be individually packaged in foil packages surrounded by one of the fluids mentioned above, or in a material such as Benadryl, a lubricant, an astringent, a local anesthetic, an antibiotic, or other material, which packages can be chilled individually or as a group.
It will be understood that other variations, and uses, of the medical device of the present invention will be envisioned by those skilled in the art reading the present disclosure or viewing the drawings herein, and it is to be understood that all uses of the medical device of the invention are within the scope of the invention as defined by the appended claims. | This invention is directed to a medical device and a method of treating mammals, especially humans, to alleviate the symptoms, including pain, of several conditions and symptoms, including hemorrhoids, tissue inflammation and/or yeast infections, and open, draining wounds or incisions. | 15,025 |
This application is a continuation of application Ser. No. 07/939,819, filed on Sep. 3, 1992, now abandoned, entitled "METHOD AND SYSTEM FOR DISPLAYING ERROR MESSAGES", in the name of Steven H. Mueller.
TECHNICAL FIELD
The present invention relates to methods and systems in the field of interactive computer program development and more particularly to gathering, displaying and processing error data from a plurality of language processors.
BACKGROUND OF THE INVENTION
Computer programmers conventionally work by entering and modifying source code in files in the computer through the use of an editor. The plurality of files of source code are processed to create an executable program by having the computer translate the source code into an executable form by running a series of programs which might typically include combinations of a macro processor, various preprocessors, a compiler and linker. Each of these processors may generate error messages or error data which aid the programer in identifying the nature of the errors and the lines of code causing the errors so that the errors can be corrected. It is possible to link an editor, compiler, linker and a debugger into an integrated development system to allow the source code to be modified and processed without having to leave the development environment.
Compilers typically provide the programer with a "compiler listing" which lists the source code along with the errors. On mainframe computers, the list of errors was either at the end of the source listing, or interspersed through the source listing. On personal computers (PCs), many commercially available compilers, (such as the well known Borland Turbo C), display the errors in the same window in which the source file is being edited.
J. H. Downey has described a method which imbeds error messages into a "VS/PASCAL" source program. When a "VS/PASCAL" program is compiled, a listing file is generated containing possible errors. The "VS/PASCAL Program Debug Aid" parses the listing file and creates a new source file. The contents of the new source file includes comments placed next to the applicable error. To correct compile errors, the programmer need only edit the source file. When all errors have been corrected, the system allows for the automatic deletion of the imbedded error messages. (IBM Technical Disclosure Bulletin, 05-89, P.376).
Automatically having an editor display the line containing an error in a file for a source program having an error when an error is detected during translation of the source program has been described by M. Amano (published Japanese patent app. JP 02-244224, 09-28-90).
Special problems not solved by the prior art arise when the errors may come from multiple sources such as a local parser or compiler, as well as a remote compiler which runs on a second computer such as a mainframe host computer or minicomputer connected through a communication link. Additional problems arise when the errors occur in one or more of the plurality of files comprising the source code for a program.
SUMMARY OF THE INVENTION
The invention is a method and system for displaying error messages associated with a user's source code. The error messages may be generated by parsers, compilers or any program which processes source code or text. These processors may be local, i.e., execute on the same personal computer where the user edits the source code, or they may execute on a remote computer connected by standard communication means. The error messages are stored as error message data entries in an error list in the memory of the computer. Each entry designates an error type and specifies the location of the error in the source code. When the source code consists of multiple files the identifier of the specific file in which the error was found is also designated. All or part of the Error List is displayed for the user, preferably in a window. The user may select one error message data entry in the Error List and thereby cause the portion of the source code containing the error to be displayed for editing. When the user modifies or deletes the portion of the source code corresponding to a selected error message data entry, the Error List is updated to reflect the modification or deletion. The Error List may dynamically grow and shrink as the user corrects the source code and submits all or a unit of the code for local or remote processing. As the process is repeated responsive to keyboard input by the user, new errors will be stored in the Error List, the list will be redisplayed and errors will be deleted from the list until keyboard input indicative of a command to halt is received. When there are multiple files of source code and the user selects an error in the Error List, the file in which the error occurred may be loaded automatically into the editor. If a remote computer is connected, all or part of the source code is transmitted to the remote computer for processing when the user so requests. The error data is then received back from the remote computer and placed in the Error List. The error data may be transmitted to the Error List processor as message data when the system supports program to program messages, but it may also be communicated in file form.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an embodiment of the invention.
FIG. 2 is an overview of the information flow in an embodiment of the invention.
FIG. 3 is an example of an Error List window.
FIG. 4 illustrates the data structure containing the information used in the invention for the Error List window.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made to FIG. 1. The detailed embodiment of the invention is implemented in a conventional personal computer or workstation having a CPU System which includes a microprocessor, memory and one or more communication links to any combination of mainframes, minicomputers and personal computers. The invention is intended to function interactively; therefore, means for presenting data to a user and for receiving input from a user are required. The standard display, keyboard, mouse and hard disk(s) are preferably present. The control of the display contents and the traditional editing functions are controlled by a source file editor (Editor) which has been modified to interact with an Error List Processor. The inputs to the Error List Processor are Error List Messages. An Events File Processor converts data in Events Files into a message stream for the Error List Processor. The Editor, the Error List Processor and the Events File Processor reside on the personal computer or workstation.
FIG. 2 will be used to illustrate the flow of information. Multiple language processors such as compilers can be executed by the Source File Editor, hereinafter called the Editor. These language processors may be local, i.e., execute on the personal computer with the Editor, or they may be remote, i.e., execute on a mainframe, minicomputer or another personal computer. The language processors create an Events File which contains the information identifying the file in which the error occurs, the error types and the locations of the error in the file when possible. If the Events File is remote, it is transmitted on the communication link back to the user's computer. If the Events File is local, it can be stored on disk or in the system's RAM. The Events File is processed by the Events File Processor which generates a set of program-to-program messages which are sent to the Error List Processor which builds the Error List. An alternative mechanism is provided for local language processors to send messages directly to the Error List Processor, thereby by-passing the Events File. In the detailed embodiment a local Parser is used by the Editor to parse source lines entered by the user as they are entered or as a batch process. In the detailed embodiment the Parser communicates with the Editor which interfaces with the Error List Processor. Alternatively the Parser could be designed to send messages to the Error List Processor. Both of these paths are shown in FIG. 2.
When an error is detected, either through a local process such as a syntax checker (parser) or a remote process (like a host compiler), this information is sent to the Error List. For each file containing an error, that file's name will be displayed in the Error List Window, followed by an indented list of all errors that were detected in that file (see FIG. 3). In the method of the invention a user (computer programmer) may select an error in the Error List and the file containing that error will be displayed on the workstation with the text that caused the error highlighted in the file. In the preferred embodiment the selection is made by placing a mouse cursor on the error field and pressing a button on the mouse (`clicking`). If the user modifies a line containing the text of the error, the Error List will be updated by either removing the error from the Error List or by checkmarking the error in the Error List (dependent on whether the error was detected by a local or host process). If the user modifies the source code file and creates a new error, if the error is detectable by a local process, it will be added to the Error List and highlighted immediately in the source code.
The method of the invention has the following features:
The user can see all errors in one location (the Error List), while still being able to easily locate the file and text containing the error.
The Error List has an Application Programming Interface (API) that allows information in the window to be modified. This allows programs like tokenizers and syntax checkers to add or delete errors from the Error List without having to generate an external file.
The Error List is language independent, so errors from multiple languages may be displayed in the window.
This mechanism is not restricted to compilers and programming languages. For example, it would be straightforward to get a batch text printing control product like IBM's BookMaster program to generate the information required to have its error displayed in the IDE Error List.
The invention's method has the following advantages:
The source code is not modified and all errors are listed. Other systems either embed the error messages in the source code, which makes it difficult to see where all the errors are located (like Borland's Turbo C), or stop compiling when the first error is detected to allow it to be fixed (like Borland's Turbo Pascal). Some systems produce a summary of all errors in a file, but the user has to look in multiple places to find all the errors for the project. After doing a MAKE, for example, you would have to look in multiple listing files or multiple windows.
The Error List API allows updating the Error List quickly when the source file is changed.
The system is not tied to the compiler or language processor being used because it has a general interface.
Displaying Errors
Two types of errors can be displayed in the detailed embodiment of the invention--parsing errors detected by the live parser (which is local), and errors detected by the compiler (which may be remote) after a compilation is done. Generally, when an error is detected, the token causing the error will be highlighted in all views of the file, and the actual error message will be shown in a window called the Error List. An exception is those errors not generally associated with a location in a file, such as out-of-storage conditions or invalid compile-time options. See "User Interactions" for details on how tokens are highlighted and error messages are displayed.
Invocation
To get error information from the live parser, the parser must be active. Select Language editing options . . . from the Options pull-down and activate the live parser using the options in the Parsing events group box, or use one of the syntax checking actions in the Go pull-down. To get compile-time errors, the file must be compiled with the compiler's compile-time option that causes an Events File to be created.
User Interactions
Several facilities exist to indicate where errors occurred in the file and to locate them. Errors in the file are displayed in a different font and color than normal text, and a special window will display the files that contain errors along with the errors for each file. Also, a method exists to search for errors in a file.
Highlighting Errors in the Source
Each token or line associated with an error message in the file may be shown in a specific font and/or in a specific color, e.g., red for errors, yellow for warnings, and green for informational messages. Both parser and compiler errors may use these fonts and colors by default. However, the user should be able to change the fonts and colors for parser and compiler errors independently of each other if he wants to know if a specific error came from the parser or a compiler. If more than one class of message occurs for a token or line, the color used to display it will be that of the most severe message. For example, if a token caused both a warning and an error, it would be displayed in red, not yellow. If the messages have the same severity, the font and color of the compiler messages will be chosen over those of the parser messages.
Whenever the user changes a line containing errors, if a parse is done on the line, any previous error highlighting on that line (and possibly others) will be lost. Any corresponding parser messages will also be removed from the Error List window, but any compiler messages in the Error List window corresponding to that line or token will have a check mark placed next to them (instead of being removed from the window). This is done because changing and re-parsing a line does not guarantee that compiler errors are fixed, and the user may need to find text containing compiler error messages even though the token or line causing the error will not be highlighted as an error. Keeping these messages in the Error List also allows the user to see which errors have possibly been fixed by changes made to the text. For example, one change could fix several errors or the user could have made multiple changes to the line. Performing another compile on the file will remove compiler messages from the Error List (assuming the errors that caused the messages were fixed). If parsing is not enabled, parser messages corresponding to a changed line will have a check mark placed next to them, too.
If the entire text range corresponding to a compiler message is deleted, the message in the Error List window will be grayed out and a check mark will be placed next to it. This will indicate that the error may no longer exist in the file. Because the message is no longer associated with text in the file, however, "Find error" and "Next error" will not work for the message. If the entire text range corresponding to a parser message is deleted, the message in the Error List window will be deleted.
If new parser errors are discovered during a parse, they will be highlighted and added to the Error List.
Errors Not Contained in a Source File
The previous section dealt with errors that were located in a source file, but not all errors are the result of problems in source files. Invalid compiler options, compilers running out of memory or disk space, and so on, are examples of these types of errors.
Errors of this type will be divided into two classes: fatal and non-fatal. Fatal errors, such as a compiler running out of memory, will be displayed in gray at the top of the appropriate file grouping with an octagonal icon (suggesting a stop sign) next to them. Non-fatal errors, such as invalid compiler options being specified, will be displayed in gray at the bottom of the appropriate file grouping with a downward-pointing triangle icon (suggesting a yield sign) next to them. The messages are displayed in gray to indicate that they do not correspond to any text in a source file.
The Error List Window
All error message information is shown in a read-only window (called the Error List). An example is shown in FIG. 3. It is a standard window which displays a list of files (Files #1, #2 and #3) containing errors and the error messages in those files. It shows the user all error messages for each file and provides the user with an easy way of displaying each file in the editor.
Methods of displaying the Error List and the various pull-downs in the Error List are described below.
Displaying the Error List: The Error List window will pop up if any errors were detected after a parse or during a compilation. This window should not have keyboard focus, however, to allow the user to continue to typing in the window he is currently using. If no errors occurred during any parsing or compiling, or all messages have been deleted by fixing them, then there are no error messages in the Error List, and the "Display error list" action in the Go pull-down is grayed out. If errors occur during compilation of a file, but the user exited the integrated development environment (IDE) during the compile (for example, during a batch compile), the next time the file is opened, errors will be highlighted in the source and the Error List window will appear.
If errors were detected in the file, but the version of the file compiled does not match the version of the file available to the IDE a message will be displayed in a message box to indicate that errors might not be displayed properly. The user can choose whether or not to display the errors in this case.
The Error List window can also be displayed by selecting the Display error list action from the Go pull-down. The Error List will be placed on top of all other windows, and a line will be selected in the window according to the following rules:
1. If "Display error list" was issued from a window containing no errors, the top line in the Error List window will be selected.
2. If "Display error list" was issued from a window containing no findable errors, from a window whose file is contracted or from a window whose file has all findable errors hidden, the file name line will be selected.
3. If the cursor is at the start of text corresponding to an error message, and the last "Next error" issued placed the cursor at this point, the message selected will be the one corresponding to the text selected by the "Next error".
4. If the cursor is at the start of text corresponding to an error message, and the last "Next error" issued did not place the cursor at this point, or if the cursor is not at the start of text corresponding to an error, the line selected will be that which would have been selected if a "Next error" was issued immediately preceding the "Display error list".
Edit Pull-down: The Edit pull-down menu allows the user to place information in the Error List in the clipboard and to locate the text that caused a given error. The "Copy" and "Find error" actions are selectable in the Edit pull-down. "Copy" is the standard clipboard action. "Find error" will find and select the line or token corresponding to the message selected in the Error List window. If the file containing the corresponding error is not in an edit window, it will be loaded into one. Double-clicking on the selected message also finds the error. If the message is not associated with any text in the file (in other words, grayed out), "Find error" will be grayed out, and double-clicking on the message will have no effect.
If multiple views of a given file are open, the view that last had focus will be the one used to locate the error. If the text corresponding to the error being searched for is not contained in the view, the cursor will be placed before the hidden section containing the text corresponding to the message and a system message will be issued. The user can either select a view where the text is visible or change the view so that the error is visible, and issue the "Find error" again. Pressing the OK button in response to the system message will cause the latter action to be done for the user.
View Pull-down: The View pull-down menu allows the user to view all error information or only a subset of it. The following described actions are available in the View pull-down.
Selecting "Contract file" will "contract" the selected file name and the error messages beneath it so that only the file name is displayed. If a "-" icon is shown next to the file name, the file can be contracted. Contracting can be done either by selecting the "Contract file" action, clicking on the "-" icon, or typing the "-" key (the accelerator for "Contract file").
Selecting "Expand file" will "expand" the selected file name so that the file name is displayed with associated error messages displayed beneath the file name. If a "+" icon is shown next to the file name, the file can be expanded. Expanding can be done either by selecting the "Expand file" action, clicking on the "+" icon, or typing the "+" key (the accelerator for Expand file).
"Contract all files" contracts all the files in the Error List window. "Expand all files" expands all the files in the Error List window. By default, all files are expanded when the Error List is first displayed. When an error message is added to the Error List window for a contracted file, the file is automatically expanded so that the new message is visible.
"Hide error" hides the selected error message. If a file name is selected, this action is grayed out. This action allows the user to temporarily remove error messages from the Error List that he believes he has fixed or that he believes have the same cause as another message in the Error List.
"Restore errors" restores all hidden error messages. This is especially useful if the user has accidentally hidden an error message. "Hide error" and "Restore errors" are independent of file contraction and expansion. If a message is hidden, the file containing the message is contracted, and when "Restore errors" is selected, the message will not be visible until the file is expanded again.
"Show error numbers" toggles the display of the assigned message numbers and severity codes to the left of the corresponding error messages. Message numbers are generally only useful for looking items up in a book or reporting problems to service, and so are not shown by default. A check is displayed next to this action when selected.
Searching for Errors
In addition to the Error List window, which allows a user to find a specific error in the file, a method is provided to find the next error after a given point in the file. In the search menu, the "Next error" action will select the next token or line containing an error in the file starting from the current cursor position. If no errors exist in the current file, "Next error" is grayed out. If multiple error messages exist for a token or line, the cursor will not move, but text corresponding to a different message (which could be the same text previously found) will be selected.
If the text corresponding to the next error is not contained in the current view, the cursor will be placed before the hidden section containing the text corresponding to the next error and a system message will be issued. The user can change the view so that the error is visible, and issue the "Next error" again. Pressing the OK button in response to the system message will cause this to be done for the user. If the bottom of the file is reached, the search will wrap and a system message will be displayed to indicate this wrapping. "Next error" will only find errors that are associated with text in the file. Thus, tokens or lines containing compiler errors which are not highlighted any more due to re-parsing will still be found, but errors not associated with a particular line or token in the file (for example, out-of-storage or invalid compiler option errors) will not be found.
This section describes the design of all interactions with the Error List window and error marking in the Edit Window. The main components of error feedback include:
Building the Error List from Messages and Events Files
Modifying data in the Error List
Handling user interactions with the Error List
Indicating and locating errors in the source file
Displaying the Error List
Locating the next error in a file
Displaying message help
The Error List is a data structure which is usually stored in RAM. There are two main ways to add or delete errors to the Error List--the Events File and a message interface to the Error List. The Events File is for use by compilers that cannot send messages directly to the Error List or that need special processing to locate errors in the original source file. The messages are for syntax checkers and compilers that can send messages to the Error List and know the exact locations of errors in the original source file. The system support for sending messages is outside of the invention and must be supplied by an operating system such as IBM's OS/2 or AIX. When an Events File is processed, messages contained in the Events File will be added to the Error List using the message interface. Therefore, a processor or program should use the message interface if at all possible, as it will avoid the overhead of processing an Events File.
The Error List window will be created at initialization, and the window handle will be stored in the Global Control Block (GCB), the main control block used by the IDE editor. A pointer in a structure pointed to by the Error List's window words will point to the start of the Error List data structure. If the Error List is empty, the "Display error list" action will be grayed-out, and the Error List window will not be in the window list. If the Error List is ever displayed, the Error List window will be added to the Window List. When the Error List is closed, it will be removed from the Window List.
The basic structure of the information needed by the IDE for displaying the Error List window is illustrated in the data structure shown in FIG. 4. File 1 has a pointer to File 2 and File 2 has a pointer back to File 1 and so forth. File information is kept in a doubly-linked list. For each file, a pointer points to the first error in the file (used when writing out the Error List window). File information is kept in a File Information Record (FIR). Each error in the file is kept in a doubly-linked list with a pointer back to the corresponding file. This pointer is used when "Find error" is selected to determine which file the message is located in. Error information is kept in an Error Information Record (EIR).
The information in this data structure is used to fill the Error List window. The Error List window itself is implemented as a list box. Each line in the list box corresponds to a filename or a message. Associated with each line is an item handle, which for a file is a pointer to the corresponding FIR, and for a message is a pointer to the corresponding EIR. This allows easy checking whether the selected line is a file or error message, and allows us to get the details of the item.
All requests to update the Error List will be initiated by sending messages to the Error List's window procedure. There are five actions that can cause the Error List to change:
Invoking the live parser or syntax checking all or part of the file
Compiling a file (using either a compiler or program verifier)
Issuing a Get events file . . . to retrieve an Events File (usually after a batch compile) Deleting a text range that contains an error
Changing a text range that contains an error
Actions which add a message to the Error List cause it to pop up. Other actions keep the Error List as it was, although changes will be visible if the Error List is visible and not minimized.
In the following sections, message names are arbitrary:
Updating the Error List after parsing: To make an update to the Error List, an EVF -- BEGINERRLISTUPDATE message is first sent to the Error List. An EVF -- DELMSGCLASSFROMERRLIST message is then sent with a File Location Information Record (FLIR) containing a pointer to the Edit Control Block (ECB) of the file and specifying the insertion point (IPT) range being parsed to delete messages corresponding to text in that range, followed by one EVF -- ADDMSGTOERRLIST for each new error detected. Finally, an EVF -- ENDERRLISTUPDATE is sent to complete the update process.
Updating the Error List after compiling: After compiling a file interactively or verifying a program, a call to the routine which processes Events Files should be made. This routine will process the Events File (if any), and then send messages to update and display the Error List if the Events File contains any error records. The messages sent are similar to those specified in "Updating the Error List after parsing" except that the EVF -- DELMSGCLASSFROMERRLIST should specify that Compiler errors are being deleted, and should place the Server name and File name instead of the pointer to the ECB in the FLIR. Also, the IPT range specified should be (0,0).
Updating the Error List after a Get events file action: The processing is similar to the actions that occur after compiling a program interactively.
Updating the Error List after deleting text corresponding to an error: When a text range containing an error is deleted, the internal editor label marking the error will be destroyed and a routine will be called to gray out and check a compiler message or delete a parsing error in the Error List.
Updating the Error List after changing text corresponding to an error: When a text range containing an error is changed, a routine will be called to place a check mark next to the message in the Error List.
Indicating and Locating Errors in the Source File
Each error in the source file will be marked using a label. The label will have a pointer to the corresponding EIR. This allows highlighting the appropriate message in the Error List when the user selects "Display error list".
Displaying the Error List
When the user selects the "Display error list" action, a routine bound to that action will be called which will determine which line in the Error List to select, then send a message to the Error List to display itself, highlighting that message.
Locating the Next Error in a File
When the user selects the "Next error" action, a routine bound to that action will be called which will locate the next error shown in the Error List, retrieve the IPT range of the error from the label corresponding to that message, and send a message to the Edit Window to select the text in that IPT range.
Displaying Message Help
When the user hits a selected function key, e.g. F1, while a message is selected, help for that message is displayed. To do this, the message ID of the selected message is used to perform a lookup in a table that associates message IDs with help IDs. This table is supplied in the Language Profile for a given language.
The lookup will first be tried using the profile associated with the Edit Window if the file containing the message is in an Edit Window. If the IPF ID is not found, a lookup will be tried in all profiles pointed to by the GCB. This second lookup is required in case the file is open, but not using the profile for the language the message is associated with (for example, the file is C code, but was opened with a default profile). This requires each processor to have unique message IDs. For example, RPG 400 could issue messages from the syntax checker, the Program Verifier, or the compiler. Each of these must produce different message IDs, even if the message says basically the same thing. After the lookup, if the IPF ID is found, the message is displayed.
External File Information Record (XFIR)
The XFIR is used when sending messages to the Error List. It points to either the server and file names of the file (for example, when processing an Events File), or to the ECB of the file (for example, when tokenizing a file).
______________________________________XFIR typedef struct .sub.-- xfir { PSZ pszServer; //Pointer to name of server PSZ pszFileName; //Pointer to name of file PECB pECB; //Pointer to ECB of file} XFIR; typedef struct .sub.-- xfir *PXFIR; //Pointer to XFIR______________________________________
External Error Information Record (XEIR)
The XEIR is used when sending messages to the Error List. It provides information on the type and location of the message. If the IPT range of the error is known, it should be saved in iptRange and fRangeValid should be set to TRUE. Otherwise, ulStartLine, ulStartCol, ulEndLine, and ulEndCol should be set, and fRangeValid should be set to FALSE.
______________________________________XEIR typedef enum { All, Parser, Scanner, Compiler } ERRCLASS; typedef enum { Top, Middle, Bottom } ANNOTCLASS; typedef struct .sub.-- xeir { ERRCLASS ErrClass; //Type of Error ANNOTCLASS AnnotClass; //Location of error in list ULONG ulStartLine; //Starting line of error ULONG ulStartCol; //Starting column of error ULONG ulEndLine; //Ending line of error ULONG ulEndCol; //Ending column of error EPIPTRANGE iptRange; //IPT range of error BOOL fRangeValid; //TRUE if valid iptRange PSZ pszMsgID; //Message ID CHAR Severity; //Severity of message PSZ pszMessage; //Text of message PSZ pszTag; //Used to differentiate //messages in same file} XEIR; typedef struct .sub.-- xeir *PXEIR; //Pointer to XEIR______________________________________
File Location Information Record (FLIR)
The FLIR is used when deleting a group of messages from the Error List. It points to the ECB of the file being edited; processors which create an Events File should set this to NULL. It also specifies an IPT range to process errors in; set both IPTs to zero if the whole file should be processed. Processors which create an Events File should set both IPTs to zero.
______________________________________FLIR typedef struct .sub.-- flir { PECB pECB; //Pointer to file's ECB IPTRANGE iptRange; //Range to process PSZ pszTag; //Used to differentiate //messages in same file} FLIR; typedef struct .sub.-- flir *PFLIR; //Pointer to FLIR______________________________________
The Events File
The Events File is produced sequentially. Each processor is simply appending new records to it. When an important event occurs, a record is written to the Events File. Thus every compilation process will produce an Events File.
On each platform, the external characteristics of the Events File (for example, record format, logical record length, access method, etc. on MVS) produced by the various processors should be the same. This is not required across platforms. Each record will be typed according to its contents. This allows future extensions by creating new records allowable in the Events File.
The definitions below may not work for mechanisms like the COBOL BASIS/INSERT/DELETE statements, which are, in essence, a language-specific update facility.
The following record types are defined:
Timestamp record--Indicates when the Events File creation started.
Processor record--Indicates a new processor has been invoked.
File ID record--Indicates an input file has been opened.
File end record--Indicates an input file has been closed.
Error information record--Indicates that an error has been detected in the input source code.
Program record--Indicates beginning of a second program source within the source code file being processed.
Map define record--Indicates a macro definition within the input source code.
Map start record--Indicates beginning of generated source code.
Map end record--Indicates end of generated source code.
Since different types of records will be included in this one file, the first word in each record will identify the record type. The formats of these record types are described below. In the syntax diagrams, each token should be separated by exactly one blank.
Timestamp Record
This record indicates when the Events File was created, and allows an application to determine if the Events File is current (if the timestamp is older than a file indicated in a File ID record, the Events File may be incorrect for that file). This record is always the first record in the Events File. It is not required that this record be written by a processor; it may be written by the caller of the first processor. This allows each processor to append to the Events File without having to determine if the file exists.
The timestamp record is described as follows:
______________________________________TIMESTAMP -- version -- timestamp Where Represents version The revision of this record, used for upward compatibility. timestamp The date and time the Events File was created in yyyymmddhhmmss format.______________________________________
Processor Record
This record indicates that a new processor has been invoked. One will always follow the timestamp record in the Events File (although there may be more than one).
The processor record is described as follows:
______________________________________PROCESSOR -- version -- output-id -- line-class Where Represents version The revision of this record, used for upward compatibility. output-id The file ID of an output file produced by this processor. If the output of this processor is intended to be used as input to another processor, this file ID represents that file, and the file ID record of the file will follow this record. If this is the last processor that will be invoked for which the IDE will be expected to display messages, the file ID is 0. line-class Method used to number lines. Specify zero if a temporary file or internal file containing an expanded source representation is being used; the line number represents the line number in the expanded source. Specify one if the line number represents the physical line number in the source file indicated in source file ID field.______________________________________
File ID Record
This record contains the full name of the source file processed and associates an integer with the file name. There should be one record of this type for each source file processed by the compiler, the main source file as well as any included source units (copylib members) and macros. Because the location where a file is included is important, if a file is included several times during processing, a file id record should be written for each inclusion. A processor should not keep track of files it has already included and only write a file id record if a file record had not been written for this file.
The file ID record is described as follows:
______________________________________FILEID -- version -- source-id -- line -- length -- filename Where Represents version The revision of this record, used for upward compatibility. source-id A file identifier expressed as an integer to be used in place of the file name to correlate an error record with the source file in which it occurred, without having to use the character based file name. Use zero if the input file is not known, such as input coming from a user exit. line Source file line number where a new file is referenced, or zero if the file was not referenced from a file. length Length of the file name filename The name should be the fully-qualified physical file name. If none exists (for example, getting text from the user) or the name can't be determined, place a null string here.______________________________________
File End Record
This record indicates that an included file is ending. It provides a method for viewing a file which includes a file containing an error. This is useful when the included file does not contain enough information to determine what caused the error.
The file end record is described as follows:
______________________________________FILEEND -- version -- file-id -- expansion Where Represents version The revision of this record, used for upward compatibility. file-id The file ID of this file. expansion Number of expanded source lines in this file, including any nested includes and macro expansions.______________________________________
Error Information Record
A record of this type contains information required to highlight a token or line causing a message in the source file, as well as enough information to allow the message itself to be displayed. This information includes location information (such as what file and line the error occurred on) and information related to the error itself (such as the number, text, and severity of the message).
The error information record is described as follows:
______________________________________ERROR -- version -- file-id -- annot-class -- stmt-line -- start-err-line -- token-start -- end-err-line -- token-end -- msg-id -- sev-char -- sev-num -- length -- msg Where Represents version The revision of this record, used for upward compatibility file-id The file ID number of the source file containing this error.annot-class Indicates where in a listing of messages this message should be placed. The following positions are defined: Class Meaning 0 Top of list. Generally used for very important messages that aren't really associated with a specific line in a file (for example, compiler ran out of storage). The sorting order for multiple instances of messages of this type is not defined. Because no text generally corresponds to this error, no highlighting will be done in the edit window. 1 Middle of list. Generally used for messages which are associated with a single line or token (for example, an undeclared identifier). Multiple messages of this type are sorted by line number. 2 Bottom of list. Generally used for less important messages that aren't really associated with a specific line in a file (for example, compiler option invalid). The sorting order for multiple instances of messages of this type is not defined. Because no text generally corresponds to this error, no highlighting will be done in the edit window.stmt-line Line number (in the source file associated with the above source file ID number) of the first line of the statement containing the error. This is required in case the error does not occur on the first line of the statement. This number is interpreted using the line class field of the Processor Record. start-err-line Line number (in the source file associated with the above source file ID number) containing the start of the error. This number is interpreted using the line class field of the Processor Record. token-start Column (or character in the line) of the start of the token in error. If this information is not available, a zero here will cause the first column (or character) to be used as the start of the error. end-err-line Line number (in the source file associated with the above source file ID number) containing the end of the error. This number is interpreted using the line class field of the Processor Record. token-end Column (or character in the line) of the end of the token in error. If this information is not available, a zero here will cause the last column (or character) to be used as the end of the error. msg-id Message ID, left justified. For example, AMPX999 sev-char Severity code letter (I, W, E, S, or T). sev-num Severity level number. For some systems, this is the return code associated with the severity code letter (I=0, W=4, E=8, S=12, T=16). length The actual length of the next field (message text). msg The message text of the error message. Any replacement of fields should have already been done.______________________________________
Program Record
This record indicates a new program in the same source file is being compiled. It is used when multiple programs are contained in one file. Expanded source line is assumed to start over at 1 when this record is written. It is not needed to indicate the first program in the file.
The program record is described as follows:
______________________________________PROGRAM -- version -- line Where Represents version The revision of this record, used for upward compatibility. line The position in the file that this program starts.______________________________________
Map Define Program Record
This record indicates that a macro is being defined. It is used to allow errors to be reflected back to a macro definition instead of the place the macro is used.
The map define record is described as follows:
______________________________________MAPDEFINE -- version -- macro-id -- line -- length -- macro-name Where Represents version The revision of this record, used for upward compatibility. macro-id Integer representing this macro definition. It should be incremented sequentially within a specific file. line Physical line in the current file where the macro definition starts. length Length of the macro name. macro-name The name of the macro being defined.______________________________________
Map Start Record
This record indicates that source expansion is starting. It is used where any textual replacement is being done (for example, a macro).
The map start record is described as follows:
______________________________________MAPSTART -- version -- macro-id -- line Where Represents version The revision of this record, used for upward compatibility. macro-id Identifier of a macro specified in a map definition record. line Physical line in the current file where expansion starts.______________________________________
Map End Record
This record indicates that source expansion is complete. It is used at the end of a textual replacement to show how many lines were created.
The map start record is described as follows:
______________________________________MAPEND -- version -- macro-id -- line -- expansion Where Represents version The revision of this record, used for upward compatibility. macro-id Identifier of a macro specified in a map definition record. line Physical line in the current file where expansion ends. expansion Number of lines resulting from this macro expansion, including any nested expansions.______________________________________
Using the foregoing specifications the invention may be implemented using standard programming and/or engineering techniques. The resulting program(s) may be stored on disk, diskettes, memory cards, ROM or any other memory device. For execution, the program may be copied into the RAM of the computer. User input may be received from keyboard, mouse, pen, voice, touch screen or any other means by which a human can input data to a computer. One skilled in the art of computer science will easily be able to combine the software created as described with appropriate general purpose or special purpose computer hardware to create a computer system embodying the invention. While the preferred embodiment of the present invention has been illustrated in detail, it should be apparent that modifications and adaptations to that embodiment may occur to one skilled in the art without departing from the scope of the present invention as set forth in the following claims. | A method and system for interactively displaying error messages, such as parser or compiler messages, associated with a user's source code is described. The processors generating the messages may execute on a remote computer. Whether locally or remotely generated, the error messages are stored as error message data entries in an error list. Each entry designates an error type and specifies the location of the error in the source code. When the source code consists of multiple files the identifier of the specific file in which the error was found is also designated. When the error list is displayed for the user, the user may select one error message data entry in the error list and thereby cause the portion of the source code containing the error to be displayed for editing. When the user modifies or deletes the portion of the source code corresponding to a selected error message data entry, the Error List is updated to reflect the modification or deletion. The file in which the error occurred may be loaded automatically into the editor. If a remote computer is connected, the source code is transmitted to the remote computer for processing and the error data is then transmitted back. | 49,111 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Under 35 USC § 120, this application is a continuation application and claims the benefit of priority to U.S. patent application Ser. No. 10/387,847, filed Mar. 13, 2003 entitled “Method for Message Distribution to a Heterogeneous System”, all of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to messaging in distributed network processing systems and more specifically to message distribution in heterogeneous distributed network processing systems.
BACKGROUND OF THE INVENTION
[0003] FIG. 1 is a schematic block diagram of a distributed network processing system 100 . System 100 includes a control point (CP) 105 that is communicated to one or more network processors (NP) 110 by a switch 115 . CP 105 communicates to the NPs 110 by use of messages sent through switch 115 . Each message is marked with a destination address that is used by switch 115 to route the message. The destination address may be a unicast address or a multicast address. A unicast address identifies a single destination while a multicast address identifies one or more destinations. Switch 115 has a lookup table with an entry for each multicast address that indicates the members of the multicast set.
[0004] CP 105 includes a number of software components. There is a layer of software referred to as the Network Processor Application Services (NPAS) in CP 105 that provides services to User Applications to control NPs 110 . An application programming interface (API) exists between the NPAS and the user application. The user application defines programming calls and returns that are used to communicate with the NPAS. A management application 120 learns about each NP 115 through the NPAS. For example, the hardware version and the software version of each NP 115 is provided to management application 120 by the NPAS. A user is thereby enabled to know which level of hardware and software exists for each NP 110 .
[0005] The NPAS often is divided into multiple components, for example a first component 125 , a second component 130 and a controller 135 , with each of the components controlling a different NPAS function coordinated by control 135 . For example, component 125 may control an internet protocol (IP) function and component 130 may control a multi-protocol layer switch (MPLS) function. The components are often independent but are able to share common utilities within the NPAS.
[0006] The components take requests from the user application, process those requests, build messages based upon the requests and issue the messages to the appropriate NP or NPs. The appropriate NPs are indicated by the application through use of an address parameter in an API call. The address in the address parameter is often the same address used by the switch to direct the messages to the appropriate NP or NPs as it may be a unicast or a multicast address.
[0007] FIG. 2 is a schematic process flow diagram for a processing operation 200 of the NPAS shown in FIG. 1 . Processing operation 200 begins with an API call 205 from an application. Processing operation 200 first checks the call inputs for validity at step 210 . After step 210 , processing operation 200 processes the call inputs at step 215 . This processing step 215 includes performing calculations or consulting internal data structures. Next at step 220 , processing operation 200 builds an appropriate message according to the processing results. The appropriate message is then sent to the appropriate NPs in step 225 and control is returned to the application.
[0008] In a homogeneous network environment in which all the NPs all have the same or equivalent versions the processing operation of FIG. 2 operates satisfactorily. However, in a heterogeneous environment in which one or more NPs having a different or nonequivalent version are introduced into the network system a problem can arise. For purposes of this discussion, a different version of an NP is having a different hardware level or operating with a different software level as compared to a reference NP. An NP of a different version may require different messages or different message formats or have different functional capabilities as compared to the reference NP. For purposes of this discussion, an equivalent version for an NP as compared to a reference NP is one having a different version but the messages, the formats of these messages and the functional capabilities are the same for purposes of a particular API call or other relevant metric.
[0009] When the versions of the NPs are nonequivalent, the NPAS components need to perform different processing and send different messages and/or different message formats to various subsets of NPs as a result of a single API call. It is desirable to allow the processing overhead and burdens consequent to heterogeneous networks to be virtually transparent to any user application. What is needed is a solution that (a) reduces/minimizes an impact on current APIs, (b) reduces/minimizes an impact on NPAS components, (c) reduces/minimizes the number of messages sent through the switch, (d) the components should be independent of a coverage algorithm and (e) the NPAS components should not have to be aware of the many versions of hardware and/or software in the network system. Specifically, in (a), user applications may not be aware of the different versions of the NPs and it is preferable that a user application be able to operate in a heterogeneous system the same as it operates in a homogeneous network and to provide a single address (unicast or multicast) indicating the entire set of targeted NPs. In (b), it is not desirable to change the components in the NPAS when one or more NPs with a different version are introduced into a system. In (c), it is desirable to use multicast whenever possible to distribute the messages in order to minimize switch bandwidth usage. For (d), it is preferable that any algorithm used for determining the messaging subsets should be a common utility or function shared by all components. And (e), it would be advantageous that any additions of a new version NP not necessitate any change to any NPAS component.
[0010] Accordingly, what is needed is a method and system for providing transparent NP messaging in a heterogeneous network. The present invention addresses such a need.
SUMMARY OF THE INVENTION
[0011] A system and method is disclosed for communicating with a first network processor having a first operating environment and a second network processor having a second operating environment different from the first operating environment. The system includes a destination management service (DMS) including a memory, the memory registering (a) an application programming interface (API) call and recording an associated operating environment supporting the API call, (b) a messaging method appropriate for the API call in each operating environment; (c) a unicast address for each of the network processors and the operating environment for the network processor at each unicast address, and (d) a multicast address including the unicast addresses for the network processors; and a network processor application service, responsive to the API call from a user application identifying one or more network processors using a call address, the call address including the multicast address of one of the unicast addresses, for passing an identifier for the API call and the call address to the destination management service and for receiving a set of messaging methods for issuing the API call in appropriate form for the one or more operating environments implemented by the network processors addressed by the call address. The method for communicating with a plurality of network processors, one or more of the processors having a different operating environment, includes receiving an application programming interface (API) call from a user application, the API call including a call address identifying one or more of the network processors; and accessing a memory that identifies an appropriate form for the API call for each operating environment implemented by each network processor identified by the call address; and building one or more messages for the network processors identified by the call address, each of the one or more messages including the appropriate form for the API call for the operating environment of each of the network processors to receive any particular message.
[0012] The present invention permits transparent NP messaging in a heterogeneous network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic block diagram of a distributed network processing system;
[0014] FIG. 2 is a schematic process flow diagram for a processing operation of the NPAS shown in FIG. 1 ;
[0015] FIG. 3 is a flowchart of a preferred embodiment of the present invention for a message distribution process in a heterogeneous network;
[0016] FIG. 4 is a schematic block diagram of a distributed network processing system;
[0017] FIG. 5 is a schematic process flow diagram for a processing operation of an NPAS component shown in FIG. 4 including DMS message sets with associated messaging methodologies.
DETAILED DESCRIPTION
[0018] FIG. 3 is a flowchart of a preferred embodiment of the present invention for a message distribution process 300 in a heterogeneous network. The preferred embodiment introduces a destination management service (DMS) into the NPAS in lieu of the previous control 135 shown in FIG. 1 , as well as an architecture for components that are called messaging methods. In this new architecture, there are five entities including the user application, the NPAS component, a messaging entity, a transmission services and the new destination management service (DMS). The DMS tracks the various NP versions in a network system and determines a preferred set of messaging methods to be used for API call. The DMS interacts with the management component of the user application and the NPAS components in message distribution method 300 as shown in FIG. 3 .
[0019] Process 300 performs a registration step 305 when the NPAS software is initialized. Each NPAS component registers with DMS. The NPAS component registers each API call within the component with the set of versions supported by the specific API call. Also indicated during the registration are the messaging methods required to process those versions. Versions are grouped as ranges so that all versions are not enumerated
[0020] After registration step 305 , message distribution process 300 performs another registration step 310 . Registration step 310 is performed during application initialization in which the user management function registers with the DMS all the unicast addresses in the system giving the version number associated with the NP at that address.
[0021] After registration step 310 , message distribution process 300 performs another registration step 315 . Registration step 315 is also performed during application initialization in which the user management application registers with the DMS all the multicast addresses in the system and provides the unicast addresses that make up the multicast set.
[0022] Thereafter message distribution process 300 , at API step 320 , includes an NPAS component receiving a request from an application. This request is an API call and includes a unicast or multicast address as a parameter.
[0023] At invocation step 325 the NPAS component receiving the API call invokes the DMS by passing it the API call (or an identifier to the API call) and the destination address from the API call parameter.
[0024] In response to invocation step 325 , message distribution process 300 executes DMS process 330 . DMS process 330 computes a preferred/optimal set of messages that must be sent to achieve the result requested in the original API. DMS process 330 also associates the proper messaging method for each message in the message set and returns the message set and methods to the NPAS component that invoked the DMS. It is believed that there are different ways of computing the message set and associating the methods with the messages, each may be preferable in a various scenario or specific embodiment. The present invention contemplates that each of these ways may be used in the preferred embodiment. DMS process 330 does consider the various versions of the NPs included within the destination address when computing the message set and methods to return.
[0025] After DMS process step 330 , message distribution process 300 processes the API call at step 335 . The NPAS component that receives the message set and associated messages processes the API call by using the messages of the message set using the messaging methods prescribed by the DMS and sends the messages to the addresses (also identified by the DMS).
[0026] FIG. 4 is a schematic block diagram of a distributed network processing system 400 according to the preferred embodiment. System 400 includes a control point (CP) 405 that is communicated to one or more network processors (NP) 410 by a switch 415 . CP 405 communicates to the NPs 410 by use of messages sent through switch 415 . Each message is marked with a destination address that is used by switch 415 to route the message. The destination address may be a unicast address or a multicast address. A unicast address identifies a single destination while a multicast address identifies one or more destinations. Switch 415 has a lookup table with an entry for each multicast address that indicates the members of the multicast set.
[0027] CP 405 includes a number of software components. There is a layer of software referred to as the Network Processor Application Services (NPAS) in CP 405 that provides services to User Applications to control NPs 415 . An application programming interface (API) exists between the NPAS and the user application that defines programming calls and returns used to communicate with the NPAS. A management application 420 learns about each NP 415 through the NPAS. For example, the hardware version and the software version of each NP 415 is provided to management application 420 by the NPAS. A user is thereby enabled to know which level of hardware and software exists for each NP 415 .
[0028] The NPAS often is divided into multiple components, for example a first component 425 , a second component 430 and a controller 435 , with each of the components controlling a different NPAS function coordinated by destination management service (DMS) 435 . For example, component 425 may control an internet protocol (IP) function and component 430 may control a multi-protocol layer switch (MPLS) function. The components are often independent but are able to share common utilities within the NPAS.
[0029] The components take requests from the user application, process those requests, build messages based upon the requests and issue the messages to the appropriate NP or NPs. The appropriate NPs are indicated by the application through use of an address parameter in an API call. The address in the address parameter is often the same address used by the switch to direct the messages to the appropriate NP or NPs as it may be a unicast or a multicast address.
[0030] FIG. 5 is a schematic process flow diagram for a processing operation 500 of an NPAS component including DMS message sets with associated messaging methodologies. Processing operation 500 begins with an API call 505 from an application (like step 205 shown in FIG. 2 ). Processing operation 500 first checks the call inputs for validity at step 510 . After step 510 , processing operation 500 calls DMS at step 515 . DMS returns the set of processing methods and processing operation 500 iteratively uses the processing methods as indicated by the DMS to process the inputs (step 520 ), to build the appropriate message (step 525 ) and to send the appropriate message (step 530 ). After sending a message, processing operation 500 returns to perform step 520 through step 530 for each processing method until all processing methods have been executed by processing, building and sending all messages to all the addressed NPs. Once all processing methods are executed, processing operation 500 returns control to the application issuing the API call.
[0031] Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. | A system is disclosed for communicating with a plurality of network processors, one or more of the processors having a different operating environment, includes receiving an application programming interface (API) call from a user application, the API call including a call address identifying one or more of the network processors; and accessing a memory that identifies an appropriate form for the API call for each operating environment implemented by each network processor identified by the call address; and building one or more messages including the appropriate form for the API call for the operating environment of each of the network processors to receive any particular message. | 17,534 |
FIELD OF THE INVENTION
This invention relates to carbon dioxide capture and energy recovery from the exhaust gas stream of an internal combustion engine in order to reduce carbon dioxide emissions into the atmosphere.
BACKGROUND OF THE INVENTION
The currently accepted thinking is that global warming is due to emissions of greenhouse gases such as carbon dioxide (CO 2 ) and methane (CH 4 ). About a quarter of global human-originated CO 2 emissions are currently estimated to come from mobile sources, i.e., automobiles, trucks, buses and trains that are powered by an internal combustion engine (ICE). This proportional contribution is likely to grow rapidly in the foreseeable future with the projected surge in automobile and truck ownership in developing countries. At present, the transportation sector is a major market for crude oil, and controlling CO 2 emissions is both an environmentally responsible and a desirable goal in order to maintain the viability of the crude oil market in the transportation sector in the face of challenges from alternative technologies, e.g., cars powered by electric motors and storage batteries.
Carbon dioxide management from mobile sources presents many challenges including space and weight limitations, the inability to achieve economies of scale and the dynamic nature of the operation of the ICE powering the mobile source.
Prior art methods for the capture of CO 2 from combustion gases have principally focused on stationary sources, such as power plants. Processes have been developed that use, for example, amines and amine-functionalized liquids and solutions to absorb CO 2 at temperatures ranging from ambient up to about 80° C. At temperatures above 100° C., and particularly in the range of from about 130° C. to 600° C. that are encountered in vehicles powered by an ICE, the amines exhibit low capacity for CO 2 absorption. Thus, the high temperature of the ICE exhaust gas makes direct treatment to remove CO 2 with liquid amine solutions impractical.
Aqueous ammonia has also been used in power plants to capture not only carbon dioxide, but SO x and NO x compounds. The absorption process must be conducted at relatively low temperatures to be effective, so that the solution must be cooled, e.g., to about 27° C. The so-called chilled ammonia process is described in international patent application WO 2006/022885 (2006), the disclosure of which is incorporated herein by reference.
An accepted prior art thermodynamic process used in stationary or fixed sources such as electrical power generation facilities for converting thermal energy into usable mechanical power is the Kalina Cycle. The Kalina Cycle can be implemented in order to increase the overall efficiency of the energy recovered from the fuel source. The process is a closed system that utilizes an ammonia-water mixture as a working fluid to improve system efficiency and to provide more flexibility under varying operating conditions that have cyclical peak energy demand periods. The Kalina Cycle would not be suitable for use on board a mobile source as a separate mechanical energy/work producing system due to the added weight and associated capital expense as compared to Rankine cycle systems.
Historically, the capture of CO 2 from mobile sources has generally been considered too expensive, since it involves a distributed system and a reverse economy of scale. The solution to the problem must take into account the practical considerations of on-board vehicle space limitations, the additional energy and apparatus requirements and the dynamic nature of the vehicle's operating cycle, e.g., intermittent periods of rapid acceleration and deceleration.
Some prior art methods that address the problem of reducing CO 2 emissions from mobile sources employ sorbent materials that can be subjected to regeneration and reuse of the CO 2 capture agent and make use of waste heat recovered from the various on-board sources. Oxy-combustion processes employed with stationary sources using only oxygen require an oxygen-nitrogen separation step which is more energy-intensive than separating CO 2 from the exhaust gases and would be more problematic if attempted on board a vehicle.
For purposes of describing the present invention, “mobile source” means any of the wide variety of known conveyances that can be used to transport goods and/or people that are powered by one or more internal or external combustion engines that produce a hot exhaust gas stream containing CO 2 . This includes all types of motor vehicles that travel on land, as well as trains and ships where the exhaust from the combustion is discharged into a containing conduit before it is discharged into the atmosphere.
As used herein, the term “waste heat” is the heat that a typical internal combustion engine (ICE) produces that is contained principally in the hot exhaust gases (˜300° C. to 650° C.) and the hot coolant (˜90° C. to 120° C.). Additional heat is emitted and lost by convection and radiation from the engine block and its associated components, and other components through which the exhaust gas passes, including the manifold, pipes, catalytic converter and muffler. This heat energy totals about 60% of the energy that typical hydrocarbon (HC) fuels produced when combusted.
As used herein, the term “internal heat exchanger” means a heat exchanger in which the respective heating and cooling fluids originate in the mobile source.
As used herein, “stationary source” means any of the wide variety of known industrial systems and processes that burn carbon-containing fuels and emit CO 2 to produce heat, work, electricity or a combination thereof and that are physically fixed.
As used herein, the term “lean loading” means the amount of CO 2 remaining in the lean adsorption/absorption solution coming out of the bottom of the CO 2 stripper. In accordance with established usage in the field, loading is defined as the moles of CO 2 per mole of the amine group or other compound that captures the CO 2 by adsorption or relative absorption. As used herein, the terms “CO 2 -rich solution” and “CO 2 -lean solution” are synonymous with “rich loaded CO 2 solution” and “lean loaded CO 2 solution”.
The problem of improving the efficiency of the energy recovered from hydrocarbon fuel combustion in an ICE has been addressed by taking advantage of the waste heat that is present in the engine coolant, the exhaust gas stream and the engine block, manifolds and other metal parts.
Incorporating an energy recovery system requires space, added weight and a specific capital expenditure. However, this investment can be worthwhile if the energy recovery system improves the overall efficiency of the fuel conversion to mechanical power, while reducing the CO 2 emissions into the atmosphere, and does this without substantially increasing fuel consumption.
It had long been the practice to use CO 2 as a non-toxic and non-flammable refrigerant gas in air conditioning systems prior to the use of chlorofluorocarbon (CFC) refrigerants. It has been proposed more recently in order to improve vehicle efficiency to operate an air conditioning system in reverse, utilizing heat from the vehicle's hot exhaust gas stream to generate additional power for use on board the vehicle. See, e.g., Chen et al., Theoretical Research of Carbon Dioxide Power Cycle Application in Automobile Industry to Reduce Vehicle's Fuel Consumption, Applied Thermal Engineering 25 (2005) 2041-2053. The systems contemplated are closed systems and are based on the moderate value of the critical pressure of CO 2 . There is no capture and recovery of CO 2 from the exhaust gas stream in order to reduce CO 2 emissions into the environment.
A so-called thermal engine for power generation has been described that uses waste heat from the flue gases produced by a stationary source in a closed loop system that uses supercritical CO 2 (ScCO 2 ) as the working fluid. See Persichilli et al., Transforming Waste Heat to Power Through Development of a CO 2 -Based Power Cycle, Electric Power Expo 2011 (May 2011) Rosemont, Ill. The ScCO 2 passes in heat exchange with hot flue stack gases and then through a turbine where the waste heat is converted to mechanical shaft work to produce electricity. A recuperator recovers a portion of the residual heat and the remainder is discharged from the system through a water or air-cooled condenser, from which the CO 2 exits as a subcooled liquid for passage to the pump inlet. Again, this closed system is adapted for integrated use with an industrial heat source to improve the overall efficiency of the associated system. It does not capture CO 2 for the purpose of directly reducing its emission into the atmosphere with the exhaust gases.
Incorporating a CO 2 capture system on board a mobile source to reduce CO 2 emissions adds weight, energy consumption, capital expenditures and maintenance. The problem is to provide a compact system that is easy to operate and maintain at an acceptable and competitive cost of manufacture.
Another problem addressed by the present invention is how to provide an effective and efficient CO 2 capture system in combination with an energy recovery and conversion system to produce the electrical and/or mechanical energy needed to compress the CO 2 for on-board storage, operate the associated systems and power the mobile source accessories.
A related problem is how to combine the CO 2 capture and energy recovery systems to increase the overall efficiency and reduce the number of components, weight, capital expenditure, and maintenance of the overall system and the vehicle.
Technical problems associated with CO 2 capture from mobile sources include how to further increase the efficiency of on-board CO 2 capture so that operating a conventional ICE powered by hydrocarbon fuels will remain economically and environmentally competitive with the all-electric and hybrid automobiles. These traditional problems are addressed by the processes and systems disclosed, for example in WO/2012/100149, WO/2012/100165, WO/2012/100157 and WO/2012/100182 which integrate CO 2 capture, heat recovery and CO 2 capture agent regeneration and reuse systems, hereinafter referred to as “multiple systems”. However, utilizing multiple systems in mobile applications also increases weight, energy consumption, capital expenditure, and maintenance associated with operation of the vehicle.
The problem remains of further improving the efficient on-board capture of CO 2 from the hot exhaust gas stream from the ICE powering a mobile source.
SUMMARY OF THE INVENTION
The present invention broadly comprehends a process and an integrated system for use on board a vehicle powered by an internal combustion engine (ICE) that combines power generation with CO 2 capture and on-board CO 2 densification and storage that reduces irreversibilities and increases the overall efficiency of the process and the operating system to thereby maximize the recovery of useful energy from the hydrocarbon fuel used to power the vehicle.
More specifically, the present invention is directed to a process and system for CO 2 capture and energy recovery from an exhaust gas stream to reduce CO 2 emissions from a variety of conventional mobile applications in which the captured CO 2 is retained in the working fluid in an energy production cycle to produce work and the CO 2 is subsequently separated from the working fluid, compressed and temporarily stored on-board for eventual on-board conversion or recovery from the mobile source. The principal method and system of the invention are also applicable to CO 2 from recovered stationary sources for disposition, e.g., by sequestration.
The process of the invention uses a CO 2 -absorbing liquid, sometimes referred to in this description and in the claims as the “solution,” or the “sorbent solution”, in an absorption zone by direct contact or indirect contact, e.g., using a membrane absorber, with a CO 2 -containing exhaust gas stream to absorb all or a portion of the CO 2 that would otherwise be discharged into the atmosphere.
Water is a preferred solvent in which amines and other CO 2 absorbents such as bicarbonates are dissolved to operate the system for reasons of economics, availability and the absence of environmental concerns if it is discharged from the system in favor of a replacement with fresh water. Alcohols can be used to capture CO 2 and can be used as the solvent or as the solute. Colloidal solutions that contain, for example, water as a solvent and suspended solid sorbents that capture CO 2 can also be used in the process of this invention. Heating such solutions will result in CO 2 desorption from the solid particles and water evaporation to drive the turbine. As will be apparent to one of skill in the art, families of CO 2 absorbents and adsorbents and solvents can be selected based on the specific conditions of use including climate, availability of sorbent and solute materials, and the type of ICE. For the purposes of the following description, water is selected as the working fluid.
The operation of the process is similar to that of prior art systems such as the Kalina Cycle and absorption systems. However, both of those processes are closed systems, used for power generation in the case of the Kalina Cycle and for cooling or heating in the case of absorption systems.
As used in the description that follows and in the claims, the term “external heat exchanger” means a heat exchanger which is air-cooled or water cooled, i.e., the energy sink that is required to close the energy loop is external to the process or system.
The CO 2 -rich solution exiting the absorber is heated via one or more heat exchangers and passed to a boiler that is heated by the hot exhaust gas stream from the ICE. In the boiler, the CO 2 is desorbed from the sorbent solution and at least a portion of the water in the solution is evaporated to form steam. Thereafter, the vapor phase is passed to a separation zone in which a hot liquid/vapor separator produces a stream of the now-concentrated sorbent solution having a higher concentration of the CO 2 -absorbing compound.
The CO 2 /water vapor stream from the separation zone is then passed to a superheating zone where it is subjected to heat exchange with the hot exhaust gas stream passed directly from the ICE that is at a temperature in the range of from 200° C. to 800° C. The superheated vapor phase is expanded in one or more turbines to generate power. In the case of multiple turbines, inter-stage heating by heat exchange with the hot exhaust gases is employed to maximize the cycle efficiency of the working fluid containing the captured CO 2 .
The liquid CO 2 -lean solution leaving the liquid/vapor separator is passed to a first internal heat exchanger to heat the CO 2 -rich solution and increase the cycle efficiency. The CO 2 -lean solution is then expanded in a turbine or through an expansion valve and it is then cooled, in an external heat exchanger by contact with ambient air or the engine coolant, to the desired absorber temperature for passage to the absorption zone.
The CO 2 /water stream leaving the turbine is passed to a second internal heat exchanger to provide heat to the CO 2 -rich solution and increase the cycle efficiency before it is cooled, by an external heat exchanger operated by contact with ambient air or the engine coolant, to the temperature of a CO 2 /water separator from which a CO 2 -rich gas stream is recovered and condensed water is recovered as a liquid.
All or a portion of the condensed water can be mixed with the concentrated sorbent solution from the separator to restore the desired concentration to the solution, which is then pumped to the absorber inlet. The CO 2 -rich gas stream is compressed in a multi-stage CO 2 compressor with inter-stage cooling and a water knock-out to remove any water carried over with the CO 2 from the condenser/separator. The compressed pure CO 2 is passed to a high pressure tank for temporary on-board storage pending ultimate disposition. Moderate or no compression can also be practical for CO 2 conversion by a chemical change or storage of CO 2 in a high-capacity retention material, such as metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs). In the case of CO 2 captured from a stationary CO 2 source for permanent disposition, the captured CO 2 can be conveyed in a pipeline for permanent storage, e.g., by underground sequestration.
The power produced by the turbine(s) can be used to drive one or more absorbent liquid pumps and/or CO 2 compressors. Any excess power can be used to charge the vehicle's battery or to power on-board electrical components.
The present invention provides a highly efficient process and system that recovers energy from the waste heat of the exhaust gas stream by utilizing the captured CO 2 as a component in a heated and pressurized working fluid in a process which produces mechanical and/or electric energy to meet the requirements of the pumps and/or CO 2 compressors on board the vehicle.
From the above description, it will be understood that the invention is directed to a process for reducing the amount of CO 2 released into the atmosphere with the exhaust gas stream produced by the combustion of a hydrocarbon fuel in an ICE used to power a vehicle by capturing at least a portion of the CO 2 with a sorbent on board the vehicle, recovering the CO 2 from the sorbent and compressing the CO 2 for temporary storage on board the vehicle, the process characterized by
a. passing the hot exhaust gas stream from the ICE through a plurality of heat exchangers in a first heat exchange zone to reduce the temperature of the exhaust gas stream to a value in a predetermined temperature range; b. contacting the cooled exhaust gas stream in an absorption zone with a liquid CO 2 sorbent solution at a temperature within a predetermined temperature range, the solution comprising water in which is dissolved at least one compound that reversibly combines with CO 2 to capture at least a portion of the CO 2 from the exhaust gas stream to provide a CO 2 -rich solution; c. separating the CO 2 -rich solution from the remaining exhaust gas stream that is of reduced CO 2 content; d. discharging the remaining exhaust gas stream of reduced CO 2 content into the atmosphere; e. pressurizing the CO 2 -rich solution and passing it into a boiler for passage in a first heat exchange relation with a partially-cooled exhaust gas stream to raise its temperature to desorb the CO 2 and provide a concentrated CO 2 -lean sorbent solution and to vaporize a portion of the water from the sorbent solution to provide a vaporized water/CO 2 mixture; f. separating the CO 2 -lean sorbent solution from the vaporized water/CO 2 mixture in a first separation zone; g. passing the vaporized water/CO 2 mixture into a superheating zone where it passes in a second heat exchange relation with the hot exhaust gas stream directly from the ICE to further increase the temperature of the mixture to about 400° C.; h. passing the superheated water/CO 2 mixture to a turbine and expanding the mixture to a predetermined lower pressure value; i. passing the hot expanded water/CO 2 mixture in heat exchange with the pressurized CO 2 -rich solution; j. passing the water/CO 2 mixture to a condensing heat exchanger to lower its temperature to condense substantially all of the water vapor to the liquid state; k. separating the condensed water from the CO 2 in a second separation zone and mixing all or a portion of the condensed water with the sorbent solution upstream of the absorption zone or discharging the water from the vehicle; l. recovering the substantially pure CO 2 from the second separation zone and passing it to a compression zone to densify the CO 2 and discharging any remaining water; m. recovering the pressurized pure CO 2 and passing it to an on-board vessel for storage or for further processing to reduce its volume by a physical and/or chemical change of state; n. passing the pressurized CO 2 -lean solution from the first separation zone in heat exchange relation to increase the temperature of the pressurized CO 2 -rich solution from the absorption zone; o. introducing the pressurized CO 2 -lean solution into an expansion device to produce mechanical energy; p. passing the reduced-pressure concentrated CO 2 -lean solution from the expansion device to a mixing valve through which water is added to restore the desired concentration of the sorbent solution; q. cooling the CO 2 -lean solution to the predetermined temperature range prior to passing it into the absorption zone; and r. pressurizing the CO 2 -lean sorbent solution upstream of the absorption zone.
As will be understood by one of ordinary skill in the art, the temperature of the superheated vaporized water/CO 2 mixture in step (g) above can vary from 400° C. and will depend on the optimum operating conditions of the system. The reduction in volume of the CO 2 can be achieved by maintaining it in a liquid, solid or super-critical state. As also noted above, solvents other than water can be employed in the practice of the process.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described below and with reference to the attached drawings in which the same or similar elements are identified by the same number, and in which:
FIG. 1 is a schematic diagram of an embodiment of the process of the invention in a basic cycle in which CO 2 is captured and compressed in a power production cycle;
FIG. 2 schematically illustrates an embodiment of the invention that includes an optional re-heat step;
FIG. 3 schematically illustrates an embodiment of the invention in which the pressure at the turbine exit is reduced to below atmospheric pressure (vacuum) in order to increase expansion power recovery;
FIG. 4 schematically illustrates a fourth embodiment of the invention in which an additional internal heat exchanger extracts heat from the exhaust gas stream; and
FIG. 5 is a screenshot of an Aspen simulation for a process that is similar to the process described in FIG. 2 .
DETAILED DESCRIPTION OF INVENTION
As discussed above, the process of the present invention operates as a semi-closed system that captures CO 2 from an exhaust gas stream of an ICE and produces mechanical energy, or work, utilizing a working fluid that contains the CO 2 in the power generation cycle. The process can be used to advantage for CO 2 capture from a mobile source powered by an internal combustion engine (ICE).
Referring to an embodiment of the invention schematically illustrated in FIG. 1 , a simplified cycle of the process is depicted in which CO 2 is captured and compressed in a power production cycle.
A lean loaded CO 2 absorbing solution (hereafter referred to as “solution”) such as aqueous potassium carbonate is transferred via pump ( 10 ) as stream ( 102 ) to the absorption unit ( 20 ) to capture CO 2 from the exhaust gas stream at atmospheric or near atmospheric pressure.
The CO 2 absorption unit ( 20 ) can be a direct contact liquid/gas column such as packed column or an indirect contact membrane absorption device such as gas-liquid membrane contactor. For convenience, the description that follows will refer to the practice of the process of the invention in a direct contact absorption unit. However, as will be understood by those of ordinary skill in the art, an indirect absorber can be employed with substantially the same effect.
The hot exhaust gas stream ( 901 ) exiting the ICE is first cooled by passage through the superheater ( 31 ) and enters the boiler ( 30 ) as reduced temperature stream ( 902 ). The exhaust gas stream ( 903 ) exiting the boiler ( 30 ) is further cooled to a predetermined temperature between 30° C. and 100° C. in a heat exchanger ( 36 ) and the cooled stream ( 904 ) enters the absorption unit ( 20 ) where CO 2 is absorbed by the cooled CO 2 -lean loaded solution that enters the absorber ( 20 ) via stream ( 102 ) at a temperature between 30° C. and 100° C.
The remaining exhaust gas ( 905 ) leaves the absorber ( 20 ) after CO 2 capture and is discharged into the atmosphere.
The CO 2 -rich solution leaves the absorber ( 20 ) via stream ( 200 ) and is pressurized by pump ( 11 ) to the high pressure value of the system, e.g., to 4 MPa, and passes as stream ( 201 ) to a first internal heat exchanger ( 34 ) where it is heated about 100° C. by the CO 2 /water stream ( 403 ) leaving turbine ( 51 ) as will be described in further detail below.
The pressurized CO 2 -rich solution ( 202 ) exits the internal heat exchanger ( 34 ) and passes through a second internal heat exchanger ( 33 ) for further heating. The second internal heat exchanger ( 33 ) is heated by the high pressure CO 2 -lean solution ( 300 ). The high pressure CO 2 -rich solution ( 203 ) then enters boiler ( 30 ).
The high pressure CO 2 -rich solution ( 203 ) is partially evaporated in boiler ( 30 ) which is heated by the hot exhaust gas stream ( 902 ) downstream of the superheater ( 31 ) which is in close proximity to the exhaust manifold of the ICE; the CO 2 and water are vaporized because of their lower normal boiling points.
The high pressure CO 2 -rich liquid/gas mixture ( 205 ) leaves the boiler ( 30 ) at an increased temperature of, e.g., about 210° C., and enters a liquid/vapor separator ( 40 ) that separates the gaseous CO 2 /water mixture from the remaining high pressure CO 2 -lean solution ( 300 ).
The high pressure CO 2 -lean solution ( 300 ) leaves the liquid/vapor separator ( 40 ), enters internal heat exchanger ( 33 ) and passes as stream ( 301 ) to an expansion device ( 50 ), e.g., a turbine or throttle valve, where it is expanded to a lower pressure before passing to the liquid header ( 100 ) as stream ( 302 ). The expansion device ( 50 ) recovers power P for the system from the waste heat and provides mechanical energy to pumps ( 10 ) and ( 11 ).
The CO 2 /water vapor mixture ( 401 ) exiting the liquid/vapor separator ( 40 ) passes through the superheater ( 31 ) that is heated by the exhaust gas stream ( 901 ) and exits as superheated stream ( 402 ) at a temperature of approximately 400° C. and expands in a turbine ( 51 ) to produce power, exiting at approximately atmospheric pressure as stream ( 403 ).
The power P from the turbine ( 51 ) is applied to operate pumps in the system, to compress CO 2 and/or to operate the process utilities, as required.
The low pressure CO 2 /water exiting the turbine ( 51 ) as stream ( 403 ) passes through an internal heat exchanger ( 34 ) and exits via stream ( 406 ) to another heat exchanger ( 37 ) where it is further cooled to approximately 40° C. in order to condense the water. After exiting the heat exchanger ( 37 ) via stream ( 407 ), the low pressure CO 2 /water passes to a separator ( 41 ) where the condensed water is separated from the CO 2 gas. The condensed water stream ( 500 ) exiting the separator ( 41 ) is composed of water with some dissolved CO 2 , all or a portion of which can be passed to the liquid header ( 100 ) as stream ( 502 ); any excess water can be discharged from the system as stream ( 501 ).
The liquid solution ( 100 ) is further cooled in heat exchanger ( 35 ) to the desired CO 2 absorption temperature before it is fed to the suction line ( 101 ) of pump ( 10 ) that feeds the CO 2 absorber ( 20 ).
The vapor stream ( 600 ) consisting principally of CO 2 passes from the separator ( 41 ) to the compression zone ( 60 ) where it is compressed to produce a high-purity CO 2 stream ( 601 ). The high-purity CO 2 stream ( 601 ) can be passed to on-board storage in mobile applications and to storage and/or a pipeline in the case of stationary or fixed CO 2 sources. Any remaining water is condensed by intercooling and phase separation and discharged from the system as water stream ( 700 ).
All or a portion ( 704 ) of the condensed water ( 700 ) can optionally be returned via a three-way valve ( 702 ) to the loop ( 100 ) or to the pump suction line ( 101 ) in order to control the water content of the lean absorption solution in the process and prevent salt precipitation. Fresh make-up water can also be used for this purpose, alone or in combination with condensed water stream ( 700 ). Alternatively, the condensed water ( 700 ) can be discharged ( 706 ) from the system.
In another embodiment of the invention schematically illustrated in FIG. 2 , an optional re-heating step is provided in which the exiting vapor stream is re-heated after a first expansion of the working fluid in order to increase the overall cycle efficiency.
In this embodiment, the hot exhaust gas stream ( 900 ) enters the system through heat exchanger ( 32 ) where the medium pressure CO 2 /water mixture ( 403 ) at, e.g., one Mpa, is re-heated to about 400° C. and exits as heated stream ( 404 ).
The cooled exhaust gas stream ( 901 ) from heat exchanger ( 32 ) enters the superheater ( 31 ) and follows the same path that was described in FIG. 1 .
The superheated CO 2 /water stream ( 402 ) from superheater ( 31 ) is expanded in turbine ( 51 ) to a medium pressure of about 1 MPa and exits as stream ( 403 ). Stream ( 403 ) passes to heat exchanger ( 32 ) to be re-heated by the entering exhaust gas stream ( 900 ) to a temperature of about 400° C. and then passes as stream ( 404 ) to turbine ( 52 ). The expanded low pressure stream ( 405 ) exits the turbine ( 52 ) at approximately atmospheric pressure and passes to internal heat exchanger ( 34 ) to exchange heat with the high pressure CO 2 rich solution stream ( 201 ), and exits as stream ( 406 ).
The process steps of stream ( 406 ) are the same as those described above in conjunction with the embodiment of FIG. 1 .
The re-heating step is followed by a further expansion step to reduce the irreversibilities in the system and increase the overall system efficiency. Other aspects of the process of FIG. 1 , including the use of the condensate stream ( 700 ) that may be injected back into the loop via line ( 100 ) or ( 101 ) as make-up water in order to control the water content in the process and prevent salt precipitation is also applicable to the embodiment of FIG. 2 .
In a third embodiment of the invention that is schematically illustrated in FIG. 3 , the pressure at the turbine exit is reduced to below atmospheric pressure, e.g., to a vacuum in order to increase expansion power recovery.
This advantage can be realized because the CO 2 water saturation pressure at ambient temperature is less than atmospheric pressure allowing for a higher power recovery from the fluid expansion and an increase in the net power and efficiency of the process of the invention.
The process in FIG. 3 is similar to the first embodiment as described above in connection with FIG. 1 , with the difference being that the outlet pressure of stream ( 403 ) exiting the turbine ( 51 ) is reduced to, i.e., 20 kPa absolute pressure and a pump ( 12 ) is added to the process to pressurize the liquid stream ( 500 ) to near atmospheric pressure.
The superheated CO 2 /water stream ( 402 ) leaving the superheater ( 31 ) is expanded in turbine ( 51 ) to 20 kPa in order to recover the expansion energy. The CO 2 /water stream leaves the turbine via stream ( 403 ) to enter internal heat exchanger ( 34 ) and the CO 2 water stream exits as stream ( 406 ).
The CO 2 /water stream ( 406 ) is further cooled in heat exchanger ( 37 ) to achieve the desired separation of the CO 2 by condensing the water. Stream ( 407 ) exiting heat exchanger ( 37 ) passes to a separator ( 41 ) where a CO 2 -rich stream ( 600 ) is recovered under a vacuum, e.g., 20 kPa, and compressed in the multi-stage compressor ( 60 ) to the required outlet pressure and the pressurized stream ( 601 ) and passed for storage or further processing.
The condensate stream ( 500 ) composed mainly of water is pressurized by pump ( 12 ) to the liquid header line ( 100 ) pressure, e.g., 100 kPa to complete the cycle. Stream ( 510 ) exiting pump ( 12 ) is conveyed in whole or in part for addition to stream ( 100 ) via stream ( 502 ), the excess being discharged from the system as stream ( 501 ).
The same vacuum condensation principle can be applied to the re-heat configuration by reducing the outlet pressure of turbine ( 52 ), e.g., to 20 kPa, in order to recover additional work energy and increase the efficiency of the process.
In a fourth embodiment of the invention that is schematically illustrated in FIG. 4 , the exhaust gas stream ( 903 ) is further cooled exchanging heat with the high pressure CO 2 -rich solution stream ( 202 ) in a step to increase the overall cycle efficiency, capturing more CO 2 or providing more power for a same CO 2 capture rate.
The process in FIG. 4 is similar to the embodiment as described above in connection with FIG. 3 , with the difference of the inclusion of an additional internal heat exchanger ( 39 ) between heat exchanger ( 30 ) and external heat exchanger ( 36 ) on the exhaust gas line, and between heat exchanger ( 34 ) and heat exchanger ( 33 ) on the high pressure CO 2 -rich solution.
The exhaust gases leaving heat exchanger ( 30 ) in stream ( 903 ) heat the high pressure CO 2 -rich solution stream ( 202 ) exiting heat exchanger ( 34 ). The cooler exhaust gas stream ( 934 ) leaves heat exchanger ( 39 ) to enter heat exchanger ( 36 ) and continue the process as described in FIG. 3 .
The high pressure CO 2 -rich solution stream ( 202 ) leaving heat exchanger ( 34 ) is heated in heat exchanger ( 39 ) by the hot exhaust gases before entering heat exchanger ( 33 ) for further heating via stream ( 222 ). Afterwards, the high pressure CO 2 -rich solution undergoes the same steps described in FIG. 3 of the process.
In yet another embodiment, it is possible to integrate heat exchanger ( 39 ) in the re-heat configuration of the system as described in FIG. 2 or in the above atmospheric pressure outlet configuration as described above and represented in FIG. 1 of the invention.
As will be apparent to one of ordinary skill from the above description of the process and system, the fluids circulated to the three heat exchanges (e.g., 33 , 34 and 39 ) can be varied depending upon the operating characteristics and requirements of the process. For example, the thermodynamic characteristics can be adjusted in order to obtain additional power from the turbines ( 50 , 51 , 52 ), as discussed further below.
As described above in connection with the previous embodiments, all or a portion of water stream ( 700 ) can be injected back into the loop in line ( 100 ) or ( 101 ) in order to control the water content of the solution used in the process and prevent salt precipitation. Fresh make-up water can also be used for this purpose, either alone or in combination with water from stream ( 700 ).
It is noted that the process shown in FIG. 4 also includes a re-heat step as was previously shown in FIG. 2 to further increase process efficiency.
The process according to the invention can be operated to achieve a predetermined CO 2 capture goal, e.g., 25%, or to produce a predetermined required amount of power.
In a CO 2 capture application, CO 2 compression is the main energy-intensive component of the system and the net power output is the net power produced by the turbines minus the power consumed by the pumps and in the CO 2 compression step or steps.
Since pumps are indispensable to the operation of the system, there can be little or no variation in meeting requirements for the operation of the pump; however, the extent of CO 2 compression can be varied and is dependent on the CO 2 capture rate and/or the on-board storage capacity.
In a power-oriented operational mode with no CO 2 capture rate requirements, the rate can be adjusted according to the desired net power output, e.g., by reducing the CO 2 capture rate to reduce the CO 2 compression power requirement, thereby increasing the net power output of the system.
Alternatively, if the CO 2 capture rate is to be fixed, e.g., within a given range, or not less than a predetermined value, the system should operate at the required CO 2 capture flow rate with no degree of freedom on the net power production.
The choice of the pressure and temperature throughout the system dictates the parameters of the production cycle and the potential CO 2 capture rate. For example, superheating and re-heating can be used to increase the power output and reduce the irreversibilities in the system. As a result, superheating and re-heating do not affect the CO 2 capture rate, but do affect the net power produced.
An important parameter that does affect the CO 2 capture rate is the temperature and pressure of stream ( 205 ) exiting heat exchanger ( 30 ) and entering separator ( 40 ) since the conditions of this stream will determine how much CO 2 and water go into the vapor phase in separator ( 40 ).
The temperature and pressure at the outlet of heat exchanger ( 37 ), as well as the operating temperature and pressure of separator ( 41 ) relate to the actual rate of CO 2 capture because the temperature and pressure of separator ( 41 ) control the ratio between the liquid and vapor phase. It is therefore possible to regulate the system's operation to achieve the desired power production and/or level of CO 2 capture and emissions reduction by controlling the temperature and pressure in these devices ( 37 , 41 ).
The process according to the invention can use, in addition to the heat of the exhaust gas stream, one or more different sources of energy such as engine coolant energy, solar energy, or any other available form of recoverable thermal energy, to support the operation of the heat exchangers ( 30 ) and/or ( 31 ) and/or ( 32 ) and/or ( 39 ) to maximize the power production.
Recoverable energy such as kinetic, mechanical and/or electrical energy can be used in the process to increase the output of the turbines and/or operate the CO 2 compressor. Energy recovery systems and devices that are used on all-electric or hybrid motor vehicles can also be employed on vehicles powered by an ICE to provide electrical power directly or through a storage battery or other device.
Any cooling device in the process used to cool a stream with an ambient or external stream, e.g., an air-cooled heat exchanger ( 36 ), can be replaced by an energy recovery device, e.g., a thermo-electric device or other device that captures and converts heat to energy while cooling the working fluid stream to the desired temperature, and the recovered energy can be utilized in the process. For example, instead of cooling the exhaust gas stream from 200° C. to 60° C. in a heat exchanger, a thermoelectric device can be utilized to cool stream ( 903 ) to the desired temperature while producing electricity from the recovered energy.
The process of the invention can also be modified by changing the position of the pumps or replacing the pumps with ejectors. It is also possible, depending on the type of the absorber ( 20 ), i.e., closed type, membrane absorber, or other, to combine pump ( 10 ) and pump ( 11 ) in a single pump that is either upstream of the absorption unit ( 20 ) or, preferably in the location of downstream pump ( 11 ) in order to carry out the absorption at a lower solution pressure.
The process of the invention can also employ various processes for CO 2 and water separation such as membranes or other separation means.
The CO 2 absorbing solution used in the process according to the invention can be a water-based solution containing salts and/or amines and/or other molecules that capture CO 2 , by either a physical or chemical process. The CO 2 sorbent solution used in the process of the invention can be selected from the following:
a. a solvent-based solution containing salts and/or amines and/or other molecules that physically or chemically absorb CO 2 ; b. a solvent-based or water-based carrier in which solid CO 2 adsorbent particles are dispersed and the CO 2 is adsorbed by the particles at low temperature and desorbed from the particles at high temperatures, the particles being regenerated and recycled, and the liquid carrier also preferably adsorbs or absorbs the CO 2 physically or chemically at low temperatures and desorbs the CO 2 at high temperatures in order to reduce the flow rate and contactor size; c. a colloid fluid or crystalloid fluid reversibly absorbing and/or adsorbing CO 2 and desorbing CO 2 at the appropriate conditions; and d. a mixture of absorbing and adsorbing liquids.
As will be understood from the above descriptions and examples, the process of the invention broadly comprehends the combination of CO 2 capture in an integrated system that reduces irreversibilities and thereby increases the overall efficiency of the processing and operating system.
In addition to increased efficiency and waste heat recovery in mobile applications, the process of the invention includes the advantages of requiring a reduced number of components as compared to separate heat recovery and CO 2 recovery systems. The integrated system saves space and weight on board mobile sources and reduces capital expenditures and operational maintenance costs.
FIG. 5 is a screen shot of an Aspen Plus Simulation flowsheet representing an embodiment of the invention similar to the process that is depicted in FIG. 2 .
Example
The process according to the best mode of the embodiment illustrated in FIG. 3 for the practice of the process of the invention for mobile applications will be described in further detail in this example. A lean aqueous potassium carbonate CO 2 absorbing solution is pressurized by pump ( 10 ) and introduced as stream ( 102 ) into the absorption unit ( 20 ) to capture CO 2 from the cooled exhaust gas stream. The CO 2 absorption unit ( 20 ) can be a direct contact liquid-gas column or an indirect contact membrane absorption device that operates at atmospheric or near atmospheric pressure.
The hot exhaust gas stream ( 901 ) is cooled in passes through superheater ( 31 ) and boiler ( 30 ). The exhaust gas stream ( 903 ) exiting the boiler ( 30 ) is further cooled to a predetermined temperature between 30° C. and 100° C., depending on ambient conditions, in a heat exchanger ( 36 ) and the cooled exhaust gas stream ( 904 ) enters the absorption unit ( 20 ) where CO 2 is absorbed by the CO 2 -lean solution ( 102 ) to complete the absorption.
The remaining portion of the exhaust gas stream ( 905 ) of reduced CO 2 content exits the absorber ( 20 ) and is discharged into the atmosphere. In an alternative embodiment, prior to its discharge into the atmosphere, the flue gas stream ( 905 ) can be reheated, e.g., to expand its volume. The reheating of stream ( 905 ) can be accomplished using the heat from stream ( 903 ) entering heat exchanger ( 36 ). In this embodiment, heat exchanger 36 can be replaced by an internal heat exchanger or the system can incorporate an internal heat exchanger upstream of heat exchanger ( 36 ) in which stream ( 903 ) provides heat to stream ( 905 ).
The CO 2 -rich solution ( 200 ) exits the absorber ( 20 ) and is pressurized by pump ( 11 ) to the high pressure value of the system, e.g., to 4 MPa, and passes as pressurized stream ( 201 ) to a first internal heat exchanger ( 34 ) where it is heated by the CO 2 /water stream ( 403 ) leaving turbine ( 51 ) as will be described in further detail below.
The heated high pressure CO 2 -rich solution ( 202 ) exits the first internal heat exchanger ( 34 ) and passes through a second internal heat exchanger ( 33 ) for additional heating. The second internal heat exchanger ( 33 ) is heated by the hot high pressure CO 2 -lean solution ( 300 ) from which CO 2 has previously been recovered. The high pressure CO 2 -rich solution ( 203 ) then enters the boiler ( 30 ).
The pressurized CO 2 -rich solution ( 203 ) is partially evaporated in boiler ( 30 ) which is heated by the hot exhaust gas stream ( 902 ); the portion of absorbed CO 2 is desorbed and some water is vaporized because of their lower normal boiling points. As the concentration of the potassium carbonate increases, the boiling point of the solution also rises, so that the solution remains in a flowable liquid state.
The high pressure CO 2 -rich solution ( 205 ) passes from the boiler at a temperature of about 210° C. and enters a liquid/vapor separator ( 40 ) that separates the CO 2 /water gaseous mixture from the remaining pressurized CO 2 -lean solution.
The pressurized CO 2 -lean solution ( 300 ) leaves the liquid/vapor separator ( 40 ), passes through internal heat exchanger ( 33 ) and then as stream ( 301 ) enters expansion device ( 50 ), e.g., a turbine or throttle valve, where it is expanded to a lower pressure before passing as stream ( 302 ) to the lower pressure process liquid header or conduit ( 100 ).
The expansion device ( 50 ) can be a throttle valve or a turbine that recovers the power P required for the operation of pumps ( 10 ), ( 11 ) and as in FIG. 4 ( 12 ). The expansion device ( 50 ) is preferably linked directly to the shaft of the high pressure pump ( 11 ). Alternatively, electric power can be recovered to charge a battery that delivers the electricity to drive the pumps. In another embodiment, one or more pumps can be connected to a common drive shaft from the turbine.
The CO 2 /water vapor mixture ( 401 ) exiting the liquid/vapor separator ( 40 ) passes through the superheater ( 31 ) that is heated by the hot exhaust gas stream ( 901 ) and exits as a superheated CO 2 /water mixture ( 402 ) at a temperature around 400° C. Stream ( 402 ) is expanded in a turbine ( 51 ) to the vacuum pressure value of the system, e.g., 20 kPa, and produces power P which is applied as needed to operate pumps in the system, to compress CO 2 and to operate the process utilities
The low pressure CO 2 /water mixture leaves the turbine ( 51 ) as stream ( 403 ) to enter internal heat exchanger ( 34 ) and then heat exchanger ( 37 ) as stream ( 406 ).
The CO 2 /water stream ( 406 ) is cooled to condense the water to achieve the desired separation of CO 2 and water. Stream ( 407 ) exits heat exchanger ( 37 ) and passes to separator ( 41 ) where a CO 2 -rich stream ( 600 ) is recovered under vacuum, e.g., 20 kPa.
The vapor stream ( 600 ) is composed mainly of CO 2 and passes to the compression zone ( 60 ) where it is compressed to provide the compressed high-purity CO 2 stream ( 601 ). The high purity CO 2 stream ( 601 ) can be passed to on-board storage in mobile applications, and eventually to permanent underground or other storage via pipeline. Any remaining water is condensed by intercooling and phase separation and discharged from the system as waste water stream ( 700 ).
The condensate stream ( 500 ) from the separator ( 41 ) is mainly composed of water with some dissolved CO 2 and is pressurized by pump ( 12 ) for introduction into the liquid header line ( 100 ) at a pressure of about 100 kPa. Stream ( 510 ) exiting pump ( 12 ) is passed in whole or in part to sorbent solution stream ( 100 ) as stream ( 502 ), any excess being discharged from the system as stream ( 501 ).
The absorbent solution stream ( 100 ) is further cooled in heat exchanger ( 35 ) to the predetermined CO 2 absorption temperature and then passed to the suction line ( 101 ) of pump ( 10 ) for introduction into the CO 2 absorber ( 20 ).
No systems of the prior art concerned with reduction of CO 2 emissions contemplate the utilization of CO 2 from exhaust streams as a working fluid in energy recovery systems.
Example
A computer analysis/simulation was prepared using the Aspen Technology program model in lieu of bench testing. The model corresponds generally to the schematic arrangement depicted in FIG. 1 . The calculations are based on a 25% CO 2 capture rate with no pressure drop across the equipment.
It will be understood that the results are indicative and although some uncertainties remain, the results provide useful data for the specified condition. The following Table includes the characteristics of the various streams described above for the Aspen Simulation presented in FIG. 5 .
TABLE
(Based on Aspen Simulation)
Temperature
Pressure
Vapor
Mass Flow Rate
Stream
(° C.)
(kPa)
Fraction
(kg/sec)
901
600
100
1
1
902
562
100
1
1
903
242
100
1
1
904
35
100
1
1
905
40
100
1
0.91
200
39
200
0
3.5
201
40
4000
0
3.5
202
62
4000
0
3.5
203
222
4000
0.02
3.5
205
241
4000
0.05
3.5
300
241
4000
0
3.34
301
65
4000
0
3.34
302
65
100
0
3.34
401
241
4000
1
0.16
402
400
4000
1
0.16
403
99
100
1
0.16
406
45
100
0.16
0.16
407
40
100
0.14
0.16
500
40
100
0
0.1
600
40
100
1
0.06
601
40
10000
1
0.06
While various exemplary embodiments of the invention have been described above and in the attached drawings, further modifications will be apparent to those of ordinary skill in the art from these examples and the description. The scope of the invention is to be determined with reference to the claims that follow. | A process for reducing the amount of CO 2 released into the atmosphere with the exhaust gas stream produced by the combustion of a hydrocarbon fuel in an internal combustion engine (ICE) used to power a vehicle by capturing at least a portion of the CO 2 in a liquid sorbent on board the vehicle, recovering the CO 2 from the sorbent and compressing the CO 2 for temporary storage on board the vehicle, where the process is operated as a semi-closed system in which the liquid sorbent that captures the CO 2 serves as a working fluid and retains the CO 2 during the power generation cycle to produce mechanical energy or work, after which the CO 2 is desorbed for densification and recovery as an essentially pure gas stream and the working fluid is recycled for use in the process. | 54,194 |
This is a division of application Ser. No. 52,306, filed June 26, 1979, now U.S. Pat. No. 4,308,763.
BACKGROUND OF THE INVENTION
The invention is directed to a new shoe stiffening and likewise non-slip inner material and to a heel region of customary street shoes having this shoe inner material; it is not concerned for example with light, counterless shoes and/or shoes free of stiffening heel pieces in the heel portion.
The customary street shoes in the heel region consist of at least three shaped layers: First the leg or leg material (also called the upper material), second the stiffening heel piece (cap) or the stiffening material (also designated as rear heel piece material or short heel piece material) and third the slip band or non-slip material. In reciting these layers there are not counted the customary adhesive layers or coats.
SUMMARY OF THE INVENTION
The new inner shoe material serving to stiffen the heel region of street shoes is suitably produced in the form of continuous sheets or lengths and used in blanks (pieces) produced therefrom. It is thermoplastic, i.e. deformable under the action of heat or softenable by the action of solvent. It consists of a single layered fiber structure (thus it is not constructed multiplyed). It is loaded or filled with at least one synthetic resin acting as stiffener at normal temperature (about 15° to 25° C.) up to about 60°, specifically in amounts of 100 to 900 grams per square meter of fiber structure in which the loading set forth in a given case contains additional fillers, dyestuffs, pigments, plasticizers, stabilizers, propellants, processing aids and/or known extenders in each case in customary amounts. The inner material of the shoe advantageously is finely porous and absorbent for water and solvents.
Suitably one of the large surface sides of the shoe inner material continuous length or the blank made therefrom is provided with a coat based on a synthetic resin, preferably a thermoplastic synthetic resin, brought to the adhesive condition by the action of heat or the action of a solvent or mixture of solvents. In order to be able to produce with the new shoe inner material, the effect of the previously used non-slip materials in the production of shoes, this surface has a shape or character which is slip or slide diminishing. The surface of the new material thus has a certain roughness which prevents or makes more difficult the slipping out of the heel. It is particularly advantageous when the side of the new material which comes in contact with the heel or the hose by this procedure maintains a velvet-like character that the surface in question is treated mechanically, for example, by buffing on appropriate known apparatus (buffing rolls).
The above described inner shoe material is worked into the heel portion of the shoe and secured there suitably by gluing. Surprisingly and contrary to the structure of the previous conventional street shoes the new shoe inner material replaces both the function of the stiffening shoe capping material and the function of the non-slip material which should prevent the easy slipping out of the heel from the back part of the shoe, i.e. the inner material can be designated to be skid preventive too. This bifunctionality of the new shoe inner material simplifies the production of shoes in considerable measure and reduces the production costs which is of advantage in the developing countries because of the type of shoes produced there. The previous long time practice in the production of shoes of adding both flexible, pliable non-slip materials and besides that also stiffening effecting capping materials now can be unexpectedly changed by the present invention and be substantially simplified. The invention permits the more economical production of particularly simple footwear.
The consequently produced new heel region of shoe thus no longer has a separate customary heel stiffener and it consists of the accurate last shaped shoe inner material blank of the above described type and of the leg glued therewith.
Accordingly to the invention there is also claimed the process of stiffening the heel portions of shoes which is characterized by fastening by securely sewing or similar method a suitable blank of the new moldable shoe inner material at the upper edge of the inner side of an upper material without a counter to simultaneously stiffen the heel region and produce the non-slip effect. In the case of the insertion of the shoe inner material which is not provided with an adhesive layer the inner side of the blank is provided with an adhesive coating and then the combination worked on the last through the effect of pressure and if desired of heat and thus the cementing is effected.
If the shoe inner material on one side is provided with a dry, thus not adhesive, but activatable adhesive layer and has been cut for use, the above described stiffening process is varied and simplified by softening the shoe inner material blank fastened or securely sewn on the upper by means of a solvent or a mixture of solvents which at the same time brings said layer into the adhesive condition after which the upper and inner material blank are molded together on the shoe last in customary manner during which the adhesion of the two takes place. The solvent or solvent mixture can be applied in simple manner for example with a brush to the side of the inner shoe material not provided with an adhesive whereupon the solvent (or mixture of solvents) gradually penetrates into and through the shoe inner material, it softens and then even activates the adhesive film. Consequently it is possible with the correct selection of the solvent or solvent mixture in sufficient time to mold the softened shoe inner material blank in customary manner together with the upper and at the same time to adhere them. The shoe inner material blank can also be so immersed in the solvent (or mixture of solvents) that practically only the blank and not the upper is wetted by the solvent whereupon the described molding and adhering takes place.
The new shoe inner material has very good tear resistance properties both in the dry and in the wet state and it has a good shape retention even after the influence of moisture. The abrasion resistance as well as the water absorption and release of water, which latter are comparable with the uptake and release of foot perspiration, as well as the stitch tear strength are likewise very good. The new shoe inner material also exhibits a favorable stress-strain ratio as well as small swelling and shrinkage values. All of these valuable properties make the new material especially suited for use as a shoe inner material.
The fiber structures used are cloth, knitted fabrics, non-wovens and preferably fleece made of natural or synthetic fibers such as cotton, wool, rayon staple, rayon and/or synthetic fibers of polyamide (e.g., polycaprolactam or polyhexamethylene-adipamide), polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride, polypropylene and especially polyesters such as, e.g., polyethylene glycol terephthlate (e.g. Dacron). The fiber structure has a square meter weight between 80 and 500 grams, preferably between 150 and 400 grams; as fleece it is 150 to 400 grams.
The synthetic resins acting as stiffening agents which are suited for loading include particularly polymers of styrene and copolymers of styrene and butadiene and also polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer and the like known polymers. They are used in such amounts that the loading finally amounts to 0.1 to 0.9 kg, preferably 0.2 to 0.7 kg, per square meter of fiber structure (dry weight without fiber structure weight). The synthetic resins mentioned advantageously also can be used with known natural resins such as rosin or synthetic resins such as ureaformaldehyde or melamine-formaldehyde resins or their precondensates and/or with polyvinyl alcohols, particularly those types of polyvinyl alcohols which are obtained by substantial to complete hydrolysis of a polyvinyl ester, e.g. polyvinyl acetate.
Additionally there can be used for the loading fillers such as kaolin, chalk, talc, clays, silica fillers, siliceous chalk, keiselguhr as well as in a given case titanium dioxide, carbon blacks and other pigments in amounts of about 10 to 200 parts by weight, preferably up to 80 parts by weight based on 100 parts by weight of the synthetic resin. Other auxiliaries which can be present in the loading are dyestuffs, pigments, plasticizer, stabilizers, propellants, processing aids and/or extenders in customary amounts. The mixture provided for the loading, according to its composition, its amounts of constituents and condition, e.g., as dispersion, paste or dough, is so chosen that the loaded or filled as well as dried fiber structure stands or remains at normal temperatures up to 60° C. stiffly-elastic and relatively hard. Therefore there are preferably added as synthetic resins polystyrene and copolymers of styrene and butadiene with styrene contents between about 85 and 60 as well as between about 40 to 20 weight percent, balance butadiene, in amounts of 250 to 600 grams per square meter of fiber structure. With advantage the styrene butadiene copolymers can be so called carboxylated copolymers, thus copolymers with carboxyl groups in the molecule. The loading mixture suitably is a pasty brushable composition.
As solvents which softens the shoe inner material and in a given case the adhesive layer there are employed the customary fast and slow evaporation solvents, volatile organic compounds such as ketones, e.g., acetone, esters, e.g. methyl acetate, ethyl acetate and butyl acetate, volatile hydrocarbons, e.g. gasoline and benzene, alcohols, e.g. methyl alcohol, ethyl alcohol, isopropyl alcohol and n-butyl alcohol, tetrahydrofuran, ethers, e.g. diethyl ether and dibutyl ether and their mixtures, especially methyl propyl ketone, ethyl butyl ketone, methyl isobutyl ketone and methyl-n-butyl ketone, as well as preferably methyl ethyl ketone and diethyl ketone.
The synthetic resin provided for the adhesive layer brought into the adhesive condition by the action of heat or through the action of solvent is preferably a thermoplastic synthetic resin. The adhesive thus is one based on at least one of the following polymers polychlorobutadiene, polyvinyl acetate, polyacrylic acid esters, e.g., polyalkyl acrylates such as poly (methyl acrylate), poly (ethyl acrylate), poly (butyl acrylates), poly (2-ethylhexyl acrylate), nitrile rubber (i.e. butadiene acrylonitrile) or preferably an ethylene-vinyl acetate copolymer. These adhesive bases can, if desired and frequently with advantage, be mixed in with other resins, for example natural resins, e.g. rosin, phenol resins (e.g., phenolformaldehyde resins), maleinate resins, modified colophony resins or the like known resins and in customary proportions.
The adhesive is brushed on in corresponding preparation, e.g. in the mixture with the solvent or as dispersion, on the shoe inner material or on the blank. This can take place mechanically e.g. immediately after the production of the continuous sheet material or the blank can be coated with the adhesive preparation in the production of the shoe. In the latter case the adhesion can be undertaken immediately. If the shoe inner material already has a dry adhesive layer then this material can be activated again as described above with heat or by the effect of solvent.
The loading of the fiber structure is attained by steeping, impregnating or coating, e.g. using a trough containing the loading composition through which the fiber structure is led. The loading can also be carried out as a coating during which the fiber structure rests upon a rubber blanket or there can also be employed a doctor blade conventionally used for coating purposes during which there is used a loading mass having an appropriate viscosity. By suitable apparatus such as squeeze rolls or doctor blades the desired amount of coating is applied and consequently the desired total weight of the shoe inner material is obtained (in grams per square meter of surface area).
Preferably the drying takes place on heated drying rolls arranged in succession or in drying conduits or in drying ovens, through which the continuously running sheet is conducted by known means.
The application of the adhesive layer on one side of the loaded or coated continuous sheet also can be carried out besides as described above by melting, spraying, knife coating or dusting whereby the synthetic resin must have the necessary form of consistence for each of the stated process variants as for example the form of a powdery granulate or a paste (dispersion).
To improve the surface of the continuous sheet this can be smoothed by using heated rolls, by pressure, heat and the like known processes or preferably can be finished by a mechanical treatment such as for example buffing. Through the buffing (with buffing paper or sand paper) it receives advantageously a particular uniform, velvet like surface.
The new shoe inner material subsequent to the production in continuous length is cut into sheets of for example one by one meter size or in suitable blanks. The shoe producers mostly prefer to produce the blank itself from said sheets, for example by means of a cutting die to make a blank according to the non-slip model or size.
Frequently these cut-pieces or blanks are not skived, this means using blanks without having removed their edges by skiving. The ability of the material to be skived without problem is an important advantage, because the skived blanks or shapes improve the appearance and the wearability of the shoe. The skiving of the edges is performed either only on the upper line or also on the sides of the blanks which is subsequently sewn onto the upper, i.e. either only on the upper line or also on the sides. In the production of lined shoes the material according to the invention can be bound by sewing or gluing with the lining, too.
Now the preforming is done with a so-called preform machine and simultaneously there is performed the adhesion by the heated mold, the adhesive used being activated by the heat involved. If preform machines are not available the shaping according to the last can be carried out also by brushing on the blank with one of the above mentioned organic solvents or a mixture of solvents by which the blank becomes soft and flexible, and subsequently shaping is done.
The remaining operations on the shoe are as is customary.
The finished shoe with the new shoe inner material is distinguished by a line according to the last resulting in a slim counter form. The valuable advantage is that in place of the customary three layers (upper material, counter and non-slips only two layers (upper material and the new shoe inner material) form the heel region of the shoe.
Unless otherwise indicated all parts and percentages are by weight. The compositions can comprise, consist essentially of, or consist of the materials set forth and the process can comprise, consist essentially of or consist of the steps set forth.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
There were produced the following mixtures as loading compositions for the later coating, steeping or impregnating of a fiber structure. For this purpose the individual components of the mixture were mixed together in the stated sequence under slow stirring and further stirred at room temperature until complete homogeneity.
The parts (for short P) given below are always by weight.
I
1. 75.0 P of an aqueous dispersion of a homopolymer of styrene containing 50 weight percent dry material (solids) and a pH of 11.5; the styrene polymerizate itself had a softening temperature of about 105° C. and formed a closed film at 185° C. (film forming temperature),
2. 23.0 P of an aqueous, colloidal dispersion of poly-2-chlorobutadiene containing 58 weight percent of polymer and a pH of 13.0; the poly-2-chlorobutadiene itself is a type having only a slight tendency toward crystallization and in the dispersion has an average particle size of about 160 microns.
3. 2.0 P of a plasticizer-emulsifier mixture of 60.0 P dibutyl phthalate, 5.0 P of a commercial emulsifier (OFA-emulsifier of Chemische Werke Huls A.G. in Marl, Germany) and
4. 35.0 P water.
II
1. 85.0 P of an aqueous dispersion of a carboxylated styrene-butadiene copolymer with 50 weight percent dry material and a pH of 8.0 to 9.0 produced from a copolymer containing 81% styrene (Dow Latex 210 of Dow Chemical S.A. Europe in Zurich, Switzerland) and
2. 15.0 P of a natural, crystalline, finely ground calcium carbonate.
III
1. 14.0 P of an aqueous dispersion of a carboxylated styrene-butadiene-copolymer (same dispersion as under II, 1.).
2. 50.0 P of an aqueous dispersion of a carboxylated styrene-butadiene copolymer containing 48 weight percent of dry material and a pH of 8.0 to 9.0 produced from a copolymer containing 63% of butadiene (Synthomer Latex 9340 of Synthomer Chemie GmbH, Franfurt am Main, Germany),
3. 5.8 P of a water containing precondensate of urea and formaldehyde (Urecoll® 181 of BASF A.G. in Ludwigshafen, Germany), with a viscosity of 5 to 8 Pa s (viscosity determination according to DIN 53015 (German Industrial Standard 53015) in a 4% aqueous solution), containing 70 weight percent dry material, a density of 1.3 and a pH of 8.0 to 9.0 wherein the precondensate (as dry material) has a nitrogen content of 18 to 19 weight percent,
4. 1.2 P ammonium chloride and
5. 29.0 P of a natural, crystalline, finely ground calcium carbonate (same product as under II, 2.)
(a) The loading composition according to I was now applied to a continuous fleece with help of an impregnating apparatus (from impregnating tank with composition I and an immersed return guide roll as well as a dosing pair of rolls at the edge of the tank). This fleece was a customary endless fiber fleece of 3.5 dtex size fibers of poly ethylene glycol terephthalate held together by known binders and had a weight of about 180 g/m 2 . The loaded fleece was then dried until constant weight at an increasing temperature up to about 130° C. and subsequently brought to a thickness of about 1.5 mm with help of conventional calender rolls. The total weight of the finished goods was 750 g/m 2 , which corresponds to a loading of 570 g/m 2 .
The goods had a pleasant homogeneous appearance visible over the entire surface and the desired feel which was found to be slip and skid resistant and felt somewhat napped or of good hand.
About half the entire metric (i.e. the footage) of this goods was now buffed on one of the large surface sides with the help of a conventional grinder or roll buffing apparatus whose buffing rolls were coated with an abrasive-coated paper having a 120 mesh grain.
Through this the buffed surface of the good receive a pleasant, velvet like character. These goods are suitably so used that the buffed side, later worked into the shoe is turned to the heel or the hose.
(b) The loading composition according to II was applied with a conventional brushing machine one a web of the following type and composition: staple fiber-crosshead, both sides napped; weight about 250 g/m 2 ; fiber density 27/19 fibers per cm. Count of yarn Nm=28/14. The loading was 500 g/m 2 . Final weight of the finished goods 750 g/m 2 ; thickness 0.90 mm. It was especially suited as stiffener and at the same time non-slip material for shoes.
(c) The loading composition III was applied on a cotton fabric napped on both sides (weight 250 g/m 2 ; fiber density 17/15 fibers per cm. Count of yarn Nm=34/8 calico construction) with a conventional coating machine. After the drying and calendering the goods weighed 780 g/m 2 , had a thickness of 1 mm and is very well suited for stiffening the rear caps of shoes.
(d) To apply color to the loadening composition III a mixture of pigments was mixed into it, i.e. per 100 kg of loading composition 140 grams brown, 120 grams yellow and 19 grams black (Volcanosol® pigments of BASF A.G. in Ludwigshafen, Germany) and the finished composition applied on the above described endless fiber fleece in such an amount that the loaded, dry goods then weighed 750 g/m 2 . The calendering gave a goods thickness of around 1.1 mm. As was described under (a) the goods were then buffed on one side whereby its appearance became uniform and its feel was less rough.
For the working into the shoe there were now cutted out pieces from the continuous length cut into size and these skived on one side. The pieces, worked into the heel region of the shoe gave this a permanent, last accurate heel shape and simultaneously there was prevented the easy slipping out of the heel part of the shoe.
(e) The shoe inner material described above under (a) with a surface buffed on one side was provided on the other side with an adhesive layer of the following composition:
(1) 22.0 P of an ethylene-vinyl acetate copolymer (containing 40% vinyl acetate; melt index 2-5 [grams per 10 minutes at 190° C. and 2.16 kp load]; Mooney-viscosity ML4=20).
(2) 16.5 P of a terpene-phenol resin (melting range 120°-130° C.; acid number 60-70, determined as milligrams KOH per grams solid resin),
(3) 16.5 P of a maleinate resin (melting range 108°-118° C., acid number 120, determined in the manner stated above) and
(4) 45.0 P of toluene as solvent for (1) and (3).
The toluene solution was applied to a continuous length of the loaded fleece with help of a conventional blanket coater with a doctor knife and dried on a subsequent tenter. After evaporating the toluene there was ascertained an increase of weight of the continuous length of material of around 100 grams per square meter.
The dry adhesive coat is easily brought again into the adhesive condition by the action of heat or through solvents. In the further processing together with this activation of the adhesive the cutted and skived piece becomes pliable and moldable and is molded on the last. This implies an advantageous simplification of the process.
There is hereby incorporated by reference the priority German applications Nos. P 28 28 509.8 and G 78 19 462.4. | There are provided thermoplastic or through the action of solvent shapable, shoe stiffening and likewise non-slip inner material for the heel region in the form of continuous sheets or blanks consisting of an embedded fiber structure which is loaded or filled with at least one synthetic resin acting as a stiffening agent at normal temperature up to about 60° C. in an amount of 0.1 to 0.9 kg per square meter fiber structure in the course of which the loading in a given case can contain fillers, dyestuffs, pigments, plasticizers, propellants, stabilizers, processing aids and/or extenders in the customary amounts. | 22,674 |
FIELD OF INVENTION
[0001] The present invention relates to a game involving opposing teams, using opposing goals and a ball, as well as a scoring goal for scoring points in the game.
BACKGROUND
[0002] There are, of course, many ball games involving opposing goals, including soccer, basketball and American football. Scoring points in sports games using a ball or the like involves a wide variety of mechanisms. For example, in basketball the object is to throw the ball through a hoop ten feet above the playing surface. In soccer, the object is to kick the ball into a net guarded by a goal keeper, and the same idea exists in ice hockey (which uses a puck instead of a ball) and in other sports as well. In American football, the objective of scoring points is achieved by advancing the ball into the opposing team's endzone over a goal line or kicking the ball over a goal post.
[0003] In target sports such as darts and archery, the object used by the players to shoot or throw, i.e. a dart or an arrow, is adapted to strike a target and at least partially penetrate the target.
[0004] However, insofar as is known, there is no game utilizing opposing teams in which it is an object to score points by throwing a ball or the like in such a way so as to strike a target on an opponent's goal post with the ball or the like, and thereby score points, and without adhering to the target.
SUMMARY OF INVENTION
[0005] The present sport game can be played co-ed or by all males or all females, and is played with two teams. Each team desirably has approximately ten players, but preferably a minimum of only four players per team are allowed to play at a single time.
[0006] The present sport game is desirably played on a court which may be 100 feet by 50 feet, but can be larger or smaller, preferably no more than about 20 percent larger or smaller. If played on a court, indoor and outdoor, the court surface may be any hard surface, and playing on surfaces such as dirt, gravel and grass is not desired because the ball will not react properly and because of the preferred rules of the game.
[0007] At each end of the court there is located a scoring goal post with a backboard the top of which is desirably about 15-18 feet off the surface of the court, plus or minus about 15 percent. If the backboard is less than 12 feet above the court or more than 20 feet above the court, it becomes difficult to play the game according to the desired objectives. Each backboard at the top of the goal post has an area of preferably approximately five feet by five feet containing preferably three striking and scoring pads, each desirably of circular configuration and each having a diameter of about 12-18 inches, the three scoring pads preferably and desirably being arranged in a triangle shape.
[0008] The object of the game is for the players, at least four on each side, to throw or smack a ball so as to forcefully strike/slam the pads on or behind the backboard of the opposing team with the ball or the like.
THE DRAWINGS
[0009] FIG. 1 is an example of a court in accordance with the present invention.
[0010] FIG. 2 is a prospective view of a backboard for use in the game of the present invention, such backboard having three scoring/striking pads thereon.
[0011] FIG. 3 shows a facing side view of the goal posts including backboards.
[0012] FIG. 4 shows a back perspective view of such a backboard including supporting structure.
[0013] FIG. 5 shows a pair of goal posts including backboards, shown from the rear.
[0014] FIG. 6 shows an alternate embodiment of the backboard.
[0015] FIG. 7 shows the erection of such a goal post including backboard, without striking/scoring pads.
DETAILED DESCRIPTION
[0016] According to one embodiment, the sport game of the present invention is played in a league called “SKY BALL® LEAGUE” having the following preferred game rules:
[0017] SKY BALL® games are played with four active players vs. four active players, e.g. co-ed, wherein each team can have a maximum of ten players on the team roster, and the players desirably wear a SKY BALL® glove to facilitate smacking the ball.
[0018] SKY BALL® games consist of four ten-minute quarters with a three minute overtime if the score is tied at the end of regulation play.
[0019] SKY BALL® games have free substitutions throughout play.
[0020] To initiate play at the beginning of the game and at each quarter, the referee “slams” the ball with a “starting slam” at center court so that the ball bounces upwardly about 40-75 feet off the court into the air. After a score by the other team, a player must pass the ball when crossing half court to a team mate with a “passing slam” by hitting the ball so that the ball bounces off the court, for example 8-10 feet into the air. However, opposing team players can attempt to make a steal, in which case the opposing team does not need to start with a “slam.” A “smack” is the contact that a player uses to propel the ball, so a player “smacks” the ball using his/her gloved hand, either directly towards the goal attempting to score, or to a team mate, or into the court surface to create a bounce.
[0021] SKY BALL® games have scoring means or mechanisms at each end of the court and desirably comprise three scoring pads 10 which are 12-17 feet above the court surface 12 .
[0022] In SKY BALL® scoring, each time a player smacks or throws the SKY BALL® and hits a scoring pad, the scoring team receives one point. However, a player smacks the SKY BALL with sufficient force to register a “smash”, especially while using/wearing a SKY BALL® glove, the scoring team will receive three points. In another presently preferred embodiment as shown in FIG. 6 , the backboard is provided with holes 14 of diameter 12-18 inches through which the ball passes to score, and approximately 5 to 9 inches behind the hole is a scoring pad 10 ′.
[0023] A SKY BALL® player fouls out of the game once he or she reaches four (4) fouls. The foul rules are similar to those of basketball, although less contact is intended to result in fouls because the game may be played co-ed. Acceptable forms of contact among or between opposing players include intercepting a pass, interceptions during a loose ball, and blocked shots. An opposing team player can “steal” the ball without fouling, so long as no more than minimal physical contact between the players occurs.
[0024] If a player is fouled, his or her team automatically restarts an offensive series. If a player is fouled while smacking or throwing the SKY BALL® at the scoring mechanism, he or she receives a free smash at the SKY BALL® foul line. The smack must be a smash in this case (foul situation) worth one point if the fouled player scores, in which case the opposing team gets the ball after the score. If the fouled player misses, the ball is in play.
[0025] At the end of the four quarters, the team with the highest points total wins.
[0026] The type of ball used is a SKY BALL® desirably of size 10 cm (4 inches) diameter. The SKY BALL® is disclosed in Kessler U.S. Pat. No. 8,123,638.
[0027] As indicated above, the terms “smack” and “smash” are similar to a smack or smash in volleyball, and to be distinguished from a throw. A “smash” is a type of “smack” directed at a goal to score, and which registers to produce a three point score. To distinguish a “smash”, each pad 10 or 10 ′ may be provided with an electronic sensor which registers when the pad is impacted sufficiently hard by the ball, although other sensing means could be used such as pads which create a non-electronic sound, e.g. a rattle, when impacted by the ball or ball substitute.
[0028] For desirable and optimum play of the present sport game, the goal post and the ball are particularly important. As indicated above, the ball desirably has a diameter of 10 cm and is capable of a very great ability to bounce, such as shown in Kessler U.S. Pat. No. 8,123,638, and sold under the trademark “SKY BALL®. The goal post 16 has a height of approximately 15 feet and carries a backboard 18 , desirably of a flexible metal mesh or fabric mesh, having a plurality of scoring pads, e.g. three scoring pads 10 as shown in FIG. 2 .
[0029] As indicated in FIG. 2 , there are preferably three pads 10 , and these are preferably each 12-18 inches in diameter and placed in a triangular pattern as shown in FIG. 2 . As indicated above, the scoring pads 10 can be made of a material that rattles upon contact, have pockets to capture balls instead of or in addition to the pads, or can trigger an electronic sensing device, such as lights or sounds.
[0030] The backboard 18 on the goal post 16 is desirably an open mesh having resilience and flexibility and the mesh is desirably an open weave fabric or metal mesh, of dimensions which are desirably approximately 5 feet by 5 feet in the preferred embodiment. The metal mesh or fabric mesh backboard is resilient and absorbs the impact of the ball, allowing it to drop downwardly rather than expressively bounce backwards, and thus keeping the ball in play.
[0031] The rules of the game permit a player to throw the ball to a team mate, shoot the ball at a scoring pad by throwing or smacking the ball toward the pad, or to dribble the ball. Running or “travelling” as in basketball is not permitted.
[0032] As indicated above, the scoring surfaces comprise pads 10 , preferably three pads on or behind the backboard 18 , the pads being in any desired arrangement, e.g. preferably arranged in a triangle. The pads 10 are desirably circular, each being preferably about 12-18 inches in diameter in a preferred embodiment. Electronic sensors are desirably located in the pads to signal scoring when a pad is impacted by a smacked ball or the like.
[0033] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.
[0034] Thus the expressions “means to . . . ” and “means for . . . ”, or any method step language, as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i.e., other means or steps for carrying out the same functions can be used; and it is intended that such expressions be given their broadest interpretation. | A sports game is played on a field or court having opposing goals, each goal having a plurality of striking pads at least 12 feet above the height of the field or court. Two teams are provided, each having at least four players. A ball of high bouncing ability and capability is used. Each opposing goal has a backboard and preferably three scoring pads either on the backboard or behind the backboard. The object of a team is to throw or smack the ball so as to strike a scoring pad and thereby score points. | 11,773 |
FIELD OF THE INVENTION
This disclosure involves the field of computer system networks and is specifically directed to handling the problems of power control in each of the various units involved in the system network, by the use of a master-slave logic system.
CROSS REFERENCES TO RELATED APPLICATIONS
This disclosure is related to a patent application filed Sept. 25, 1984 as U.S. Ser. No. 654,080, now U.S. Pat. No. 4,635,195 issued Jan. 6, 1987 entitled "Power Control Network Using Reliable Communications Protocol" by inventors James H. Jeppesen, III and Bruce E. Whittaker.
BACKGROUND OF THE INVENTION
In the present day advance of computer and communications network technology, it is now possible that many types of units are interconnected both by direct bus connection and by remote telephone lines. These networks may involve a variety of processors, a variety of input/output systems located in separate cabinets, plus other cabinetry in addition to large portions of memory cabinetry.
In such a separate and complex network, one major problem often arises as to the conditions of the supply power at each of the individual units in order that this system may operate intercooperatively and effectively.
For example, it is never known what the status or power condition of each of the interconnected units may be in relationship to the units which are powered up and operating.
Many times certain areas of the network may not be desired for use and in order to save power and energy, it is desired that these units be turned off for certain periods of time when not in use. Likewise, other units of this system may be desired for use and will need to be controlled or checked to make sure that the power conditions in these units are properly up.
Thus, in order to provide control and flexibility in a system and to make sure that all those units that are needed are powered up and operable, and those units which are not needed can be turned off to save energy and unnecessary use, it is important to system operators that some means be devised for knowing the power status of each and every unit in the system and also for being able to "centrally control", that is to say, to power up or to power down, each and every unit in the system as required.
To this end, the problems have been handled in this arrangement only catch as catch can, with the hope that each unit is powered up properly and each unit is sufficiently powered up to operate properly. Generally there has been no flexibility as to be able to shut down certain unused units when they are not needed also.
The presently devised power control network system overcomes the major inadequacies involved in a large computer system network by providing a centralized power control logic system whereby the each and every one of the modules or cabinet units in this system may be communicated to, in order to find out their power status; and further commands may be transmitted to each addressed element in the system in order to power-up or to power-down the unit thus to provide the utmost flexibility and also provide the utmost in energy conservation permissible under the circumstances.
SUMMARY OF THE INVENTION
It has long been a problem in a complex system network which involves a multitude of independent processors, independent I/O systems, and independent memory systems to regulate the "on-off-ness" of power and the power status of each of the units in the system when all the units are able to communicate with each other.
The present system provides a central master power control logic unit which can communicate with a slave power control logic unit which is located in each individual system cabinet of the system. The central master power control logic unit can poll, and selectively address each and every unit in the system in order to control the condition of its power as to being on or off, or to select marginal voltage conditions, or to find out the power status of that particular unit.
Thus, one central location can operate to control and monitor the power conditions of each unit in the entire system so that no unit is inadvertently off-line or shut down or depowered without the knowledge of the central master power control logic unit.
In this regard, a master logic unit and slave logic unit operate with a specialized protocol having exceptional reliability where the master transmits a unique address to all slave units and the "properly-addressed" slave unit returns its unique address to the master unit. It is only then that the master will transmit instructional command data to the slave unit.
The slave logic unit then transmits power control instructions to a power control circuit which executes power on/off operations or executes marginal step voltage adjustments on various ones of the power supply modules attached to that power control circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a network of cabinets which house processors, I/O systems and memories whereby a power control network is connected to command and control the power conditions within each and every one of the connected cabinets.
FIG. 2 is a block diagram of a typical processor type cabinet and its connection to the power control network.
FIG. 3 shows a "dependently-powered" input/output cabinet in block diagram form and its connection to the power control network.
FIG. 4 is a block diagram showing an "independently-powered" cabinet and its connection to the power control network.
FIG. 5 is a basic block diagram of the power control network showing the central power net master logic unit connected to control various power net slave logic units in this system.
FIG. 6 is a block diagram showing the interconnection between the master logic unit and the slave logic units in the system.
FIG. 7 is a block diagram of a typical power slave logic unit.
FIG. 8 is a block diagram of the master network power logic unit showing the interconnections to the other parts of the system network.
FIG. 9 is a block diagram of the peripheral power slave logic unit showing its connection to a peripheral cabinet and to the power control network of FIG. 5.
FIG. 10 is a schematic diagram showing the protocol used for communication between master and slave units and additionally the byte format used.
FIG. 11 is a flow diagram which summarizes the protocol activity for the master power network logic unit.
FIG. 12 is a flow diagram which summarizes the protocol activity of the slave power control logic unit.
FIG. 13 is an illustration showing the output signals from the slave logic to the power control circuit.
FIG. 14 is an illustration showing the input signals from the power control circuit to the slave logic unit.
FIG. 15 shows a block diagram illustrating the circuitry for failure detection and power control.
FIG. 16 is a block diagram illustrating the circuitry for margin control voltages in local and remote modes.
GENERAL OVERVIEW
This subsystem relates to a computer network and system which interconnects the following type of cabinets:
(a) processor cabinets;
(b) dependently-powered I/O cabinets;
(c) independently-powered I/O cabinets;
(d) independently-powered memory cabinets.
A "dependently-powered" cabinet is a cabinet which derives its AC power and its high voltage input DC power from another cabinet (other than itself)--in this case the other cabinet is called the "processor cabinet". Thus, the "dependently-powered" cabinet must be physically attached to the source cabinet.
An "independently-powered" cabinet is a cabinet which has its own AC power Source. It may, therefore, be considered as a "free-standing" unit.
FIG. 1 indicates a block diagram of the network power control subsystem 10. Shown therein are a dependent power I/O cabinet 20 and 30, in addition to two processor cabinets 40 and 50. Additionally connected to the power control network are the independent power I/O cabinets 60 and 70.
FIG. 2 shows the power components of processor cabinets 40 and 50 which were shown in FIG. 1. The power energization of the processor cabinets 40 and 50 is controlled by the power control card 80 shown in FIG. 2. The power control card 80 is controlled by a "system operator" through the cabinet control circuits via an "operator panel" 44, and by the operating maintenance personnel who work through the control display 45 (maintenance switches and indicators) within the processor cabinet.
The power control card 80 additionally monitors the cabinet environmental conditions such as over-temperature and cooling air-loss. This card is further described later under the title of "Power Control Subsystem".
The state of the cabinet power is further controlled by the power control network (PCN) through a card called the Power Net Slave Card 90. The processor cabinet (40, 50) also provides an AC power module 41 and a DC power module 43 for providing a high voltage DC to the attached-dependently-powered cabinets such as 20, 30.
FIG. 3 illustrates the power components involved in the "dependently-powered" cabinets such as 20 and 30 of FIG. 1. The power for these "dependently-powered" cabinets is controlled by the power control card 80 d . This power control card 80 d is controlled by a system operator (operating technician) through the cabinet control circuits and operator panel 44 d , and also by the operating maintenance personnel through the control display 45 d (via maintenance switches and indicators) inside the cabinet.
The power control card 80 d also is used to monitor the cabinet environmental conditions such as over-temperature and the cooling air-loss.
The power in the dependently powered I/O cabinet of FIG. 3 is also controlled by the power control network through the power net slave card 90 d .
As seen in FIG. 3 the "dependently-powered" I/O cabinet (such as 20 and 30) receive their AC and their high voltage DC input voltage from the attached processor cabinets such as 40 and 50 of FIG. 1.
In FIG. 4 there is shown a block diagram of the various power components of the "independently-powered" cabinets such as 60 and 70 of FIG. 1. The power for these independently-powered cabinets is controlled by the power control card 80 i . The power control card 80 i is controlled by a "system operator" through the cabinet control circuits and operator panel 44 i ; and also by the operating maintenance personnel through the control display 45 i (via maintenance switches and indicators inside the cabinet).
Likewise, as previously described, the power control card 80 i also monitors the environmental conditions in the cabinet such as over-temperature or the loss of "air". The cabinet power of the independently-powered cabinet of FIG. 4 is also controlled by the power control network through the power net slave card 90 i .
As seen in FIG. 4 the "independently-powered" I/O cabinets contain two I/O backplanes which are referred to as backplane A, 70 a , and also backplane B, 70 b , in addition to two interface panels described hereinafter. The DC power to each backplane is separately controlled. The DC power to both interface panels will be supplied the same as on backplane A, 70 a .
The operator panel 44 i will provide separate controls for each backplane. The power control network (PCN) will also provide separate controls for each of the backplanes 70 a and 70 b .
The DC power to each backplane is controlled separately. The operator panel 44 i will provide separate controls for each backplane and also the power control network connections 95 n shown in FIG. 4 will provide separate controls for each backplane.
Thus, the independently-powered cabinets will have their own AC power source and therefore may be considered as "free standing".
Additionally, the "independently-powered" memory cabinet may provide a remote support interface adapter. This adapter adds the power net master logic card to the cabinet as discussed hereinafter.
DESCRIPTION OF PREFERRED EMBODIMENT
Power Control Network (PCN):
To provide an integrated system, a Power Control Network (PCN, FIGS. 1 and 5, via 95 n ) connects all system cabinets. This allows a "SINGLE-POINT" of on-site operator control of the entire system of many cabinets. That is, the on-site operator need only depress a single power-on or power-off switch to control the entire system.
In addition to the single-point of on-site control, the PCN provides total "power control" from an external remote support center 300 via telephone connection. With the integrated PCN system, only a single remote connection is needed to drive the entire system.
In addition to the basic power on and off control functions, the PCN provides a number of system failures and status monitoring functions and system maintenance controls. These functions are described in paragraphs that follow.
The PCN allows the capability for an UNATTENDED site, that is, no local system operator is required. All system power controls, failure condition monitoring, and maintenance controls are available via the PCN to the remote center, 300.
The PCN is specifically implemented through power net slave cards contained in each system cabinet and interconnected to the PCN. Each slave card is "always" powered, that is, is powered if the AC breaker for its cabinet is on. The slave within a cabinet is powered whether the cabinet operating DC power is on or not.
The power net master logic card 100 of FIG. 8, which is part of the before mentioned remote support interface adapter (contained within an independently-powered memory cabinet), drives the Power Control Network and therefore all the power net slaves. The master logic unit 100 provides the central hub between the power control functions (Power Control Network), the remote support center (300) telephone connection and the system maintenance (200, FIG. 8) subsystem. The master card 100 is also "always" powered.
TABLE I______________________________________OPERATOR PANELS______________________________________Operator Control PanelsThe Operator Control Panels 44, 44.sub.d, 44.sub.i,FIGS. 2, 3, 4, are accessible to the operator on theoutside of the respective cabinets. The panels providethe following functions:PROCESSOR CABINET OPERATOR PANEL (44)POWER-ON/POWER-OFF indicator & switch.CABINET/SYSTEM MODE indicator & switch.POWER FAIL/AIR LOSS indicator.DEPENDENTLY-POWEREDI/O CABINET OPERATOR PANEL (44.sub.d)POWER-ON/POWER-OFF indicator & switch.CABINET/SYSTEM MODE indicator & switch.POWER FAIL/AIR LOSS indicator.INDEPENDENTLY-POWEREDMEMORY CABINET OPERATOR PANEL (44.sub.i)POWER-ON/POWER-OFF BACKPLANE A indicator& switch.POWER-ON/POWER-OFF BACKPLANE B indicator& switch.CABINET/SYSTEM MODE indicator & switch.POWER FAIL/AIR LOSS indicator.REMOTE MODE ENABLE key switch.INDEPENDENTLY-POWEREDI/O CABINET OPERATOR PANEL (44.sub.i)POWER-ON/POWER-OFF BACKPLANE A indicator& switch.POWER-ON/POWER-OFF BACKPLANE B indicator& switch.CABINET/SYSTEM MODE indicator & switch.POWER FAIL/AIR LOSS indicator.______________________________________
(A) Cabinet Power Control Functions:
The cabinet power control circuitry controls and monitors all the power modules of the various cabinets. It also monitors the various cabinet environmental conditions such as over-temperature, etc.
The power control circuitry of the network system can be controlled from three sources:
(1) by the operator through the cabinet operator panel 44;
(2) by maintenance personnel through the control display 45;
(3) by the power control network through the network interface slave as will be discussed in connection with FIG. 5.
The operator panel control switches, in element 44, are active only when the cabinet is in the "cabinet mode" with the exception of the processor's power-on/power-off functions, and the cabinet/system switch. Table I indicates the switches for both the cabinet mode or system mode.
The maintenance switches are active only when the cabinet is in the "cabinet mode".
The power control network drive functions (the switch type functions) are active only when the cabinet is in the "system mode". The power control network monitor functions (that is the status) are always valid.
When a cabinet is changed from the "system" to the "cabinet" mode, the power state of the cabinet will not change, except that marginal conditions will follow the cabinet margin switches.
When a cabinet is changed from the "cabinet" to the "system" mode, the power state of the cabinet will follow the external power control signals derived from the slave units, as 90, 90 d , 90 i , etc.
(B) Functions of the Cabinet Maintenance Power Control:
Maintenance personnel can control the following maintenance functions from the control display 45 (FIGS. 2, 3, 4) within a cabinet:
(a) Margin indicators; these are used to indicate that the associated logic voltages within the cabinets are in a marginal high or marginal low state;
(b) Margin switches--these will manually set the associated logic voltages within the cabinet to the marginal high or marginal low state. These switches are active in the "cabinet" mode only;
(c) Power fail indicators--these indicate that a power failure has occurred in one of the power modules within the cabinet. This indicator is valid in either the "cabinet" or in the "system" mode;
(d) Over temperature/air loss failure indicators--will indicate an over temperature or an air loss condition in the cabinet. This indicator operates in either the cabinet or the system mode;
(e) Power fault indicators--these will indicate faults in the various power modules in the cabinet and they will operate validly in either the "cabinet" mode or the "system" mode.
(C) Operator Power Control Functions:
Certain functions are controlled by the "system operator" from the cabinet control operator panel 44. These are:
(1) Power-on/power-off switch indicator: in the "cabinet" mode this switch controls the state of the cabinet power (on or off). In the "system" mode this switch is inactive except for the processor cabinet switch. The processor power-on/power-off switch, in the "system" mode, acts as system control switches. Activation of this switch in the "system" mode will cause a "power-on" request or a "power-off" request to be sent to the power control network. The network may then drive the power-on or drive the power-off to all system cabinets which are in the "system" mode. All cabinet "power-on/power-off" indicators are valid for either the cabinet mode or the system mode.
(2) The cabinet/system mode switch: this controls the "mode" of the cabinet. This switch is always active whether the cabinet is in the "cabinet" mode or the "system" mode.
(3) Power fail/air loss indicators: these indicate the respective failure conditions within the cabinet and the indicators are valid in either the cabinet mode or the system mode;
(4) Remote enable switch: this key lock switch enables the connection to be made to the remote system support center 300. This key switch is active in either the cabinet mode or the system mode.
(D) Power Control Network (PCN) Functions:
Table I and paragraph C above described the functions that an on-site operator can control via the operator panels 44 for each cabinet. Paragraph B above described the additional functions that a maintenance engineer can control from the maintenance panels "internal" to each cabinet. The Power Control Network allows remote control of all the above mentioned functions. In this context, "remote" means distant from a cabinet, that is, single-point on-site control; or distant from the site itself, that is, via telephone connection.
Each system cabinet is uniquely addressable over the Power Control Network (PCN). PCN commands are actions to a cabinet driven by the PCN. PCN commands can only affect a cabinet when it is in "system" mode, described in paragraph A above. PCN status is information about the cabinet returned over the PCN. PCN status is available in either "system" or "cabinet" local modes. For cabinets with separately controllable backplanes, the PCN functions are selected separately for each backplane.
The PCN (Power Control Network) functions are:
(1) Power-On Command: Turns the addressed cabinet to power on.
(2) Power-Off Command: Turns the addressed cabinet to power off.
(3) Reset Command: Resets, clears any power fault conditions within the addressed cabinet.
(4) Set Margins Commands: Sets voltage margins conditions within the addressed cabinet for the selected voltage source to either high or low states. This is controllable for the +5 VDC, -2 VDC and -4.5 VDC supplies.
(5) Send Status Command: Requests the addressed cabinet to send specified "status" information over the PCN.
(6) Miscellaneous Control Bit Commands: Command activates or deactivates four external signals which may be used to control clock or other sources in dual processor systems.
(7) Power-On/Off Status: Indicates the power "on or off" state of the addressed cabinet.
(8) System/Cabinet Mode Status: Indicates whether the addressed cabinet is in "cabinet" local mode (no "external" control allowed) or "system" mode (external control via PCN allowed).
(9) Over-Temperature Failure Status: Indicates that the addressed cabinet has experienced an over temperature condition and is shut down.
(10) High-Temperature Warning Status: Indicates that the addressed cabinet is running under conditions outside of range and over-temperature failure may be imminent.
(11) Air Loss Failure Status: Indicates that the addressed cabinet has lost cooling fan(s) and is shut down.
(12) Power Fault Status: Indicates that the addressed cabinet has experienced a power supply fault condition and is shut down. This is reported for the +5 VDC, -2 VDC, -4.5 VDC, +-12 VDC and 15 KW supplies.
(13) Voltage Margin Status: Indicates a specific voltage supply is running in a margin condition. This is reported for +5 VDC, -2 VDC, and -4.5 VDC supplies in both high and low conditions.
(14) Power-On Request Status: Reported only by processor cabinets in "system" mode. It indicates that the power-on switch was depressed by the operator. In system mode, this switch is the power-on switch for the entire site.
(15) Power-Off Request Status: Reported only by processor cabinets in "system" mode. It indicates that the power-off switch was depressed by the operator. In system mode, this switch is the power-off switch for the entire site.
Power Control Network Electrical/Mechanical Characteristics:
The PCN shown in FIGS. 5 and 6 is serially routed, two-wire, twisted-pair. The PCN circuit uses RS422 standard differential drivers and receivers (FIG. 6).
Connected on the PCN will be numerous power net slaves and peripheral slaves and one power net master. The total number of connections is 64. The maximum transfer rate may reach 10K bits/second.
FIG. 6 shows the connection of the RS422 drivers and receivers for slave cards and the master card. Also shown is the network termination resistors of 120 and 470 ohms.
Each slave and master card provides two PCN (Power Control Network) connectors. One connector receives the PCN cable from the previous unit and the other connector sends the PCN cable to the next unit. The PCN is thus serially routed.
For PCN connections between units within attached cabinets, the PCN cable is a simple, inexpensive, twisted-pair cable.
For PCN connections to non-attached cabinets, the PCN cables first are routed through interface panel cards in an I/O cabinet through RFI shielded cable into the non-attached cabinet.
FIG. 7 shows a block diagram for a power net slave card. The diagram shows the controlling microprocessor 92 and the address switches 94 which give each cabinet an unique PCN address. Each slave has two parallel connecting ports 96, 97 to the power control cards of its cabinet. The slave also provides, via circuit 98, clock select or other signals and connects the RS422 interface to the PCN network itself.
FIG. 8 shows the power net master logic unit 100 card block diagram, and FIG. 9 shows a peripheral-slave card block diagram. This slave can also control the power-on and power-off of a peripheral cabinet (disk pack controller).
Power Network Slave Logic:
As seen in FIG. 7, the power network slave logic shows a logic card connected between the power control circuits of a cabinet and the power control network.
A major element of the slave logic card is a microprocessor such as an 8748 chip which contains internal program PROM and internal RAM. A typical chip of this designation is manufactured by Intel Corporation, whose address is 3065 Bowers Avenue, Santa Clara, California, and wherein this chip is described in a publication entitled "Microcontroller User's Manual", Order #210359-001, copyright 1982, and published by Intel Corporation, Literature Dept. SU3-3, of 3065 Bowers Avenue, Santa Clara, California.
Each slave logic unit has a unique address which is set within the card by means of switches shown as element 94, address switches, in FIG. 7. The slave logic is connected to the power control network of FIG. 5 using the circuits shown in FIG. 6, which are RS422 receiver and driver chips. The RS422 receiver and driver chips are those such as typically manufactured by Advanced Micro Devices Company of 901 Thompson Place, (P.0. Box 453), Sunnyvale, California. These circuits are described in a publication entitled "Bipolar Microprocessor Logic & Interface Data Book" published by Advanced Micro Devices Company, copyright 1983.
The power network slave logic in FIG. 7 has two ports designated as port A interface 96 and port B interface 97. These interfaces connect to the power control circuits within each of the cabinets such, for example, as power control card 80 of FIG. 2, power control card 80 d of FIG. 3, and power control card 80 i of FIG. 4. The signals to and from the port A96 and port B97 are described hereinafter.
The power network slave logic unit 90 has four output signals (shown in FIG. 7 at the extreme right side) which may be activated or deactivated under the control of commands sent over the power control network. Thus, these four output signals may be used in cabinets containing a DPM (dual port memory), or for independent memory cabinets, in order to select the source for the DPM clocks. These four signals are individually controlled, raised or lowered, by commands from over the power net from the power net master logic unit 100 of FIG. 5.
These four output signals are driven by the slave logic of FIG. 7 by means of high-drive transistor type logic (TTL) inverter buffer chips. The output physical connection to the slave logic unit card is by "slip-on" posts to which clock-type, backplane type coaxial cables can be attached. A grounded post is provided with each signal post.
Thus, the Select Circuits 98 of FIG. 7 use the inverter-buffer chips to provide a signal from the slave logic over a coaxial cable over to the DPM (Dual Port Memory) back plane.
The power network slave logic unit 90 requires the use of control signals or "always power" from the cabinet in which it resides.
Two on-board indicators and one switch are used to control each of the power network slave logic units 90, 90 i , 90 d , 90 p . A push-button switch (the re-set switch) is used to initialize the slave logic to run its own "self-test". This is the same function that occurs at slave power-up time. One indicator (self-test) is "on" when the slave self-test program is in operation. If a self-test error occurs, this indicator will remain "on".
The second indicator (NET ERROR) is "on" whenever the slave logic detects a "NET" problem while the slave is communicating on "NET". These NET errors include a framing error (too few or too many discs), a parity error, a NET protocol error, and an invalid command. The "NET ERROR" indicator will be deactivated when a "good" net communication to the slave logic unit occurs.
Power Network Master Logic:
A block diagram of the power network master logic is shown in FIG. 8. The power network master logic 100 of FIG. 8 is housed in an independently-powered memory cabinet within the system, such as cabinet 70 of FIG. 1. The power network master logic will require power from this cabinet.
The master logic 100 is the controlling device on the power control network of FIG. 5. It initiates all communications over the network; and thus, all communications over the network are effectuated between the master 100 and a slave logic unit such as 90. There is only one "active" master logic unit, such as 100, which may be connected to the power control network of FIG. 5 at any given time.
The network master logic 100 also interfaces to the Maintenance Subsystem (200 shown in FIG. 8) through the System Control Network shown in FIG. 5. Also, as indicated in FIG. 5, the power network master logic is the single point of connection of the system to a Remote Support Center (RSC, 300 in FIGS. 5 and 8).
FIG. 8 also shows the connections to the Remote Support Center 300 and also to the power control network of FIG. 5.
As seen in FIG. 8, the power network master logic unit 100 is provided with a microprocessor 100 u to which are connected a PROM 100 m1 and EEPROM 100 m2 in addition to a RAM unit 100 a . A power control interface 100 p connects the microprocessor to the power control network and a remote support interface 100 r connects the microprocessor to the remote support center 300. A time of day circuit 100 t with battery back-up provides time signals for the unit.
The power network master logic unit 100 of FIG. 8 provides a central interconnection point for the power control network of FIG. 5, in addition to the system control network which is connected through the interface 100 s . It is also the central interconnection point for the remote support center interface (remote diagnostic) of element 100 r .
The power network master logic unit 100, as the master unit for the power network, controls all the actions on this network.
In any multi-processor system, there may be only one "active" power network master logic unit. Since, however, this unit is of considerable importance to the system operation and maintenance, there is generally provided a spare power network master logic unit, even though a failure in the power subsystem will not affect the operation of the overall processing unit.
The microprocessor 100 u (Intel 8088) of FIG. 8 may be set to run at 8 megahertz. It executes its code out of the 32K bytes of PROM 100 m1 . The 8K bytes of RAM 100 a are used for data buffers and for operating stacks. The 256 bytes of electrically erasable PROM 100 m2 are used to store configuration-dependent option flags. The time of day circuit 100 t is backed up by a battery for use during times of power failure. Six indicators and five switches are provided on the master logic unit 100 for maintenance of the master card itself.
Peripheral Slave Power Control Adaptor:
As seen in FIG. 5, the power control network may include peripheral devices which are provided with a peripheral slave power control adaptor 90 p .
FIG. 9 shows a block diagram of such a peripheral slave power control adaptor 90 p . Provided therein is a microprocessor 92 p which connects to a peripheral power control driver circuit 95 p having connections to the peripheral cabinet. Also provided are address switches 94 p which provide an input to the microprocessor 92 p , and also a driver-receiver circuit 99 p which connects to the power control network of FIG. 5.
The peripheral slave power control adaptor, such as 90 p of FIG. 9, is located in an interface panel within the I/O cabinets such as 60 and 70 of FIG. 1, and also in cabinets 20 and 30 of FIG. 1.
The peripheral slave power control adaptor 90 p of FIG. 9 connects between the power control network of FIG. 5 and any selected system peripheral cabinets. There are certain cabinet types to which the peripheral slave power control adaptor may be connected. These are:
(a) a disk pack controller (without status signals)
(b) a disk pack controller (with status signals)
(c) a disk pack exchange unit (without status signals).
The peripheral slave adaptor 90 p provides only "power-on" and "power-off" control for these cabinets.
The peripheral slave adaptor 90 p is logically a simple slave unit. The microprocessor 92 p may use an 8748 microprocessor chip (previously described) and interfaces to the power control network with the RS422 driver receiver chip designated 99 p .
The peripheral slave logic of FIG. 9 differs from the internal power slave logic unit of FIG. 7 in that, in place of the port A and port B interfaces (96, 97) of FIG. 7, the "peripheral" slave logic has special driver circuits 95 p in order to control the "on/off" state of the connecting peripheral cabinets.
Power Control Network Communications:
All commands and communications over the power control network are initiated by the power net master logic unit 100 of FIGS. 5 and 8.
FIG. 10 is an illustrative drawing showing the particular sequence of events over the network. The master logic unit 100 first sends the Address byte shown in line 1 of the drawing of FIG. 10. This Address is the address of the desired slave unit to be addressed. Each slave unit receives and evaluates the Address received and then the appropriate slave unit will return its Address to the master power unit 100.
If the "correct" slave address is returned to the master power logic unit 100, as shown in line 2 of FIG. 10, then the master logic unit 100 will send a Command byte (shown in line 3) to the previously addressed slave unit, such as 90 of FIG. 7.
The slave unit, such as 90, then returns the Command byte to the master as illustrated in line 4 of FIG. 10. Thus, when the slave has received the Command byte, it returns it to the master and if the byte received by the master logic unit 100 then agrees with the byte that it (master unit) had previously sent, the master logic unit 100 re-sends the Command byte again, as illustrated in line 5 showing the Command byte being re-sent from master to slave.
If the second Command agrees with the first Command byte, the slave logic unit 90 will decode and execute the Command received. The slave will then return its General Status byte to the master as seen in line 6 of FIG. 10.
If the Command was a Send Status Command, then the specified Status byte is returned instead of the General Status byte.
If the command sent by the master logic unit 100 to a slave logic unit 90 was either a "power-on" or a "power-off", then the General Status byte which is returned to the slave logic unit 90 will not reflect the new power state of the cabinet involved. It will show the status of the cabinet "prior to" the command. To check the new state of the cabinet involved, a Send Status Command will be sent about 15 seconds later after the power on/off Command was sent.
Thus FIG. 10 indicates the general network flow for the master power logic unit 100 as it polls the various slaves 90 over the network. After the master logic unit 100 sends an Address, it waits for the return of the addressed slave unit's address. If an incorrect address is returned from the slave logic unit 90, the master power logic unit 100 will re-try the expected address. It will try the desired address three times before it assumes that the Address slave logic unit 90 may be "bad".
The master power logic unit 100 also does the same re-try/time-out procedures for the Command bytes. When the master power logic unit 100 finds an "improperly" responding slave logic unit 90, while polling, it will report the condition to the maintenance subsystem 200 over the system control network connected as shown in FIG. 8.
FIG. 10 also indicates the network byte format for the power network. As shown therein, there is one bit used for a start bit, then 8 bits are used for a data byte, then one bit is used for odd parity, and one bit is used as a stop bit.
FIG. 11 shows a drawing of a flow chart showing the network flow for the master power control logic unit 100 which summarizes the various protocol steps used in FIG. 10 on lines 1-6.
FIG. 12 is a flow chart diagram which summarizes the protocol involved for the slave power logic unit in the system operation.
Table II shows one scheme on which Addresses may be provided for the processor cabinets, the independent memory cabinets, the I/O cabinets, and the various peripheral cabinets, whereby the power control network system may address and communicate with specific cabinets in order to provide Command and Control functions in the power network system.
TABLE II______________________________________POWER NETWORK ADDRESS BYTE DEFINITIONSAddress Bits7654 3210______________________________________1000 0000 Power Control Network (Maintenance only)1000 00xx (Spare)1000 01xx Processor Cabinets1000 1xxx Independently-Powered Memory Cabinets1001 xxxx Dependently-Powered I/O Cabinets101x xxxx Independently-Powered I/O Cabinets1100 1xxx Disk Exchange Cabinets1101 0xxx Disk Controller Cabinets1101 1xxx Disk Controller Cabinets -- Memorex Type______________________________________ Note: Only 64 connections are allowed on the network.
Power Control Network Protocol:
Since the PCN has "great power" over a system, that is, it can turn off a system, it is necessary that the network protocol be fault tolerant and reliable. The PCN protocol was designed with several layers of redundancy and checking.
FIG. 10 shows the PCN byte format. The PCN byte contains one start bit, eight bits of information (data byte), one odd-parity bit and one stop bit.
FIG. 10 also shows the PCN message transfer protocol between the power net master card and a slave card. All transfers on the PCN are initiated by the master. All transactions follow the steps described below:
(1) Master sends an address byte to all slaves. An address byte has a "one" in the most significant bit position. Each slave compares the address byte to its address switches. Each slave has an unique address and that address values are predefined and grouped to also indicate that type of cabinet in which the slave is located. The master program can generate an address or pull an address from memory 100 a of FIG. 8. The master program gives the address to microprocessor 100 u which transmits it from master logic 100 to slave units 90, 90 d , 90 i , etc. via the network lines of FIG. 6.
(2) The slave, whose address switches equal the address byte value, then returns its address over the PCN to the master. The master checks the received value with the sent value to ensure the proper cabinet is responding. Thus, the slave program receives the transmitted address when it matches its own unique address and retransmits its address via the network of FIG. 6. The program gets its address from the settable address switches 94 of FIG. 7. The master program in the master logic unit compares the received-back address which comes through 100 p of FIG. 8. This address came from the slave unit 90 (or 90 d or 90 i , etc.) via FIG. 6.
(3) The master then sends a command byte to the addressed slave. A command byte has a zero in the most significant bit position. The master program can generate an instruction or pull one from memory 100 a of FIG. 8 in the master logic unit. The microprocessor 100 u will instruct 100 p , FIG. 8, to transmit it via the circuit of FIG. 6.
(4) If the command is a good command, the slave returns the command over the PCN. The slave logic unit receives the instruction and the slave program checks the instruction for validity, then retransmits the instruction (if valid) via the circuit of FIG. 6 back to the master unit 100.
(5) The master compares the returned command with the sent command; if it compares accurately, it re-sends the command byte to the slave. Thus, the master program then causes the master logic unit 100 to compare the "returned-instruction" from slave unit 90 with the originally sent instruction. When these two instructions are verified as being in agreement, the program instructs master logic unit 100 to transmit the instruction again over to the addressed slave unit via 100 p of FIG. 8 and FIG. 6.
(6) The slave compares the second command byte with the first command byte; if they agree, it checks the command, and if valid, the slave will begin execution of the command. Thus here, the slave unit receives the instruction for the second time and the slave unit program compares this instruction with the originally received instruction whereupon (if both instructions coincide) the slave unit generates control signals. These generated control signals are placed on circuits 96, 97 or 98, FIG. 7 (depending on the instruction) and especially to the Power Control Card 80 i (FIG. 4) or to 80 d (FIG. 3) or 80 (FIG. 2) via the port interfaces 96, 97 of FIG. 7. In the case of the peripheral slave unit 90 p (FIG. 8), the slave unit generates a pulse which is sent to the peripheral cabinet (disk control unit of FIG. 9) via circuit 95 p .
(7) In response to the second command byte, the slave returns a status byte of information to the master. The normal status byte returned contains "general status" information about the cabinets condition: on/off, system/cabinet local modes, any failure condition, any margin condition, on/off request. If the command was a "send status" command, the slave will send the specific information desired: specific margin conditions, specific cabinet power failure conditions, clock select signal states. Thus, after generating the needed control signals, the slave unit will get "cabinet status" information via circuits 96, 97 of FIG. 7. This information creates the "general status" byte (or other status byte depending on the instruction from the master unit 100). The slave unit (90, 90 d , 90 i , etc.) will then transmit the status information to the master unit 100 via, for example, the driver 90 d of FIG. 6. When the master unit 100 gets the status information (via 100 p of FIG. 8), the master program can act on the basis of the type of information it received.
(8) One additional safety check is performed by the master card on the status byte returned. Since power-on request and power-off request status bits are so critical to the entire system, these status bits are double-checked if they are returned in the general status byte. This is done as follows:
(a) A "send status" command is sent; the general status byte is received for the second time to see if the power-on/off request status bit is still active.
(b) A reset command is sent to the slave in question. This clears the power-on/off request bit.
(c) A "send status" command is again sent (the request status should now be inactive).
(d) If each step above was correct, the master will execute the power-on or power-off request sequence to the system.
Any time-outs or miscompares, in any of steps 1-8 above, abort the transfer and prevent the execution of any action to cabinets in the system. FIG. 11 gives the master flow (less steps a-d). FIG. 12 gives the slave flow.
Power Control Subsystem
The power control subsystem shown in FIGS. 13, 14, 15 and 16 is used to controllably sequence various power supply modules either "on" or "off" and to detect failures in the power modules or cooling systems that could damage the logic cards, interfaces or memory storage devices.
The power sequence control and failure detection is oriented around the power control circuit card 80 (80 i , 80 d ) in conjunction with its interface to the slave logic units 90 (90 i , 90 d ) as shown in FIGS. 13 and 14. FIG. 13 shows the output control signals from the slave logic 90 to the power control circuit 80. Then FIG. 14 shows the various "indicator" signals which the power control circuit provides to the slave logic 90.
In order to control each power supply module on or off, a transistor type logic (TTL) compatible signal is sent to each power supply module from the power control circuit card 80, according to instructional data received from the slave logic unit 90.
Each power supply module (as 41, 43, 70 a , 70 b , of FIGS. 2, 3, 4) will send a TTL signal back to the power control circuit 80 (80 i , 80 d ) to indicate if that module failed or was under voltage, over voltage, over current or over temperature. Thus, the over temperature or air loss sensors of FIG. 15 can send failure signals to the sequencer 80 q in power control circuit 80.
As indicated in FIG. 16, a precision reference voltage unit 80 r has programmable voltage steps of + (plus) or - (minus) 5 percent which can be controlled by input signals via a local interface from margin switches 80 s , or via a remote interface from slave logic 90. This permits "margining" of the output voltages on each power supply module.
The voltage output of the logic power supplies (+5 V, -4.5 V and -2.0) can thus be adjusted + or -5% via the "margin step function". Each power supply module has a +5V reference supplied by reference unit 80 r which controls the output voltage of each power module, and any change in reference voltage causes a proportional change in output voltage.
The precision +5 V reference voltage has two programmable inputs for effecting +5% and -5% voltage change steps. The margin steps can be activated "locally" by a switch or "remotely" by the slave logic 90. Each logic power module has its own separate reference voltage and margin circuit.
The main AC power module (such as the 15KW input module 41 of FIG. 15) can be set on or off via a TTL signal "S" from the power control circuit 80.
The cabinet control panel 44 (FIGS. 2, 15) enables "local mode" operation by a technician or system operator, and has an on/off push button with light-indicator, with power-failure/temperature-failure indicator and local/remote switch with indicator light.
Thus, the two modes for controlling power on/off are the "local" mode and the "remote" mode.
The local mode requires an "on-site" operator to manually start the power control on/off responses by use of an ON/OFF switch on cabinet control panel 44.
The remote mode allows the "system control" in the network whereby the master logic 100 (FIG. 8) instructs the appropriate slave logic 90 to command certain actions to its power control circuit 80.
The local/remote keyswitch in the cabinet control panel 44 enables or disables the local/remote interface (FIG. 16) in the power control circuit 80. Then depending on what mode the system is in, the sequencer 80 q turns each power supply module on/off in the appropriate sequential order.
If a failure signal occurs on a power module, air sensor or temperature line (FIG. 16), then the sequencer 80 q will power off the power modules in the appropriate sequence.
On "power-up" the proper sequence is to first turn on the main AC supply 41 after which power is turned on to the 12 V supply, then the 5 V supply and the 4.5 V and 2.0 V supplies.
On "power-off", the sequence is effected in the reverse order.
As indicated in FIG. 15, each power module can furnish a TTL compatible "fail" signal to the sequencer 80 p in the power control circuit 80.
The power sequencer 80 q is a circuit which ensures that the main power module 41 is operating before checking the subordinate power modules, after which any incoming failure signal which is detected will make the sequencer shut off all the power modules in that subsystem. The sequencer 80 q will also signal the slave logic 90 with a TTL compatible signal. Any failures are also indicated by light-emitting diodes which make reference to each power module. A similar failure indicator on the cabinet control panel 44 is also turned on.
There has herein been described a power control network which interconnects a multitude of digital modules where each digital module has a slave logic unit capable of receiving power control instructions from a master logic unit. The communications protocol between the master logic unit and any addressed slave logic unit insures that accurate instruction transfer will occur without error in all cases.
While a preferred embodiment of the power control subsystem has been described, it should be understood that other possible embodiments may be devised within the framework of the following claims: | A power network control system has a plurality of digital modules interconnected. A master logic unit in the network communicates with a specialized protocol to slave logic units in each module. The slave logic unit can instruct a power control circuit to turn-off or turn-on various power supply modules in addition to adjusting a power module in steps of plus or minus fixed percentage amounts. | 50,556 |
FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus and method for downhole water chemistry analysis.
BACKGROUND OF THE INVENTION
[0002] Well operators commonly need to understand downhole water chemistry to help them decide production strategies and determine corrosion rates, scale formation rates, formation geochemistry etc.
[0003] More specifically, the pH and qualitative/quantitative analysis of the presence of specific ions in downhole water are often required.
[0004] Conventionally, water chemistry measurements are performed in the laboratory on fluid samples retrieved from below ground. However, water chemistry is not often preservable over the temperature and pressure changes typically induced by transportation from subterranean locations to the surface, and so a chemistry measurement of a sample collected for laboratory analysis will not always provide a result that can be related to the downhole value. Consequently, the water chemistry measured in the laboratory may vary significantly from that existing downhole.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a more reliable analysis of downhole water chemistry.
[0006] Accordingly, in a first aspect, the present invention provides an apparatus for analysing water chemistry, the apparatus being adapted to operate downhole and comprising:
[0007] a colouring agent supply device for supplying a colouring agent to a water sample, the colour of the water sample thus supplied being indicative of the water sample chemistry, and
[0008] a calorimetric analyser arranged to determine the colour of the water sample.
[0009] An advantage of the apparatus is that it allows in situ analysis to be performed, thereby avoiding the problems associated with transporting water samples to the surface. The present invention is at least partly based on the realisation that colorimetric analysis is a technique that can be adapted for performance downhole, i.e. in relatively demanding and hostile conditions.
[0010] In one embodiment the apparatus is installed downhole (e.g. in a hydrocarbon well or an aquifer).
[0011] Preferably the calorimetric analyser is connected to a processor for determining the water sample chemistry from the colour of the water sample. The processor may also be adapted for use downhole, or alternatively it may be intended for remote installation e.g. at the surface. For example the processor may be a suitably programmed computer.
[0012] The water sample colour may be indicative of e.g. water pH or a selected ion concentration level.
[0013] In one embodiment the calorimetric analyser comprises a spectrometer. An advantage of a spectrometer-based approach to colour analysis is that it has the potential to provide fast answers to questions of pH, corrosion chemistry and scale formation, which can be crucial for deciding e.g. completion design and materials and scale treatment programs.
[0014] A further aspect of the present invention provides for the use of the apparatus of the previous aspect for in situ analysis of downhole water chemistry.
[0015] In another aspect the present invention provides a method for analysing downhole water chemistry, the method comprising the steps of:
[0016] (a) supplying a colouring agent to a downhole water sample, the colour of the water sample thus supplied being indicative of the water sample chemistry, and
[0017] (b) determining the colour of the water sample,
[0018] wherein steps (a) and (b) are performed in situ.
[0019] In another aspect the present invention provides a method for monitoring contamination of downhole water, the method comprising the steps of:
[0020] (a) adding a tracer agent to a fluid which is a potential contaminant of the downhole water,
[0021] (b) supplying a colouring agent to a sample of the downhole water, the colour of the water sample thus supplied being indicative of the presence of the tracer agent, and
[0022] (c) determining the colour of the water sample,
[0023] wherein steps (b) and (c) are performed in situ.
[0024] The potential contaminant may be drilling mud filtrate. The downhole water may be either connate or injected water.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Specific embodiments of the present invention will now be described with reference to the following drawings in which:
[0026] FIG. 1 shows a schematic diagram of a Live Fluid Analyser installed on a flow line,
[0027] FIG. 2 a shows the room temperature absorbance spectra of (a) the acid form of phenol red, (b) the base form of phenol red, (c) phenol red in a pH 8 solution, and (d) a weighted sum of the acid and base form spectra fitted to the pH 8 solution absorbance spectrum,
[0028] FIG. 2 b shows graphs of base fraction of phenol red (right hand vertical axis) and calculated pH (left hand vertical axis) as functions of prepared solution pH,
[0029] FIG. 3 a shows the room temperature absorbance spectra obtained from (a) phenol red in deionised water and (b) phenol red in deionised water after heat treatment at 150° C. for 24 hours, and
[0030] FIG. 3 b shows the absorbance spectra obtained from (a) phenol red in a pH 7.4 buffer solution at 22° C. and (b) phenol red in the pH 7.4 buffer solution at 150° C.
DETAILED DESCRIPTION OF THE INVENTION
[0031] In general terms, the present invention relates to downhole colorimetric analysis. A preferred approach for the determination of pH and detection of the presence of specific ions involves injecting a specific indicator or reagent into a sample of water and determining the resulting colour of the fluid with an optical spectrometer.
[0032] Ions of interest for detection include those of Ca, Ba, Sr, Al, Cl, F, Fe, Mg, K, Si, Na, and ions containing sulphur and carbon (for example carbonate, bicarbonate, sulphate). Use of colorimetric and spectrometric analysis along with procedures and reagents required to determine the presence/quantity of some of these ions have been described in the literature (Vogel, A. I., Text - Book of Quantitative Inorganic Analysis, 3 rd Edition, Chapter 10, John Wiley, 1961; Sandell E. B., Colorimetric Determination of Traces of Metals, 3 rd Edition, Interscience Publishers, 1959). However, we propose, for the first time, the application of these methods, in a downhole environment, to the analysis of downhole water as found in oil and gas fields, as well as aquifers. Typical temperatures and pressures found in a downhole environment are in the range of 125° C. and 10,000 psi, respectively; however they can go up to as high as 175° C. and 20,000 psi.
[0033] To perform quantitative measurements of pH or ion concentration, the optical absorption of the unknown species can be determined either relative to a standard solution (which could be the water sample itself prior to indicator/reagent addition) or with a stable and previously calibrated spectrometer.
[0034] Desirably, the spectrometer should be capable of operating over the visible spectrum of 400 to 760 nm, which is from ultraviolet to infrared respectively.
[0035] In one embodiment we propose fitting a known Modular Dynamic Tester (MDT) with a Live Fluid Analyzer (LFA) module (R. J. Andrews et al., Oilfield Review, 13(3), 24-43). The LFA would inject coloured indicators to the water flowing through the MDT so that pH can be determined. It can also add suitable reagents to the water for determination of the presence/concentration of selected ions.
[0036] FIG. 1 shows a schematic diagram of the LFA installed on a flow line 1 , the other parts of the MDT not being shown. An arrow indicates the direction of water flow in the flow line. The LFA has an upstream dye injector 6 and a downstream optical analyser 2 . The analyser comprises a light source 3 on one side of the flow line and a facing light detector 4 on the opposite side of the flow line. When a preselected indicator or reagent 5 is injected into flow line it mixes with the water and is carried downstream to the analyser, whereupon the detector generates a signal indicative of the colour of the water. If required a mixer, not shown in the figure, such as a double helix, can be used to promote mixing of the water and dye. A processor (not shown) then determines the water chemistry from the signal e.g. using approaches discussed below.
[0037] Such colorimetric analysis also allows contamination of formation water by water-based mud filtrate to be detected. This can be achieved by suitable indicator/reagent selection such that the water-based mud filtrate and formation water generate different respective colours.
[0038] Another option is to add a tracer ion or other species (for example, nitrate, iodide or thiocyanate ions) to the drilling fluid. A reagent can then be used in the LFA, which produces a colour change in the presence of the tracer so that the tracer can be detected and preferably quantified. In this way real-time monitoring of connate water for contamination by the filtrate can be achieved.
[0039] A possible reagent for detecting iodide is the iodobismuthite ion, formable from a solution of bismuth in dilute sulphuric acid. This ion gives a yellow orange colouration and is sensitive up to 1% iodide (Vogel, A. I., Text - Book of Quantitative Inorganic Analysis, 3 rd Edition, Chapter 10, p803 John Wiley, 1961).
[0040] We now describe how indicator colouration can be used to measure pH. However, similar considerations apply when the colour of any reagent is being used to measure ion concentration.
[0041] For pH measurements the choice of indicator depends to a significant extent on the accuracy with which the pH is required. As an example, we take a universal indicator, a volume of which has been injected into the sample flowline upstream of the optical detector. The indicator volume is determined by the flow rate of the water and intensity of the colour and is usually a small fraction of the total volume. The universal indicator may be formed e.g. from a mixture of 0.2 g of phenolphthalein, 0.4 g methylred, 0.6 g dimethylazobenzene, 0.8 g bromothymol blue, and 1 g of thymol blue in 1 l ethanol. To this solution is added NaOH(aq) until the solution appears yellow. The colours of the solution as a function of pH are listed in the table below (Vogel, A. I., Text - Book of Quantitative Inorganic Analysis, 3 rd Edition, Chapter 1.30, p59 John Wiley, 1961).
pH 2 4 6 8 10 12 Colour Red Orange Yellow Green Blue Purple
[0042] An alternative is to use a plurality of indicators each of which is specific to a respective pH range. This may result in a more precise determination of pH.
[0043] The pH of an unknown solution may be obtained using the equation below (R. G. Bates, Determination of pH: Theory and Practice , Chapter 6, John Wiley, 1964):
pH = pKa + log γ B γ A + log B A ( 1 )
where Ka is the thermodynamic equilibrium constant for the indicator and is a function of temperature; A and B are the respective fractions of the acid and base forms of the indicator; and γ A and γ B are respective activity coefficients of the acid and base forms of the indicator, and depend on ionic strength of the solution and temperature. Both Ka and activity coefficients could be weak functions of pressure as well.
[0044] The fraction of the indicator that exists in the acid form (A) and base form (B) may be measured spectroscopically. The absolute concentration of the dye does not appear in the equation and hence the pH calculation is independent of the volume of dye injected or the flow rate of the water stream as long as the concentration is such that Beer's law is satisfied. The functional dependence of Ka on temperature (T) has been studied and measured for a number of reactions and a general equation that can describe this dependence is (D. Langmuir, Aqueous Environmental Geochemistry , Chapter 1, Section 1.6.2, Prentice Hall, 1997):
log Ka = a + bT + c T + d log T + ⅇ T 2 ( 2 )
[0045] The parameters in this equation may be obtained by calibration in the laboratory over the desired temperature range using standard buffers of known pH. Dependence on pressure may also be obtained through experimental calibration if necessary. Several models have been proposed for activity coefficient estimation. For example, the Debye-Huckel equation is commonly used for low ionic strength solutions and the Pitzer model at higher ionic strengths (D. Langmuir, Aqueous Environmental Geochemistry , Chapter 4, Section 4.2, Prentice Hall, 1997). Ionic strengths can be derived from downhole water sample conductivity/resistivity measurements as is done in the MDT or alternatively from other wireline measurements such as resistivity logs. For very dilute solutions and/or for acid and base forms that have similar behaviours, the activity coefficient term may be neglected. Thus equation (1) provides a means for determining pH under downhole conditions for most temperatures, pressures and ionic strengths encountered in practice.
[0046] As an example, FIG. 2 a shows the room temperature absorbance spectra of (a) the acid form of phenol red and (b) the base form of phenol red. The acid form has a peak at about 432 nm and the base form at about 559 nm. FIG. 2 a also shows (c) the measured absorbance spectrum of phenol red in a pH 8 solution, and (d) a weighted sum of the acid and base form spectra fitted to the measured absorbance spectrum, the weightings providing the base and acid fraction of phenol red in the pH 8 solution.
[0047] Similar analyses can be performed for solutions prepared with different pH levels. FIG. 2 b shows a graph of base fraction of phenol red (right hand vertical axis) as a function of prepared solution pH (horizontal axis). Using equation (1) it is then possible to, calculate the pH of each solution. The calculated pH values (left hand vertical axis) are also plotted on FIG. 2 b . They show that, in this example, pH determined by spectroscopy is highly accurate for phenol red base fractions in the range of about 0.05 to 0.95 corresponding to pH values from 6.5 to 9. The range of pH measurement can be increased to 6 to 9.5 if the acid and base fractions can be spectroscopically detected at lower levels of 0.02.
[0048] The accuracy of the pH measurement is higher when the pH is close to the pKa value and decreases when the pH departs from the pKa. Thus, if the likely pH range is known, an indicator can be selected which has a pKa value such that a desired level of accuracy can be achieved. A combination of indicators may be chosen to cover the pH range typically expected in formation waters. In this way, provided the optical analyser has suitable wavelength windows to observe the colour changes, the pH can be obtained to within a value of a few tenths. Depending on how the indicators interact with each other, multiple injectors in series or parallel may be used for the different indicators or a single injector with a mixed indicator solution may be deployed.
[0049] The analysis may be performed using a stable and calibrated colorimeter/spectrophotometer. Alternatively, the absorbance spectra of the water sample in the flow line prior to indicator injection can yield the baseline. Yet another option is to use a reference solution to calibrate the colorimeter/spectrophotometer. The last two options provide a means of compensating for any possible inherent water colour.
[0050] Further improvements may be obtained if a series of buffer reference solutions are supplied, each differing in pH e.g. by about 0.2 and covering the range around the expected pH value. Indicator is then added to known volumes of the buffer solution and the water sample and the colours compared to determine the pH. To ensure accuracy, preferably the water sample is a captured sample.
[0051] For downhole use, the indicator should be stable and chemically active at the temperatures expected downhole. As an example, FIG. 3 a shows the room temperature absorbance spectra obtained from (a) phenol red in deionised water and (b) phenol red in deionised water after heat treatment at 150° C. for 24 hours. The heat treatment results in only a 10% loss in absorbance, demonstrating that the phenol red indicator can survive prolonged exposure to temperatures of up to 150° C.
[0052] However, it may be necessary to calibrate each indicator/reagent for the different temperatures and ionic strengths to which it will be exposed downhole. FIG. 3 b shows the spectra obtained from (a) phenol red in a 7.4 pH buffer solution at 22° C. and (b) phenol red in the 7.4 pH buffer solution at 150° C. At 150° C. the phenol red is still chemically active, the increase in base fraction at the higher temperature being due to changes in pKa and the pH of the buffer solution with temperature.
[0053] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention. | The invention concerns an apparatus for analysing water chemistry. According to the invention, the apparatus is adapted to operate downhole and comprises a colouring agent supply device for supplying a colouring agent to a water sample, the colour of the water sample thus supplied being indicative of the water sample chemistry, and a colorimetric analyser arranged to determine the colour of the water sample. | 18,587 |
FIELD OF THE INVENTION
The present invention relates to a chip crushing device more particularly the present invention relates to surface designs for cooperating working surfaces adapted to squeeze wood chips there between and modify the structure of the chip to make it more uniformly receptive to impregnating chemicals.
BACKGROUND TO THE INVENTION
In the manufacture of pulp and paper wood is usually chipped into wood particles using a chipper. Many types of chippers available, however the conventional chipper cuts across the wood at an angle to the grain to define the length of the chip and the thickness is determined by splitting along the grain. Therefore, despite the fact that major investigations have been made on cutting angles of the knives etc., the thickness of the chips produced by such conventional chippers is not accurately controlled.
Wafer chippers have also been used to produce chips for pulping, such chippers or waferizers as they are sometimes called cut generally along (parallel to) and across the grain with the main cutting edge parallel to the grain to produce chips that have a uniform thickness and therefore a more uniform impregnation characteristic. However, the benefits derived from wafer chips can only be obtained if only wafer chips are used to charge the digester. However, since it is normal practice to purchase chips from a variety of different suppliers and not all suppliers have the same type of wafer chipper the uniformity in thickness obviously is not obtained and therefore neither would the benefits. Furthermore the wafer chipper is much more expensive to maintain since it generally requires the use of a plurality of discrete knives, each of which cuts a single chip.
It has been proposed to treat chips produced by a conventional chipper to render them more uniformly impregatable for example by shredding of conventional chips to reduce them to smaller particles which may be more quickly and more uniformly impregnated, however, such shredding generally increases the number of fines which cause problems during digestion that to a degree defeat the purpose of the shredding operation.
It is also proposed to crush chips using a chip crusher such as the crusher shown in Canadian patent No. 825,416 issued Oct. 29, 1969 to Kutchers et al which utilizes a pair of rolls to crush the chips and fissure them to render them more easily and more uniformly penetrable by cooking liquor in the pulping process.
In the said Kutchera et al patent a specific surface design is proposed wherein each of the rolls are provided with ribs spaced 0.375 to 0.91 inch and have uniform heights between about 0.007 and 0.13 inch, and surfaces or land areas of 0.12 inch to 0.2 inch with the rib height ratio of the two rolls never exceeding about 4 to 1.
The device of the Kutchera et al patent has been tried but it is believed it is no longer in operation, part of the problem being the limited capacity of the equipment.
U.S. Pat. No. 3,962,966 issued June 15, 1976 to Lapointe describes an improved arrangement for increasing the throughput through the crusher. In this device the chips are fed axially onto a rotating disc which flings them out radially in a substantially one chip thickness layer, that passes between a roll and a working surface of the disc to squeeze chips of greater than a certain thickness.
BRIEF DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide a new surface design of the working surfaces of a crusher such as those shown in the said Canadian patent of Kutchera et al or in the Lapointe type crusher shown in U.S. Pat. No. 3,962,966.
Broadly the present invention relates to a chip crusher composed of a pair of co-operating surfaces defining a pressing nip, said surfaces being mounted to move in substantially the same direction through said nip, one of said surfaces being provided with a plurality of land areas separated by valleys, said land areas being substantially continuous and extending substantially in said direction of movement as said one surface passes through said nip, each of said land areas being between about 0.1 to 0.04 inch in width in the direction perpendicular to said direction of movement and being spaced centre to centre of said land areas by 0.2 to 0.6 inch said valley having a depth of at least 0.03 inch and having sloping side walls extending no greater than 160° and preferrably between 135° and 160° to said land areas, the other of said surfaces forming the periphery of a roll being provided with a plurality of teeth with the crown of each said looth defining a line preferably extending substantially perpendicular to said direction of movement through said nip and having a tooth depth of between about 0.05 inch and 0.1 inch and having their crowns spaced between about 0.1 and 0.6 inch.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features, objects and advantages will be evident in the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings in which.
FIG. 1 is a section through a plate or roll illustrating the surface configuration of one of the surfaces.
FIG. 2 is an end view of a roll incorporating the co-operating or mating surface.
FIG. 3 is a cross section of the preferred embodiment of a device employing the mating crushing surfaces of the present invention.
FIG. 4 is a plan view of the two discs used in the embodiment of FIG. 3.
FIG. 5 is an alternative embodiment incorporating the present invention in a chip crusher of the type described in the said Kutchera et al patent.
FIG. 6 is a plan view schematically illustrating the pressure pattern applied to a chip passing through a nip formed between a pair of surfaces incorporating the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The configurations of the two mating surfaces are depicted in FIGS. 1 and 2.
The surface 10 of FIG. 1 is composed of a plurality of spaced land areas designated at 12. Each being positioned in the same plane and having a width W and spaced from the adjacent land areas 12 by a distance centre to centre as indicated at S. The valleys 14 between each of the land areas 12 are formed by a pair of sloping sidewalls 16 and 18 extending between the surfaces or land areas 12 and the planer bottom sections 20 of the valleys. The sections 20 are substantially parallel to the areas 12. These sidewalls 16 and 18 extend at an angle θ to the sections 20 at the bottom of the valleys 14 and thus to the land areas 12. The sections 20 each have a width generally indicated at Z in FIG. 1.
The land areas 12 and thus the valley 14 there between extend generally in the direction of relative movement between the surface 10 and the co-operating surface 22 shown in FIG. 2. If the surface 10 is incorporated on the disc as shown in FIG. 4 the land areas 12 form concentric rings spaced by the valleys 14 or if the surface 10 is provided on a roll such as that indicated schematically in FIG. 5 the land areas 12 will extend circumferentially on the roll and form a plurality of spaced ring pressure members each on substantially the same radius extending circumferentially around the roll as right circular rings.
It has been found by experiment that the width of the land areas 12 as indicated by the letter W must be within certain limits as must the spacing S between the land areas 12 if proper fissuring of the chips is to be obtained. These dimensions may vary depending on the thickness and or length of the chip to be treated using the device however they will generally lie within the following ranges W=0.1 to 0.04 inch, S=0.2 to 0.6 inch and θ should never be less than about 20°, i.e. the angle between the land area and the side wall should not exceed 160°, it being important that the depth d i.e. the total depth of the valleys between the land areas 12 and the bottom surfaces 14 be at least 0.03 inch, obviously the dimension Z will depend on the angle θ spacing S and width W as well as the depth d for any given configuration. The spacing S should be such that the nominal chip length to be treated will substantially always contact at least two land areas.
The mating surface 22 adapted to cooperate with the surface 10 is provided on a roll such as the roll indicated at 24 in FIG. 2 since at least one of the surfaces 22 or 10 will be the surface of a roll to form a nip. The peripheral surface 22 of the roll 24 is formed by plurality of uniformly spaced teeth having their apex ends or crowns 26 extending in lines substantially longitudinal of the axis of rotation of the roll (see FIGS. 2 and 3). Each of these teeth has its crown 26 formed by the extention of a front face 28 and a trailing face 30 which form a saw tooth like configuration. These faces 28 and 30 preferably meet at 90° generally between about 60° and 120° and the faces 30 will preferably be at an angle α to a tangent to the surface of the roll 24. The angle α will be between about 5 and 45 degrees, preferably about 15°. The circumferencial spacing C between a pair of adjacent crowns 26 will generally be about equal about 0.1 to 0.6 inch so that 2 teeth will normally engage a chip and the depth of these teeth i.e. the height of the walls 28 as indicated by D will be at least 0.03 inch and generally will not exceed 0.1 inch.
The radius of the roll 24 i.e. of the crowns 26 of the teeth determines the angle of attack of the teeth to the chip thus when the roll diameter changes it may be desirable to modify the size and shape of the teeth. The diameter of the roll should be chosen to ensure the chips will be drawn into the nips by the action of the two surfaces 10 and 22. The diameter of the roll for use in a roll and disc combination as illustrated in FIGS. 3 and 4 should be between about 3 and 12 inches preferably between 5 and 8 inches. The height of gap or clearence G (see FIG. 5) of the nip for either the disc and roll combination or the pair of rolls embodiments will depend on the maximum tickness chip to be fed to the nip and the thickness of the treated chips or spacing between fissures in the treated chips. Generally the nips will have gaps G of 0.04 to 0.1 inch. In one design a roll having a diameter of about 5 3/4 inches, with the angle α=15°, depth D=0.06 inch and the spacing C=0.4 inch, the height or gap G was set at 0.06 inch for treating chips having a maximum thickness of slightly over 0.25 inch using a disc with W=0.06 inch, S=0.3 inch, Z=0.06 inch and d=0.055.
As above indicated mating surfaces extend such that the ridges or crowns 26 are substantially perpendicular to the longitudinal axis of the land areas 12 in the nip formed between the surfaces 10 and 22.
In the embodiment illustrated in FIG. 3 and 4 the roll 24 is mounted on a fixed housing in a device somewhat similar to that described in the above referred to Lapointe patent. The chips enter each nip 32 formed between the surface 10 on the rotating disc 34 and the surface 22 on the mating rotating roll 24. The disc 34 as illustrated in FIG. 4 is provided with the spaced land areas 12 in the form of concentric rings extending around the axis of rotation of the disc 34 as shown for example in FIG. 4 with the valleys 14 as formed by the walls 16, 18 and the bottom wall 20 there between.
The preferred crusher arrangement uses the disc 34 and roll 24 in combination similar to that disclosed in the said Lapointe U.S. Pat. No. 3,962,966 modified to use the orienting mechanism described in copending Lapointe application 360,827 filed March 23, 1982. The chips enter through the inlet 36 and are flung by flingers or orienting bars 38 up an inclined orienting surface 40 wherein the chips are laid on their larger area face and the oversized material acted on to reduce it to a certain predetermined thickness to pass out through the outlet passage 42 formed by a pair of substantially parallel walls one on the disc 46 and the other on the housing 44, for further details see the said copending Lapointe application. Chips that pass through outlet 42 are flung from the disc 46 onto the disc 34 for movement through the nip 32 between the disc 34 and the roll 24. A plurality of rolls 24 will be spaced around the circumference of the disc 34 to provide a plurality of spaced apart nips 32 through which chips may pass. The disc 46 preferably is driven by a drive belt 48 at a speed higher than the speed of rotation of the disc 34 which is driven via a belt 50 i.e. the angular velocity of the disc 46 is higher than that of the annular ring formed by the disc 34. The rolls 24 may also be driven via a suitable motor such as that indicated at 52 through suitable belt drives such as that schematically illustrated at 54 in FIG. 3. The roll surface 22 preferably will travel at about the same speed and in substantially the same direction as the surface of the disc through the nip 32. (Obviously the surface 22 of roll 24 at any one time has the same tangential velocity in the direction of movement through the nip while the tangential velocity of the disc varies with the radius and thus provision must be made for the drive for the roll 24 to permit some slippage. Usually the surface 22 will be driven by drive 52 at a velocity substantially equal to the velocity of the surface 10 at the mid point of the nip and obviously if the roll 24 is driven by the surface 10 through a chip the velocity of the roll will vary depending on the radial location of the chip relative to the surface 10.
The surface of the disc 46 preferably will be slightly lower than the wall of the outlet 42 formed by the disc 46 so that the chips pass from the disc 46 and at least part way across the surface 10 in free flight.
If desired the present invention may also be applied to a pair of mating compression rolls such as those indicated at 56 and 58 in FIG. 5, the roll 56 may be provided with a working surface equivalent to the surface 10 as illustrated in FIG. 1 and the roll 58 with a surface configuration such as the surface configuration 22 used on the roll 24. In any event the nip 60 formed between these rolls will function in a manner quite similar to the nip 32 formed between the roll 24 and the annular disc 34. However, the radius of the two rolls may be larger than 12 inches for this embodiment provided the approach angle between the two rolls will accept the chips to be fed thereto.
In any embodiment employing the present invention the concept is to have a pressure applied to the chips at spaced locations longitudinally and transversly of the chips. These spaced locations as indicated by the blackened areas 62 are formed where the land area mates with the apexes 26 of the teeth on the roll 24 as shown in FIG. 6 as the apex 26 of one of the teeth comes down and approaches the surface 10 of say the disc 34, pressure points are developed between the land areas 12 and the adjacent points or crowns 26. The first tooth 26 shown in FIG. 6 provides a first line of areas 62 extending across the chip generally indicated at 64 by a dot dash line, press the chip between the surfaces 10 and 22 at points 62, this pressing tends to force the chip into the valleys between the land areas 12 and thereby deflect the chip beyond the elastic limit while simultanously compressing the chip (depending on the chip thickness) so that internal cracking and fissuring occurs either longitudinally of the chip or transversly of the chip depending on the orientation of the chip relative to the teeth 26 and to the land areas 12 but substantially always along fibre boundries. These pressure points 62 are repeated further along the chip 64 as indicated by the areas 62' as defined by the second tooth 26' the spacing between the pressure points 62 and 62' being determined by the spacing between the tips 26 of the teeth and the rate of rotation of the surface 22 relative to the movement of the chip 64. Obviously the illustration is schematic and the pressure points 62 will take place in the same vertical plane as the pressure points 62' in spaced locations along the surfaces 10 and 22.
In operation the surfaces 10 and 22 cooperate in the nip to apply forces as above described to compress thick chips with localized spaced high pressure points or with thinner chips to apply local spaced compression points without substantially densifying the surface at the chip to resist impregnation yet with sufficient force to fissure and crack oversize chips to render them more easily impregnated and facilitate more uniform impregnation of the chips.
Having described the invention, modifications will be evident to those skilled in the art without departing from the spirit of the invention as defined in the appended claims. | The cooperating surfaces defining a pressing nip in a chip crusher are formed with specific patterns to treat the chips by fissuring to facilitate penetration by cooking chemical for the making of pulp for papermaking and the like. One of the surfaces is provided with a plurality of land areas separated by valleys, the land areas being substantially continuous and extending in the direction of movement of the surface as it passes through the crushing nip. The surface cooperates with the surface of a roll which defines the other side of the nip, the roll surface is provided with a plurality of teeth with the crown of each tooth defining a line preferably extending substantially perpendicular to the direction of movement of the roll surface through the nip. | 17,016 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/418,536 filed on Apr. 18, 2003. The entire disclosure of the above application is incorporated herein by reference.
TECHNICAL FIELD
This invention relates to a fuel cell stack assembly and more particularly to a bipolar plate assembly having a pair of stamped metal plates bonded together to provide coolant volume therebetween.
BACKGROUND OF THE INVENTION
Fuel cells have been proposed as a power source for many applications. One such fuel cell is the proton exchange member or PEM fuel cell. PEM fuel cells are well known in the art and include an each cell thereof a so-called membrane-electrode-assembly or MEA having a thin, proton conductive, polymeric membrane-electrolyte with an anode electrode film formed on major face thereof and a cathode electrode film formed on the opposite major face thereof. Various membrane electrolytes are well known in the art and are described in such U.S. Pat. Nos. 5,272,017 and 3,134,697, as well as in the Journal of Power Sources , vol. 29 (1990) pgs. 367-387, inter alia.
The MEA is interdisposed between sheets of porous gas-permeable, conductive material known as a diffusion layer which press against the anode and cathode faces of the MEA and serve as the primary current collectors for the anode and cathode as well as provide mechanical support for the MEA. This assembly of diffusion layers and MEA are pressed between a pair of electronically conductive plates which serve as secondary current collectors for collecting the current from the primary current collectors and for conducting current between adjacent cells internally of the stack (in the case of bipolar plates) and externally of the stack (in the case of monopolar plates at the end of the stack). Secondary current collector plates each contain at least one active region that distributes the gaseous reactants over the major faces of the anode and cathode. These active regions also known as flow fields typically include a plurality of lands which engage the primary current collector and define therebetween a plurality of grooves or flow channels through which the gaseous reactant flow between a supply header and a header region of the plate at one of the channel and an exhaust header in a header region of the plate at the other end of the channel. In the case of bipolar plates, an anode flow field is formed on a first major face of the bipolar plate and a cathode flow field is formed on a second major face opposite the first major face. In this manner, the anode gaseous reactant (e.g., H 2 ) is distributed over the surface of the anode electric film and the cathode gaseous reactant (e.g., O 2 /air) is distributed over the surface of the cathode electrode film.
Various concepts have been employed to fabricate a bipolar plate having flow fields formed on opposite major faces. For example, U.S. Pat. No. 6,099,984 discloses bipolar plate assembly having a pair of thin metal plates with an identical flow field stamped therein. These stamped metal plates are positioned in opposed facing relationships with a conductive spacer interposed therebetween. This assembly of plates and spacers are joined together using conventional bonding technology such as brazing, welding, diffusion bonding or adhesive bonding. Such bipolar plate technology has proved satisfactory in its gas distribution function, but results in a relatively thick and heavy bipolar plate assembly and thus impacts the gravimetric and volumetric efficiency of the fuel cell stack assembly.
In another example, U.S. Pat. No. 6,503,653 discloses a single stamped bipolar plate in which the flow fields are formed in opposite major faces thereof to provide a non-cooled bipolar plate. A cooled bipolar plate using this technology again requires a spacer element interposed between a pair of stamped plates, thereby increasing the thickness and weight of the cooled plate assembly. U.S. Pat. No. 6,503,653 takes advantage of unique reactant gas porting and staggered seal arrangements for feeding the reactant gases from the header region through the port in the plate to the flow field formed on the opposite side thereof. This concept is very desirable in terms of cost but its design constraints on flow fields may rule out some application. Furthermore, this design concept does not lend itself readily to providing an internal cooling flow.
Applications with high powered density requirements need cooling in about every other fuel cell. Thus, there is an ever present desire to refine the design of a bipolar plate assembly to be efficiently used in a fuel cell stack to provide a high gravimetric power density, high volumetric power density, low cost and higher, reliability. The present invention is directed to a stamped fuel cell bipolar plate that offers significant flow field design flexibility while minimizing the weight and thickness thereof.
SUMMARY OF THE INVENTION
The present invention is directed to a bipolar plate assembly having two thin metal plates formed with conventional stamping processes and then joined together. In another aspect, the centerlines of the flow fields must be arranged to align the channels for plates on opposite sides of the MEA wherever possible to further provide uniform compression of the diffusion media. In another aspect, the configuration of the flow fields formed in each of the two stamped metal plates are such that the contact area therebetween is maximized to enable the bipolar plate assembly to carry compressive loads present in a fuel cell stack. Thus, the centerlines of the flow fields formed in the two thin metal plates of a bipolar plate assembly need to be coincident in many places to carry the compressive loads. However, since the interior volume defined between the plates and their context areas form an interior cavity for coolant flow, it is necessary to have sufficient instances where the centerlines are not coincident in order to allow adequate coolant flow. The present invention achieves these two apparently opposing objections with a unique flow field design in which adjoining areas of the flow channels adjacent the inlet and exhaust margins provide a geometric configurations to provide the desired flow field and contact area requirements.
The present invention provides a bipolar plate assembly which includes a pair of plates having reactant gas flow fields defined by a plurality of channels formed the outer faces of the plates. The plates are arranged in a facing relationship to define an interior volume therebetween. A coolant flow field is formed in an interior volume defined between the pair of plates at the contact interface therebetween. The coolant flow field has an array of discrete flow disruptors adjacent a coolant header inlet and a plurality of parallel channels interposed between the array and the coolant exhaust header. Fluid communication is provided from the coolant inlet header through the coolant flow field to the coolant exhaust header.
The present invention also provides a separator plate which includes a thin plate having an inlet margin with a pair of lateral inlet headers and a medial inlet header formed therethrough, an exhaust margin including a pair of lateral exhaust headers and a medial exhaust header formed therethrough and a reactant gas flow field formed on a major face of the thin plate. The reactant gas flow field includes a first set of flow channels, each having an inlet leg with a first longitudinal portion in fluid communication with one of the pair of lateral inlet headers and a first transverse portion, a serpentine leg having a first end in fluid communication with the first transverse portion and a second end and an exhaust leg having a second transverse portion in fluid communication with the second end of the serpentine leg and a second longitudinal portion in fluid communication with one of the pair of lateral exhaust headers. Either of the transverse portion of the inlet leg adjacent the medial inlet header and the transverse portion of the exhaust leg adjacent the medial exhaust header may be defined by an undulating flow channel.
These and other aspects of the present invention provide a bipolar plate assembly which increases the design flexibility in terms of flow field options, while achieving the cooling requirements as well as providing a relatively high gravimetric power density and high volumetric power density from a fuel cell stack incorporating the bipolar plate assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood when considered in the light of the following detailed description of a specific embodiment thereof which is given hereafter in conjunction with the several figures in which:
FIG. 1 is a schematic isometric exploded illustration of a fuel cell stack;
FIG. 2 is an isometric exploded illustration of a bipolar plate assembly and seal arrangement in accordance with the present invention;
FIG. 3 is a plan view of the flow field formed in the major face of an anode plate in the bipolar plate assembly shown in FIG. 2 ;
FIG. 4 is a plan view of the flow field formed in the major face of a cathode plate in the bipolar plate assembly shown in FIG. 2 ;
FIG. 5 is a plan view showing the contact areas at the interface between the anode and cathode plates;
FIG. 6 is an isometric view of multiple cells within the fuel cell stack and further showing a section taken through the cathode header;
FIG. 7 is a cross-section taken through the coolant header and showing the coolant flow path;
FIG. 8 is a cross-section taken through the anode header and showing the anode gas flow path; and
FIG. 9 is a cross-section taken through the cathode header and showing the cathode flow path.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. With reference to FIG. 1 , a two-cell stack (i.e., one bipolar plate) is illustrated and described hereafter, it being understood that a typical stack will have many more such cells and bipolar plates. FIG. 1 depicts a two-cell bipolar PEM fuel cell stack 2 having a pair of membrane-electrode-assemblies (MEAs) 4 , 6 separated from each other by an electrically conductive, liquid-cooled bipolar plate 8 . The MEAs 4 , 6 and bipolar plate 8 are stacked together between clamping plates 10 , 12 and monopolar end plates 14 , 16 . The clamping plates 10 , 12 are electrically insulated from the ends plate 14 , 16 . The working face of each monopolar end plates 14 , 16 , as well as both working faces of the bipolar plate 8 contain a plurality of grooves or channels 18 , 20 , 22 , 24 defining a so-called “flow field” for distributing fuel and oxidant gases (i.e., H 2 and O 2 ) over the faces of the MEAs 4 , 6 . Nonconductive gaskets 26 , 28 , 30 and 32 provide seals and electrical insulation between the several components of the fuel cell stack. Gas-permeable diffusion media 34 , 36 , 38 , 40 press up against the electrode faces of the MEAs 4 , 6 . The end plates 14 , 16 press up against the diffusion media 34 , 40 respectfully, while the bipolar plate 8 presses up against the diffusion media 36 on the anode face of MEA 4 , and against the diffusion media 38 on the cathode face of MEA 6 .
With reference to FIG. 2 , the bipolar plate assembly 8 includes two separate metal plates 100 , 200 which are bonded together so as to define a coolant volume therebetween. The metal plates 100 , 200 are made as thin as possible (e.g., about 0.002-0.02 inches thick) and are preferably formed by suitable forming techniques as is known in the art. Bonding may, for example, be accomplished by brazing, welding diffusion bonding or gluing with a conductive adhesive as is well known in the art. The anode plate 100 and cathode plate 200 of a bipolar plate assembly 8 are shown having a central active region that confronts the MEAs 36 , 38 (shown in FIG. 1 ) and bounded by inactive regions or margins.
The anode plate 100 has a working face with an anode flow field 102 including a plurality of serpentine flow channels for distributing hydrogen over the anode face of the MEA that it confronts. Likewise, the cathode plate 200 has a working face with a cathode flow field 202 including a plurality of serpentine flow channels for distributing oxygen (often in the form of air) over the cathode face of the MEA that it confronts. The active region of the bipolar plate 8 is flanked by two inactive border portions or margins 104 , 106 , 204 , 206 which have openings 46 - 56 formed therethrough. When the anode and cathode plates 100 , 200 are stacked together, the openings 46 - 56 in the plates 100 , 200 are aligned with like openings in adjacent bipolar plate assemblies. Other components of the fuel cell stack 2 such as gaskets 26 - 32 as well as the membrane of the MEAs 4 and 6 and the end plates 14 , 16 have corresponding openings that align with the openings in the bipolar plate assembly in the stack, and together form headers for supplying and removing gaseous reactants and liquid coolant to/from the stack.
In the embodiment shown in the figures, opening 46 in a series of stacked plates forms an air inlet header, opening 48 in series of stacked plates forms an air outlet header, opening 50 in a series of stacked plates forms a hydrogen inlet header, openings 52 in a series of stacked plates forms a hydrogen outlet header, opening 54 in a series of stacked plates forms a coolant inlet header, and opening 56 in a series of stacked plates forms a coolant outlet header. As shown in FIG. 1 , inlet plumbing 58 , 60 for both the oxygen/air and hydrogen are in fluid communication with the inlet headers 46 , 50 respectively. Likewise, exhaust plumbing 62 , 64 for both the hydrogen and the oxygen/air are in fluid communication with the exhaust headers 48 , 52 respectively. Additional plumbing 66 , 68 is provided for respectively supplying liquid coolant to and removing coolant from the coolant header 54 , 56 .
FIG. 2 illustrates a bipolar plate assembly 8 and seals 28 , 30 as they are stacked together in a fuel cell. It should be understood that a set of diffusion media, an MEA, and another bipolar plate (not shown) would underlie the cathode plate 200 and seal 30 to form one complete cell. Similarly, another set of diffusion media and MEAs (not shown) will overlie the anode plate 100 and seal 28 to form a series of repeating units or cells within the fuel cell stack. It should also be understood that an interior volume or coolant cavity 300 is formed directly between anode plate 100 and cathode plate 200 without the need of an additional spacer interposed therebetween.
Turning now to FIG. 3 , a plan view of the anode plate 100 is provided which more clearly shows the anode flow field 102 formed in the working face of anode plate 100 . As can also be clearly seen in FIG. 3 , the inlet margin 104 of anode plate 100 has a pair of lateral inlet headers 46 and 50 to transport cathode gas and anode gas, respectively, through the fuel cell stack and a medial inlet header 54 to transport a coolant through the stack. Similarly, the exhaust margin 106 has a pair of lateral exhaust headers 48 , 52 for transporting anode affluent and cathode affluent, respectively through the fuel cell stack, and a medial exhaust header 56 for transporting coolant through the fuel cell stack.
The anode flow field 102 is defined by a plurality of channels formed to provide fluid communication along a tortuous path from the anode inlet header 50 to the anode exhaust header 52 . In general, the flow channels are characterized by an inlet leg 108 having a longitudinal portion 110 with a first end in fluid communication with the anode inlet header 50 and a second end in fluid communication with a transverse portion 112 . As presently preferred, the transverse portion 112 of the inlet leg 108 branches to provide a pair of transverse inlet legs associated with each longitudinal portion 110 . Furthermore, the path of these transverse inlet portions 112 undulate within the plane of the anode plate 100 to provide an undulating flow channel adjacent the coolant inlet header 54 as represented in the area designated 114 . The transverse portion 112 of inlet leg 108 is in fluid communication with a serpentine leg 116 . The flow channel 108 further includes an exhaust leg 118 having transverse portions 120 and a longitudinal portion 122 to provide fluid communication from the serpentine leg 116 to the anode exhaust header 52 . The exhaust leg portion 118 is configured similar to the inlet leg portion 108 in that each longitudinal portion 122 is associated with a pair of transverse portions 120 . The path of the transverse exhaust portions 120 undulate within the plane of the anode plate 100 to provide an undulating flow channel adjacent the coolant exhaust header 56 as represented in the area designated 124 .
Turning now to FIG. 4 a plan view of the cathode plate 200 is provided which more clearly shows the cathode flow field 202 formed in the working face of cathode plate 200 . As can also be clearly seen in FIG. 4 , the inlet margin 204 of cathode plate 200 has a pair of lateral inlet headers 46 , 50 to transport cathode gas and anode gas, respectively, through the fuel cell stack and a medial inlet header 54 to transport a coolant through the stack. Similarly, the exhaust margin 206 has a pair of lateral exhaust headers 48 , 52 for transporting anode affluent and cathode affluent, respectively through the fuel cell stack, and a medial exhaust header 56 for transporting coolant through the fuel cell stack.
The cathode flow field 202 is defined by a plurality of channels formed to provide fluid communication along a tortuous path from the cathode inlet header 46 to the cathode exhaust header 48 . In general, the flow channels are characterized by an inlet leg 208 having a longitudinal portion 210 with a first end in fluid communication with the cathode inlet header 46 and a second end in fluid communication with a transverse portion 212 . A single transverse portion 212 is associated with each longitudinal portion 210 . Thus, the transverse portion 212 of the inlet leg 208 does not branch off to provide a pair of transverse inlet portions as the transverse portion 112 of anode inlet leg 108 . The path of the transverse inlet portions 212 undulate within the plane of the cathode plate to provide an undulating flow channel adjacent the coolant inlet header 54 as represented in the area designated 214 . The flow channel further includes a serpentine leg 216 which is in fluid communication with the end of transverse inlet portion 212 . The flow channel further includes an exhaust leg 218 having a transverse portion 220 and a longitudinal portion 222 . The exhaust leg portion 218 is configured similar to the inlet leg portion 208 to provide fluid communication from the serpentine leg 216 to the cathode exhaust header 48 . The path of the transverse exhaust portions 220 undulate within the plane of the cathode plate to provide an undulating flow channel adjacent the coolant exhaust header 56 as represented in the area designated 224 .
Referring now to FIGS. 2 and 6 , the anode plate 100 and the cathode plate 200 are positioned in an opposed facing relationship such that the various inlet and exhaust headers are in alignment. The anode plate 100 and the cathode plate 200 are then joined together using conventional techniques. The centerlines of the anode flow fields 102 and cathode flow fields 202 are arranged to align the flow channels on opposing plates (e.g. on opposite sides of the MEA as shown in FIG. 6 ) wherever possible to provide uniform compression of the diffusion media and the MEA. Likewise, the contact area between the adjacent, joined anode plate 100 and cathode plate 200 (as shown in FIG. 2 ) are coincident in many places so as to carry the compressive loads imposed on the fuel cell stack. Specifically, the flow channels of anode flow field 102 formed in the working face of anode plate 100 provide a complimentary contact surface on an inner face opposite the working face. Similarly, the flow channels of the cathode flow field 202 formed in the working face of the cathode plate 200 define a contact surface on an inner face of the cathode plate 200 . Thus, when the anode plate 100 and cathode plate 200 are joined together, an interference or contact area is defined therebetween.
With reference now to FIG. 5 , the contact area between the anode plate 100 and the cathode plate 200 defines a coolant flow field 302 between an inlet margin 304 and an exhaust margin 306 within coolant cavity 300 . The coolant flow field 302 includes an array of discrete flow disruptors 308 adjacent the coolant inlet manifold 54 formed at the interface of the anode inlet legs 108 and the cathode inlet legs 208 . Similarly, a set of flow disrupters 310 are formed adjacent the coolant exhaust header 56 at the interface of the anode exhaust leg 118 and the cathode exhaust legs 218 . The coolant flow field 302 further includes a plurality of parallel flow channels 312 interposed between the inlet margin 304 and the exhaust margin 306 which are defined at the interface of the serpentine legs 116 and the serpentine legs 216 . In accordance with the configuration of the anode flow field 102 and cathode flow field 202 , the array of discrete flow disruptors 308 extend obliquely from the area of the coolant flow field 302 adjacent the coolant inlet header 54 as indicated by directional arrow 314 into the parallel flow channels 312 . Likewise, the array of discrete flow disruptors 310 extend from the parallel flow channels 312 obliquely towards the coolant exhaust header 56 as indicated by directional arrow 316 .
Turning now to FIGS. 6-9 , the present invention incorporates a staggered seal and an integral manifold configuration for directing fluid communication from the header into the appropriate flow field. For example, the location of the seal beads between the inlet margin 104 , 204 and the flow field structure 102 , 202 step left and right (as seen in FIGS. 7-9 ) for each successive layer. Thus, the seal position shifts to provide fluid communication therebetween. Ports in the form of holes or slots penetrate vertically through the anode plate 100 or cathode plate 200 to provide means for fluid communication from the header to the flow field. In this manner, the present invention employs a staggered seal concept similar to that disclosed in U.S. Pat. No. 6,503,653, which is commonly owned by the assignee of the present invention and whose disclosure is expressly incorporated by reference herein. This approach allows the combined seal thicknesses to equal the repeat distance minus the thickness of the anode plate and cathode plate. This approach also provides an advantage over other conventional fuel cell stack design in which the thickness available for seals is reduced by the height required for the fluid passage from the header region to the active area region. By utilizing a staggered seal concept, the present invention affords the use of thicker seals which are less sensitive to tolerance variations.
The present invention further improves upon the staggered seal concept disclosed in U.S. Pat. No. 6,503,653 with the use of separate anode plate 100 and cathode plate 200 in each bipolar plate assembly. Specifically, a second plate enables the use of an integral manifold with the space between the plates. Reactant gases or coolant fluid can now enter on the top side of the upper plate, travel between the upper and lower plate through such integral manifolds and then enter the lower side of the upper plate to feed the bottom side of the MEA. As a result, the width of the region where the reactant gases enter the flow field is twice as wide as that disclosed in U.S. Pat. No. 6,503,653, thereby lowering the overall pressure drop across a given flow field. This aspect of the present invention is best illustrated in FIGS. 7-9 . Specifically, as illustrated in FIG. 7 , the coolant flow path is indicated by the arrows A showing flow from the coolant header (not shown) between the anode plate 100 and the cathode plate 200 and into the coolant flow field 302 defined therebetween. Similarly, in FIG. 8 the anode gas flow path is indicated by the arrows B showing flow from the anode header (not shown) between the cathode plate 200 and the anode plate 100 and into the anode flow field 102 . Similarly, in FIG. 9 the cathode gas flow path is indicated by the arrows C showing flow from the cathode header (not shown) between the anode plate 100 and the cathode plate 200 and into the cathode flow field 202 . In this manner, a wider manifold region is provided between the header region and the flow field region for each of the fluids passed through the fuel cell stack.
As presently preferred, the design of the bipolar plate assembly further includes an additional feature to support the seal loads given the effect of widening the inlet manifold region between the headers and the active flow fields. Specifically, as best seen in FIGS. 4 and 6 an in-situ support flange 226 extends transversely across the inlet margin through the cathode inlet header 46 , the coolant inlet header 54 and the anode header 50 . This support flange 226 is formed with a wavy or corrugated configuration to allow inlet fluids to freely pass from the header region through the manifold region into the flow field region while at the same time providing through-plane support for the bipolar plate assembly. For example, as best seen in FIG. 6 , the support flange 226 for the cathode plate 200 of the bipolar plate 8 occurs directly over the support flange 126 for the anode plate 100 of the neighboring cell. In this manner, compressive loads are readily transmitted through the fuel cell stack. Alternately, the support function could be provided with grooved blocks of a non-conductive material or similar features which could be formed in the seals to replace the in-situ configuration provided by the transverse support flange.
When using this configuration, these adjacent regions must be insulated since they are at different electrical potentials. Various suitable means are available such as the use of a non-conductive coating such as that disclosed in U.S. application Ser. No. 10/132,058 entitled “Fuel Cell Having Insulated Coolant Manifold” filed on Apr. 25, 2002 which is commonly owned by the assignee of the present invention and the disclosure of which is expressly incorporated by reference. Alternately, a film of non-conductive plastic tape may be interposed for providing electrical isolation therebetween.
The present invention provides a two piece bipolar plate assembly having a coolant flow field formed therebetween. The configuration of the various flow fields are such that the bipolar plate assembly may be a formed of relatively thin material, and still support the required compressive loads of the fuel cell stack. Furthermore, the present invention provides much greater design flexibility in terms of flow field options. In this regard, the present invention provides an improvement in the gravimetric and volumetric power densities of a given fuel cell stack as well as significant material and cost savings.
The description of the invention set forth above is merely exemplary in nature and, thus, variations that do not depart from the jest of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | An electro-conductive plate assembly for a fuel cell has a pair of stamped plates joined together to define a coolant volume therein. Each of the pair of stamped plates has a flow field on a major outer surface arranged to maximize the contact area between major inner surfaces of the plates while allowing coolant to distribute and flow readily within the coolant volume. The flow fields formed on the major outer surfaces provide corresponding sets of lands on the major inner surfaces that contact to form a third flow field of the coolant volume. The third flow field formed by the lands includes a plurality of longitudinal channels and an array of flow disruptors. The bipolar plate assembly further includes a seal arrangement and integral manifolds to direct reactant gas and coolant flow through the fuel cell. | 28,634 |
This is a continuation-in-part of application Ser. No. 07/815,248, filed Dec. 31, 1991, entitled "Jumper Ready Battery," now U.S. Pat. No. 5,214,368.
BACKGROUND OF THE INVENTION
This invention relates to batteries, in general; and, in particular, to apparatus for conveniently storing jumper cables in proximity to a vehicle battery for jump-starting the vehicle.
Several problems face the motorist, confronted with a "dead" battery, who seeks to jump-start an automobile. Jumper cables get lost, and are never with you when you need them. Establishing electrical connection using jumper cable clamps, between your automobile battery and the battery of another automobile is a nuisance. Battery posts are not always readily accessible, and knowing whether good contact has been made is always a problem, especially when (as is good safety practice) the last clamp attachment is made indirectly through the automobile frame. Unless good contact is confirmed, you can never be sure whether a breakdown is caused by a "dead" battery, or not.
The jumper cable attachment of the invention provides conveniently readily accessible jumper cables, that are easy to use and offer beneficial contact establishing advantages. The jumper cable attachment of the invention eliminates the need to carry a separate set of jumper cables.
SUMMARY OF THE INVENTION
In accordance with the invention a jumper cable attachment is provided for an automobile or similar battery, either internally or externally, to give significant jump start related improvements. The attachment includes a set of retractable jumper cables that are pre-attached to the positive and negative poles of the battery. The retractable cables are housed inside the battery or in an auxiliary structure closely associated with the battery. The battery clamps may be made luminescent, to glow in the dark. For contact confirmation purposes, the battery is augmented to include a small flashlight that can be used either as a mechanic's light or to assist in the jumping process. The retractable cables are preferably four gauge wire with a length of six to ten feet. In one illustrative embodiment, described in greater detail below, the cables are housed in a separate chamber formed within the battery casing itself. In other embodiments, a "jumper ready battery" is provided by means of a retractable cable fixture mounted as an add-on to a conventional battery housing.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention have been chosen for purposes of illustration and description, and are shown in the accompanying drawings, wherein:
FIG. 1 is a view of a jumper cable attachment in accordance with the invention, incorporated as part of the battery itself;
FIG. 2 is a view of a jumper cable attachment in the form of a battery add-on unit;
FIG. 3 is a circuit diagram of the attachment of FIG. 2;
FIG. 4 is a view of another form of add-on attachment unit; and
FIG. 5 is a view of a modified form of the attachment unit of FIG. 4.
Throughout the drawings, like elements are referred to by like numerals.
DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIG. 1, an automobile battery 10 includes positive and negative terminal posts 11, 12 connected via seals 13, 14 through cover 15 of a container 16 to post straps 17 and plate lugs 18 for electrical communication with plates 19 immersed in an electrolyte 20, such as a water-based solution of sulfuric acid. This connection is made in conventional manner, with caps 21 of vent plugs being located on the cover 15 to enable gas evacuation and replenishment of electrolyte. In conventional manner, conductors 23, 24 connect the battery terminals 11, 12, respectively, to positive and negative sides of an automobile electrical system 25; the negative connection being made, as is customary, by attachment of the conductor 24 to the automobile frame 26. The base of the battery casing 16 is supported in suitable fashion, such as in a tray 27 mounted on the frame 26. Well-known means (not shown) are utilized to lock the battery 10 within the tray 27.
In accordance with the invention, the container 16 includes a separate chamber 30, isolated from the electrolyte chamber 31, and within which jumper cables 34, 35 are stored. Each cable includes, at one end, an alligator clamp or similar mechanism 36 for establishing electrical contact between the associated cable 34, 35 and a corresponding positive or negative post of a remote battery of another automobile used for jumping purposes. For ease of manipulation in the dark, the handle parts of the clamps 36 are coated with a luminous material, such as phosphorescent paint. At its other end, each cable 34, 35 includes means for establishing electrical connection to the respective positive or negative pole 11, 12 of the battery 10. For the embodiment of FIG. 1, such communication is established by a lead 37 which electrically couples the inside end of the cable 34, 35 through a seal 38 to the appropriate post strap 17.
The cables 34, 35 are made retractable by attachment about a spool 41 of a retracting mechanism 40 mounted in the chamber 30. Suitable mechanisms 40 may be of a type such as used to retract the electrical cord of a canister vacuum cleaner (see, e.g., the cord reel assembly Part No. 700858 of a Kenmore vacuum cleaner, Model No. 116.2399182) or of a mechanic's guarded work lamp (see, e.g., the mechanism used to retract the cord of a commercially available Quality cord reel). The electrical connection of the lead 37 to the spool-mounted end of the jumper cables 34, 35 is made using brushes, rotating contacts, or similar known devices. To prevent retraction of the clamps 36 into the interior of chamber 30, so that they remain accessible, externally-opening cavities 42, 43 are formed in the cover 15 over the chamber 30. The cavities 42, 43 have open box-like constructions adapted for receiving a major portion of the clamps 36 therein. The bases 44 of the cavities 42, 43 have openings 45, dimensioned to pass the insulated wire portion of the cables 34, 35 but block movement of the clamps 36 into the interior of chamber 30.
For the embodiment illustrated in FIG. 1, the chamber 30 is formed integrally within the same container 16 as the chamber 31 which contains the conventional battery components. The clamps 36 will normally be located in conveniently accessible storage positions (as shown by the right clamp 36 in FIG. 1), within the open cavities 42, 43 formed in the cover 15. When it is desired to jump the battery 10, the cables 34, 35 are drawn out of the cavities 42, 43 (to a position such as shown by the left clamp 36 in FIG. 1) and attached in known manner to the corresponding posts of a remote battery or similar jumping source. Of course, normal safety procedures (such as attachment of the clamp 36 of the negative cable 35 to a frame rather than directly to the remote negative terminal post) must be observed. When the jumping procedure is completed, the clamps 36 are retrieved and the mechanisms 40 are operated to retract the insulated wire portions of the cables 34, 35 about the respective spring-loaded spools mounted for rotation within the chamber 30. The mechanisms 40 are advantageously of a spring-action, ratcheted-type which permit the cables to be withdrawn and held at any one of a plurality of selected uncoiled lengths. In the illustrated embodiment 10, each cable 34, 35 has its own associated retracting mechanism 40.
The described battery 10 provides security and convenience for the motorist, by enabling convenient location of the jumper cables 34, 35 at all times, with one end of each cable 34, 35 already situated in attachment with the associated battery posts 11, 12.
FIGS. 2 and 3 illustrate another form 110 of a battery jumper cable attachment in accordance with the invention. The embodiment 110 is constructed using a conventional battery 10' to which an abutting separate chamber 30' has been added by attachment of an auxiliary container 116. The container 116 is dimensioned to match the casing of the conventional battery 10' and is suitably secured thereto by mating Velcro straps 112, 113, joined to opposite sides of casing 116 and wrapped about the casing 16' of battery 10'.
In variation of the structure of the embodiment 10, the embodiment 110 utilizes a single retracting mechanism 40' for retracting the cables 34, 35. The inner lengths of those cables are joined together and wrapped about a single spool 41', configured in accordance with known principles, to provide electrical attachment of the inner ends of cables 34, 35 to the respective positive and negative terminal posts 11, 12. For the illustrated structure, leads 37' connect externally to the posts 11, 12, thereby requiring no separate seals 38 as in FIG. 1.
According to another advantageous feature of the invention, a flashlight 120 is provided in conjunction with the cables 34, 35. The flashlight 120 includes a hand-operable switch 121 and a bulb 122, electrically connected as shown in FIG. 3. The switch 121 has three positions A, B, C, as indicated. Position A operates flashlight 120 so that bulb 122 is illuminated conventionally by a dry cell battery source 123 installed within the interior of the flashlight housing 125. Position B is the flashlight "off" position, whereby the bulb 122 is open-circuited. And, position C connects the bulb 122 between the cables 34, 35. With the switch 121 in position C, the conventional automobile battery terminals 11, 12, to which the auxiliary jumper housing casing 116 is attached, will operate the flashlight 120. Such connection provides significant advantages. First with a "live" battery 10', good connection between cables 37' and posts 11, 12 can be confirmed. With switch 121 in position C, bulb 122 will light only if good connection exists. Second, with a "dead" battery 10' good connection between clamps 36 and the terminals (i.e., terminal and automobile frame) of a remote jumping battery can be confirmed. With switch 121 in position C, bulb 122 will light only if good connection exists. It is very frustrating in jumping a "dead" battery, when there is no way to check whether the clamps are making adequate contact. Use of a visual indicator, such as the bulb 122 of flashlight 120 connected as shown in FIG. 3, provides the needed assurance.
A modified cavity 42', larger than cavities 42, 43, is formed in the cover 115 of the container 116 to receive both the flashlight 120 and clamps 36 in retrievable storage position. An opening 45' in the base wall 44' of cavity 42' permits the insulated wire portions of the cables 34, 35 and the narrow rear of flashlight 120 to pass into the interior of cavity 30', but does not pass the enlarged bulb end of the flashlight 120. The flashlight 120 can be secured to one or both of the insulated wire portions of the cables 34, 35, as shown, or may be mounted on its own separate insulated wire. Mounting the light 120 in this manner, provides a convenient retractable work light, operable off the automobile battery, for checking the engine. The negative clamp 36 can be attached to the automobile frame structure to hang the lamp.
FIG. 4 illustrates yet another form 210 of a battery jumper cable attachment in accordance with the invention. The embodiment 210, like the embodiment 110 discussed above, takes the form of an add-on unit for attachment to the casing 16' of a conventional battery 10'. As with embodiment 110, a retracting mechanism 40' is housed within a chamber 30" defined by an auxiliary container 216. Unlike container 116, however, container 216 has a dimension which is made variable to match differences in spacing between terminals 11, 12 found in different battery sizes. Length adjustability is achieved by constructing container 216 in two parts 217, 218, one telescopingly received within the other. Each part 217, 218 has a box-like rectangular configuration, with a closed outer end and an open inner end. A cable retracting mechanism, which may be identical to the mechanism 40' of attachment 110, is located within the interior 219 of inner part 218 and clamps 36 are housed within a cavity 42" made accessible externally on outer part 217.
For the illustrated embodiment 210, each part 217, 218 includes horizontally extending upper and lower surfaces 220, 221, between corresponding extreme corners of which extend identical terminal displacement elements 224. Each element 224 comprises a block of conductive material including a downwardly opening vertical bore 225 at its bottom end and an upwardly directed vertical post 226 at its top end. Bore 225 is made accessible from the underside of surface 221 and is dimensioned to fit in electrical contact over a corresponding battery terminal post 11, 12. Post 226 projects upwardly through surface 220 and is dimensioned to simulate the corresponding post 11, 12 received within the associated bore 225.
The illustrated arrangement enables container 216 to be matched to the top of container 16' of battery 10' by positioning lower surface 221 over the top of battery 10', with one terminal displacement element 224 brought over battery terminal post 11 and the other terminal displacement element 224 brought over battery terminal post 12, with part 218 is shifted into or out of the open end of part 217 as needed to match the spacing of posts 11, 12. Conductors 23, 24 (see FIG. 1) can then be attached in vertically displaced positions to the upper end posts 226 of elements 224, instead of attaching them in conventional manner to the correspondingly dimensioned posts 11, 12 of the battery.
Clamps 36 may conveniently be housed within a cavity 42" formed by a rectangular compartment 227 made accessible centrally between projections 226 of elements 224 on upper surface 220 of container 216. Compartment 227 may comprise vertically extending walls 228, between opposing ones of which is pivotally mounted a lid 229 dimensioned, configured and adapted to normally cover the open top of compartment 227. Base 44" of compartment 227 has an opening 45" through which jumper cable leads 34, 35 extend into chamber 30" and cavity 219 for connection to the wind-up spool of the cable retraction mechanism. Opening 45" is large enough to enable the cables to be drawn therethrough, but is sufficiently small to block passage of clamps 36 into the interior of container 216. For the purpose of establishing a flat storage orientation of clamps 36 within the closed compartment 227, dummy posts 230 are located in laterally spaced positions away from opening 45". Walls 228 and dummy posts 230 are dimensioned, configured and adapted so that clamps 36 lay flat when attached to dummy posts 230 and lid 229 can be closed over clamps 36 and dummy posts 230, while maintaining a minimum height profile. Connection between clamp leads 34, 35 and terminal displacement conductive elements 224 is established by electrical connection of leads 37" between the retracting mechanism and points of attachment 231.
Accommodation is also made in apparatus 210 of FIG. 4, for electrical connection to terminals of batteries which are located in other than vertically extended positions. For the embodiment 210, each lead 37" is also connected through a conductive member 233 to a terminal connector 234 accessible through a side surface 235 of each telescoping part 217, 218. Electrical connection between terminal connector 234 and the battery posts can then be established by means of a conductor, such as the wire strap 236 which can be attached to a threaded protrusion 237 of connector 234 by a corresponding fastener 238.
FIG. 5 shows a modified embodiment 210' having conductive cables 236' which connect to elements 224 internally of container 216 and extend externally through openings 239. As shown in FIG. 5, the lower surface 221 of housing 216 can be provided with peel-off adhesive or other known permanent or removable bonding elements 240, for securing container 216, after size adjustment, to the top of battery 10'.
Those skilled in the art to which the invention relates will appreciate that other substitutions and modifications can be made to the described embodiment without departing from the spirit and scope of the invention as described by the claims below. | A standard automobile battery is modified to contain a set of retractable jumper cables, pre-attached to the positive and negative terminals of the battery. The cables are housed in a separate chamber formed either internally in a modified battery casing or externally in an auxiliary structure augmenting the usual casing. A bulb is connected across the cables to provide visual indication of good cable contact. Jumper clamps are made luminescent. | 16,747 |
FIELD OF THE INVENTION
[0001] This invention relates to image processing and particularly to a restoration of colour components in a system for storage or acquisition of digital images.
BACKGROUND OF THE INVENTION
[0002] Blurring or degradation of an image can be caused by various factors, e.g. out-of-focus optics, or any other aberrations that result from the use of a wide-angle lens, or the combination of inadequate aperture value, focal length and lens positioning. During the image capture process, when long exposure times are used, the movement of the camera, or the imaged subject, can result in motion blurring of the picture. Also, when short exposure time is used, the number of photons being captured is reduced, this results in high noise levels, as well as poor contrast in the captured image.
[0003] Various methods for restoring images that contain defects, e.g. blurring, are known from related art. For example spatial error concealment techniques attempt to hide a defect by forming a good reconstruction of the missing or corrupted pixels. One of the methods is to find a mean of the pixels in an area surrounding the defect and to replace the defect with the mean pixel value. A requirement for the variance of the reconstruction can be added to equal the variance of the area around the defect.
[0004] Different interpolation methods can also be used for restoration. For example a bilinear interpolation can be applied to pixels on four corners of the defect rectangle. This makes a linear, smooth transition of pixel values across the defect area. Bilinear interpolation is defined by the pixel value being reconstructed, pixels at corners of the reconstructed pixel and a horizontal and vertical distance from the reconstructed pixel to the corner pixels. Another method is edge-sensitive nonlinear filtering, which interpolates missing samples in an image.
[0005] The defect block can be replaced also with the average of some of all of the surrounding blocks. One example is to use three blocks that are situated above the defect. Further there is a method called “best neighbours matching” which restores images by taking a sliding block the same size as the defect region and moves it through the image. At each position, except for ones where the sliding block overlaps the defect, the pixels around the border of the sliding block are placed in a vector. The pixel values around the border of the defect are placed in another vector and the mean squared error between them is computed. The defect region is then replaced by the block that has the lowest border-pixel.
[0006] The purpose of image restoration is to remove those degradations so that the restored images look as close as possible to the original scene. In general, if the degradation process is known; the restored image can be obtained as the inverse process of the degradation. Several methods to solve for this inverse mathematical problem are known from the prior art. However, most of these techniques do not consider the image reconstruction process in the modelling of the problem, and assume simplistic linear models. Typically, the solutions in implementations are quite complicated and computationally demanding.
[0007] The methods from related art are typically applied in restoration of images in high-end applications such as astronomy and medical imaging. Their use in consumer products is limited, due to the difficulty of quantifying the image gathering process and the typical complexity and computational power needed to implement these algorithms. Some of the approaches have been used in devices that have limited computational and memory resources. The methods from the related art are typically designed as a post-processing operation, which means that the restoration is applied to the image, after it has been acquired and stored. In a post-processing operation each colour component has a different point spread function that is an important criteria that can be used to evaluate the performance of imaging systems. If the restoration is applied as post-processing, the information about the different blurring in each colour component is not relevant anymore. The exact modelling of the image acquisition process is more difficult and (in most cases) is not linear. So the “inverse” solution is less precise. Most often, the output of the digital cameras is compressed to .jpeg-format. If the restoration is applied after the compression (which is typically lossy), the result can amplify unwanted blocking artefacts.
SUMMARY OF THE INVENTION
[0008] The aim of this invention is to provide an improved way to restore images. This can be achieved by a method, a model, use of a model, a device, a module, a system, a program module and a computer program product.
[0009] According to present invention the method for forming a model for improving image quality of a digital image captured with an imaging module comprising at least imaging optics and an image sensor, where the image is formed through the imaging optics, said image consisting of at least one colour component, wherein degradation information of each colour component is found, an image degradation function is obtained and said each colour component is restored by said degradation function.
[0010] According to present invention also the model for improving image quality of a digital image is provided, said model being obtainable by a claimed method. According to the present invention also use of the model is provided.
[0011] Further according to present invention the method for improving image quality of a digital image captured with an imaging module comprising at least imaging optics and an image sensor is provided, where the image is formed through the imaging optics, said image consisting at least of one colour component, wherein degradation information of each colour component of the image is found, a degradation function is obtained according to the degradation information and said each colour component is restored by said degradation function.
[0012] Further according to present invention a system for determining a model for improving image quality of a digital image with an imaging module is provided, said module comprising at least imaging optics and an image sensor, where the image is formed through the imaging optics, said image consisting of at least one colour component, wherein the system comprises first means for finding degradation information of each colour component of the image, second means for obtaining a degradation function according to the degradation information, and third means for restoring said each colour component by said degradation function.
[0013] Further according to present invention the imaging module is provided, comprising imaging optics and an image sensor for forming an image through the imaging optics onto the light sensitive image sensor wherein a model for improving image quality is related to said imaging module. Further according to present invention a device comprising an imaging module is provided.
[0014] In addition, according to present invention the program module for improving an image quality in a device is provided, comprising an imaging module, said program module comprising means for finding degradation information of each colour component of the image, obtaining a degradation function according to the degradation information, and restoring said each colour component by said degradation function. Further the computer program product is provided, comprising instructions for finding degradation information of each colour component of the image, obtaining a degradation function according to the degradation information, and restoring said each colour component by said degradation function.
[0015] Other features of the invention are described in appended dependent claims.
[0016] In the description a term “first image model” corresponds to such an image, which is already captured with an image sensor, such as a CCD (Charged Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), but not processed in any way. The first image model is raw image data. The second image model is the one for which a degradation information has been determined. It will be appreciated that other sensor types, other than CMOS or CCD can be used with the invention.
[0017] The first image model is used for determining the blurring of the image, and the second image model is restored according to the invention. The restoration can also be regulated according to the invention. After these steps have been done, other image reconstruction functions can be applied to it. If considering the whole image reconstruction chain, the idea of the invention is to apply the restoration as a pre-processing operation, whereby the following image reconstruction operations will benefit from the restoration. Applying the restoration as a pre-processing operation means that the restoration algorithm is targeted directly to the raw colour image data and in such a manner, that each colour component is handled separately.
[0018] With the invention the blurring caused by optics can be reduced significantly. The procedure is particularly effective if fixed focal length optics is used. The invention is also applicable to varying focal length systems, in which case the processing considers several deblurring functions from a look-up table depending on the focal position of the lenses. The deblurring function can also be obtained through interpolation from look-up tables. One possibility to define the deblurring function is to use continuous calculation, in which focal length is used as a parameter to deblurring function. The resulting images are sharper and have better spatial resolution. It is worth mentioning that the proposed processing is different from traditional sharpening algorithms, which can also result in sharper images with amplified high-frequencies. In fact, this invention presents a method to revert the degradation process and to minimize blurring, which is caused e.g. by optic, whereas the sharpening algorithms use generic high-pass filters to add artefacts to an image in order to make it look sharper.
[0019] The model according to the invention is more viable for different types of sensors that can be applied in future products (because of better fidelity to the linear image formation model). In the current approach, the following steps and algorithms of the image reconstruction chain benefit from the increased resolution and contrast of solution.
[0020] Applying the image restoration as a pre-processing operation may minimize non-linearities that are accumulated in the image capturing process. The invention also may prevent over-amplification of colour information.
[0021] The invention can also be applied for restoration of video.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention is illustrated with reference to examples in accompanying drawings and following description.
[0023] FIG. 1 illustrates an example of the system according to the invention,
[0024] FIG. 2 illustrates another example of the system according to the invention,
[0025] FIG. 3 illustrates an example of a device according to the invention, and
[0026] FIG. 4 illustrates an example of an arrangement according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The description of the restoration of images according to the invention can be targeted to three main points, wherein at first the blur degradation function is determined, e.g. by measuring a point-spread function (PSF) for at least one raw colour component. Secondly, a restoration algorithm is designed for at least one raw colour component. Thirdly, a regularization mechanism can be integrated to moderate the effect of high pass filtering. In the description the optics in mobile devices are used as an example, because they may generally be limited to a wide focus range. It will, however, be apparent to the man skilled in the art, that the mobile devices are not the only suitable devices. For example the invention can be utilized by digital cameras, web cameras or similar devices, as well as by high end applications. The aim of this algorithm is to undo or attenuate a degradation process (blurring) resulting from the optics. Due to the algorithm the resulting images becomes sharper and have an improved resolution.
[0028] Wherever a term “colour component” is used, it relates to various colour systems. The example in this invention is RGB-system (red, green, blue), but a person skilled in the art will appreciate other systems such as HSV (Hue, Saturation, Value) or CMYK (Cyan, Magenta, Yellow, Black) etc.
[0029] The image model in the spatial domain can be described as:
g i ( m,n )= h i ( u,v )* f i ( m,n )+ n i ( m,n ) (1)
where g i is a measured colour component image, f i is an original colour component, h i is a corresponding linear blurring in the colour component and n i is an additive noise term. g i , f i , n i are defined over an array of pixels (m, n) spanning the image area, whereas h i is defined on the pixels (u, v) spanning blurring (point-spread function) support. The index i={1, 2, 3, 4} denotes respectively the data concerning colour components, such as red, green 1, blue and green 2 colour components. The invention is described in more detail by means of FIGS. 1 and 2 each illustrating a block diagram of the image restoration system according to the invention.
Blur Specification
[0030] The procedure for estimating the degradation ( FIG. 1, 110 ) in the image that has been captured by an optical element ( 100 ) is described next. As can be seen in FIG. 2 , the degradation can be estimated by means of the point-spread function 210 corresponding to the blur in three colour channels (in this example R, G, B) (raw data). The point-spread functions are used to show different characteristics for each colour channel. The point-spread function is an important criterion that can be used to evaluate the performance of imaging systems.
[0031] The point-spread function changes as a function of the wavelength and the position in the camera field of view. Because of that, finding a good point-spread function may be difficult. In the description an out-of-focus close range imaging and a space invariant blurring are assumed. The practical procedure for estimating the point-spread function (h i ) that is associated with each colour component, can also be used as stand-alone application to help in the evaluation process of camera systems.
[0032] Given a blurred image corresponding to one colour component of a checker-board pattern, the four outer corner points are located manually, and first a rough estimate of the corner positions is determined. The exact locations (at subpixel accuracy) are recalculated again by refining the search within a square window of e.g. 10×10 pixels. Using those corner points, an approximation for the original grid image f i can be reconstructed by averaging the central parts of each square and by asserting a constant luminance value to those squares.
[0033] The point-spread function is assumed to be space invariant, whereby the blur can be calculated through a pseudo-inverse filtering method (e.g. in Fourier domain). Since the pseudo-inverse technique is quite sensitive to noise, a frequency low-pass filter can be used to limit the noise and the procedure can be applied with several images to obtain an average estimate of the point-spread function. (The normalized cut-off frequency of the mentioned low pass filter is around 0.6, but at least any value from 0.4 to 0.9 may be applicable).
[0034] In order to quantify the extent of blur that occurs with each colour channel, a simple statistics is defined, which statistics is determined as a mean of the weighted distance from the centre of the function (in pixels), said weight corresponding to the value of the normalized point-spread function at that point:
S psf ( h i ) = M 1 N 1 ∑ m , n h i ( m , n ) ∑ m = 0 M 1 ∑ n = 0 N 1 ( m 2 + n 2 ) h i ( m , n ) ( 2 )
wherein M 1 and N 1 are the support of the point-spread function filter. S psf describes the extent of the blurring. Experiments confirm that the channels have different blurring patterns. For example when studying Mirage-1 camera, the obtained S psf values were:
S psf ( h i ) = { 5 , 42 i = 1 ( red ) 5 , 01 i = 2 ( green ) 4 , 46 i = 3 ( blue )
[0035] It can be seen from the results, that the red component was most blurred and noisy, whereby the least blurred was the blue component, which also had the least contrast.
[0000] Restoration Algorithm
[0036] The data concerning colour components is measured by a sensor 120 e.g. by Bayer sensor 220 (in FIG. 2 ), like a CMOS or CCD sensor. The colour component can be red (R), green 1 (G 1 ) blue (B) and green 2 (G 2 ) colour components as illustrated in FIG. 2 . Each of these colour “images” is quarter size of the final output image.
[0037] The second image model is provided for to be restored ( 130 ; 250 ). The images are arranged lexicographically into vectors, and the point-spread function h i is arranged into a block-Toeplitz circulant matrix H i . The second image model is then expressed as:
{overscore (g)} i =H i {overscore (ƒ)} i +{overscore (η)} i (3)
[0038] Having a reasonable approximation of H i the purpose of image restoration is to recover the best estimate {overscore (ƒ)} i from the degraded observation {overscore (g)} i . The blurring function H i is non-invertible (it is already defined on a limited support, so its inverse will have infinite support), so a direct inverse solution is not possible. The classical direct approach to solving the problem considers minimizing the energy between input and simulated re-blurred image, this is given by the norm:
J LS =∥{overscore (g)} i −H i {overscore ({circumflex over (ƒ)})} i ∥ 2 (4)
thus providing a least squares fit to the data. The minimization of the norm also leads to the solution of the maximum-likelihood, when the noise is known to be Gaussian. It also leads to the generalized inverse filter, which is given by:
( H T H ) {overscore ({circumflex over (ƒ)})} i =H T {overscore (g)} i (5)
[0039] In order to solve for this, it is common to use deterministic iterative techniques with the method of successive approximations, which leads to following iteration:
f _ ^ i ( 0 ) = μ H T g _ i
f _ ^ i ( k + 1 ) = f _ ^ i ( k ) + μ H T ( g _ i - f _ ^ i ( k ) ) ( 6 )
This iteration converges, if
0 < μ < 2 λ max ,
where λ max is the largest eigenvalue of the matrix H T H. The iteration continues until the normalized change in energy becomes quite small.
[0040] It can be seen from FIGS. 1 and 2 that the restoration ( 130 ; 250 ) is made separately for each of the colour components R, G, B.
[0041] The main advantages of iterative techniques are that there is no need to explicitly implement the inverse of the blurring operator and that the restoration process could be monitored as it progresses.
[0042] The last squares can be extended to classical least squares (CLS) technique. When spoken theoretically, the problem of image restoration is ill-posed, i.e. a small perturbation in the output, for example noise, can result in an unbounded perturbation of the direct least squares solution that is presented above. For this reason, the constrained least squares method is usually considered in the literatures. These algorithms minimize the term in equation (4) subject to the (smoothness) regularization term, which consists of a high-pass filtered version of the output. The regularization term permits the inclusion of prior information about the image.
[0000] Regularization Mechanism
[0043] In practise, the image sensor electronics, such as CCD and CMOS sensors, may introduce non-linearities to the image, of which the saturation is one of the most serious. Due to non-linearities unaccounted for in the image formation model, the separate processing of the colour channels might result in serious false colouring around the edges. Hence the invention introduces an improved regularization mechanism ( FIG. 2 ; 240 ) to be applied to restoration. The pixel areas being saturated or under-exposed are used to devise a smoothly varying coefficient that moderates the effect of high-pass filtering in the surrounding areas. The formulation of the image acquisition process is invariably assumed to be a linear one (1). Due to the sensitivity difference of the three colour channels, and fuzzy exposure controls, pixel saturation can happen incoherently in each of the colour channels. The separate channel restoration near those saturated areas results in over-amplification in that colour component alone, thus creating artificial colour mismatch and false colouring near those regions. To avoid this, a regularization mechanism according to the invention is proposed. The regularization mechanism is integrated in the iterative solution of equation (6). The idea is to spatially adapt μ in order to limit the restoration effect near saturated areas. The adapted step size is given as follows:
μ adap ( m,n )=β sat ( u, m )μ (9)
where μ is the global step-size as discussed earlier, and β sat is the local saturation control that modulates the step size. β sat is obtained using the following algorithm:
for each colour channel image g i , i={1 . . . 4}, consider the values of the window (w x w ) surrounding the pixel location g i (m, n), count the number of saturated pixels S i (m,n) in that window. The saturation control is given by the following equation:
β sat (m, n)=max(0,( w 2 −Σ i=1 4 S i ( m, n ))/ w 2 ).
β sat varies between 0 and 1 depending on the number of saturated pixels in any of the colour channels.
Image Reconstruction Chain
[0048] The previous description of the restoration of each of the colour component is applied as the first operation in the image reconstruction chain. The other operations ( 140 , 260 ) will follow such as for example Automatic White Balance, Colour Filter Array Interpolation (CFAI), Colour gamut conversion, Geometrical distortion and shading correction, Noise reduction, Sharpening. It will be appreciated that the final image quality ( 270 ) may depend on the effective and optimized use of all these operations in the reconstruction chain. One of the most effective implementations of the image reconstruction algorithms are non-linear. In FIG. 1 the image processing continues e.g. with image compression ( 150 ) or/and downsampling/dithering ( 160 ) process. Image can be viewed ( 180 ) by camera viewfinder or display or be stored ( 170 ) in compressed form in the memory.
[0049] The use of restoration as the first operation in the reconstruction chain ensures the best fidelity to be assumed linear imaging model. The following algorithms, especially the colour filter array interpolation and the noise reduction algorithms act as an additional regularization mechanism to prevent over amplification due to excessive restoration.
[0000] Implementation
[0050] The system according to the invention can be arranged into a device such as a mobile terminal, a web cam, a digital camera or other digital device for imaging. The system can be a part of digital signal processing in camera module to be installed into one of said devices. One example of the device is an imaging mobile terminal as illustrated as a simplified block chart in FIG. 3 . The device 300 comprises optics 310 or a similar device for capturing images that can operatively communicate with the optics or a digital camera for capturing images. The device 300 can also comprise a communication means 320 having a transmitter 321 and a receiver 322 . There can also be other communicating means 380 having a transmitter 381 and a receiver 382 . The first communicating means 320 can be adapted for telecommunication and the other communicating means 380 can be a kind of short-range communicating means, such as a Bluetooth™ system, a WLAN system (Wireless Local Area Network) or other system which suits local use and for communicating with another device. The device 300 according to the FIG. 3 also comprises a display 340 for displaying visual information. In addition the device 300 comprises a keypad 350 for inputting data, for controlling the image capturing process etc. The device 300 can also comprise audio means 360 , such as an earphone 361 and a microphone 362 and optionally a codec for coding (and decoding, if needed) the audio information. The device 300 also comprises a control unit 330 for controlling functions in the device 300 , such as the restoration algorithm according to the invention. The control unit 330 may comprise one or more processors (CPU, DSP). The device further comprises memory 370 for storing data, programs etc.
[0051] The imaging module according to the invention comprises imaging optics and image sensor and means for finding degradation information of each colour component and using said degradation information for determining a degradation function, and further means for restoring said each colour component by said degradation function. This imaging module can be arranged into the device being described previously. The imaging module can be also arranged into a stand-alone device 410 , as illustrated in FIG. 4 , communicating with an imaging device 400 and with a displaying device, which displaying device can be also said imaging device 400 or some other device, like a personal computer. Said stand-alone device 410 comprises a restoration module 411 and optionally other imaging module 412 and it can be used for image reconstruction independently. The communication between the imaging device 400 and the stand-alone device 410 can be handled by a wired or wireless network. Examples of such networks are Internet, WLAN, Bluetooth, etc.
[0052] The foregoing detailed description is provided for clearness of understanding only, and not necessarily limitation should be read therefrom into the claims herein. | This invention relates to a method for improving image quality of a digital image captured with an imaging module comprising at least imaging optics and an image sensor, where the image is formed through the imaging optics, the image consisting of at least one colour component. In the method degradation information of each colour component of the image is found and is used for obtaining a degradation function. Each colour component is restored by said degradation function. The image is unprocessed image data, and the degradation information of each colour component can be found by a point-spread function. The invention also relates to a device, to a module, to a system and to a computer program product and to a program module. | 28,051 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a divisional application of U.S. patent application Ser. No. 12/518,274, filed Jan. 13, 2010 (Jan. 13, 2010), now U.S. Pat. No. 8,819,989, issued Sep. 2, 2014 (Sep. 2, 2014), which claims priority to U.S. Utility patent application Ser. No. 11/452,034, filed on Jun. 12, 2006 (Jun. 12, 2006), all of which applications are incorporated in their entirety by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a gelatinous substrate for controllably delivering water and nutrients to plant tissue such as the root ball of a living plant.
[0004] 2. Background Discussion
[0005] The commercial product DRiWATER Gel (“DriWATER”) embodies U.S. Pat. No. 4,865,640 (“the '640 patent”), the entire specification of which is incorporated herein. The product has been used throughout the world for the past several years and has successfully provided users with a time-released water delivery product for plants. DRiWATER is a carboxymethylcellulose crosslinked polymer comprised of 97.85% water, 2.0% sodium carboxymethylcellulose (“CMC”), and 0.15% aluminum sulfate. When mixed together in a high sheer mixer, cross linkage between the carboxylic acid groups of the carboxymethylcellulose compound and aluminum in aluminum sulfate traps the water in a heavy gel stabilizing at a final viscosity of 45,000+ centipoises.
[0006] The time release feature of the commercially available product results from the action of micro-organisms that utilize the gel as a food source. The gel is eventually degraded by microorganisms to yield free water. Cellulose degrading microorganisms can be found in all soil types and produce enzymes for breakdown of cellulose. This technology can be thought of as a slow release method for watering plants. DRiWATER has also be used to control the rate of water release so as to not over-water any plant species. The DRiWATER product would be more beneficial to plants if it provided some value other than watering alone such as increasing roots. An increase in the root mass will result in more growth, better appearance, and improve nutrition uptake by plants. The DRiWATER Gel is packaged in cartons, cups, synthetic casing or any other suitable container that can be partially or totally opened for application in close proximity to the rhyzosphere of the plant.
[0007] Plants need 18 elements for normal growth. Carbon, hydrogen and oxygen are found in air and water. Nitrogen, phosphorus, potassium, magnesium, calcium and sulfur and carbon are found in the soil. The above mentioned elements are referred to as “macronutrients” by those skilled in the art because plants use these elements in large amounts. The nine other elements that are used in much smaller amounts are referred to as “micro-nutrients” or “trace elements” and are found in the soil. These nine micro-nutrients are iron, zinc, molybdenum, nickel, manganese, boron, copper, cobalt and chlorine. All 18 elements, both macro-nutrients and micro-nutrients are essential for plant growth. In most locations, it is likely that there are sufficient macro-nutrients in the soil that are not readily available to the plants due to a zinc deficiency.
[0008] It is a fact that the soils in at least 42 of the 48 contiguous states are deficient in zinc. Plant growth is enhanced when zinc is added. The importance of zinc for crop production has been recognized for many years. Zinc deficiency has many symptoms including; stunted growth, light green areas between the veins of new leaves, smaller leaves, shortened internodes, and broad white bands on each side of the midrib in corn and grain sorghum. Zinc is essential to many enzyme systems in plants with three main functions including catalytic, co-catalytic, and structural integrity. Zinc contributes in the production of important growth regulators that affect photosynthesis, new growth, and the development of roots. Zinc promotes the cell growth needed for increasing root development and extended root systems—improving nutrient uptake, formation of new leaves and vigorous shoot growth, more even maturity, and improved stress tolerance. If zinc is in short supply, plant utilization of other plant nutrients such as nitrogen will decrease. When zinc is deficient in soils, only small amounts are needed if placed close to the rhizospere at planting. It would therefore be advantageous to provide DRiWATER with zinc. It is a known fact that, if you mix sodium bicarbonate or any other highly alkaline product with citric acid or any other powdered acid and then add water, the result will be a violent chemical reaction. The chemical reaction neutralizes the PH and therefore will have no effect on plant material.
[0009] It would be further advantageous in many instances, if the dry ingredients of the present invention could be shipped to the end user for their mixing at the point of application. However due to the hydroscopic nature of the dry ingredients, it has not been possible to get good cross linkage without the use of a high sheer mixer. The fact that the present invention is 96 to 99% water makes it very expensive to ship.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to a substrate which releases impregnated water, gas, and nutrients when interacting with biological organisms comprising a mixture of a cellulosic compound ranging from 0.6 to 3% by weight of the water to be used, having an average molecular weight ranging between 90,000 and 700,000 represented by the formula: R—O—COOM in which “M” is a metal substituted for hydrogen on said carboxyl group of the cellulose compound and “R” is cellulosic chain, a hydrated metallic salt ranging from 0.1% to 0.3% by weight of the weight of water being used, water ranging from 96.0% to 99.5% by weight, a micro-nutrient selected from the group consisting of zinc and zinc salts, the concentration of zinc ranging from 0.006% to 0.72% by weight of the weight of water being used, at least one plant growth additive selected from the group consisting of plant growth hormones and plant growth regulators ranging from 0.00001% to 0.0003% by weight of the weight of water being used, at least one preservative selected from the group consisting of sodium benzoate, potassium sorbate, and acetic acid ranging from 0.01% to 0.3% by weight of the weight of water being used, a surfactant ranging from 0.0025% to 0.006% by weight of the weight of water being used, and an acetic acid component selected from the group consisting of acetic acid or acetic acid salts, the concentration of acetate ranging from 0.1% to 0.48% by weight of the weight of water being used.
[0011] The invention is also directed to a method of providing water, gas, and nutrients to a plant in soil at a predetermined, time release rate comprising placing a substrate in the soil, the substrate comprising a mixture of a cellulosic compound ranging from 1 to 3% by weight including glucose units and having a molecular weight ranging between 90,000 and 700,000 represented by the formula: R—O—CH2-COOM where “M” is a metal substituted on said glucose units of the cellulose compound and “R” is a cellulose chain, a hydrated metallic salt ranging from 0.1% to 0.03% by weight, water ranging from 96.0% to 99.5% by weight, a micro-nutrient selected from the group consisting of zinc and zinc salts, the concentration of zinc ranging from 0.006% to 0.72% by weight of the weight of water being used, at least one plant growth additive selected from the group consisting of plant growth hormones and plant growth regulators ranging from 0.00001% to 0.0003% by weight of the weight of water being used, at least one preservative selected from the group consisting of sodium benzoate, potassium sorbate, and acetic acid ranging from 0.01% to 0.3% by weight of the weight of water being used, a surfactant ranging from 0.0025% to 0.006% by weight of the weight of water being used, and an acetic acid component selected from the group consisting of acetic acid or acetic acid salts, the concentration of acetate ranging from 0.1% to 0.48% by weight of the weight of water being used, and placing the plant roots in the vicinity of the substrate.
[0012] The present invention relates to the DRiWATER moisturizing substrate for controllably delivering water, micro-nutrients such as zinc, macro-nutrients, plant growth additives (including plant growth hormones and plant growth regulators), preservatives, and surfactants to the plant in the same manner to the entire vertical root system of a plant. It would appear to be obvious to anyone of ordinary skill in the art, that adding macro-nutrients and micro-nutrients to the DRiWATER Gel would be beneficial to the plants. However, zinc is a divalent cation (when in an aqueous solution depending on pH) and would therefore interfere with cross linkage between the cellulose compound and the aluminum in aluminum sulfate causing the effect of an unstable viscosity. For example, the addition of fertilizer components, without the addition of the ionic counter-balancing chemicals, will destroy the gel cross-linkage and destabilize the gel viscosity or in some cases liquefy the gel entirely. Therefore the composition as well as the rate at which zinc is put into the gel system with ionic counter balancing chemicals is rate sensitive. A combination of zinc sulfate and acetic acid were incorporated into the DRiWATER gel at a rate of 0.167% (weight/weight) zinc sulfate and 0.07% (weight/weight) acetic acid. Scientific experiments have shown this combination of zinc sulfate and acetic acid in DRiWATER yielded the greatest increase in rooting of pepper plants, an increase of 208% to 283% greater root mass than treatments with original DRiWATER.
[0013] Furthermore, as discussed above, preliminary experiments have shown that the addition of plant growth additives, preservatives, and surfactants has negatively affected the viscosity of the DRiWATER gel. These compounds also must be incorporated at exact rates so as to not destabilize the viscosity. The compounds must also be in specific mathematically calculated mole equivalents of each other to prevent destabilization of the DRiWATER gel. Further, this principle is hormone/nutrient selective, meaning that some hormones/nutrients cannot be incorporated at all because they destroy gel cross-linkage. It should also be noted that each compound requires a specific balancing/countering chemical component. That is, the specific hormone/nutrient combination for each hormone/nutrient is selective and acts chemically different then every other hormone/nutrient. Therefore each hormone/nutrient requires a different balancing/countering chemical component.
[0014] One embodiment of the present invention is further directed to control the liquefaction rate of DRiWATER plus nutrients based on factors other than the degree of exposure to micro-organisms. The surface area exposed to the micro-organisms in the soil controls liquefaction rate of DRiWATER. The greater the surface area exposed, the faster the DRiWATER Gel will liquefy.
[0015] One embodiment of the present invention relates to the addition of Sodium Bicarbonate, or any other highly alkaline material and citric acid, or any other powdered acid to the other dry ingredients mentioned above. Sodium Bicarbonate ranging from 0.15 to 0.33% and citric acid ranging from 0.22 to 0.44% were added to the above mentioned formulations with the exception of acetic acid. The above percentages are by weight of the weight of the water to be added at point of application.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 is a graph showing viscosity changes resulting from the addition of zinc sulfate and acetic acid to the gel, according to one embodiment of the present invention.
[0017] FIG. 2 is a diagram of a plant treated with original DriWATER, according to one embodiment of the present invention.
[0018] FIG. 3 is a diagram of a plant treated with DRiWATER plus 0.167% (w/w) zinc sulfate and 0.07% (w/w) acetic acid, according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present invention is directed to the distribution of the DRiWATER gelatinous moisturizing substrate for controllably delivering water, micro-nutrients, macro-nutrients, plant growth additives, preservatives, and surfactants to plant tissue such as the entire vertical root system of a plant. The present invention delivers water and the aforementioned nutrition to plants, thus enhancing plant development and growth at a pre-determined rate for a pre-determined period of time and providing the desired maintenance for plants.
[0020] It is commonly known that the addition of nutrients, and hormones to plants improve plant growth. For example, many micro-nutrients can be found in most standard fertilizers, but must be in an ionic form (most elements ionize in water) to be taken up by the plant. In traditional watering, nutrients were provided to plants by mixing fertilizers and nutrients with water and pouring or dripping the mixture around a plant. However, any excess water and fertilizer that the soil was unable to retain will eventually ended up in underground aquifers.
[0021] It is the object of this invention to controllably delivering water, micro-nutrients, macro-nutrients, plant growth additives, preservatives, and surfactants to plant tissue via the DRiWATER gel. However, preliminary experiments demonstrated that the addition of most nutrients and hormones negatively affect the viscosity of the DRiWATER gel, causing the DRiWATER gel to function improperly. The present invention is directed to incorporating a rooting compound into DRiWATER without destabilizing the gel's viscosity.
[0022] Without wanting to be limited to any one theory, it is believed that the compositions of the present application help to promote the cell growth needed for extended root systems, formation of new leaves, vigorous shoot growth, more even maturity, and improved stress tolerance.
[0023] All percentages, ratios and proportions herein are by weight of the composition, unless otherwise specified. All temperatures are in degrees Celsius (° C.) unless otherwise specified. All documents cited are incorporated herein by reference in their entireties. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention.
[0024] As previously stated, the importance of zinc for crop production has been recognized for many years. Zinc is essential to many enzyme systems in plants with three main functions including catalytic, co-catalytic, and structural integrity. For example, in the plant, the plant growth hormone, indole-3-acetic acid (IAA)(anion in aqueous solution depending on pH), is a naturally occurring auxin. It also occurs in many bacteria, fungi, and algae. IAA regulates cellular elongation, phototropism, geotropism, apical dominance, root initiation, ethylene production, fruit development, parthenocaarpy, abscission, and sex expression, all of which are necessary for normal plant growth. To maintain plants normal growth, IAA must be produced and regulated by the plant. Zinc is a co-factor in the transformation of the amino acid tryptophan to the auxin IAA. Adding zinc will help maintain IAA levels in the plant and promote growth, rooting, and health.
[0025] The selection of zinc sulfate as the source of zinc was based on scientific literature. Many sources of zinc have been tested to see which compound would be utilized more efficiently by plant species. Zinc sulfate is the most readily available form for plants. Zinc sulfate also contains a sulfate ion. The sulfate ion (SO 4 2− ) is a beneficial nutrient and naturally occurring in soils. Sulfur is used to bind amino acids together by sulfide bridging to create enzymes and proteins, the building blocks of life.
[0026] Research indicates that the presence of acetic acid will improve uptake of minerals. Acetic acid is also known as a preservative and will aid in preserving the gel's viscosity as well as help protect the gel from microorganism degradation. It is essential to note that without the correct molar combination of the zinc sulfate and acetic acid components, the gel viscosity will dramatically decrease or increase to the point at which it would provide little or no benefit for any plant species.
[0027] The following experiment was conducted to illustrate that zinc sulfate and acetic acid were formed to stimulate the greatest root growth and is not intended to be in any way limiting of the invention, as many variations thereof are possible without departing from the spirit and scope of the invention:
Experiment Methods and Materials.
[0028] Materials: Sodium carboxymethylcellulose (CMC), aluminum, preservatives, surfactants, zinc sulfate heptahydrate, acetic acid and pure water. It is noted that when preparing the substrate, the concentration of water may range between 96.0% to 99.5% by weight.
[0029] Aluminum, preservatives, surfactants, zinc sulfate heptahydrate, and acetic acid were poured into 400 mL beaker and were mixed for approximately 20 minutes or until all solids were dissolved. The solution was then poured into a 10 speed Osterizer blender (6) and set to “Ice Crush”, with a maximum output of 450 watts. The blade speed was 1100 RPM.
[0030] CMC was then poured into the blender. CMC was added at a consistent rate over 15 seconds while the blender was mixing. Mixing was continued for an additional 70 seconds, for a total mix time of 85 seconds. Approximately 300 mL of gel were formed and a viscosity reading was taken approximately 15 minutes after formation to allow gel to cool to room temperature. The gel volume measured was of approximately 200 mL in a 250 mL beaker analyzed with a Brookfield HADV-II+ viscometer. The viscosity was measured in units of centipoises (cP) to ensure the gels stability. Nine oz. of the gel were then weighed and inserted into a plastic casing to limit air exposure and contamination. The gel was then allowed to stabilize in plastic casings for a minimum of 3 days to achieve a viscosity that represents that of the consumer product. Five different formulated gels labeled Gel 1 through Gel 5 were made. Each gel formulation was tested using 3 replications of each. The original DRiWATER gel was used as the control (3 replications).
[0031] Anaheim peppers were planted in a defined native Arizona soil grown for approximately three weeks. Anaheim pepper plants used were selected to be of similar height and stem size for the tests.
[0032] Approximately 12-15 centimeter slit was made on each gel casing. Each gel casing was opened slightly to expose the gel to soil. Exposed gel in the casing was laid on the soil in which the Anaheim pepper plants were growing. Each plant was watered thoroughly on first day of treatment.
[0033] No watering was done for a period of 30 days. Plants were grown in a greenhouse with an approximate daily temperature of 65° F. Observations were made daily. On day 30 of the experiment, Plants were removed from soil. Roots were cleaned and pictures were taken. Then plants were cut at the cotyledonary nodes and the fresh weight of the root mass and hypocotyls were measured. Plants were then cut at the crown of roots and the fresh weight of the root mass was measured. Fresh weight was measured and compared for all formulations.
[0034] Results and Observations
[0000]
TABLE 1
Formulations
Ingredient
Percent by weight (%)
Grams (g)
Gel 1
CMC
1.997
5.990
Alum
0.150
0.449
Sodium Benzoate
0.040
0.120
Potassium Sorbate
0.040
0.120
Zinc Sulfate
0.056
0.168
Acetic Acid
0.023
0.070
Water
97.690
293.071
RA-2
0.005
0.0150
Total Weight
100.001
300
Gel 2
CMC
1.995
5.986
Alum
0.150
0.449
Sodium Benzoate
0.040
0.120
Potassium Sorbate
0.040
0.120
Zinc Sulfate
0.112
0.335
Acetic Acid
0.047
0.140
Water
97.613
292.839
RA-2
0.005
0.015
Total Weight
100.001
300
*Gel 3
CMC
1.994
5.981
Alum
0.150
0.449
Sodium Benzoate
0.040
0.120
Potassium Sorbate
0.040
0.120
Zinc Sulfate
0.167
0.502
Acetic Acid
0.070
0.210
Water
97.536
292.607
RA-2
0.005
0.015
Total Weight
100.001
300
Gel 4
CMC
1.992
5.976
Alum
0.149
0.448
Sodium Benzoate
0.040
0.120
Potassium Sorbate
0.040
0.120
Zinc Sulfate
0.223
0.669
Acetic Acid
0.093
0.279
Water
97.459
292.376
RA-2
0.005
0.015
Total Weight
100.001
300
Gel 5
CMC
1.990
5.971
Alum
0.149
0.448
Sodium Benzoate
0.040
0.119
Potassium Sorbate
0.040
0.119
Zinc Sulfate
0.278
0.835
Acetic Acid
0.116
0.349
Water
97.382
292.145
RA-2
0.005
0.015
Total Weight
100.001
300
Control
CMC
1.998
5.04
Alum
0.150
0.378
Sodium Benzoate
0.040
0.1008
Potassium Sorbate
0.040
0.1008
Zinc Sulfate
0.000
0
Acetic Acid
0.000
0
Water
97.767
246.58
RA-2
0.005
0.0126
Total Weight
100.000
252.2122
*Bold Asterisk represents best results.
[0000]
TABLE 2
Average Gel pH and Viscosity
Average
Standard
Zn-sulfate
Acetic Acid
gel Viscosity
Deviation
Average
Gel #
% (w/w)
% (w/w)
(cP)
(cP)
gel pH
1
0.056
0.023
12829.91
608.81
5.28
2
0.112
0.047
16614.11
777.26
5.13
*3
0.167
0.07
17700
843.15
5.08
4
0.223
0.093
20470.83
905.34
4.95
5
0.278
0.116
24297.65
1134.79
4.9
Control
0
0
0
N/A
N/A
*Bold asterisk represents best results.
[0000]
TABLE 3
Soil pH Values after 30 days of DRiWATER treatment
pH of soil after
Average pH of soil
Plant #
Trial
gel treatment
after gel treatment
Std. Dev. pH
Control 1
1
7.15
7.00
0.13
2
6.91
3
6.94
1
1
7.06
6.76
0.36
2
6.37
3
6.86
2
1
6.9
6.82
0.09
2
6.73
3
6.83
*3
1
6.56
6.52
0.08
2
6.43
3
6.56
4
1
6.81
6.63
0.16
2
6.6
3
6.49
5
1
6.74
6.59
0.16
2
6.42
3
6.6
The pH of the native soil prior to testing was 5.8.
*Bold asterisk represents best results.
[0000]
TABLE 4
Fresh weight roots and hypocotyls
Increased % of
Fresh Root Weight of
Average Fresh Root
root/hypocotyl
Plant
roots and hypocotyls
Weight of roots and
Std. Dev.
compared to
Treatment
Repetition
Grams (g)
hypocotyls Grams (g)
Grams (g)
control
Control
1
0.516
0.620
0.090
N/A
2
0.677
0.620
0.090
N/A
3
0.667
0.620
0.090
N/A
gel 1
1
0.253
0.399
0.131
64.355
2
0.505
0.399
0.131
64.355
3
0.439
0.399
0.131
64.355
gel 2
1
0.949
1.009
0.128
162.742
2
0.922
1.009
0.128
162.742
3
1.156
1.009
0.128
162.742
*gel 3
1
1.447
1.287
0.339
207.634
2
0.898
1.287
0.339
207.634
3
1.517
1.287
0.339
207.634
gel 4
1
0.997
0.863
0.126
139.194
2
0.846
0.863
0.126
139.194
3
0.746
0.863
0.126
139.194
gel 5
1
0.447
1.198
0.650
193.172
2
1.592
1.198
0.650
193.172
3
1.554
1.198
0.650
193.172
*Bold asterisk represents best results.
[0000]
TABLE 5
Fresh weight of roots
Average
Fresh
Fresh
Increased
Weight
Weight
% of roots
Plant
of roots
of roots
Std. Dev.
compared to
Treatment
Repetition
Grams (g)
Grams (g)
Grams (g)
control
Control
1
0.186
0.271
0.074
N/A
2
0.305
0.271
0.074
N/A
3
0.323
0.271
0.074
N/A
gel 1
1
0.132
0.193
0.056
71.341
2
0.242
0.193
0.056
71.341
3
0.206
0.193
0.056
71.341
gel 2
1
0.544
0.523
0.043
193.112
2
0.474
0.523
0.043
193.112
3
0.552
0.523
0.043
193.112
*gel 3
1
0.892
0.769
0.244
283.764
2
0.488
0.769
0.244
283.764
3
0.927
0.769
0.244
283.764
gel 4
1
0.552
0.448
0.101
165.191
2
0.441
0.448
0.101
165.191
3
0.35
0.448
0.101
165.191
gel 5
1
0.203
0.715
0.450
263.838
2
0.892
0.715
0.450
263.838
3
1.05
0.715
0.450
263.838
The Data stated in Table 4 and Table 5 was taken immediately after the Anaheim peppers were removed from the soil.
*Bold asterisk represents best results
[0035] The results of this experiment confirm that although the addition of nutrients, fertilizers, and hormones to DRiWATER would be beneficial to plants, the addition of most nutrients and hormones negatively affect the viscosity of the DRiWATER gel (see FIG. 1 ). The objective of the experiment was to incorporate a rooting compound into DRiWATER without destabilizing the gel's viscosity. The experiment has shown that the combination of zinc sulfate and acetic acid in DRiWATER yielded the greatest increase in rooting of pepper plants—an increase of 208% to 283% (see Table 4, Table 5, and FIG. 3 ) if delivered in the proper rates. There was greater root mass than treatments with original DRiWATER, which lacked the aforementioned nutrients (see Table 4, Table 5, and FIG. 2 .). This demonstrates that the optimum rate for rooting with acetic acid and zinc sulfate was established with a concentration of 0.167% zinc sulfate and 0.07% acetic.
[0036] As previously discussed, the present invention is directed to the distribution of the DRiWATER gelatinous moisturizing substrate for controllably delivering water and nutrients to plant tissue. For example, some elements and micro/macro nutrients found in fertilizers can be incorporated into the DRiWATER Gel, but only with the addition of specialized chemicals used to counteract the viscosity reducing elements. The addition of nutrients to DRiWATER, without destroying the viscosity of the gel, would be beneficial to plants. The following nutrients may be combined with DRiWATER at the disclosed percentage combinations to maintain gel viscosity and provide optimum results to the plant.
[0037] For example, as previously discussed, a well known plant hormone is the auxin IAA. Other auxins include, but are not limited to IBA, NAA, 2,4-D, 2,4-DB, etc. IAA is a naturally occurring auxin known to improve rooting and protect against high salt activity. Because enzymes and light degrade this auxin it is impractical to work with. However, indole-3-butyric acid (“IBA”) (anion or cation in aqueous solution depending on pH) has been established in the plant world as a compound that mimics IAA in many ways. The difference is that IBA is practical to work with and will not easily degrade. As further discussed in the experiment below, IBA concentration at a range of 0.00001% to 0.0003% by weight of the weight of the water being used improves rooting and protect against high salt activity of the plant, while not destroying the viscosity of the DRiWATER gel.
[0038] Cytokinins (kinetin, zeatin, etc.,) are another well known group of plant hormones that are growth regulators. More specifically, kinetin aids in cell division in various plants and in yeast. Kinetin (anion or cation in aqueous solution depending on pH) is known to increase cell division and delay senescence in plants, but only in the presence of auxin. Therefore it would be beneficial to include an auxin with kinetin in formulation. As futher discussed in the experiment below, kinetin concentration at a range of 0.00001% to 0.0001% by weight of the weight of water being used increases cell division and delay senescence of the plant, while not destroying the viscosity of the DRiWATER gel.
[0039] Gibberellic Acid (“GA3”) (anion in aqueous solution depending on pH) is the most outstanding of the plant growth promoting metabolites in a group of plant hormones called gibberellins (GA3, GA4, GA7, etc.). Gibberellic acid is especially beneficial for new seedling growth and promoting germination of seeds. All of the above mentioned hormones are very active in physiologically low rates and although they are beneficial independently, in combination they have an additive, or in some cases a synergistic effect. As further discussed in the experiment below, GA3 concentration at a range of 0.00001% to 0.0003% by weight of the weight of water being used improves seedling growth and germination of seeds while not destroying the viscosity of the DRiWATER gel.
[0040] It is perceived that in this invention, auxins other than IBA, gibberellic acid composed of other gibberellins, and cytokinins other than kinetin can be used, as long as the concentration does not destroy the viscocity of the DRiWATER gel.
[0041] As previously stated, preservatives aid in preserving the DRiWATER gel's viscosity as well as help protect the gel from microorganism degradation. Preservatives can be selected from sodium benzoate, potassium sorbate, and acetic acid, but are not specifically limited to the above. Research at the DRiWATER lab has demonstrated that acetic acid will slow gel degradion in soil. This is done by acetic acid acting as a preservative. This is another desirable characteristic of the above additions. By adding preservatives to the composition of the present invention, such as sodium benzoate and potassium sorbate, but not limited to these preservatives, the liquefaction rate can be further regulated. A combination of two preservatives is required: one to control mold, one to control bacterial activity although there may be some activity of each to the sets of microorganisms. The concentration of each preservative can range from 0.01% to 0.3% of the weight of water being used while not destroying the viscosity of the DRiWATER gel
[0042] By adding a surfactant to the composition of the present invention, such as sodium sesquicarbonate, but not limited to this surfactant, water penetration into the soil is improved. The surfactant can be sodium sesquicarbonate or any other environmentally friendly surfactant that is compatible. The surfactant concentration at a range from 0.0005% to 0.005% of the weight of the weight of water being used improves seedling growth and germination of seeds while not destroying the viscosity of the DRiWATER gel.
[0043] An example of the invention is set forth hereinafter by way of illustration and is not intended to be in any way limiting of the invention, as many variations thereof are possible without departing from the spirit and scope of the invention.
Example 1
[0044] As an example, the present invention composition according to the preferred embodiment can comprise: 246.58 g water, 5.04 g sodium carboxymethylcellulose, 0.378 g aluminum sulfate, 0.1008 g sodium benzoate, 0.1008 g potassium sorbate, 0.423 g zinc sulfate, 0.0015 mg of other plant growth regulators and 0.0126 g sodium sesquicarbonate. This formulation combination yields one 9 oz. gelpac of DRiWATER with zinc acetate, plant growth regulators, preservatives, and surfactant added. The preferred embodiment of the present invention comprises a mixture of the following by percent weight: 97.6% water, 2.0% sodium CMC, 0.15% aluminum sulfate, 0.04% sodium benzoate, 0.04% potassium sorbate, 0.237% zinc acetate, 0.00009% kinetin, 0.00004% IBA, 0.00003% GA3 and 0.005% sodium sesquicarbonate. The DRiWATER Gel with zinc, acetic acid, plant growth regulators, preservatives and surfactant is advantageous because it waters, provides nutrition, and promotes plant development and growth on a continual time release basis and improves water penetration into the soil. The amount and type of zinc, acetic acid, and other plant growth regulators may vary dependent on the requirements of a particular plant species.
[0045] Table 1 lists examples of the present invention according to different embodiments.
[0000]
Sodium
Potassium
Growth
CMC
Alum
Benzoate
Sorbate
Zinc Acetate
Regulators
Surfactant
(gal)
(lbs)
(lbs)
(lbs)
(lbs)
(lbs)
(oz)
(lbs)
2,500
400
30
4
4
14
0.5
1
2,500
200
20
2
2
32
1.0
0.5
2,500
132
13.2
6
6
48
1.5
0.1
2,500
300
25
8
8
32
0.75
0.75
2,500
350
27.5
2
2
48
0.90
0.90
[0046] For example, Gibberellic Acid (GA3) regulates growth; application of very low concentration can have a profound effect. Indole-3-Butyric Acid is especially effective for initiating roots of both stems and leaves.
[0047] Although the process, composition and methods of the present invention have been described with reference to specific exemplary embodiments, it will be evident to those of ordinary skill in this art that various modifications and changes may be made to these embodiments without departing from the scope of the invention as set forth in the claims. Accordingly, the specification is to be regarded as illustrative and not restrictive.
[0048] According to one embodiment, the present invention provides a method of delivering the dry ingredients to the point of application and adding the water at that time. The dry ingredients were placed in the desired size container in exact proportions. Citric Acid and Sodium Bicarbonate were added, in dry form, in specific amounts in relation to the dry ingredients. The ingredients were blended by shaking the container. Water was added in proportion to the dry ingredients. The chemical reaction between the Sodium Bicarbonate and the citric acid blended the ingredients and formed a semi firm gel. This method works well for volumes up to one quart/liter which is a good size for application. According to this embodiment of the present invention, adding Sodium Bicarbonate and citric acid to the method of composition may provide a way to transport the present invention as dry ingredients. One will appreciate that actual ingredient percentages will vary dependent on the desire gel. The following chart of materials and percentage variations.
[0000]
Sodium
Potassium
Zinc
Growth
Citric
Sodium
CMC
Alum
Benzoate
Sorbate
Sulfate
Regulators
Surfactant
Acid
Bicarbonate
0.06--3%
0.1-0.3%
0.01-0.3%
0.01-0.3%
.006-.72%
0.00001-0.0003%
0.0025-0.006
.22-.44%
0.15-0.33% | The present invention relates to a gelatinous moisturing substrate for controllably delivering water and oxygen to the root zone of growing plants with micro nutrients, auxins, preservatives and surfactants added comprising a mixture, by percent weight, 97.6%, 2.0% carboxy methol cellulose, 0.15% aluminum sulfate, 0.04% sodium benzoate, 0.04% potassium sorbate, 0.0167% zinc sulfate (22.23% zinc), 0.07% acetic acid (99%.0 pure) and 0.005% sodium sesquicarbonate. The composition maintains substrates viscosity. As a result, the moisturing agent releases water, oxygen and the added nutrients, preservatives and surfactant into the root zone of the growing plant at a controlled rate. | 59,144 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation application of U.S. application Ser. No. 12/276,035 filed Nov. 21, 2008, now U.S. Pat. No. 8,050,777 issued Nov. 1, 2011, which is a continuation of U.S. application Ser. No. 10/913,023 filed Aug. 6, 2004, now U.S. Pat. No. 7,457,670 issued Nov. 25, 2008, which claims the benefit of prior U.S. Provisional Application Ser. No. 60/493,531, filed Aug. 7, 2003 and entitled “Gobo Virtual Machine.”
BACKGROUND
Stage lighting effects have become increasingly complex, and are increasingly handled using more and more computing power. During a show, commands for various lights are often produced by a console which controls the overall show. The console has a number of encoders and controls which may be used to control any number of lights.
Complex effects may be controlled by the console. Typically each effect is individual for each light that is controlled.
SUMMARY
The present system teaches an apparatus in which a computer produces an output which is adapted for driving a projector according to commands produced by a console that controls multiple lights. The projector produces the light according to the commands entered on the console.
According to an aspect, certain commands are in a special generic form which enables them to be processed by many different computers.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects will now be described in detail with reference to the accompanying drawings, wherein:
FIG. 1 shows a block diagram of the overall system;
FIG. 2 shows a block diagram of the connection between the console and the box;
FIG. 3 shows a combination of multiple layers forming a final displayed image; and
FIG. 4 shows the way that the code can be compiled for a special kind of processor.
DETAILED DESCRIPTION
The output of the console 100 may be in various different formats, including DMX 512 , or ethernet. The console 100 may be an ICON™ console. This console produces a number of outputs 110 , 114 to respectively control a number of lighting units 112 , 116 . Console is shown producing output 110 to control light 112 . Similarly, output 114 may be produced to control light 116 .
Another output 120 may be produced to control a digital light shape altering device. Such a light may be the icon M, aspects of which are described, for example, in U.S. Pat. Nos. 6,549,326, 6,617,792, 6,736,528. In this embodiment, however, the output 120 which is intended for the light is actually sent to a computer 130 which runs software to form an image according to commands from the console. The computer 130 produces an output 135 which may be a standard video output. The video output 135 may be further processed according to a dimmer 140 . The output of the dimmer is connected to a projector 150 . The projector may be, for example, a projector using digital mirror devices or DMD's.
The projector produces output according to its conventional way of producing output. However, this is based on the control 120 which is produced by the console.
In the embodiment, the computer 130 may actually be a bank of multiple computers, which respectively produce multiple outputs for multiple projectors 150 , 151 , 152 . FIG. 2 shows further detail about the connection between the console and the computer. The output of the console may be in any network format. In this embodiment, the output of the console may be in ethernet format, containing information that is directed to three different channels.
The computer 130 is actually a standalone half-height rack, on wheels, with three rack-mounted computers therein. The ethernet output 120 is coupled to an ethernet hub 125 which directs the output to each of the three computers. The three computers are shown as computer 1 ; designation 200 , computer 2 ; designation 202 , and computer 3 ; designation 204 . Each of these computers may be standard computers having keyboard input and display outputs. The outputs of each of the computers are connected to the interface board 140 .
Board 140 produces and outputs a first dimmed output 145 adapted for connection to the projector. The second, typically non-dimmed output 210 is connected to a three-way KVM switch. Each of the three computers have outputs which are coupled to the KVM switch. The KVM switch produces a single output representative of the selected computer output.
A single rack-mounted keyboard and monitor are located within the rack and driven by the KVM switch. The keyboard 220 is also connected to the KVM switch 230 , and produces its output to the selected computer. For example, when computer 3 is selected, the KVM switch sends the output from keyboard 222 to computer 3 and the output from computer 3 is sent to display 225 .
Any type of switch can be used, however standard KVM switches are typically available. Moreover, while this embodiment describes three different computers being used, there is practically no limit on the number of computers that can share input and output with a KVM switch.
The dimmer board may carry out dimming by multiplying each video output by analog values supplied by the associated computer. Moreover, the KVM switch is shown outside of the rack for simplicity, but in reality the KVM switch is rack-mounted within the rack.
As described above, the console produces a signal for each of many lights. That signal represents the desired effect. Different kinds of effects that can be produced may be described herein. The computer which actually does the image processing to form the desired result requested by the console. The computer processes the signal by receiving the command, converting that command into an image which forms a layer, and combining the multiple layers to form an overall image to be displayed by the projector/lamp.
The final image is formed by combining a plurality of layers. Each layer can have a number of different characteristics, but primarily, each layer may be considered to have a shape, a color, and/or an effect. The layers are combined such that each layer covers, adds to, subtracts, or allows transparency, to a layer below it.
An example of the operation is shown in FIG. 3 . FIG. 3 shows a first layer 300 which is an animation of clouds. The animation is continuous, so that the user sees the effect of traveling through those clouds.
Layer 2 is overlaid on the layer one. Layer 2 is shown as 310 , and corresponds to a rectangle which is rotating in a clockwise direction at a specified speed. In this layer, the perimeter area 312 is effectively black and opaque, while the interior area 314 is clear. Accordingly, as this layer is superimposed over the other layer, the area 314 allows the animation of layer 1 to show through, but the area 312 blocks the animation from showing through. The resultant image is shown as 330 , with the rotating triangle 314 being transparent and showing portions of the cloud animation 300 through it. A third layer 320 is also shown, which simply includes an orange circle 322 in its center. In the resultant image 330 , the orange circle 322 forms an orange filter over the portion of the scene which is showing.
Each layer can have a number of different effects, besides the effects noted above. An incomplete list of effects is:
color
shape
intensity
timing
rotation
Parameters associated with any of these effects can be specified. For example, parameters of rotation can be selected including the speed of rotation, the direction of rotation, and the center of rotation. One special effect is obtained by selecting a center of rotation that is actually off axis of the displayed scene. Other effects include scaling
Blocking (also called subtractive, allowing defining a hole and seeing through the hole).
Color filtering (changing the color of any layer or any part of any layer).
Decay (which is a trailing effect, in which as an image moves, images produced at previous times are not immediately erased, but rather fade away over time giving a trailing effect).
Timing of decay (effectively the time during which the effect is removed).
A movie can also be produced and operations can include
coloring the movie
scaling the movie
dimming of the image of the movie
Shake of the image, in which the image is moved up and down or back-and-forth in a specified shaking motion based on a random number. Since the motion is random, this gives the effect of a noisy shaking operation.
Wobble of the image, which is effectively a sinusoidal motion of the image in a specified direction. For wobble of the image, different parameters can be controlled, including speed of the wobble.
Forced redraw—this is a technique where at specified intervals, a command is given to produce an all-black screen. This forces the processor to redraw the entire image.
Other effects are also possible.
The computer may operate according to the flowchart of FIG. 4 . The image itself is produced based on information that is received from the console, over the link 120 . Each console command is typically made up of a number of layers. At 400 , the data indicative of these multiple layers is formed.
Note that this system is extremely complex. This will require the computer to carry out multiple different kinds of highly computation-intensive operations. The operations may include, but are not limited to, playing of an animation, rotating an image, (which may consist of forming the image as a matrix arithmetic version of the image, and rotating the matrix), and other complicated image processes. In addition, however, all processors have different ways of rendering images.
In order to obtain better performance, the code for these systems has been highly individualized to a specified processor. For example, much of this operation was done on Apple processors, and the code was individualized to an Apple G4 processor. This can create difficulties, however, when new generations of processors become available. The developers are then given a choice between creating the code, and buying outdated equipment.
According to this system, the code which forms the layers is compiled for a specified real or hypothetical processor which does all of the operations that are necessary to carry out all of the image processing operations. Each processor, such as the processor 200 , effectively runs an interpreter which interprets the compiled code according to a prewritten routine. In an embodiment, a hypothetical processor may be an Apple G4 processor, and all processors are provided with a code decompilation tool which enables operating based on this compiled code. Notably, the processor has access to the open GL drawing environment which enables the processor to produce the image. However, in this way, any processor is capable of executing the code which is produced. This code may be compiled versions of any of the effects noted above.
Although only a few embodiments have been disclosed in detail above, other modifications are possible. All such modifications are intended to be encompassed within the following claims. | Producing complicated effects based on image processing operations. The image processing operations are defined for a processor which may be different than the processor which is actually used. The processor that is actually used runs an interpreter that interprets the information into its own language, and then runs the image processing. The actual information is formed according to a plurality of layers which are combined in some way so that each layer can effect the layers below it. Layers may add to, subtract from, or form transparency to the layer below it or make color filtering the layer below it. This enables many different effects computed and precompiled for a hypothetical processor, and a different processor can be used to combine and render those effects. | 11,551 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 10/240,367, filed on Oct. 30, 2002, a 35 U.S.C. §371 National Stage of International Application Number PCT/GR01/00017 filed on Mar. 28, 2001. U.S. application Ser. No. 10/240,367 claims priority to Greek National Application Serial No. 20000100102, filed on Mar. 28, 2000 and to U.S. National application Ser. No. 09/739,089 filed on Dec. 15, 2000.
FIELD OF THE INVENTION
[0002] The present invention is directed to a method and apparatus for the in vivo, non-invasive detection and mapping of the biochemical and/or functional pathologic alterations of human tissues.
BACKGROUND OF THE INVENTION
[0003] Cancer precursor signs are the so-called pre-cancerous states, which are often curable if they are detected at an early stage. If left untreated, the pre-cancerous state can develop into invasive cancer, which can subsequently metastasize. At this stage, the possibilities of successful therapy are dramatically diminished. Consequently, the early detection and the objective identification of the severity of the pre-cancerous state are of crucial importance.
[0004] Conventional methods that utilize optical instruments are very limited in their ability to detect cancerous and pre-cancerous tissue lesions. This is due to the fact that the structural and metabolic changes, which take place during the development of the disease, do not significantly and specifically alter the spectral characteristics of the pathological tissue.
[0005] In order to obtain a more accurate diagnosis, biopsy samples are obtained from suspicious areas, which are submitted for histological examination. However, biopsies pose several problems, such as a) a risk for sampling errors associated with the visual limitations in detecting and localizing suspicious areas; b) a biopsy can alter the natural history of the intraepithelial lesion; c) mapping and monitoring of the lesion require multiple tissue sampling, which is subjected to several risks and limitations; and d) the diagnostic procedure performed with biopsy sampling and histologic evaluation is qualitative, subjective, time consuming, costly and labor intensive.
[0006] In recent years, a few methods and systems have been developed to overcome the disadvantages of the conventional diagnostic procedures. These methods can be classified into two categories: a) methods which are based on the spectral analysis of tissues in vivo, in an attempt to improve the diagnostic information, and b) methods which are based on the chemical excitation of tissues with the aid of special agents, which can interact with pathologic tissue and alter its optical characteristics selectively, thus enhancing the contrast between lesion and healthy tissue.
[0007] In the first case, the experimental use of spectroscopic techniques has been motivated by the ability of these techniques to detect alterations in the biochemical and/or the structural characteristics of tissue as the disease progresses. In particular, fluorescence spectroscopy has been extensively used in various tissues. With the aid of a light source (usually laser) of short wave length (blue-ultraviolet range), the tissue is first excited. Next, the intensity of the fluorescent light emitted by the tissue as a function of the wavelength of the light is measured.
[0008] Garfield and Glassman in No. U.S. Pat. No. 5,450,857 and Ramanajum et al. in U.S. Pat. No. 5,421,339 have presented a method based on the use of fluorescence spectroscopy for the diagnosis of cancerous and pre-cancerous lesions of the cervix. The main disadvantage of fluorescence spectroscopy is that the existing biochemical modifications associated with the progress of the disease are not manifested in a direct way as modifications in the measured fluorescence spectra. The fluorescence spectra contain limited diagnostic information for two basic reasons: a) Tissues contain non-fluorescent chromophores, such as hemoglobin. Absorption by such chromophores of the emitted light from fluorophores can result in artificial dips and peaks in the fluorescence spectra. In other words the spectra carry convoluted information for several components and therefore it is difficult assess alterations in tissue features of diagnostic importance; and b) The spectra are broad because a large number of tissue components are optically excited and contribute to the measured optical signal. As a result, the spectra do not carry specific information of the pathologic alterations and thus they are of limited diagnostic value. In short, the aforementioned fluorescent technique suffers from low sensitivity and specificity in the detection and classification of tissue lesions.
[0009] Aiming to enhance the sensitivity and specificity of the preceding method, Ramanujan et al. in the Patent No. WO 98/24369 have presented a method based on the use of neural networks for the analysis of the spectral data. This method is based on the training of a computing system with a large number of spectral patterns, which have been taken from normal and from pathologic tissues. The spectrum that is measured each time is compared with the stored spectral data, facilitating in this way the identification of the tissue pathology.
[0010] R. R. Kortun et al, in U.S. Pat. No. 5,697,373, seeking to improve the quality of the measured diagnostic information, have presented a method based on the combination of fluorescence spectroscopy and Raman scattering. The latter has the ability of providing more analytical information; however, Raman spectroscopy requires complex instrumentation and ideal experimental conditions, which substantially hinders the clinical use thereof.
[0011] It is generally known that tissues are characterized by the lack of spatial homogeneity. Consequently the spectral analysis of distributed spatial points is insufficient for the characterization of their status.
[0012] Dombrowski in U.S. Pat. No. 5,424,543, describes a multi-wavelength, imaging system, capable of capturing tissue images in several spectral bands. With the aid of such a system it is possible in general to map characteristics of diagnostic importance based on their particular spectral characteristics. However, due to the insignificance of the spectral differences between normal and pathologic tissue, which is in general the case, inspection in narrow spectral bands does not allow the highlighting of these characteristics and even more so, the identification and staging of the pathologic area.
[0013] D. R. Sandison et al., in U.S. Pat. No. 5,920,399, describe an imaging system, developed for the in vivo investigation of cells, which combines multi-band imaging and light excitation of the tissue. The system also employs a dual fiber optic bundle for transmitting light from the source to the tissue, and then from the tissue to an optical detector. These bundles are placed in contact with the tissue, and various wavelengths of excitation and imaging are combined in attempt to enhance the spectral differentiation between normal and pathologic tissue.
[0014] In U.S. Pat. No. 5,921,926, J. R. Delfyett et al. have presented a method for the diagnosis of diseases of the cervix, which is based on the combination of Spectral Interferometry and Optical Coherence Tomography (OCT). This system combines three-dimensional imaging and spectral analysis of the tissue.
[0015] Moreover, several improved versions of colpo scopes have been presented, (D. R. Craine et al., U.S. Pat. No. 5,791,346 and K. L. Blaiz U.S. Pat. No. 5,989,184) in most of which, electronic imaging systems have been integrated for image capturing, analysis of tissue images, including the quantitative assessment of lesion's size.
[0016] For the enhancement of the optical differentiation between normal and pathologic tissue, special agents are used in various fields of biomedical diagnostics, which are administered topically or systematically. Such agents include acetic acid solution, toluidine blue, and various photosensitizers (porphyrines) (S. Anderson Engels, C. Klinteb erg, K. Svanberg, S. Svanberg, In vivo fluorescence imaging for tissue diagnostics, Phys Med. Biol. 42 (1997) 815-24). The selective staining of the pathologic tissue arises from the property of these agents to interact with the altered metabolic and structural characteristics of the pathologic area. This interaction enhances progressively and reversibly the differences in the spectral characteristics of reflection and/or fluorescence between normal and pathologic tissue. Despite the fact that the selective staining of the pathologic tissue is a dynamic phenomenon, in clinical practice the intensity and the extent of the staining are assessed qualitatively and statically.
[0017] Furthermore, in several cases of early pathologic conditions, the phenomenon of temporary staining after administering the agent, is short-lasting and thus the examiner is not able to detect the alterations and even more so, to assess their intensity and extent. In other cases, the staining of the tissue progresses very slowly, resulting in patient discomfort and the creation of problems for the examiner in assessing the intensity and extent of the alterations, since they are continuously changing. The above have as direct consequence the downgrading of the diagnostic value of these diagnostic procedures. Thus, their usefulness is limited to facilitating the localization of suspected areas for obtaining biopsy samples.
[0018] Summarizing the above, the following conclusions are drawn:
[0019] a) Various conventional light dispersion spectroscopic techniques (fluorescence, elastic, non-elastic scattering, etc.) have been proposed and experimentally used for the in vivo detection of alterations in the structural characteristics of pathologic tissue. The main disadvantage of these techniques is that they provide point information, which is inadequate for the analysis of the spatially non-homogenous tissue. Multi-band imaging has the potential to solve this problem by providing spectral information, of lesser resolution as a rule, in any spatial point of the area under examination. These imaging and non-imaging techniques, however, provide information of limited diagnostic value because the structural tissue alterations, which accompany the development of the disease, are not manifested as significant and characteristic alterations in the measured spectra. Consequently, the captured spectral information cannot be directly correlated with the tissue pathology, a fact that limits the clinical usefulness of these techniques.
[0020] b) The conventional (non-spectral) imaging techniques provide the capability of mapping characteristics of diagnostic importance in two or three dimensions. They are basically used for measuring morphological characteristics and as clinical documentation tools.
[0021] c) The diagnostic methods that are based on the selective staining of pathologic tissue with special agents allow the enhancement of the optical contrast between normal and pathologic tissue. Nevertheless they provide limited information for the in vivo identification and staging of the disease.
[0022] The selective interaction of pathologic tissue with the agents, which enhance the optical contrast with healthy tissue, is a dynamic phenomenon. It is therefore reasonable to suggest that the measurement and analysis of kinetic properties could provide important information for the in vivo detection, identification and staging of tissue lesions. In a previous publication, in which one of the inventors is a co-author, (C. Balas, A. Dimoka, E. Orfanoudalci, E. koumandakis, “In vivo assessment of acetic acid-cervical tissue interaction using quantitative imaging of back-scattered light: Its potential use for the in vivo cervical cancer detection grading and mapping”, SPIEOptical Biopsies and Microscopic Techniques, Vol. 3568 pp. 31-37, (1998)), measurements of the alterations in the characteristics of the back-scattered light as a function of wave-length and time are presented. These alterations occur in the cervix by the topical administration of acetic acid solution. In this particular case, a general-purpose multi-spectral imaging system built around a tunable liquid crystal monochromator was used for measuring the variations in intensity of the back-scattered light as a function of time and wavelength at selected spatial points. It was found that the lineshapes of curves of intensity of back-scattered light versus time provide advanced information for the direct identification and staging of tissue neoplasias. Unpublished results of the same research team indicate that similar results can also be obtained with other agents, which have the property of enhancing the optical contrast between normal and pathologic tissue. Nevertheless, the experimental method employed in the published paper is characterized by quite a few disadvantages, such as: The imaging monochromator requires time for changing the imaging wavelength and as a consequence it is inappropriate for multispectral imaging and analysis of dynamic phenomena. It does not constitute a method for the mapping of the grade of the tissue lesions, as the presented curves illustrate the temporal alterations of intensity of the back-scattered light in selected points. The lack of data modeling and parametric analysis of kinetics data in any spatial point of the area of interest restricts the usefulness of the method in experimental studies and hinders its clinical implementation. The optics used for the imaging of the area of interest is of general purpose and does not comply with the special technical requirements for the clinical implementation of the method. Clinical implementation of the presented system is also hindered by the fact that it does not integrate appropriate means for ensuring the stability of the relative position between the tissue surface and image capturing module during the snapshot imaging procedure. This is very important since small movements of the patient (i.e. breathing) are always present during the examination procedure. If, after the application of the agent, micro-movements occur while an image is being recorded, then the spatial features of the captured images may not be accurate. This may substantially reduce the accuracy of the calculation of the curves in any spatial point that express the kinetics of marker-tissue interaction.
SUMMARY OF THE INVENTION
[0023] The present invention provides a method for monitoring the effects of a pathology-differentiating agent on a tissue sample. The method includes applying a pathology differentiating agent, e.g., acetic acid, on a tissue sample and measuring a spectral property, such as an emission spectrum, of the tissue sample over time, thereby monitoring the effects of a pathology differentiating agent on a tissue sample. The tissue may be a sample from: the cervix of the uterus, the vagina, the skin, the uterus, the gastrointestinal track or the respiratory track. Without intending to be limited by theory, it is believed that the pathology-differentiating agent induces transient alterations in the light scattering properties of the tissue, e.g, the abnormal epithelium.
[0024] In another aspect, the present invention features a method for the in vivo diagnosis of a tissue abnormality, e.g., a tissue atypia, a tissue dysplasia, a tissue neoplasia (such as a cervical intraepithelial neoplasia, CINI, CINII, CINIII) condylomas or cancer, in a subject. The method includes applying a pathology differentiating agent, e.g., an acetic acid solution or a combination of solutions selected from a plurality of acidic and basic solutions, to a tissue. The method further includes exposing the tissue in the subject to optical radiation, and monitoring the intensity of light emitted from the tissue over time, thereby diagnosing a tissue abnormality in a subject. The optical radiation may be broad band optical radiation, preferably polarized optical radiation.
[0025] The non-invasive methods of the present invention are useful for in vivo early detection of tissue abnormalities/alterations. The methods are also useful for mapping the grade of abnormalities/alterations in epithelial tissues during the development of tissue atypias, dysplasias, neoplasias and cancers.
[0026] In one embodiment, the tissue area of interest is illuminated with a broad band optical radiation and contacted with a pathology differentiating agent, e.g., an agent or a combination of agents which interact with pathologic tissue areas characterized by an altered biochemical composition and/or cellular functionality and provoke a transient alteration in the characteristics of the light that is re-emitted from the tissue. The light that is re-emitted from the tissue may be in the form of reflection, diffuse scattering, fluorescence or combinations or subcombinations thereof. The intensity of the light emitted from the tissue may be measured, e.g., simultaneously, in every spatial point of the tissue area of interest, at a given time point or over time (e.g., for the duration of agent-tissue interaction). A diagnosis may be made based on the quantitative assessment of the spatial distribution of alterations in the characteristics of the light re-emitted from the tissue at given time points before and after the optical and chemical excitation of the tissue. The diagnosis may also be made based on the spatial distribution of parameters calculated from kinetics curves obtained from the light re-emitted from the tissue. These curves are simultaneously measured in every spatial point of the area under examination during the optical and chemical excitation of the tissue.
[0027] In one embodiment of the invention, the step of tissue illumination comprises exposing the tissue area under analysis to optical radiation of narrower spectral width than the spectral width of the light emitted by the illumination source. In another embodiment, the step of measuring the intensity of light comprises measuring the intensity of the re-emitted light in a spectral band, the spectral width of which is narrower than the spectral width of the detector's sensitivity. In yet another embodiment, the step of measuring the intensity of light comprises measuring simultaneously the intensity of the re-emitted light in a plurality of spectral bands, the spectral widths of which are narrower than the spectral width of the detector's sensitivity.
[0028] In yet another aspect, the present invention features an apparatus for the in vivo, non-invasive early detection of tissue abnormalities/alterations and mapping of the grade of these tissue abnormalities/alterations caused in the biochemical and/or in the functional characteristics of epithelial tissues, during the development of tissue atypias, dysplasias, neoplasias and cancers. The apparatus includes optics for collecting the light re-emitted by the area under analysis, selecting magnification and focusing the image of the area. The apparatus may also include optical imaging detector(s), means for the modulation, transfer, display and capturing of the image of the tissue area of interest. In addition, the apparatus can include a computer, which has data storage, processing and analysis means, a monitor for displaying images, curves and numerical data, optics for the optical multiplication of the image of the tissue area of interest, and a light source for illuminating the area of interest. The apparatus may also include optical filters for selecting the spectral band of imaging and illumination, means for transmitting light and illuminating the area of interest, control electronics, and optionally, software for the analysis and processing of data. The software can help with the tissue image capturing and storing in specific time points and for a plurality of time points, before and after administration of the pathology-differentiating agent.
[0029] Using the foregoing apparatus, an image or a series of images may be created which express the spatial distribution of the characteristics of the kinetics of the induced alterations in the tissue's optical characteristics, before and after the administration of the agent. Pixel values of the image correspond to the spatial distribution of the alterations in the intensity of the light emitted from the tissue at given times, before and after the optical and chemical excitation of tissue. The spatial distribution of parameters may be associated with pixel gray values as a function of time. The foregoing function may be calculated from the measured and stored images and for each row of pixels with the same spatial coordinates.
[0030] In one embodiment, the step of optical filtering the imaging detector comprises an optical filter that is placed in the optical path of the rays that form the image of the tissue, for the recording of temporally successive images in a selected spectral band, the spectral width of which is narrower than the spectral width of the detector's sensitivity.
[0031] In yet another embodiment, the image multiplication optics includes light beam splitting optics that creates two identical images of the area of interest. The images are recorded by two imaging detectors, in front of which optical filters are placed. The filters are capable of transmitting light having a spectral width that is shorter than the spectral width of the detector's sensitivity, so that two groups of temporally successive images of the same tissue area are recorded simultaneously, each one corresponding to a different spectral band.
[0032] In another embodiment, the image multiplication optics include more than one beam splitter for the creation of multiple identical images of the area of interest. The images are recorded by multiple imaging detectors, in front of which optical filters are placed. The filters have different transmission characteristics and are capable of transmitting light of spectral width shorter than the spectral width of the detector's sensitivity. Thus, multiple groups of temporally successive images of the same tissue area are recorded simultaneously, each one corresponding to a different spectral band.
[0033] In a further embodiment, the image multiplication optics comprise one beam splitter for the creation of multiple identical images of the area of interest, which are recorded by multiple imaging detectors, in front of which optical filters are placed with, preferably, different transmission characteristics and capable of transmitting light of spectral width shorter than the spectral width of the detector's sensitivity, so that multiple groups of temporally successive images of the same tissue area are recorded simultaneously, each one corresponding to a different spectral band.
[0034] In yet a further embodiment, the image multiplication optics include one beam splitter for the creation of multiple identical images of the area of interest, which are recorded in different sub-areas of the same detector. Optical filters having different transmission characteristics are placed in the path of the split beams. The filters are capable of transmitting light of spectral width shorter than the spectral width of the detector's sensitivity. Multiple groups of temporally successive images of the same tissue area are recorded simultaneously in the different areas of the detector, each one corresponding to a different spectral band.
[0035] In another embodiment, the step of filtering the light source comprises an optical filter, which is placed in the optical path of an illumination light beam, and transmits light of spectral width shorter than the spectral width of sensitivity of the detector used.
[0036] In a further embodiment, the step of filtering the light source includes providing a plurality of optical filters and a mechanism for selecting the filter that is disposed in the path of the illumination light, thus enabling the tuning of the center wavelength and the spectral width of the light illuminating the tissue.
[0037] In another embodiment, the mapping of the grade of the alterations associated with the biochemical and/or functional characteristics of the tissue area of interest is based on the pixel values of one image from the group of the recorded temporally successive images of the tissue area of interest.
[0038] In a further embodiment, this mapping is based on the pixel values belonging to a plurality of images, which are members of the group of the recorded temporally successive images of the tissue area of interest.
[0039] In another embodiment, this mapping is based on numerical data derived from the pixel values belonging to a plurality of images, which are members of the group of the recorded temporally successive images of the tissue area of interest.
[0040] In a further embodiment, a pseudo-color scale, which represents with different colors the different pixel values of the image or of the images used for the mapping of abnormal tissue areas, is used for the visualization of the mapping.
[0041] In one embodiment, the image or images are used for the in vivo detection, and identification of the borders of epithelial lesions.
[0042] In another embodiment, the pixel values of the image or of the images, which are determined for the mapping of the grade of alterations in biochemical and/or functional characteristics of tissue, are used as diagnostic indices for the in vivo identification and staging of epithelial lesions.
[0043] In yet another embodiment, the image or the images can be superimposed on the color or black and white image of the same area of tissue under examination displayed on the monitor. Abnormal tissue areas are highlighted and their borders are demarcated, facilitating the selection of a representative area for taking a biopsy sample, the selective surgical removal of the abnormal area and the evaluation of the accuracy in selecting and removing the appropriate section of the tissue.
[0044] In a further embodiment, the image or the images which are determined for the mapping of the grade of alterations in biochemical and/or functional characteristics of tissue are used for the evaluation of the effectiveness of various therapeutic modalities such as radiotherapy, nuclear medicine treatments, pharmacological therapy, and chemotherapy.
[0045] In another embodiment, the optics for collecting the light re-emitted by the area under analysis includes optomechanical components employed in microscopes used in clinical diagnostic examinations, surgical microscopes, colposcopes and endoscopes.
[0046] In one embodiment of the invention directed to colposcopy applications, the apparatus may comprise a speculum, an articulated arm onto which the optical head is attached. The optical head includes a refractive objective lens, focusing optics, a mechanism for selecting the magnification, an eyepiece, a mount for attaching a camera, and an illuminator. The speculurn is attached so that the central longitudinal axis of the speculum is perpendicular to the central area of the objective lens. Thus, when the speculum is inserted into the vagina and fixed in it, the relative position of the image-capturing optics and of the tissue area of interest remain unaltered, regardless of micro-movements of the cervix, which are taking place during the examination of the female subject.
[0047] In a further embodiment, the apparatus may further comprise an atomizer for delivering the agent. The atomizer is attached to the articulated arm-optical head of the apparatus and in front of the vaginal opening, where the spraying of the tissue may be controlled and synchronized with a temporally successive image capturing procedure with the aid of electronic control means.
[0048] In another embodiment of the apparatus of the invention, the image capturing detector means and image display means include a camera system. The camera system has a detector with a spatial resolution greater than 1000×1000 pixels and a monitor of at least 17 inches (diagonal), so that high magnification is ensured together with a large field of view while the image quality is maintained.
[0049] In a further embodiment directed to microscopes used in clinical diagnostic examinations, surgical microscopes and colposcopes, a system includes an articulated arm onto which the optical head is attached. The optical head includes an objective lens, focusing optics, a mechanism for selecting the magnification, an eyepiece, a mount for attaching a camera, an illuminator and two linear polarizers. One linear polarizer is disposed in the optical path of the illuminating light beam and the other in the optical path of the rays that form the image of the tissue. The polarization planes of these polarizers may be rotated. When the planes are perpendicular to each other, the contribution of the tissue's surface reflection to the formed image is eliminated.
[0050] In another embodiment directed to endoscopy, an endoscope may include optical means for transferring light from the light source to the tissue surface. The optical means may also allow the collection and transferring of rays along substantially the same axis.
[0051] The optical means also allow the focusing of the rays that form the image of the tissue. The endoscope may also include two linear polarizers. One linear polarizer is disposed in the optical path of the illuminating light beam and the other in the optical path of the rays that form the image of the tissue. The polarization planes of these polarizers may be rotated. When the planes are perpendicular to each other, the contribution of the tissue's surface reflection to the formed image is eliminated.
[0052] In another embodiment, microscopes used in clinical diagnostic examinations, surgical microscopes and colposcopes may include a reflective objective lens that replaces a refractive lens. The reflective objective lens is contracted so that a second reflection mirror is disposed in the central part of its optical front aperture. In the rear, non-reflective part of this mirror, illumination means are attached from which light is emitted toward the object. With or without illumination zooming and focusing optics, the central ray of the emitted light cone is coaxial with the central ray of the light beam that enters the imaging lens. With the aid of illumination zooming and focusing optics, which may be adjusted simultaneously and automatically with the mechanism for varying the magnification of the optical imaging system, the illuminated area and the field-of-view of the imaging system can vary simultaneously and proportionally. Any decrease in image brightness caused by increasing the magnification is compensated with the simultaneous zooming and focusing of the illumination beam.
[0053] Other features and advantages of the invention will be apparent from the following detailed description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] FIG. 1 is a schematic representation of the present method's basic principle.
[0055] FIG. 2 , illustrates an embodiment of the invention comprising a method for capturing in two spectral bands simultaneously and in any spatial point of the area under analysis, the kinetics of the alterations in the characteristics of the remitted from the tissue light, before and the after the administration of the contrast enhancing agent
[0056] FIG. 3 illustrates another embodiment of the invention comprising a method for capturing in different spectral bands simultaneously and in any spatial point of the area under analysis, the kinetics of the alterations in the characteristics of the remitted from the tissue light, before and the after the administration of the contrast enhancing agent.
[0057] FIG. 4 illustrates a schematic diagram of a medical microscope comprising a light source (LS), a magnification selection mechanism (MS), an eyepiece (EP) and a mount for attaching the image capturing module (CA), (detector(s), readout electronics etc).
[0058] FIG. 5 illustrates an endoscope comprising an eyepiece (EP), which can be adapted to an electronic imaging system, optical fibers or crystals for the transmission of both illumination and image rays, optics for the linear polarization of light, one interposed to the optical path of the illumination rays (LE) and one to the path of the ray that form the optical image of the tissue (II).
[0059] FIG. 6 depicts a colposcopic apparatus comprising an articulated arm (AA), onto which the optical head (OH) is affixed, which includes a light source (LS), an objective lens (0133), an eye-piece (EP) and optics for selecting the magnification (MS).
[0060] FIG. 7 illustrates an optical imaging apparatus which comprises a light source located at the central part of its front-aperture.
DETAILED DESCRIPTION OF THE INVENTION
[0061] The present invention is directed to a method and system for the in vivo, noninvasive detection and mapping of the biochemical and or functional alterations of tissue, e.g., tissue within a subject. Upon selection of the appropriate pathology differentiating agent that enhances the optical contrast between normal and pathologic tissue (depending on the pathology of the tissue), this agent is administered, e.g., topically, to the tissue.
[0062] As used herein a pathology differentiating agent is any agent capable of altering the optical property of a tissue, e.g., an agent capable of altering the reflection characteristics or the fluorescence characteristics of a tissue. The pathology differentiating agent may be an acidic solution, a basic solution, a porphyrine solution or a porphyrine precursor solution. Preferred examples of a pathology differentiating agent for use in the methods of the invention include an acetic acid solution, e.g., a weak acetic acid solution, or 5-amino luvelinic acid.
[0063] In FIG. 1 , the tissue (T), is sprayed using an atomizer (A), which contains the agent, e.g., acetic acid. At the same time, the tissue is illuminated with a source that emits light having a frequency within a specific spectral band that depends on the optical characteristics of both the agent and the tissue. The characteristics of the light emitted from the source can be controlled by choosing particular sources (LS), and optical filters (OFS). Sources of light for illuminating the tissue include light emitting diodes, and lasers.
[0064] For imaging the area of interest, light collection optics (L) may be used, which focus the image onto a two-dimensional optical detector (D). The output signal of the latter is amplified, modulated and digitized with the aid of appropriate electronics (EIS) and finally the image is displayed on a monitor (M) and stored in the data-storing means of a personal computer (PC). Between tissue (T) and detector (D), optical filters (OFI) can be interposed. The filter can be interposed for tissue (T) imaging in selected spectral bands, at which the maximum contrast is obtained between areas that are subjected to different grade of alterations in their optical characteristics after administering the appropriate agent.
[0065] Before administration of the latter, images can be obtained and used as references. After the agent has been administered, the detector (D) helps to capture images of the tissue, in successive time instances, which are then stored in the computer's data-storage means. The measuring rate is proportional to the rate at which the tissue's optical characteristics are altered, following the administration of the agent.
[0066] As used herein, an optical property, P, is a property that arises from the interaction of electromagnetic waves and a material sample, e.g., a tissue, such as a tissue within a subject. For example, the property can be the intensity of light after it interacts with matter, as manifested by an absorption, emission, or Raman spectrum. A dynamic optical property is a property that is obtained from a time-dependent optical property, P(t), and is determined from the measurement of P(t) at more than one time. For example, a dynamical optical property can be a relaxation time, or a time integral of P(t).
[0067] In FIG. 1 , images of the same tissue area are schematically illustrated, which have been stored successively before and after administering the agent (STI). In these images, the black areas represent tissue areas that do not alter their optical characteristics (NAT), while the gray-white tones represent areas that alter their optical characteristics (AT), following the administration of the agent. The simultaneous capture of the intensity of the light re-emitted from every spatial point of the tissue area under analysis and in predetermined time instances, allows the calculation of the kinetics of the induced alterations.
[0068] In FIG. 1 , two curves are illustrated: pixel value at position xy (Pvxy), versus time t. The curve ATC corresponds to an area where agent administration induced alterations (AT) in the tissue's optical characteristics. The curve (NATC) corresponds to an area where no alteration took place (NAT).
[0069] Each pixel, (x,y), can be associated with a pixel value, such as intensity I, which generally depends on time. For example, at time ti and pixel (x,y), the pixel value can be denoted by PV xy (ti). One useful dynamical spectral property, which can be obtained by measuring pixel value versus time at a particular pixel (x,y), is the relaxation time t ret (x,y). Letting the maximum of a PV time curve be denoted by A, then t ret (x,y) satisfies PV xy (t ret )=A/e, where e is the base of the natural logarithm. For example, if the pixel value versus time curve can be approximated by an exponential with relaxation rate r, PV xy (t)=A exp(−rt), where r>0, then t rel (x,y)=1/r.
[0070] The calculation of these parameters (P) at every spatial point of the area under analysis allows kinetic information (KI) to be obtained, with pixel values that are correlated with these parameters. These values can be represented with a scale of pseudocolors (P min , P max ), the spatial distribution of which allows for immediate optical evaluation of the intensity and extent of the induced alterations. Depending on the correlation degree between the intensity and the extent of the induced alterations with the pathology and the stage of the tissue lesion, the measured quantitative data and the derived parameters allow the mapping, the characterization and the border-lining of the lesion. The pseudocolor image of the phenomenon's kinetics (KI), which expresses the spatial distribution of one or more parameters, can be superimposed (after being calculated) on the tissue image, which is displayed in real-time on the monitor. Using the superimposed image as a guide facilitates the identification of the lesion's boundaries, for successful surgical removal of the entire lesion, or for locating suspicious areas to obtain a biopsy sample(s). Furthermore, based on the correlation of the phenomenon's kinetics with the pathology of the tissue, the measured quantitative data and the parameters that derive from them can provide quantitative clinical indices for the in vivo staging of the lesion or of sub-areas of the latter.
[0071] In some cases it is necessary to capture the kinetics of the phenomenon in more than one spectral band. This can help in the in vivo determination of illumination and/or imaging spectral bands at which the maximum diagnostic signal is obtained. Furthermore, the simultaneous imaging in more than one spectral band can assist in minimizing the contribution of the unwanted endogenous scattering, fluorescence and reflection of the tissue, to the optical signal measured by the detector. The measured optical signal comprises the optical signal generated by the marker-tissue interaction and the light emitted from the endogenous components of the tissue. In many cases, the recorded response of the components of the tissue constitutes noise since it occludes the generated optical signal, which carries the diagnostic information. Therefore, separation of these signals, based on their particular spectral characteristics, results in the maximization of the signal-to-noise ratio and consequently in the improvement of the obtained diagnostic information.
[0072] FIG. 2 illustrates a method for measuring in two spectral bands simultaneously and in any spatial point of the area under analysis, the kinetics of the alterations in the characteristics of the light emitted from the tissue, before and the after the administration of the contrast enhancing agent. The light emitted from the tissue is collected and focused by the optical imaging module (L) and allowed to pass through a beam splitting (BSP) optical element. Thus, two identical images of the tissue (T) are generated, which can be captured by two detectors (D 1 , D 2 ). In front of the detector, appropriate optical filters (Of λ1 ), (Of λ2 ) can be placed, so that images with different spectral characteristics are captured. Besides beam splitters, optical filters, dichroic mirrors, etc., can also be used for splitting the image of the object. The detectors (D 1 ), (D 2 ) are synchronized so that they capture simultaneously the corresponding spectral images of the tissue (Ti λ1 ), (Ti λ2 ) and in successive time-intervals, which are stored in the computer's data storage means. Generalizing, multiple spectral images can be captured simultaneously by combining multiple splitting elements, filters and sources.
[0073] FIG. 3 illustrates another method for capturing in different spectral bands simultaneously and in any spatial point of the area under analysis, the kinetics of the alterations in the characteristics of the light emitted from the tissue, before and the after the administration of the contrast enhancing agent. With the aid of a special prism (MIP) and imaging optics, it is possible to form multiple copies of the same image onto the surface of the same detector (D). Various optical filters (OF λ1 ), (OF λ2 ), (OF λ3 ), and (OF λ4 ), can be interposed along the length of the optical path of the rays that form the copies of the object's image, so that the multiple images correspond to different spectral areas.
[0074] For the clinical use of the methods of the invention, the different implementations of imaging described above can be integrated to conventional optical imaging diagnostic devises. Such devises arc the various medical microscopes, colposcopes and endoscopes, which are routinely used for the in vivo diagnostic inspection of tissues. Imaging of internal tissues of the human body requires in most cases the illumination and imaging rays to travel along the same optical path, through the cavities of the body. As a result, in the common optical diagnostic devices the tissue's surface reflection contributes substantially to the formed image. This limits the imaging information for the subsurface characteristics, which is in general of great diagnostic importance. This problem becomes especially serious in epithelial tissues such as the cervix, larynx, and oral cavity, which are covered by fluids such as mucus and saliva. Surface reflection also obstructs the detection and the measurement of the alterations in the tissue's optical properties, induced after the administration of agents, which enhance the optical contrast between normal and pathologic tissue. More specifically, when an agent alters selectively the scattering characteristics of the pathologic tissue, the strong surface reflection that takes place in both pathologic (agent responsive) and normal (agent non responsive) tissue areas, occludes the diagnostic signal that originates from the interaction of the agent with the subsurface features of the tissue. In other words, surface reflection constitutes optical noise in the diagnostic signal degrading substantially the perceived contrast between agent responsive and agent non-responsive tissue areas.
[0075] For accurate diagnoses using the aforementioned imaging devices, appropriate optics can be used to eliminate noise arising from surface reflection. FIG. 4 illustrates a schematic diagram of a medical microscope that includes a light source (LS), a magnification selection mechanism (MS), an eyepiece (EP) and a mount for attaching the image capturing module (CA), (detector(s), readout electronics etc). To eliminate surface reflection, a pair of linear polarizers is employed. Light from the source passes through a linear polarizer (LPO) with the resulting linearly polarized light (LS) then impinging on the tissue. The surface reflected light (TS) has the same polarization plane as the incident light (Fresnel reflection). By placing another linear polarizer (IPO), oriented at a right angle with respect to the first, in the path of the light emitted from the tissue, the contribution of the surface reflected light is eliminated. The light that is not surface reflected enters the tissue, where due to multiple scattering, light polarization is randomized. Thus, a portion of the re-emitted light passes through the imaging polarization optics, carrying improved information for the subsurface features.
[0076] FIG. 5 illustrates an endoscope that includes an eyepiece (EP), which can be adapted to an electronic imaging system, and optical fibers or crystals for the transmission of both illumination and image rays. The endoscope also includes a first linear polarizer (LPO), disposed in the optical path of the illumination rays (LE), and a second polarizer (IPO), oriented at right angles to the first, disposed in the path of the light emitted by the tissue (II). The polarizer (LPO) can be disposed as shown in the figure, or, alternatively, where the light enters the endoscope (IL). In the latter case, the endoscope has to be constructed using polarization preserving crystals or fiber optics for transferring the light. If polarization preserving light transmission media are used, then the polarizers for the imaging rays can be disposed in their path, in front or in back of the eyepiece (EP).
[0077] A problem for the effective clinical implementation of the method described above involves the micro-movements of the patient, which are present during the snapshot imaging of the same tissue area. This problem is eliminated when the patient is under anesthesia (open surgery). In most cases, however, the movements of the tissue relative to the image capturing module, occurring during the successive image capturing time-course, result in image pixels, with the same image coordinates, which do not correspond to exactly the same spatial point x,y of the tissue area under examination.
[0078] This problem is typically encountered in colposcopy. A method for eliminating the influence to the measured temporal data of the relative movements between tissue and image capturing module is presented below.
[0079] A colposcopic apparatus, illustrated in FIG. 6 , includes an articulated arm (AA), onto which the optical head (OH) is affixed. The head (OH) includes a light source (LS), an objective lens (OBJ), an eyepiece (EP) and optics for selecting the magnification (MS). The image-capturing module is attached to the optical head (OH), through an opto-mechanical adapter. A speculum (K.D), which is used to open-up the vaginal canal for the visualization of the cervix, is connected mechanically to the optical head (OH), so that its longitudinal symmetry axis (LA) is perpendicular to the central area of the objective lens (OBJ). The speculum enters the vagina and its blades are opened up compressing the side walls of the vagina. The speculum (I(D), being mechanically connected with the optical head (OH), transfers any micromovement of the patient to the optical head (OH), which, being mounted on an articulated arm (AA), follows these movements. Thus the relative position between tissue and optical head remains almost constant.
[0080] An important issue that must also be addressed for the successful clinical implementation of the diagnostic method described herein is the synchronization of the application of the pathology differentiating agent with the initiation of the snapshot imaging procedure. FIG. 6 , illustrates an atomizer (A) attached to the optical head of the microscope. The unit (MIC) is comprised of electronics for controlling the agent sprayer and it can incorporate also the container for storing the agent. When the unit (MIC) receives the proper command from the computer, it sprays a predetermined amount of the agent onto the tissue surface, while the same or another command initiates the snapshot image capturing procedure.
[0081] The diagnostic examination of non-directly accessible tissues located in cavities of the human body (ear, cervix, oral cavity, esophagus, colon, stomach) is performed with the aid of common clinical microscopes. In these devices, the illumination-imaging rays are near co-axial. More specifically, the line perpendicular to the exit point of light into the air, and the line perpendicular to the objective lens, form an angle of a few degrees. As a result, these microscopes operate at a specific distance from the subject (working distance), where the illuminated tissue area coincides with the field-of view of the imaging system. These microscopes are found to be inappropriate in cases where tissue imaging through human body cavities of small diameter and at short working distances is required. These technical limitations hinder the successful clinical implementation of the method described herein. As discussed above, elimination of surface reflection results in a substantial improvement of the diagnostic information obtained from the quantitative assessment of marker-tissue interaction kinetics. If a common clinical microscope is employed as the optical imaging module, then as a result of the above-mentioned illumination-imaging geometry, multiple reflections occur in the walls of the cavity before the light reaches the tissue under analysis. Multiple reflections are more numerous in colposcopy because of the highly reflective blades of the speculum, which is inserted into the vagina to facilitate the inspection of the cervix.
[0082] If the illuminator of the imaging apparatus emits linearly polarized light, the multiple reflections randomize the polarization plane of the incident light. As discussed above, if the light impinging on the tissue is not linearly polarized, then the elimination of the contribution from the surface reflection to the image can not be effective.
[0083] FIG. 7 illustrates an optical imaging apparatus that includes a light source located at the central part of its front-aperture. With this arrangement, the central ray of the emitted light cone is coaxial with the central ray of the light beam that enters the imaging apparatus. This enables illumination rays to directly reach the tissue surface under examination before multiple reflections occur with the wall of the cavity or speculum. A reflective-objective lens is used, which includes a first reflection (1RM) and a second reflection (2RM) mirror. A light source (LS) is disposed at the rear of the second reflection mirror (2RM), together with, if required, optics for light beam manipulation such as zooming and focusing (SO). The reflective-objective lens (RO), by replacing the common refractive-objective used in conventional microscopes, provides imaging capability in cavities of small diameter with the freedom of choosing the working distance. The zooming and focusing optics of the light beam can be adjusted simultaneously with the mechanism for varying the magnification of the optical imaging system so that the illumination area and the field-of-view of the imaging system vary simultaneously and proportionally. Thus, image brightness is preserved regardless of the magnification level of the lens. The imaging-illumination geometry embodied in this optical imaging apparatus, along with the light beam manipulation options, helps to eliminate the surface reflection contribution to the image and consequently helps to efficiently implement the method described herein.
EQUIVALENTS
[0084] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. | The present invention provides a method and an apparatus for the in vivo, non-invasive, early detection of alterations and mapping of the grade of these alterations, causing in the biochemical and/or in the functional characteristics of the epithelial tissues during the development of tissue atypias, dysplasias, neoplasias and cancers. The method is based, at least in part, on the simultaneous measurement of the spatial, temporal and spectral alterations in the characteristics of the light that is re-emitted from the tissue under examination, as a result of a combined tissue excitation with light and special chemical agents. The topical or systematic administration of these agents result in an evanescent contrast enhancement between normal and abnormal areas of tissue. The apparatus enables the capturing of temporally successive imaging in one or more spectral bands simultaneously. Based on the measured data, the characteristic curves that express the agent-tissue interaction kinetics, as well as numerical parameters derived from these data, are determined in any spatial point of the examined area. Mapping and characterization of the lesion, are based on these parameters. | 53,902 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of priority to U.S. Provisional Patent Application Ser. No. 60/959,811 filed Jul. 16, 2007 and U.S. Provisional Patent Application Ser. No. 60/923,832, filed Apr. 17, 2007, which applications are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to surgical methods and devices therefor, including surgical access devices. Particularly, the present invention is directed to surgical access ports for use in endoluminal or transluminal procedures, such as through the human esophagus or lower gastrointestinal tract, and related methods.
[0004] 2. Description of Related Art
[0005] A variety of devices are known in the art for assisting surgical procedures-including cannulas for accessing internal cavities of a patient, and other devices, such as endoscopes.
[0006] Endoscopy is a term for a range of medical procedures that allow a doctor to observe the inside of the body without performing major surgery. An endoscope (e.g., a fibrescope) is a long tube with a lens at the distal end and an eyepiece and/or camera at the proximal end. The end with the lens is inserted into a patient. Light is transmitted through the tube (via bundles of optical fibres) to illuminate the surgical site, and the eyepiece magnifies the area so the doctor can visualize the surgical site. Usually, an endoscope is inserted through one of the body's natural openings, such as the mouth, urethra or anus, but depending on the particular procedure, may require a small incision through the skin. Such procedures are often performed under general or local anesthetic. Specially designed endoscopes are used to perform simple surgical procedures, such as tubal ligation (“tying” of the female fallopian tubes); locating, sampling or removing foreign objects or tumors from the lungs or digestive tract; removal of the gallbladder; taking small samples of tissue for diagnostic purposes (biopsy).
[0007] A range of endoscopes have been developed for many parts of the body. Each has its own name, depending on the part of the body it is intended to investigate. For example, an arthroscope is inserted through a small incision to examine a skeletal joint. A bronchoscope is inserted down the trachea (windpipe) to examine the lungs. A colonoscope is inserted through the anus to examine the colon. A gastroscope is inserted down the esophagus to examine the stomach. A hysteroscope is inserted through the cervix to examine the uterus. A laparoscope is inserted through a small incision to examine the abdominal organs. A cystoscope is inserted via the urethra to examine the urethra and urinary bladder. Many of the foregoing procedures can be carried out with one or more instruments used in conjunction with an endoscope. Such procedures often also require an opening through which the endoscope and/or instruments can pass. Such working channels can be natural openings—e.g. the mouth and esophagus, or artificial openings such as an incision made in the abdomen of a patient.
[0008] Applicants recognize that current endoscopic systems suffer from various limitations, particularly when used in conjunction with certain medical procedures. Some endoscopes may be configured with an integral working channel. Such working channels are often small, and may or may not be suitable for a particular instrument to be inserted therethrough. Moreover, it can prove difficult to obtain good working instruments in very small sizes. Further, imaging through fibers can be limiting-often due to low resolution images. If an endoscope is provided with an imaging chip on a scope having a circular cross-section, this can restrict the size and quality of images obtained therefrom. Moreover, if insufflation is required for a particular procedure, insufflation through an endoscope is typically maintained with mechanical seals. Even state-of-the-art mechanical seals typically present difficulty for a surgeon due to substantial friction, which results in difficult manipulation and restricted instrument access.
[0009] Applicants recognize that with the foregoing problems in the art, there remains a need for improved visualization and access devices that allow for easier access and movement and better quality imaging. The present invention provides a solution for these problems.
SUMMARY OF THE INVENTION
[0010] The purpose and advantages of the present invention will be set forth in and apparent from the description that follows. Additional advantages of the invention will be realized and attained by the devices and methods particularly pointed out in the written description and claims hereof, as well as from the appended drawings. The present invention is directed to devices, as described hereinbelow, as well as to methods utilizing such devices.
[0011] To achieve these and other advantages and in accordance with the purpose of the invention, as embodied, the invention includes an access device adapted and configured to be inserted through a natural biological orifice is provided. The access device includes a body, a nozzle means and means for delivering a pressurized flow of fluid to the nozzle means. The body is configured and dimensioned to be inserted through a natural bodily orifice and has proximal and distal end portions and defines at least one lumen therethrough to accommodate passage of one or more surgical instruments. The nozzle means is operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough.
[0012] In accordance with the invention, the body can be substantially rigid or substantially flexible, or include both rigid and flexible elements, as required. The access device can include at least one control element for manipulation of the curvature of the access device. Alternatively, two individual control elements can be used to control orthogonal motion—e.g., with respect to X and Y axes. Such control elements can further be provided in one or more opposing pairs. Such control elements can be, for example flexible or semi-rigid rods, wires or ribbons. Manipulation of the curvature of the entire access device can be controlled, or alternatively, the curvature of only the distal tip can be controlled, depending on the precise implementation.
[0013] One or more image sensors can be arranged in the distal end portion of the access device, which are adapted and configured to capture images of a region distal the distal end portion of the access device. If multiple image sensors are provided, they can facilitate stereoscopic imaging of the subject region. One or more working channels can be provided in the wall of the access device, and one or more of said working channels can be configured and adapted to provide irrigation to a surgical site. Alternatively or additionally, one or more of said working channels can be configured and adapted to provide drainage to a surgical site and one or more channels can be configured to allow a surgical instrument to pass therethrough.
[0014] One or more light sources can be arranged in the distal end portion of the access device, and adapted and configured to illuminate a region distal the distal end portion of the access device. Alternatively or additionally, illumination means can be provided in the wall of the access device.
[0015] Further, one or more guide elements adapted and configured to guide surgical instruments in the lumen of the access device can be provided. One or more pressure sensing channels can be arranged in the wall of the access device, and be configured and adapted to be in fluid communication with a surgical site.
[0016] Devices in accordance with the invention can be of any length desired or required. For example, the length of the body can be between about 30 cm and about 50 cm, depending on the precise application. A range of length between about 30 cm and 40 cm is particularly advantageous for a transesophageal access route for an endoluminal intra-gastric procedure—accessing a patient's stomach or duodenum. In alternate embodiments, the length of the body can be between about 40 cm and 50 cm, which range of length is particularly advantageous for transluminal access to internal organs via a trans-gastric route—that is, accessing a an organ through the wall of a patient's stomach. If desired, devices in accordance with the invention can be in the range of about 15 cm to about 20 cm for use as an anoscope and transanal access to the rectum, and can be up to about 160 cm in length for use as, or in conjunction with, a colonoscope, depending on the precise implementation. In accordance with one embodiment of the invention, a device provided with integral optics and illumination is between about 90 cm and 130 cm in length, preferably about 110 cm in length. Internal diameters of access devices in accordance with the invention can be any size that is practical for the application, but preferably range between about 10 mm and 20 mm, and in a preferred embodiment, between 15 mm and 18 mm.
[0017] Access devices in accordance with the invention can further comprise an integral image display provided in the proximal end portion thereof.
[0018] In accordance with another aspect of the invention, an insertion device is provided for inserting access devices in accordance with the invention. Such insertion devices can have a tip portion to facilitate insertion of the access device through a natural orifice. The tip can taper to a substantially blunt end and/or can include a dilating element. The tip portion can include at least one transparent region. The insertion device can be provided with illuminating means for illuminating a region distal the insertion device. Also, the insertion device can be configured and adapted to interface with an endoscope to facilitate guidance of the user during insertion. The insertion device can further include an integral lens arranged in a distal end portion thereof.
[0019] Further in accordance with the invention, a method of accessing an internal region of a body is provided. The method includes inserting through a natural body orifice an elongated body having longitudinally opposed proximal and distal end portions. The body defines at least one lumen configured and dimensioned to accommodate passage of one or more surgical instruments. The body further includes nozzle means operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough. The method further includes the steps of delivering pressurized fluid to the nozzle means to create said pressure differential; and inserting one or more surgical instruments through the body to access the interior of the body.
[0020] In accordance with another aspect of the invention, an access device is provided which is adapted and configured to be inserted through an orifice. The access device includes a body, a nozzle means, means for delivering a pressurized flow of fluid to the nozzle means and at least one control element. The body is configured and dimensioned to be inserted through an orifice and has proximal and distal end portions and defines at least one lumen therethrough to accommodate passage of one or more surgical instruments, and is flexible in at least one region. The nozzle means is operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough. The at least one control element is arranged within the body and is adapted and configured to effect a change in curvature of the at least one flexible region of the body. In accordance with the invention, the orifice can be a natural biological orifice, or alternatively can be formed from an incision made in the patient.
[0021] In accordance with still another aspect of the invention, a method for performing a cholecystectomy is provided. The method includes the steps of inserting a first access device through the esophagus of a patient and into the stomach, penetrating the stomach wall and extending the first access device through the stomach wall, inserting a second access device through the umbilicus of the patient, inserting an endoscope through the first access device, retracting the gallbladder, exposing the cystic duct and cystic artery, applying at least two dips on each of the cystic duct and artery, transecting each of the cystic duct and artery, dissecting and removing the gallbladder from the liver bed, and removing the gallbladder.
[0022] It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the method and system of the invention. Together with the description, the drawings serve to explain the principles of the invention, wherein:
[0024] FIG. 1 a illustrates a first embodiment of an access device in accordance with the invention, having a generally elliptical cross-section;
[0025] FIG. 1 b is a proximal end view of the embodiment of FIG. 1 a;
[0026] FIG. 1 c is a distal end view of the embodiment of FIG. 1 a;
[0027] FIG. 2 a illustrates a further embodiment of an access device in accordance with the invention, in which the wall of the device houses additional working channels;
[0028] FIG. 2 b is a cutaway view of a portion of the access device of FIG. 2 a , illustrating a fluid seal in accordance with the invention;
[0029] FIG. 2 c is a distal end view of the embodiment of FIG. 2 a , illustrating working channels and other features;
[0030] FIG. 3 a illustrates an access device in accordance with the invention, which is flexible and manipulable, in which instrument guides can be provided integrally with the access device, or can be provided in an attachable cap;
[0031] FIG. 3 b is a partial view of the access device of FIG. 3 a , illustrating surgical instruments inserted through the access device;
[0032] FIG. 3 c is a proximal end view of the access device of FIG. 3 a , illustrating an instrument guide provided therewith;
[0033] FIG. 3 d is a partial view of the distal end of the access device of FIG. 3 a , illustrating an insertion device inserted therethrough;
[0034] FIG. 4 a illustrates an access device in accordance with the invention having a proximal display, such as an LCD display;
[0035] FIG. 4 b is a distal end view of the access device of FIG. 4 a;
[0036] FIG. 5 illustrates a further embodiment of an access device in accordance with the invention, including control knobs which manipulate control elements provided within the access device;
[0037] FIG. 6 is an enlarged cross-sectional view of a distal end portion of an access device in accordance with the invention, through which an insertion device has been inserted;
[0038] FIG. 7 a illustrates a flexible access device, that is particularly configured and adapted for transanal insertion;
[0039] FIG. 7 b illustrates a rigid access device that is particularly configured and adapted for transanal insertion;
[0040] FIG. 7 c is a distal end view of the access devices of FIGS. 7 a and 7 b;
[0041] FIG. 7 d is a proximal end view of the access devices of FIGS. 7 a and 7 b , illustrating instrument guides provided thereon.
[0042] FIG. 8 is a side view of a further embodiment of an access device constructed in accordance with the invention having a distal end with open distal side portion;
[0043] FIG. 9 is an illustration of the access device of FIG. 8 inserted through a patient's esophagus into the stomach;
[0044] FIG. 10 is a side view of another embodiment of an access device constructed in accordance with the invention, with a distal end having a side-grasping feature with undulating grasping elements;
[0045] FIG. 11 is a partial view of the distal end of a variation of the embodiment of FIG. 10 , with straight grasping elements;
[0046] FIG. 12 illustrates three stages of an example procedure utilizing the access device of FIG. 10 ;
[0047] FIG. 13 a is a partial view of the distal end of a further embodiment of an access device constructed in accordance with the invention having internal steering elements;
[0048] FIG. 13 b is a cutaway view of the distal end of the access device of FIG. 13 a;
[0049] FIG. 14 is a schematic representation of a cholecystectomy in accordance with the invention; and
[0050] FIG. 15 are side and end views of a frangible tip in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0051] Reference will now be made in detail to select embodiments of the invention, examples of which are illustrated in the accompanying drawings.
[0052] The devices and methods presented herein may be used as surgical access ports, particularly for endoluminal or transluminal medical procedures. The devices described and set forth herein can incorporate any feature from the following U.S. patent applications and patents, which are each incorporated herein by reference in their entirety: U.S. patent application Ser. No. 11/517,929, filed Sep. 8, 2006 (U.S. Patent Publication No. US 2007/0088275, published Apr. 19, 2007), which is a continuation-in-part of U.S. patent application Ser. No. 10/776,923, filed Feb. 11, 2004 (now U.S. Pat. No. 7,338,473), which is a continuation-in-part of U.S. patent application Ser. No. 10/739,872, filed Dec. 18, 2003 (now U.S. Pat. No. 7,285,112), which is a continuation-in-part of U.S. patent application Ser. No. 10/441,149, filed May 17, 2003 (now U.S. Pat. No. 7,182,752). Each of the foregoing applications also claims priority to U.S. Provisional Application Ser. No. 60/461,149, filed Apr. 8, 2003, which itself is also hereby incorporated by reference in its entirety. The devices described and set forth herein can further incorporate any feature from U.S. patent application Ser. No. 11/544,856 (U.S. Patent Publication No. US 2008/0086167), and U.S. Provisional Application Ser. No. 60/850,006 both filed Oct. 6, 2006, which are also incorporated herein by reference in their entirety.
[0053] FIGS. 1 a - 1 c illustrate a first embodiment of an access device 100 in accordance with the invention. This embodiment has a generally elliptical cross-section, as can be seen at its proximal end 101 ( FIG. 1 b ). Further, this access device 100 , as embodied in FIGS. 1 a - 1 c , is sufficiently flexible to navigate a natural body orifice through which it is intended to be inserted. The access device 100 includes an insufflation input 120 a , and a pressure sensing channel having proximal and distal openings 110 a , 110 b , respectively. The body of the access device 100 includes a lumen 170 , and can be embodied so as to include manipulating elements 180 , such as wires, to effect curvature of the access device 100 , when desired. An image sensor 130 may be provided at the distal end region, as may be at least one light source 140 . In this embodiment it is contemplated that the at least one light source, may be one or more light-emitting diodes (LEDs), and that one or more CMOS, CCD or other small image sensors may be mounted at the distal end of the device and used as image sensors. Images can be transmitted to the external environment through conductive elements provided on or within the access device 100 , or can be provided wirelessly, such as by radio frequency transmission to a receiver. Alternatively, it is contemplated that the access device might not contain integrated optics and that known types of viewing devices may be inserted through the central lumen or a working channel of the access device for viewing purposes.
[0054] Devices in accordance with the invention can be of any length desired or required. For example, the length of the body can be between about 30 cm and about 50 cm, depending on the precise application. A range of length between about 30 cm and 40 cm is particularly advantageous for a transesophageal access route for an endoluminal intra-gastric procedure. In alternate embodiments, the length of the body can be between about 40 cm and 50 cm, which range of length is particularly advantageous for transluminal access to internal organs via a trans-gastric route—that is, accessing a an organ through the wall of a patient's stomach. If desired, devices in accordance with the invention can be in the range of about 15 cm to about 20 cm for use as an anoscope and transanal access to the rectum, and can be up to about 160 cm in length for use as, or in conjunction with, a colonoscope, depending on the precise implementation. In accordance with one embodiment of the invention, a device provided with integral optics and illumination is between about 90 cm and 130 cm in length, preferably about 110 cm in length. Internal diameters of access devices in accordance with the invention can be any size that is practical for the application, but preferably range between about 10 mm and 20 mm, and in a preferred embodiment, between 15 mm and 18 mm.
[0055] Additional features that can be incorporated into access devices in accordance with the invention include, but are not limited to having an outer cross-sectional shape ranging from circular, through an elliptical shape to near linear in shape.
[0056] With respect to the embodiment of FIGS. 1 a - 1 c , one or more fluid seals 120 b are provided to seal between instruments passing through the lumen 170 , and the wall of the lumen, in order to maintain pressure within an operative space. Various embodiments of access devices having fluid seals (or alternatively “air seals” or “pneumatic seals”) are set forth in the documents referenced above. Although mechanical sealing can additionally be incorporated into different embodiments of access devices described therein, as well as into those described in connection with the present invention, such mechanical seals can equally be absent, allowing substantially unencumbered movement of instruments through and within such access devices.
[0057] In accordance with the present invention the access device 100 of FIG. 1 or any access device set forth herein can be provided with a fluid seal, as described in the documents referenced above. The subject access devices can further include one or more of the following features: one or more endoscopes; one or more working channels; illumination capability; and/or the capability to be steered by a user. Incorporation of non-mechanical seals into endoluminal and transluminal access devices in accordance with the invention can allow for easier, safer procedures as well as new approaches to procedures.
[0058] Fluid seals in accordance with the invention can be embodied in a variety of suitable manners. Nozzles can be provided that are substantially annular in configuration, or alternatively, if desired, a plurality of discrete nozzle apertures can be defined in place one such annular nozzle. These discrete nozzle apertures can be arranged as necessary, about the wall of the access device, to form an effective barrier to proximal egress of insufflation gas from a surgical site. Such discrete nozzles can each be substantially round in shape, or alternatively can be oblong or another shape. The nozzles can be placed at regular intervals about the circumference of the lumen, can extend part way around, or can be spaced from each other in groups. If turbulence is desired, surface features such as protrusions, vanes, grooves, surface texture can be added in the path of fluid flow, as desired. Further, one or more nozzles or groups of nozzles can be provided in access devices in accordance with the invention, with such nozzles being located in one region, or in a plurality of regions along the length of the access device.
[0059] FIGS. 2 a - 2 c illustrate a further embodiment of an access device 200 , in accordance with the invention. The access device 200 includes an insufflation fluid input 220 a , which is in fluid communication with a fluid seal 220 b . The fluid seal may be positioned within the proximal housing of the device or may be positioned at any desired location between the proximal housing and the distal tip of the device. A lumen 270 serves as a working channel for passage of surgical instruments and the like, and is defined by the wall 275 of the access device 200 . The wall 275 itself also houses additional working channels, such as an irrigation port 260 , drainage port 261 and pressure sensing port 210 a . Additional ports can be used for additional functions, as desired or required. Optionally, illumination can be provided by way of one or more light sources, which can be provided directly in the wall 275 , or whose light can be transmitted through the wall 275 , to the distal end thereof by one or more fiber optic elements 250 . Further, one or more optional image sensors 230 can be provided in the wall 275 in order to capture images of a surgical site.
[0060] In accordance with the invention, the foregoing and following embodiments can be flexible or rigid, as desired or required. Further the foregoing and below-described access devices allow a user to pass a plurality of surgical instruments through a natural lumen into the human body. Such natural openings include, for example, the mouth and esophagus, the anus and rectum or vagina.
[0061] Entrance through such natural openings can provide access into the digestive tract without surgical incisions penetrating the external abdominal wall. Furthermore, gastrointestinal pressures can be maintained within the organ(s), such as the stomach, without any interference with inserted instruments which would typically be caused by mechanical seals used in a typical endoscope, colonoscope, trocar, cannula or other access systems. Moreover, manipulation of surgical instruments is less encumbered, as compared with more conventional devices having mechanical seals. The subject access devices suffer less from frictional resistance between inserted instruments and the access device. Reducing such interference and friction is advantageous, and may reduce torque and other forces transmitted from the inserted instrument through the access device to surrounding tissue, which can cause trauma and prolong healing and recovery. The access device may also allow crossing of paths of the inserted instruments, as when switching hands, without having to retract and then reinsert an instruments.
[0062] Endoscopic surgical or exploratory access via a transesophageal or transanal route can be intraluminal—that is, it can be used for accessing the natural lumen itself (e.g., the esophagus, stomach, rectum, colon), or can be transluminal, that is—used to access other anatomy through the wall of such structures. Such an approach can be referred to as Natural Orifice Transluminal Endoscopic Surgery™ (“NOTES”). Such access can allow for imaging, insertion of one or more surgical instruments, removal of a tissue specimen, or insufflation of the lumen (e.g., the stomach). For example, access to a patient's peritoneum can be achieved through an internal endoluminal route. Moreover, insufflation of the peritoneum is possible using access devices in accordance with the invention. The following is a sample list of minimally-invasive procedures that can be accomplished by surgeons operating through access devices as described herein:
Endoluminal Access to the Upper GI Tract
[0063] Reflux procedures, such as fundoplication
[0064] Obesity procedures, such as gastric restriction
[0065] Diabetes procedures such as duodenal bypasses
[0066] Gastric tumor removal
Endoluminal Access to the Lower GI Tract
[0067] Tumor removal
[0068] Diverticulum removal, repair
Transluminal Access Through Esophagus, Rectum or Vagina
[0069] All current abdominal and pelvic surgery such as:
Gallbladder Appendectomy Ovarian cysts Oophorectomy Sterilization Hernia repair
[0076] Devices in accordance with the invention can allow, in general, for new approaches to accessing anatomy. Any instrument inserted through the lumen of an access device equipped with one or more fluid seals in accordance with the invention will experience markedly reduced frictional resistance, due to replacement of mechanical seals with fluid seals. It may, at times, prove useful to include one or more mechanical valves, such as for example a duckbill valve or other so-called “zero seal” intended to seal the access device when no instrument is inserted therethrough. However, typically the number of such valves will be reduced if not eliminated, for every fluid seal that is used. Without mechanical seals protruding into a lumen of access devices in accordance with the invention, more space for instruments is available, while free insertion and movement of the instruments is not hampered by mechanical seals.
[0077] Further, gas, such as carbon dioxide, can be supplied to such fluid seals in a continuous manner—thereby insufflating an operative space while also sealing the operative space. Such a continuous flow of insufflation gas is distinct from prior systems, in that prior insufflation technologies operate in a cyclic manner—alternately insufflating and sensing pressure. Such systems do not allow for insufflation when pressure is being sensed. A further advantage to access devices in accordance with the invention, is that maintaining a pressure barrier in an access device, between an insufflated space and the surrounding environment without the use of elastomeric seals provides the capability for safe relief from pressure buildup from any possible system failures or sources of additional pressure. Additionally, bucking is reduced when operating using devices in accordance with the invention. Bucking is the phenomenon where a patient tightens his diaphragm while his abdomen is insufflated. This tightening dramatically increases pressure within the abdomen. Further, if used in laparoscopic procedure, fluid seals incorporated with devices constructed in accordance with the invention all use of open type instrumentation.
[0078] Additionally, access devices in accordance with the invention allow for more freedom in instrument design. Because contact seals are not required, instruments inserted through access devices in accordance with the invention do not need to conform to the shape and size of such mechanical seals. Accordingly, instruments having a non-symmetrical shape can be used, which may be more efficient and cost-effective, and multiple instruments can be inserted simultaneously to improve manipulation through the access device. Advantageously, the absence of mechanical seals reduces the likelihood of smudging of optical components of surgical instruments inserted through access devices constructed in accordance with the invention.
[0079] Moreover, devices in accordance with the present invention can be provided with various cross-sectional shapes, including, but not limited to circular, elliptical, or as set forth above, cross-sectional shapes that approach a linear morphology when not in use. If embodied in an elliptical shape, access devices in accordance with the invention advantageously allow insertion of instruments of various sizes, such as instruments having an oblong cross-section. An elliptical cross-section can also allow for insertion of the access device in regions of the anatomy that would otherwise not allow insertion of an access device having a round cross-sectional shape.
[0080] Surgical instruments that can be used through access devices in accordance with the invention include, but are not limited to rigid or flexible versions of the following, depending on the procedure: graspers, scissors, snares, staplers, ultrasonic imaging devices, ultrasonic cutting and/or coagulating devices, vessel sealing devices, RF devices, microwave energy delivery devices glue delivery devices and suturing devices.
[0081] Access devices in accordance with the invention can further incorporate various imaging technologies. One or more image sensors can be utilized for image acquisition, which sensors can be incorporated into an access device, for example at or near the distal end thereof. Alternatively, standard fiber optic imaging technology may be inserted through the fluid seal or may be incorporated into a wall of the access device, such that an objective (lens) is at the distal end portion of the access device, and an image sensor and/or eyepiece is provided elsewhere, such as at the proximal end thereof. Such imaging devices can be embodied so as to obtain still images, but video images can alternatively or additionally be obtained to allow for real-time guidance of a procedure, and can allow for guidance during insertion of the access device itself. Additionally, illumination can be provided in the subject access devices in the form of integrated fiber-optics, connected to an external light source and/or integrated sources of light, such as LEDs (light-emitting diodes) integrated into the distal end portion of the access device. Capability for infrared imaging for diagnostic purposes can further be provided, in the form of an optical sensor capable of capturing light in the infrared region, and additionally, if needed, an infrared light source.
[0082] FIGS. 3 a - 3 d illustrate a surgical access device 300 in accordance with the invention, which is flexible and manipulable, as with foregoing embodiments. One or more fluid seals 320 b are provided therein, to which fluid (such as compressed air or inert gas, or in the case of arthroscopic or other surgery which utilizes liquid, saline or other suitable biocompatible liquid) is supplied via a fluid input 320 a . A sensing input 310 is also provided, as described above in connection with other embodiments. If desired, instrument guides 385 (shown in the end view of FIG. 3 c ) can be provided integrally formed with the access device 300 , or in the form of an attached cap 380 ( FIG. 3 a ). As shown in FIG. 3 b , surgical or exploratory instruments 305 a , 305 b , 305 c pass through the guides 385 , and thereby are prevented from moving undesirably, or unnecessarily interfering with one another.
[0083] Further in accordance with the invention, an insertion device 390 can be provided, which is inserted into the access device 300 , prior to insertion in a patient. The insertion device 390 includes a tip 395 , which facilitates insertion into a patient. Tip 295 may be blunt or sharp, rounded or pointed or such other configuration as appropriate for the intended insertion. Tip 395 also may be transparent to provide optical viewing during or after insertion.
[0084] As illustrated in FIG. 4 a , a proximal display 489 , such as an LCD display, can be provided with access devices in accordance with the invention, such as access device 400 of FIGS. 4 a and 4 b . Such displays 489 can be integrated with respective access devices, or can be attached thereto in order to provide optimum viewing nearer the location in which the procedure is taking place, rather than on a display mounted far from the operating table. Such displays can provide high resolution direct images of the anatomy. In the embodiment of FIGS. 4 a and 4 b , the display 489 receives images from an image sensor 430 arranged in the distal end region of the access device 400 . If desired, video signals from the image sensor 430 can be additionally output to display monitors by one or more wired and/or wireless connections. Of course, images may alternatively or additionally be displayed on a traditional monitor in the vicinity.
[0085] As best seen in FIG. 4 b , illumination elements 451 may also be provided at the distal end region of the access device 400 , and can include light sources, such as light-emitting diodes (LEDs) or alternatively or additionally, fiberoptic conduits that deliver light from an external light source. It is preferable, generally, that such illumination elements 451 be capable of providing bright, controllable illumination and be relatively small in size. As can be seen in FIG. 4 b , the foregoing elements can be provided directly in a wall of the access device 400 , which has a lumen 470 , running therethrough, with openings 470 a ( FIG. 4 a ), 470 b at proximal and distal ends of the access device 400 , respectively.
[0086] The nature of access devices in accordance with the invention, particularly because fluid seals can be integrated therewith, allows the ability to use new flexible instruments of different shapes, geometries and mechanics. Such instruments might otherwise not be satisfactorily sealable with conventional sealing techniques. The absence of mechanical seals also can allow for passage of instrument drive and steering mechanisms, as well as for tissue manipulation, repair and/or retrieval.
[0087] FIG. 5 illustrates a further embodiment of an access device 500 in accordance with the invention. The access device 500 includes control knobs 581 , 583 , which manipulate control elements provided within the access device 500 . When the control elements are placed in tension, the access device will tend to bend toward that control element. Conversely, when a control element is placed in compression, the access device 500 , will tend to bend away from that control element. In the embodiment of FIG. 5 , two controls 581 , 583 control bending of the access device in two orthogonal directions, such as “X” and “Y” in a Cartesian coordinate system.
[0088] FIG. 6 is an enlarged cross-sectional view of a distal end portion of an access device 600 , in accordance with the invention, through which an insertion device 660 has been inserted. The insertion device 660 may receive an endoscope 670 therethrough, which views the insertion site through one or more transparent windows or lenses 665 . The lenses 665 can also be adapted to provide illumination to the insertion site. In this embodiment, the insertion device 660 may terminate in an elongate tip 661 , which may facilitate dilation of a natural orifice through which the insertion device 660 and access device 600 assembly pass during insertion. Further, the contour 663 of the insertion device provides a relatively smooth transition to the diameter of the access device 600 from that of the tip 661 .
[0089] FIGS. 7 a - 7 d illustrate rigid and flexible access devices 700 a , 700 b , respectively, that are particularly configured and adapted for transanal insertion into the rectum of a patient. Features for these embodiments can be any of those set forth in connection with foregoing embodiments, including but not limited to use with an insertion device, incorporation of one or more fluid seals or insufflation means and/or steerability (in the case of flexible access devices). Further, as illustrated in FIG. 7 d , which is a proximal end view of a cap for attachment to the access device 700 a , 700 b , instrument guides 785 can be provided. As best seen in the distal end view of FIG. 7 c , irrigation channels 781 , illumination capability 783 , visualization components, such as one or more image sensors 787 , or fiber optics to allow image transmission, and drainage capacity, such as in the form of drainage channels 789 can be incorporated. The foregoing elements can be arranged within the wall 775 of the access devices 700 a , 700 b , as with the embodiment described in connection with FIGS. 2 a - 2 c , for example. Additionally, an insertion device 790 can be utilized to facilitate insertion into the body of a patient.
[0090] FIG. 8 is a side view of a further embodiment of an access device 800 constructed in accordance with the invention. The access device 800 has a distal end 870 with open distal side portion 875 . This embodiment allows instrumentation to be oriented to act on the side as an alternative to or in addition to through a distal end aperture. This arrangement is particularly advantageous when performing a procedure on the wall of a passage, such as the esophagus, stomach or duodenum, for example. A wall of such passage can be sucked via vacuum or pulled by mechanical means into contact with the access device 800 to facilitate a procedure. When in contact with the access device 800 , steps including cutting, stapling and removal of tissue can be carried out. Vacuum can be applied in a number of ways, in accordance with the invention. Preferably, suction is applied directly through the access device 800 . A single pump can be provided, which is adapted and configured to both provide insufflation pressure to the access device 800 and to provide suction to the access device 800 . Use of a single pump allows for more streamlined surgical equipment and controls—reducing unnecessary clutter in the operating room and reducing cost by obviating a second pumping device. Naturally, if desired, separate pumps can be connected to the access device 800 , and selectively activated in order to switch between insufflation and suction. Alternatively still, a secondary suction device can be utilized—either inserted through a central internal lumen of the access device 800 or external thereto.
[0091] Additionally, the access device 800 can be flexible to allow manipulation through the anatomy of a patient, as seen in FIG. 9 . Moreover, the overall shape of the access device 800 can be preformed, as illustrated, so that the device has a tendency to revert to a shape that facilitates insertion and/or comfortable retention in the patient. The entire access device 800 , or a portion thereof, such as the distal end portion, can be steerable to aid insertion of the access device and procedures performed therewith.
[0092] A fluid seal can be provided in the proximal end portion 815 of the access device 800 , or additionally or alternatively at one or more other locations throughout the length of the access device 800 .
[0093] FIG. 10 is a side view of another embodiment of an access device 1000 constructed in accordance with the invention. The access device 1000 is similar to that of FIGS. 8 and 9 , but includes at its distal end 1070 , a side-grasping feature with undulating grasping elements 1071 . Alternatively, the side-grasping elements can be straight grasping elements 1171 as illustrated in FIG. 11 .
[0094] FIG. 12 illustrates the side grasping elements in closed, open and grasping positions, respectively. The grasping elements can be used to engage a wall of a passage, internal organ or other element, for example, to move the wall or steady the wall for another step, such as a puncture or incision. Actuation can be effected in any suitable manner. In accordance with one aspect of the invention, tension within the wall 1079 of the distal end 1071 is adjusted to effect closure or opening of the grasping elements 1071 . Such tension can be adjusted by way of, for example, shape-memory alloy ribs 1278 arranged within the wall of the distal end 1070 . Such ribs 1278 can have a first shape at normal room and/or body temperatures. The ribs 1278 can be electrically connected to a power source, such that when voltage is applied, resistive heating of the ribs 1278 effects a change in shape of the ribs to a second shape. Depending on the desired implementation, the normal state of the ribs can be open or closed.
[0095] Alternatively, the grasping elements 1071 can be actuated by providing one or more control elements (e.g., wires) terminating in a plurality of ends that terminate in or near the grasping elements 1071 , within the wall 1079 of the distal end 1071 . Accordingly, applying compression to such control cables will cause the grasping elements to close.
[0096] FIGS. 13 a and 13 b illustrate a distal end portion 1370 of a surgical access device constructed in accordance with the invention having a steerable distal end portion 1370 . Control elements 1310 , such as wires are provided within or adjacent the wall 1379 of the access device. The control elements 1310 are anchored in one or more locations 1320 to the wall of the access device. Although illustrated within the lumen 1340 of the access device, the control elements 1310 are provided with in the wall 1379 . Tension applied to one or more control elements 1310 effects a change in curvature of the distal end portion 1370 . In conjunction with applied rotation to the entire access device by a surgeon, navigation through the patient's anatomy is facilitated.
[0097] The present invention also relates to surgical procedures performed utilizing devices set forth herein. FIG. 14 illustrates an endoluminal and transluminal access device 1400 being used in a trans-gastric cholecystectomy (removal of gall bladder). As illustrated, the access device 1400 is inserted by way of the esophagus 1490 of a patient, into the stomach 1420 of the patient. Access is made by way of an incision through the wall of the stomach 1420 , into the abdominal cavity 1410 . An incision is made in any suitable manner, but preferably by an endoscopic cutting implement placed through the lumen of the access device 1400 , which induces coagulation, such as by electrocautery or ultrasonic vibrations.
[0098] Either preceding or following this step, a second access device 1450 is inserted through the navel or umbilicus 1411 of the patient. This mode of external access obscures any scarring that may occur. Naturally, the trans-esophageal entry of the access device 1400 carries no risk of visible scarring.
[0099] Prior to or upon entering the abdominal cavity 1410 , the cavity may be insufflated by way of the access device 1400 . Alternatively, the abdominal cavity can be insufflated by way of the second access device 1450 and/or still another element, such as a veress needle.
[0100] In the illustrated embodiment, a flexible endoscope 1405 is inserted through the transluminal access device 1400 . Any number of additional instruments that can physically fit through the lumen of the access device 1400 can be inserted therethrough, and the fluid seal formed by the access device 1400 will maintain a seal around the instruments. An entire cholecystectomy can be performed via this access device 1400 . At present it is more effective to close the incision made in the stomach wall by accessing the stomach 1420 from the outside, and for this reason, the second access device 1450 is used with a surgical stapler 1457 to close the incision made in the stomach. Therefore, the second access device 1450 is also used during the cholecystectomy. Through the channel of the second access device, an endoscope, grasper shears or any other necessary instrument can be inserted.
[0101] Upon severing the cystic duct, vascular tissue and connecting tissue, the gall bladder can be removed by either the transluminal access device 1400 or the second access device 1450 . If necessary, the gall bladder can be separated into smaller pieces for removal, as by a morcellator or the like.
[0102] In accordance with one embodiment of the invention, a method for performing a cholecystectomy includes the steps of:
Inserting a first access device in accordance with the invention through the esophagus of a patient and into the stomach; Penetrating the stomach wall and extending the first access device through the stomach wall; Inserting a second access device through the umbilicus of the patient; Inserting an endoscope through the first access device; Retracting the gallbladder with the at least one grasper; Exposing the cystic duct and cystic artery; Applying at least two clips on each of the cystic duct and artery; Transecting each of the cystic duct and artery with surgical scissors or another suitable instrument; Dissecting and removing the gallbladder from the liver bed; and Removing the gallbladder.
In accordance with this method, the second access device can have, for example, a diameter of 21 mm. The endoscope can be flexible and can have a diameter, for example, of about 10 mm. The cystic duct and artery can be exposed with dissectors, such as 5 mm dissectors. One or more graspers can be inserted through the second access device to manipulate the gallbladder. Clips can be applied with a 5 mm clip applier. The scissors can be 5 mm scissors, for example. Dissecting and removing the gallbladder can be accomplished with shears, such as ultrasonic shears. The gallbladder can be removed through the second access device. Alternatively, the gallbladder can be removed from the first access device, and can be removed from either access device whole or morcellated.
[0113] FIG. 15 illustrates one embodiment of a distal end portion of an access device in accordance with the invention. The access device of FIG. 15 includes a frangible tip 1510 that maintains sterility of the lumen of the access device during insertion through a cavity, such as the gastrointestinal tract, until a point when the tip is ruptured or intentionally cut. The frangible tip may have any shape, and may include lines of weakness 1513 , such as regions of decreased material thickness or score lines.
[0114] Having a sealed tip, instruments, such as endoscopes inserted through the access device benefit from a sterile path essentially the entire way to the surgical site. This reduces or eliminates any problems in sterilizing equipment, such as endoscopes with working channels. Advantageously, utilizing access devices in accordance with the invention eliminates the need for using endoscopes with integral working channels, because instruments can be inserted in parallel with the endoscope while maintaining a seal around all instruments. Even though sterility using access devices in accordance with the invention is enhanced as compared with simply inserting such instruments through a particular bodily opening, by including a sealed tip, sterility of a working channel is further enhanced.
[0115] Other types of tips or seals can be provided at the distal end of access devices in accordance with the invention, such as a removable cap, a sheath capable of being remotely withdrawn proximally, away from the distal tip or hinged hemispheric shutters, that function similarly to an eyelid and close over the distal opening of the lumen.
[0116] In accordance with the invention, transluminal access can be made through the rectum, colon, stomach (as illustrated in FIG. 14 ), esophagus or vagina, for example. Instruments that can be inserted through access devices in accordance with the invention include, but are not limited to dissectors, clip appliers, shears, automatic suturing devices, endoscopes, graspers, morcellators, suction tubes, electrocautery or coagulation devices, specimen retrieval tools, surgical staplers, as well as specialized tools for specific procedures.
[0117] Surgical procedures which may be performed with devices set forth herein, and in accordance with methods set forth herein include: cholecystectomy, appendectomy bariatric procedures, such as adjustable gastric banding (lap band), gastrectomy, such as sleeve gastrectomy, any of a variety of procedures to alleviate gastroesophageal reflux disease (GERD), tubal ligation, oophorectomy, nephrectomy, prostatectomy, colorectal procedures, hernia repair, gynecological resection, resection of the spleen, and splenectomy.
[0118] Such procedures, as well as others applicable in accordance with the invention, can mitigate damage caused by or aide recovery from such conditions as obesity, diabetes, gastroesophageal reflux disease (GERD), gallstones, appendicitis, colon disease, ideopathic thrombocytopenia purpura (ITP) and other diseases.
[0119] It should be noted that features described and/or illustrated in connection with one embodiment described herein can be combined with or substituted for other features described and/or illustrated in connection with any other embodiment set forth herein. Although a feature may be described in one particular embodiment, it should be understood that such a feature is not limited to being provided precisely in that manner or only in that embodiment.
[0120] The access devices and related methods of the present invention, as described above and shown in the drawings, provide, among other things, access devices with superior properties including the capability to provide substantially frictionless sealing of instruments passing therethrough. Endoluminal and transluminal procedures advantageously require less time for recovery than traditional procedures, among other benefits. It will be apparent to those skilled in the art that various modifications and variations can be made in the device and method of the present invention without departing from the spirit or scope of the invention. | An access device adapted and configured to be inserted through a natural biological orifice, and related surgical methods are provided. The access device includes a body, a nozzle means and means for delivering a pressurized flow of fluid to the nozzle means. The body is configured and dimensioned to be inserted through a natural bodily orifice and has proximal and distal end portions and defines at least one lumen therethrough to accommodate passage of one or more surgical instruments. The nozzle means is operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough. | 55,474 |
[0001] This invention relates to improved training ammunition and to a method of modifying a gun to fire the training ammunition.
BACKGROUND OF THE INVENTION
[0002] Low powered training cartridges are known, and examples of such cartridges are disclosed in PCTGB98/00620, PCT/GB99/02859, PCT/GB99/02556, GB 9819928.4 and U.S. Pat. No. 5,492,063. Training cartridges are characterised in that they impart much less energy to a projectile than a live (“killing”) round. Thus, whereas a live round may impart 800 ft/lbs of energy to a bullet and a shotgun may impart as much as 1000 ft/lbs of energy to the shot, training cartridges are much less energetic. For example, the energy imparted to a projectile by a training cartridge is typically less than 5 ft/lbs and more usually less than 4 ft/lbs. The term “training cartridges” as used herein therefore refers to such low energy cartridges, unless the context indicates otherwise.
[0003] The aforementioned training cartridges typically contain only a primer and do not contain a conventional amount of propellant. Consequently, they must be carefully designed to ensure that there is sufficient energy both to recycle a weapon and eject a projectile such as a bullet. Many training cartridges, see for example the cartridges disclosed in the patent documents supra, are of the expanding type in which the body of the cartridge comprises a “piston and cylinder” arrangement. With such cartridges, part of the energy of the primer is used to force the piston and cylinder apart (i.e. expand the cartridge) and drive the rear end of the cartridge back to recycle the weapon, and part of the energy is used to discharge the projectile from the front end of the cartridge. Careful control of gas flow within the cartridge is required in order to make sure that the projectile is discharged at a consistent and appropriate velocity and that the weapon is recycled at every firing.
[0004] All (so far as the Applicants are aware) current training ammunition, and most live military ammunition, is of the centre fire variety. Exceptions are certain 0.22″ (5.56 mm) rounds generally used in target shooting (and occasionally in military training) which are of the rimfire type. Live cartridges of the centre fire variety generally have a primer carried in a cup or “can” set into the rear end of the cartridge. However, with live rounds of the rim fire type (for example the 0.22″ rounds referred to above) the primer is not carried in a cup or can but is held in the hollow rim of the cartridge case itself.
[0005] FIG. 1 shows a sectional elevation through the primer for a centre fire cartridge of the type typically used in live military ammunition. The primer comprises a can 2 formed from, for example, nickel plated brass, and containing a suitable pyrotechnic primer material 4 . The can is held in a recess in the centre of the rear surface (not shown) of the cartridge. An anvil 6 is set into the front of the can 2 to close the can and retain the primer in place. As the anvil is inserted into the can, the protruding central part 6 a of the anvil greatly compresses the primer to create a compressed region 4 a which is highly sensitive to shock. The region 4 a which is sensitive to shock has an approximate width I, and this represents the impact area for the firing pin of a centre fire weapon. Thus, a centre fire firing pin will impact against the impact area and further compress the primer between the wall of the can and the anvil thereby detonating the primer. However, it will be appreciated that the firing pin of a rimfire weapon would impact against the can outside the impact area I and hence would not detonate the primer.
[0006] Although training cartridges that are constructed to provide consistent low energy discharge of bullets are generally safe per se, safety problems can arise when live killing cartridges are inadvertently mixed with or substituted for low powered training cartridges. As stated above, all of the known existing training cartridges use centre fire type of primers which are very similar and often identical to the types of primers used in the equivalent live killing cartridge for a particular gun type. Attempts have been made to prevent confusion between the two types of cartridge by modifying the gun so that it will not fire the cartridge type usually fired from the gun, but will only fire a training cartridge. Unfortunately, this safety feature can sometimes be bypassed by using a different live cartridge type which, when chambered, fits the gun, or by using damaged live cartridges. In such circumstances, firing live cartridges rather than training cartridges can result in serious injury or death.
[0007] It is an object of the present invention to provide a solution to the aforementioned problems by preventing live killing cartridges from being fired inadvertently in place of training cartridges.
SUMMARY OF THE INVENTION
[0008] The present invention makes use of peripheral fire primers in the training cartridges, and a gun modification which allows the firing pin of the gun to strike the periphery (i.e. rim) of the primer which fires a cartridge. If any type of centre fire cartridge is fitted into the gun whilst the conversion is fitted, the firing pin cannot set off the centre fire primer as the point of impact of the firing pin is beyond the sensitive part of the centre fire primer. Thus, the present invention prevents the standard centre fire military ammunition from being fired inadvertently instead of low velocity training ammunition.
[0009] Accordingly, in one embodiment the invention provides a training cartridge having a peripheral fire primer.
[0010] The primer typically takes the form of a cup or “can” which is set into the rear end of the cartridge. The cup typically has a hollow peripheral rim in which the primer material is located, the primer material being in a compressed state and highly sensitive to shock. The primer material can thus be detonated when the peripheral rim of the can is impacted by a firing pin. This arrangement is in contrast to conventional live rimfire cartridges (i.e. 0.22″ calibre) in which the primer material is located in the rim of the cartridge itself rather than the peripheral rim of a cup set into the rear of the cartridge.
[0011] The training cartridges of the invention are preferably expandable upon firing, expansion of the cartridge serving to urge a rear surface of the cartridge rearwardly against a breech block of a gun to initiate recycling of the gun.
[0012] For example, in one embodiment, there is provided an expandable training cartridge configured to enable a projectile (e.g. a bullet) to be mounted in or on a nose portion thereof, a gas passage though the nose portion providing communication between the cartridge interior and the projectile. The cartridge has valve means for controlling propellant gas flow through the gas passage to the projectile, and a movable member which upon firing is propelled rearwardly from the cartridge against a breech block of the firearm by the pressure of propellant gas within the cartridge so as to recycle the firearm. The valve means is preferably arranged to close in order to stop or substantially reduce the flow of propellant gas through the said gas passage after the projectile has been fired from the cartridge, thereby to facilitate rearwards propulsion of the movable member.
[0013] The precise nature of the training cartridge is not critical but, for example, the training cartridge can be of the general type described in any one of PCT98/00620, PCT/GB99/02859, PCT/GB99/02556 and GB 9819928.4, but with an appropriately modified primer. The diameter of the training cartridge is generally greater than the diameter (usually approximately 0.375″ (9 mm)) of live 0.22″ (5.65 mm) rounds although the training cartridge may carry a 0.22″ (5.65 mm) bullet or projectile, and may be provided with a primer of a diameter typically associated with a 0.22″ (5.65 mm) round.
[0014] In general, the primer is the only pyrotechnic material in the cartridge; i.e. there is no propellant other than the primer. The primer is such that the cartridge produces an energy of less than 4 ft/lbs, more preferably less than 3 ft/lbs, for example less than 2.5 ft/lbs, and most preferably 2 ft/lbs or less.
[0015] In another aspect, the invention provides a method of modifying a gun to prevent it from firing live ammunition but permit the firing of a rimfire primer training cartridge, which method comprises (i) replacing a centre fire firing pin with a rim fire firing pin and/or (ii) replacing a barrel of the gun such that a centre firing pin is misaligned for centre firing of the cartridge but is aligned for rim firing of the cartridge, but excluding the modification of a gun capable of firing live 0.22″ (5.56 mm) cartridges by replacing the centre firing pin with a rimfire firing pin.
[0016] In a further aspect, the invention provides a method of modifying a gun to prevent it from firing live ammunition but permit the firing of a rimfire primer training cartridge other than a 0.22″ (5.56 mm) calibre cartridge, which method comprises replacing a centre fire firing pin with a rim fire firing pin.
[0017] In another aspect, the invention provides the combination of a training cartridge having a rimfire primer and a gun that has been modified to fire a rimfire primer-containing training cartridge.
[0018] In a further aspect, the invention provides a peripheral fire primer for use in a cartridge as hereinbefore defined, the primer comprising a cup for setting into the rear end of the cartridge, the cup having a hollow peripheral rim containing compressed primer material.
[0019] In a further aspect, the invention provides a method of modifying a gun to prevent it from firing live ammunition but permit the firing of a rimfire primer training cartridge, which method comprises selecting a gun having a centre fire firing pin and replacing the barrel of the gun with a barrel in which the breech is offset such that the centre fire firing pin can impact against and fire the rimfire primer training cartridge but not a centre fire cartridge.
[0020] In a still further aspect, the invention provides a gun having a centre fire firing pin and a barrel in which the breech is offset such that the centre fire firing pin can impact against and fire a rimfire primer cartridge but not a centre fire primer cartridge.
[0021] Which modification is selected will depend upon the nature of the gun. For pistols or other guns which have sliding or removable barrels, a barrel conversion may offer the simplest means of modifying the weapon. On the other hand, if the barrel is fixed, and the breech block is slidable, as with most rifles and machine guns, then the simplest conversion is to modify or change the firing pin to a rimfire firing pin.
[0022] In the case of a barrel modification, the centre fire firing pin of a gun prior to modification is arranged such that it strikes at a location which is central with regard to the bore or breech of the barrel, i.e. the centre line of the firing pin is coincident with the centre line of the barrel. After modification in accordance with the invention, the centre line of the bore of the barrel is offset relative to the centre line of the firing pin. This means that a firing mechanism incorporating a centre fire firing pin will not impact against the sensitive central area of a centre fire cartridge but will instead impact against the rim. Thus, the modification to the barrel allows rimfire training cartridges to be fired but prevents the corresponding centre fire live ammunition from being detonated.
[0023] A further advantage of the offset of the bore is that the bore can be inclined with respect to the axis of the barrel thereby providing a means of correcting the trajectory of the low velocity projectile without the user of the gun needing to make any changes to his normal sighting.
[0024] In cases where it is more appropriate to modify the firing pin, rather than the barrel, the centre line of the firing pin may still be aligned with the centre line of the bore of the barrel but the modified pin typically has a laterally extended leading end portion, the laterally extended leading end portion having a leading surface profiled such that it impacts against the rim of a rimfire primer but not against the centre of a centre fire primer. The laterally extended leading end portion can be laterally extended in one plane or in two planes.
[0025] For example, when it is extended in one plane, the end of the pin can take the form of a flat spade-like structure that slides in a slot cut into the breech block. The flat spade-like structure may have one or two (and preferably two for balance) forwardly oriented projections at the edges thereof for impacting against the rim of a rimfire primer but not the central impact area of a centre fire primer.
[0026] When the leading end portion of the modified firing pin is laterally extended in two planes, it can, for example, have a cylindrical form. In such a case, the leading surface can have one or more (preferably more than one) discrete projections protruding forwardly therefrom, or the leading surface can be provided with a forwardly projecting annular rim having a diameter such that it impacts against the impact area of a rimfire primer but not the impact area of a centre fire primer.
[0027] In order to reduce still further the possibility of a centre fire primer being detonated by the modified pin (for example as a consequence of a piece of particulate matter or debris between the firing pin and cartridge), the region of the leading surface between or inwardly of the projection(s) can be cut away, at least over the area that would overlap with the impact area of a centre fire primer.
BRIEF DESCRIPTION OF THE DRAWING
[0028] The invention will now be illustrated, but not limited, by reference to the particular embodiments shown in the accompanying schematic drawings, FIGS. 1 to 9 .
[0029] FIG. 1 is a side sectional elevation through a centre fire primer.
[0030] FIG. 2 is a side sectional elevation through a rimfire primer.
[0031] FIG. 3 is a schematic elevation of a conventional arrangement of a centre fire primer in a gun fitted with a centre fire firing pin.
[0032] FIG. 4 is a schematic elevation of a conventional arrangement of a rimfire primer in a gun fitted with a rimfire firing pin.
[0033] FIG. 5 illustrates schematically part of a standard centre fire pistol having a barrel containing a centre fire primer cartridge.
[0034] FIG. 6 illustrates schematically the centre fire gun of FIG. 5 but wherein the barrel has been replaced by a modified barrel.
[0035] FIG. 7 illustrates a standard rifle fitted with a centre fire firing pin and containing a centre fire primer cartridge.
[0036] FIG. 8 illustrates the rifle of FIG. 7 but with a modified firing pin.
[0037] FIG. 9 illustrates an explosive blank cartridge having a peripheral fire primer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] A peripheral fire primer for use in a cartridge according to the invention is shown in FIG. 2 and comprises a can 102 , the closed end of which is formed to provide a hollow peripheral rim area 103 . A pyrotechnic primer composition 104 is placed in the can and the can is spun thereby forcing the pyrotechnic material into the hollow peripheral rim area 103 . With the primer of FIG. 2 , the impact area I′ is annular in shape and extends around the peripheral rim of the primer. As can be seen from FIGS. 1 and 2 together, for cartridges of the same calibre, there will be a dead zone S between the impact region I of a centre fire primer, and the impact region I′ of a peripheral fire region in which any impact will not detonate the primer. When a cartridge containing the primer of FIG. 2 is placed in a weapon having an appropriately configured and aligned firing pin and the weapon is fired, the firing pin strikes impact area I′ and compresses the pyrotechnic composition between the two walls 103 a and 103 b of the hollow rim region 103 , the shock imparted to the pyrotechnic composition causing it to detonate.
[0039] Referring now to FIG. 3 , there is shown a conventional arrangement of a gun 200 having a centre firing pin 202 , a training cartridge 204 being inserted into the breech thereof. In this case, in accordance with conventional practice, the cartridge 204 has a centre fire primer 206 fitted into the end thereof, the primer being of the type shown in FIG. 1 . It will be noticed that the centre line L 1 of the firing pin 202 is coincident with the centre line L 2 of the barrel of the gun.
[0040] In FIG. 4 , there is shown an arrangement in which a gun 300 has been modified to provide it with a peripheral fire firing pin 302 which is offset from the centre line of the barrel so that it can fire a training cartridge 304 having a peripheral fire primer 306 of the type shown in FIG. 2 .
[0041] As indicated above, a problem with centre fire training cartridges is that on occasions training cartridges and live killing ammunition can become confused. In order to avoid this problem the invention provides a training cartridge which is detonated by impact on the peripheral rim of the primer, and makes use of a gun which is specially modified to allow use of the peripheral fire primer.
[0042] FIG. 5 shows a standard centre fire pistol into which has been inserted a cartridge having a centre fire primer. The arrangement shown in this Figure corresponds to FIG. 3 except that the barrel of the pistol is removable. FIG. 6 shows a modification of the gun shown in FIG. 5 . As demonstrated in FIG. 6 , the gun is still provided with a centre fire firing pin 410 which, with a normal gun barrel, would allow the firing of centre fire cartridges. However, in order to prevent centre fire cartridges from being fired, the gun is converted by replacing the normal gun barrel with a gun barrel 412 in which the bore 414 is offset. As can be seen from FIG. 6 , the bore 414 is inclined at an angle α with regard to the axis 16 of the barrel. The centre line of the bore 414 is also inclined with respect to the centre line of the firing pin 410 .
[0043] If a training cartridge having a peripheral fire primer is inserted into the breech, the relative geometry of the gun barrel and firing pin are such that the firing pin can fire the cartridge. On the other hand, if a centre fire cartridge (for example a live killing cartridge) is inserted into the gun barrel, the firing pin 410 will fail to strike the centre fire impact area 318 , and hence the cartridge will not detonate. Thus, the modification of the invention greatly enhances the safety in that it prevents live killing ammunition from being inadvertently mixed with training ammunition.
[0044] A further advantage of the arrangement shown in FIG. 6 is that it can enable training ammunition to be used more accurately. One of the problems with training ammunition is that the low velocity means that the bullet will often fall away before it reaches a target, and consequently there will be a tendency for the user to compensate for this by aiming above the target. Thus shooting at targets using low velocity ammunition can be less realistic than is desirable. With the gun barrel arrangement shown in FIG. 6 , the user of the gun can fix his sights on the target in the normal way, and the angle of the bore, rather than the angle of the barrel, provides the necessary correction to enable the projectile to reach its target. Thus, the range of the training ammunition is much closer to the range of normal live killing ammunition.
[0045] The modification shown in FIG. 6 is particularly suited to pistols since in many cases the barrel of a pistol can be removed fairly easily. However, the barrels of rifles are typically fixed and hence a barrel modification of the type shown in FIG. 6 would involve somewhat more complex alterations to the gun and would not be a practical proposition.
[0046] Therefore, with rifles and machine guns and other firearms with fixed non-sliding barrels, it is easier to modify the firing pin and this is demonstrated in FIGS. 7 and 8 .
[0047] FIG. 7 shows a part of a conventional rifle equipped with a centre firing pin and having a centre fire training bullet inserted in the breech thereof. FIG. 8 illustrates the same rifle but wherein the firing pin has been modified. Thus the firing pin is no longer pin-shaped but instead has a leading end which is extended laterally to give a spade-like shape. The leading surface of the leading end has forwardly oriented projections 512 at either edge thereof, the projections being aligned with the impact region 514 of the peripheral fire primer 513 of the cartridge. The central part 516 of the leading end is recessed, the width of the recess being at least as great as the width of the impact area of the centre fire primer 318 . In use, when the weapon is fired, the projections 512 on the edges of the leading end of the modified firing pin impact against the sensitive impact region of the peripheral fire primer to detonate the primer. However, if a cartridge (e.g. a live killing round) having a centre fire primer is inadvertently inserted into the gun, it will not be detonated. The safety of the modified firing pin arrangement shown in FIG. 8 is further enhanced by virtue of the recessed central region 516 which ensures that centre fire primers cannot accidentally be detonated as a result of the presence of particles of debris between the firing pin and cartridge.
[0048] The modified firing pin of FIG. 8 can be fitted, for example, by shortening an existing firing pin, cutting a thread on the end thereof, and fixing the threaded end into a suitably profiled end piece. The circular channel or opening in which the firing pin normally slides is machined out to form a slot to accommodate the spade-like shape of the end piece.
[0049] FIG. 9 illustrates an explosive blank cartridge that can be fired in the modified gun of FIG. 8 . The blank cartridge comprises a casing 602 closed at its nose 604 and containing an explosive material 606 . The rear end of the blank cartridge has a flange 608 to enable the spent cartridge to be extracted from the breech in the usual manner. Thus far, the blank cartridge is of conventional construction. However, the cartridge differs from conventional blank cartridges in that the primer 610 set into the centre of the rear of the cartridge is a peripheral fire primer. The primer 610 , which can be of the form shown in FIG. 2 or an appropriate modification thereof, comprises a cup or can 612 having a hollow peripheral rim 614 containing compressed primer material. In use, the off centre firing pin 616 of the gun impacts against the peripheral rim 614 thereby detonating the primer material which in turn detonates the explosive material 606 . Expanding gases created by the detonation of the primer and explosive material burst through the nose 604 in the usual manner to give a realistic bang.
[0050] The foregoing examples illustrate merely some of the ways in which the invention can be put into effect, and it will readily be apparent that numerous modifications and alterations can be made to the arrangements shown in the accompanying drawings without departing from the principles underlying the invention. All such modifications and alterations are intended to be embraced by this application. | The invention provides a training cartridge having a peripheral fire primer and a gun modified to fire the cartridge. The combination of modified gun and peripheral fire cartridge avoids the potentially adverse consequences that could arise if live ammunition and training ammunition were to become inadvertently confused or mixed up by preventing the firing of live center fire ammunition. | 24,502 |
[0001] The present invention relates to the connection of a lithium or lithium alloy foil electrode or electrodes to a contact lead, so as to promote good electrical and mechanical contact therebetween.
BACKGROUND
[0002] Primary and rechargeable batteries using metallic lithium as the active material for the negative electrode are known to have the highest energy per unit weight. In such batteries, the negative electrode, or anode, may be a lithium or lithium alloy foil component having a negative potential. The negative electrode may also include a current collector and a contact tab.
[0003] A current collector is an electrically conductive metallic foil, sheet or mesh that is generally used to provide a path for electrons from the external electrical circuit to the electrochemically active portion of the battery. A current collector will typically include a contact tab.
[0004] A contact tab is typically a metal foil portion of the current collector, which does not take part in the electrochemical process. It may extend from an edge of the main body of the current collector and is used to form the mechanical base for a weld to a contact lead.
[0005] A contact lead is a piece of electrically conductive metallic material used to form an electrical contact from the contact tab through a hermetically sealed battery container to the external electrical circuit. It is typically welded (in cells where metallic lithium is not used) or mechanically connected to the contact tab.
[0006] The contact lead must be connected or joined to the lithium in such a manner that a low resistance electrical connection is formed. Further, the connection or join must be mechanically strong enough to last for the expected life of the battery.
[0007] The current collectors in lithium primary batteries are typically composed of a metallic conductor other than lithium. The contact lead may be exposed to the electrolyte in an electrochemically active zone of the battery. This is not generally a problem in primary batteries; however it may cause problems in rechargeable (or secondary) batteries. In secondary batteries, lithium must be electrochemically deposited when the battery is recharged. In order to provide good reproducibility of performance, when the battery is repeatedly recharged, an excess of lithium is used so that lithium is only ever deposited onto lithium. If the contact lead or current collector is left exposed, then lithium will be plated onto a non-lithium substrate. This greatly increases the probability of unpredictable lithium deposition and hence poor cycling performance. This typically takes the form of active dendrite formation resulting in the quick degradation of the rechargeable lithium system. Examples of such failure mechanisms are described in U.S. Pat. No. 5,368,958, the full disclosure of which is incorporated into the present application by reference.
[0008] In a secondary battery with a lithium-based anode, the lithium is typically connected to the external circuit by one of two methods. Either a contact lead similar in design to that described for primary lithium batteries is used; as in U.S. Pat. No. 7,335,440, the full disclosure of which is incorporated into the present application by reference. U.S. Pat. No. 7,335,440 discloses the provision of a current collector in the form of a flat, solid piece of titanium, nickel, copper or an alloy of nickel or copper. The current collector is provided with a contact tab. A relatively long strip of alkali metal foil, having a width similar to the height of the current collector, is placed under the current collector and the two are pressed together. It is to be noted that, following assembly of the battery, the current collector (which is not made of an alkali metal) is immersed in electrolyte. Moreover, U.S. Pat. No. 7,335,440 states that this arrangement has problems in coiled, anode-limited cells of the type disclosed therein since there is a potential for a short circuit to be formed between the cathode material and the anode current collector when the thin layer of lithium has substantially depleted into the cathode in the outermost winding.
[0009] A variation of this method uses the metallic cell casing for the dual purpose of collecting current from the lithium, as in U.S. Pat. No. 7,108,942, the full disclosure of which is incorporated into the present application by reference. Additionally, the reverse face of the lithium electrode may be pressed or rolled against a thin metal current collector, as in U.S. Pat. No. 5,368,958, the full disclosure of which is incorporated into the present application by reference. The current collector can then be welded to a metal contact lead. However, if the current collector becomes exposed to the electrolyte, there is a risk that lithium will be plated onto the non-lithium current collector with the possible formation of dendrites that may short-circuit the battery. The metal current collector also adds unnecessary mass to the battery and reduces its specific energy.
[0010] In all of the examples described above, the metallic lithium is merely placed or pressed into contact with the current collector; there is no physical or chemical bond. This may be acceptable for primary batteries. However, for lithium metal rechargeable batteries such contact is not reliable. Indeed due to the reactive character of metallic lithium, corrosion layers may readily form on the interface of the mechanical connection between the lithium and the current collector. This may result in lower battery reliability as well as faster degradation in the capacity and cycle life of rechargeable lithium metal batteries.
BRIEF SUMMARY OF THE DISCLOSURE
[0011] Viewed from one aspect, there is provided a method of connecting at least one electrode to a contact lead, wherein the electrode comprises a sheet or foil having a contact zone, and wherein the contact lead comprises an electrically conductive lead with an end portion, the method comprising the steps of:
[0012] positioning the end portion of the contact lead and the contact zone of the at least one electrode so that there is overlap between the end portion and the contact zone;
[0013] ultrasonically welding the contact zone to the end portion so as to join the at least one electrode to the contact lead,
[0014] wherein at least the contact zone of the sheet or foil is formed from an alkali metal or an alloy of an alkali metal.
[0015] Preferably, the entire sheet or foil is formed from an alkali metal or an alloy of an alkali metal. The alkali metal may be lithium. Lithium metal and lithium allows are preferred as these tend to be useful as anode materials in secondary batteries, and are also soft and malleable, which allows a good connection to be made with the end portion of the contact lead when the welding step is performed.
[0016] Preferably, the contact zone is provided on a tab that protrudes from the edge of the sheet or foil. In a preferred embodiment, the tab provides the only point of contact between the sheet or foil and the end portion of the contact lead. Accordingly, the sheet or foil of the electrode may include a region for contact with the electrolyte that is not in direct contact with the end portion of the contact lead. The ultrasonic weld is preferably provided in a region that is not in contact with any of the electrolyte in the electrochemical cell or battery.
[0017] Preferably, there is no current collector in direct contact with the region for contact with the electrolyte. In fact, the electrode may be devoid of a current collector altogether.
[0018] Preferably, the end portion is formed from a metal that does not form an alloy with the alkali metal or alloy of alkali metal used to form the tab. Examples include metals or metal alloys comprising at least one of copper and/or nickel.
[0019] Without wishing to be bound by any theory, the ultrasonic welding step is believed to cause metal of the tab and/or the end portion to melt or soften, allowing the tab and end portion to be welded together under the applied pressure. The ultrasonic acoustic vibrations may also remove or disperse at least part of the alkali metal oxide layer formed on the tab, facilitating the formation of the bond. An advantage of the present invention is that melting or softening can be confined to the area of the join or weld, allowing a strong bond to be formed over a relatively small area. The area of the weld may be less than 50%, preferably less than 30%, more preferably less than 20%, yet more preferably, less than 10% (e.g. 1-5%) of the area of the sheet or foil.
[0020] Preferably, the ultrasonic welding step is carried out at frequencies of 15 to 70 kHz, more preferably 20 to 60 kHz, even more preferably 20 to 40 kHz, for example, about 40 kHz. The ultrasonic welding step may be carried out at a maximum pressure of 0.4 MPa, preferably 0.1 to 0.4 MPa, for example, 0.2 MPa.
[0021] The ultrasonic welding step may be carried out at a power of 100 to 5000 Watts. Amplitudes of 2 to 30 urn may be used.
[0022] In one embodiment, the ultrasonic welding step is carried out using an apparatus comprising a first clamping portion and a second clamping portion. The first clamping portion and second clamping portion are movable relative to one another from a first spaced apart position to a second position in which the first and second clamping portions are closer to one another. Preferably, only the second clamping portion is movable; the position of the first clamping portion is fixed.
[0023] The first clamping portion acts as a support for the materials to be welded. The second clamping portion is configured to vibrate at an ultrasonic frequency. To perform the welding step, the end portion of the contact lead is placed in contact with the contact zone of the at least one electrode so that there is overlap between the end portion and the contact zone. The overlapping structure is then placed between the first and second clamping portions, preferably on top of the first clamping portion. Optionally, a positioning jig may be used to support the overlapping structure in position. The second clamping portion is then moved relative to the first clamping portion so as to apply a clamping pressure between the materials to be welded. The second clamping portion is then vibrated at ultrasonic frequency. This pre-shapes and rubs the electrode and end portion of the contact lead against one another to prepare the surfaces for the formation of a join. The amplitude of the ultrasonic vibrations plays an important part in pre-shaping and preparing the relevant parts for weld formation. The first clamping portion is typically held in a fixed position while the second clamping portion vibrates. The contact zone of the electrode and end portion of the contact zone are then welded together in the main welding phase.
[0024] The end portion of the contact lead may be substantially flat or planar, or may take other shapes or configurations depending, for example, on the shape or configuration of the welding equipment that is used.
[0025] In one embodiment, a method of connecting at least one electrode to a contact lead, wherein the electrode comprises a sheet or foil having a contact zone, and wherein the contact lead comprises an electrically conductive lead with an end portion, the method comprising the steps of:
[0026] positioning the end portion of the contact lead and the contact zone of the at least one electrode so that there is overlap between the end portion and the contact zone;
[0027] ultrasonically welding the contact zone to the end portion so as to join the at least one electrode to the contact lead,
[0028] wherein at least the contact zone of the sheet or foil is formed from an alkali metal or an alloy of an alkali metal.
[0029] In some embodiments, there may be provided a plurality of electrodes, each comprising a sheet or foil with a tab (defining a contact zone) protruding from each sheet in substantially the same location, so that the tabs of the stack of electrodes are substantially aligned when the electrodes are aligned with each other and arranged as an electrode stack. For the avoidance of doubt, the tab defining the contact zone is formed of an alkali metal or an alloy of an alkali metal, preferably lithium or lithium alloy.
[0030] In these embodiments, the end portion of the contact lead may be placed on top of the tabs of the electrode stack, underneath the tabs of the electrode stack, or at an intermediate position between the top and the bottom (i.e. with at least one tab above and at least one tab below). The tabs of the electrode stack may be pressed together before the end portion is placed on top of or underneath the compressed tabs and the ultrasonic welding is performed.
[0031] In embodiments where there is provided a stack of electrodes, the welding step causes the tabs to bond together physically. Preferably, the ultrasonic welding step causes the tabs (contact zones) of at least two sheets or foils formed from an alkali metal or an alloy of an alkali metal to be welded together. In a preferred embodiment, the ultrasonic welding step creates, for example, a lithium to lithium weld in addition to a weld between lithium and the end portion of the contact lead.
[0032] The end portion of the contact lead may be planar and devoid of through-holes. Alternatively, the end portion may optionally be perforated, punched or have a mesh-like or reticulated form. When such through-holes are present, it is important is that the metal of the tabs is sufficiently malleable to enable it to pass through the through holes so as to cause the end portion to become embedded in what is preferably a single phase of the first metal. This forms an intimate contact between the metals of the end portion of the contact lead and the contact zone of the electrode, and thus between the contact lead and the electrode.
[0033] Where the end portion has through-holes, the openness of the end portion may be defined as the ratio of open area to the full surface area of the end portion. The openness of the end portion of the contact lead may be in the range of 5% to 95%, preferably 20% to 90%, for example, 50% to 80%.
[0034] The electrically conductive lead of the contact lead may itself be generally planar, for example in the form of a ribbon, although other profiles may be useful. The electrically conductive lead may be made of the same metal as the end portion, or of a different metal.
[0035] In this way, it is possible for form a reliable connection with a contact lead made of a metal other than the metal of the electrode. It will be understood that the contact lead, which will generally be exposed outside the casing of the battery, must be made of a metal that has good electrical conductivity but is not highly reactive when exposed to air or moisture. Suitable metals include nickel, copper, stainless steel or various alloys.
[0036] Moreover, the metal of the contact lead, since it is connected only to the protruding tabs of the electrodes, is desirably not directly exposed to electrolyte when the battery is assembled.
[0037] A further advantage is that a good connection can be made to the at least one electrode without the electrode as a whole needing to be formed or disposed on a current collector made of a metal other than the metal used in the sheet or foil of the electrode. In other words, the main part of the electrode that is exposed to the electrolyte consists solely of the first metal (e.g. lithium or a lithium alloy), with no need for a copper or nickel or other current collector that would add unnecessary weight and act as a substrate for the formation of dendrites during cycling.
[0038] Moreover, it is important that the metal of the contact lead is selected so that it does not form an alloy with the metal of the electrode. This is in order to avoid reduction of the amount of the first metal that is available to the electrochemical system of the battery. For example, lithium will form an alloy with aluminium, but not with nickel or copper.
[0039] According to a further aspect of the invention, there is provided a device obtainable according to the method described above. The device comprises at least one electrode comprising a sheet or foil having a contact zone formed from an alkali metal or an alloy of an alkali metal, and a contact lead comprising an electrically conductive lead with an end portion, wherein the end portion of the contact lead overlaps and is ultrasonically welded to the contact zone of the at least one electrode.
[0040] Preferably, the device comprises at least two electrodes comprising a sheet or foil having a contact zone formed from an alkali metal or an alloy of an alkali metal, and wherein at least a portion of said contact zones are ultrasonically welded to one another. Thus, for example when the contact zone is formed from lithium or a lithium alloy, an ultrasonic weld between lithium/lithium alloy and lithium/lithium alloy is formed.
[0041] In one embodiment of the device, at least two electrodes are aligned with each other and arranged as an electrode stack. The end portion of the contact lead may be placed on top of or underneath the electrode stack, such that the end portion overlaps and is ultrasonically welded to the contact zone of the at least one electrode. Alternatively, the end portion of the contact lead may be placed at an intermediate position between the top and the bottom of the electrode stack. In the latter embodiment, the contact zones on either side of the end portion of may preferably also be ultrasonically welded to one another. Accordingly, an alkali metal/alkali metal alloy to alkali metal/alkali metal alloy ultrasonic weld may also be formed.
[0042] Viewed from another aspect, there is provided a method of connecting at least one electrode to a contact lead, wherein the electrode comprises a sheet or foil of a first metal with a tab protruding from an edge of the sheet or foil, and wherein the contact lead comprises an electrically conductive lead with an end portion made of a second metal that does not alloy with the first metal and having a plurality of through holes, the method comprising the steps of:
[0043] i) positioning the end portion of the contact lead and the tab of the at least one electrode so that there is substantial overlap between the end portion and the tab;
[0044] ii) causing the metal of the tab to penetrate through the through holes of the end portion so as to join the at least one electrode to the contact lead.
[0045] In step ii), the metal of the tab may be caused to penetrate through the through holes by pressing and welding, for example by way of ultrasonic welding, thermal contact welding, laser welding or induction welding. Advantageously, the welding is effected in such a way so as not to cause significant thermal deformation or changes in the main laminar sheet or foil of the at least one electrode, but to concentrate the applied energy in the locality of the tab.
[0046] The end portion of the contact lead may be substantially flat or planar, or may take other shapes or configurations depending, for example, on the shape or configuration of any welding equipment that is used.
[0047] In some embodiments, there may be provided a plurality of electrodes, each comprising a sheet or foil of metal with a tab protruding from each sheet in substantially the same location, so that the tabs of the stack of electrodes are substantially aligned when the electrodes are aligned with each other and arranged as an electrode stack.
[0048] In these embodiments, the end portion of the contact lead may be placed on top of the tabs of the electrode stack, underneath the tabs of the electrode stack, or at an intermediate position between the top and the bottom (i.e. with at least one tab above and at least one tab below). The tabs and the perforated end portion are then pressed together and the first metal (of the tabs) is caused to penetrate through the holes in the perforated planar end portion (made of the second metal) of the contact lead. Alternatively, the tabs of the electrode stack may be pressed together before the perforated end portion is placed on top of or underneath the compressed tabs and the penetration of step ii) is performed.
[0049] In embodiments where there is provided a stack of electrodes, the pressing and welding step causes the tabs to join together physically as well as to penetrate into the through holes of the contact lead. Preferably, the welding step is an ultrasonic welding step. This welding step preferably causes the tabs of at least two sheets or foils (preferably formed from an alkali metal or an alloy of an alkali metal) to be welded together. In a preferred embodiment, the ultrasonic welding step creates, for example, a lithium to lithium weld between at least two lithium tabs in addition to a weld between at least one lithium tab and the end portion of the contact lead.
[0050] Particularly preferred metals for the first metal are lithium and lithium alloys, since these tend to be useful as anode materials in secondary batteries, and are also soft and malleable, which allows a good connection to be made with the perforated end portion of the contact lead when the pressing and welding step is performed.
[0051] The end portion of the contact lead may be perforated, punched or have a mesh-like or reticulated form. What is important is that when the first metal of the tabs is sufficiently malleable that it can pass through the through holes so as to cause the second metal of the end portion to become embedded in what is preferably a single phase of the first metal. This forms an intimate contact between the first and second metals, and thus between the contact lead and the electrodes.
[0052] The greater the openness or surface area of the end portion of the contact lead, the better the electrical (and physical) connection between the contact lead and the electrodes. The openness of the end portion may be defined as the ratio of open area to the full surface area of the end portion. The openness of the end portion of the contact lead may be in the range of 5% to 95%.
[0053] The electrically conductive lead of the contact lead may itself be generally planar, for example in the form of a ribbon, although other profiles may be useful. The electrically conductive lead may be made of the same metal as the second metal forming the end portion, or of a different metal.
[0054] In this way, it is possible for form a reliable connection with a contact lead made of a metal other than the metal of the electrode. It will be understood that the contact lead, which will generally be exposed outside the casing of the battery, must be made of a metal that has good electrical conductivity but is not highly reactive when exposed to air or moisture. Suitable metals include nickel, copper, stainless steel or various alloys.
[0055] Moreover, the metal of the contact lead, since it is connected only to the protruding tabs of the electrodes, is not directly exposed to electrolyte when the battery is assembled.
[0056] A further advantage is that a good connection can be made to the at least one electrode without the electrode as a whole needing to be formed or disposed on a current collector made of a metal other than the first metal. In other words, the main part of the electrode that is exposed to the electrolyte consists solely of the first metal (e.g. lithium or a lithium alloy), with no need for a copper or nickel or other current collector that would add unnecessary weight and act as a substrate for the formation of dendrites during cycling.
[0057] Moreover, it is important that the second metal (of the contact lead) is selected so that it does not form an alloy with the first metal (of the electrode). This is in order to avoid reduction of the amount of the first metal that is available to the electrochemical system of the battery. For example, lithium will form an alloy with aluminium, but not with nickel or copper.
[0058] In certain embodiments, the electrode is configured as an anode, or negative electrode, for a battery. However, it will be appreciated that the method is applicable also to cathodes, or positive electrodes, where these are made of a metal that is suitable for pressing and welding to a perforated second metal as described.
[0059] Viewed from a third aspect, there is provided, in combination, at least one electrode for a battery and a contact lead, wherein the electrode comprises a sheet or foil of a first metal with a tab protruding from an edge of the sheet or foil, and wherein the contact lead comprises an electrically conductive lead with an end portion made of a second metal that does not alloy with the first metal and having a plurality of through holes, wherein the first metal of the tab has been pressed and welded so as to penetrate through the through holes of the second metal end portion.
[0060] Embodiments of the present invention seek to provide a negative electrode (anode) eliminating the need for the current collector, and a method of forming a reliable physical contact between different pieces of metallic lithium and the contact lead, thereby to promote good electrical contact between metallic lithium and the material of the contact lead.
[0061] In preferred embodiments, an excess of metallic lithium is used such that at the end of the battery life there is a substantial amount of lithium metal which serves as the current collector for the negative electrode. The use of lithium as the current collector eliminates mechanical contact between metal lithium and another current collector material.
[0062] In some embodiments, there may be provided a plurality of electrodes, each comprising a sheet or foil of the first metal with a tab protruding from each sheet in substantially the same location, so that the tabs of the stack of electrodes are substantially aligned when the electrodes are aligned with each other and arranged as an electrode stack.
[0063] The lithium metal of the negative electrode in the region of the tabs may form a single phase connection from lithium electrode to lithium electrode in the electrode stack. Such connection is achieved by using pressing and welding as hereinbefore described.
[0064] The contact lead, or at least the end portion thereof, may be thin (for example, with a thickness of 5 to 50 μm), or may be thick (for example, with a thickness of 50 to 10,000 μm).
[0065] The contact lead may be substantially linear, or may have a ‘T’-shaped or ‘L’-shaped configuration.
[0066] The sheet or foil of the electrode may have a thickness of 30 to 150 μm, for example, 50 to 100 μm prior to the welding or joining step.
[0067] The end portion of the contact lead may be an integral part of the contact lead (in other words, formed from the same material as the rest of the contact lead and integral therewith), or may be a separate metal component, not necessarily of the same material as the rest of the contact lead, and welded thereto (for example by ultrasonic welding, thermal contact welding, laser welding, induction welding or other types of welding).
[0068] The electrodes described above may be used in a battery or electrochemical cell, preferably a lithium cell, such as a lithium-sulphur cell. The electrodes may be used as the anode of such cells. In one embodiment, the cell comprises i) at least one electrode as described above as the anode(s), and ii) at least one cathode, such as a cathode comprising sulphur as an active material. The anode(s) and cathode(s) may be placed in contact with a liquid electrolyte comprising a lithium salt dissolved in an aprotic organic solvent. A separator may be positioned between the anode and cathode. The electrolyte may be sealed within a container to prevent it from escaping. Preferably, the seal also prevents the alkali metal of the sheet or foil from being exposed to the surrounding environment. Thus, the weld between the contact zone or tab and the end portion of the contact leas is preferably located within the container, while at least a portion of the conductive lead accessible from outside of the sealed container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:
[0070] FIGS. 1 a to 1 c shows a battery stack with anodes, cathodes and tabs, and three alternative positionings for a contact lead;
[0071] FIGS. 2 a to 2 e show possible designs for the contact lead;
[0072] FIG. 3 shows the contact lead being ultrasonically welded to the tabs; and
[0073] FIGS. 4 a to 4 d show an apparatus suitable for use in forming an ultrasonic weld in use.
DETAILED DESCRIPTION
[0074] A battery can be formed by an alternating stack of numerous cathodes and anodes. Each of these layers is divided by a separator. An ionic pathway is maintained by the presence, between each electrode, of an electrolyte. Each electrode 1 features a tab 2 protruding from its electrochemically active area and beyond the edge of the separator. These tabs 2 provide the first surface through which the stack 3 of lithium anodes will be welded to each other and joined to a contact lead 4 . The tabs 2 are first folded and/or formed by pressing. A contact lead 4 is then positioned at the top ( FIG. 1 a ) or bottom ( FIG. 1 b ) of the stack 5 of tabs 2 , or it may be positioned between any two lithium tabs 2 ( FIG. 1 c ).
[0075] The contact leads 4 may take a number of forms ( FIGS. 2 a to 2 e ). The body 6 is composed of a conductive metal ribbon, typically nickel, copper, stainless steel or some composite conductor. The end portion 7 (the area to be welded) may be perforated, meshed or punched. Alternatively, the end portion 7 may be devoid of any through-holes (not shown). The end portion 7 may be an integral part of the metal ribbon 6 , or it may be a separate piece welded to the ribbon 6 . Where the end portion 7 is a separate piece welded to the ribbon 6 , it may be made of a different metal to that of the ribbon 6 . The contact may be linear, “T” or “L” shaped. The perforations, when present, may be rhombic, circular, square, rounded, polygonal or any other suitable shape.
[0076] The tabs 2 and the contact lead 4 are then positioned between the two weld fixtures 8 of an ultrasonic welder ( FIG. 3 ). The ultrasonic welder then simultaneously applies pressure and an ultrasonic wave to the weld area. This causes the numerous lithium layers 2 to fuse together to form a lithium-lithium weld. Further, where the contact lead 4 includes through holes, the softened lithium percolates through the perforated or meshed area 7 of the contact lead 4 . The contact lead 4 is hence joined to the lithium 2 as the mesh 7 is intimately surrounded by lithium. The high surface area contact between the mesh 7 of the contact lead 4 and the lithium electrode 1 produces a low resistance and a mechanically strong electrical contact. When the ultrasonic wave ceases and the pressure is released, the contact lead 4 will be joined to the lithium anodes 1 .
[0077] FIGS. 4 a to 4 e depict an apparatus that may be used for forming an ultrasonic weld. The apparatus comprises a first clamping portion 12 and a second clamping portion 14 that are movable from a first spaced apart position to a second position where the portions 12 , 14 are closer to one another. The apparatus also includes a positioning jig 16 for supporting the parts 18 to be welded in position. The second clamping portion 14 is configured to vibrate at ultrasonic frequencies.
[0078] As best seen in FIG. 4 a , the parts 18 to be welded are placed on top of the first clamping portion 12 while the clamping portions are in their first spaced apart position. The second clamping portion 14 is then moved relatively towards the first clamping portion 12 to apply a clamping pressure between the parts 18 to be welded. The second clamping portion 14 is then vibrated at ultrasonic frequency ( FIG. 4 b ). This pre-shapes and rubs the parts 18 together, so that their surfaces are prepared for weld formation. In the main welding phase, the parts 18 are joined together (see FIG. 4 c ). The first and second clamping portions 12 , 14 are then moved apart to allow the welded parts 18 to be removed from the apparatus (see FIG. 4 d ).
Example 1
[0079] A linear nickel contact lead, composed of 50 μm thick nickel ribbon, was used. The endmost 5 mm of the contact lead was expanded to form a mesh. A battery with 60 lithium anodes, each of 78 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The lithium contact tabs were formed and trimmed to produce a flat welding area and to ensure that each of the tabs, regardless of its position, in the stack used the minimum quantity of lithium. The formed stack of lithium tabs was then positioned between the welding fixtures of an ultrasonic welder. The contact lead was then positioned on top of the stack of lithium tabs, such that the meshed region overlapped with the flat lithium welding zone. The welding conditions listed in Table 1 were then entered into an AmTech 900B 40 kHz ultrasonic welder. A single weld was then performed. Each of the 60 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the contact lead. This join had been created by the softened lithium penetrating through the mesh of the contact lead.
[0000]
TABLE 1
The welder setting used in Example 1.
Energy/J
Amplitude/μm
Trigger Pressure/Psi
Pressure/Psi
180
5
20
20
Example 2
[0080] A “T” shaped contact lead was made by welding a piece of nickel ribbon (50 μm thick) to a piece of copper mesh. The mesh opening was approximately 200×700 μm, with a bar width of 100 μm. The mesh was thrice as long as the nickel ribbon was wide. The mesh was 5 mm wide; the same as the welding zone. The mesh was positioned centrally to form the cross of the “T” and welded into position by an ultrasonic welder using the conditions given in Table 2, weld A. The contact lead was positioned between the welding fixtures of an ultrasonic welder such that the meshed region fell into the welding zone.
[0081] A battery with 20 lithium anodes, each of 78 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The stack of lithium contact tabs was formed and trimmed to produce a flat welding area and to ensure that each of the contact tabs, regardless of its position, in the stack used the minimum quantity of lithium.
[0082] The stack of lithium contact tabs was then positioned on top of the contact lead, between the welding fixtures of an ultrasonic welder. The copper mesh “arms” of the “T” shaped contact lead were then folded around the stack of lithium contact tabs. The welding conditions listed in Table 2, weld B were then entered into an AmTech 900B 40 kHz ultrasonic welder. A single weld was then performed. Each of the 20 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the contact lead. This join had been created by the softened lithium penetrating through the mesh of the contact lead.
[0000]
TABLE 2
The welder settings used in Example 2
Weld
Energy/J
Amplitude/μm
Trigger Pressure/Psi
Pressure/Psi
A
70
80
80
5
B
10
5
20
20
Example 3
[0083] An “L” shaped contact lead was manufactured by photochemical etching from a sheet of 100 μm thick stainless steel. The upright section of the “L” is continuous steel foil. The base of the “L” was etched with a mesh pattern. The mesh opening was 500×500 μm and the bar width was 100 μm. The base of the “L” was twice the width of the upright section. The width of the base section was 5 mm, the same as the weld zone.
[0084] A battery with 20 lithium anodes, each of 78 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The contact lead was positioned between the top face to the lowermost lithium contact tab and the bottom face of the remainder of the stack. The remainder of the stack of lithium contact tabs was pushed down onto the meshed region of the contact lead. The protruding meshed section of the contact lead was folded over the stack of contact tabs. The contact assembly was positioned between the welding fixtures of an ultrasonic welder such that the meshed regions fell into the welding zone.
[0085] The welding conditions listed in Table 3 were then entered into an AmTech 900B 40 kHz ultrasonic welder. A single weld was then performed. Each of the 20 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the contact lead. This join had been created by the softened lithium penetrating through the mesh of the contact lead.
[0000]
TABLE 3
The welder settings used in Example 3
Energy/J
Amplitude/μm
Trigger Pressure/Psi
Pressure/Psi
40
5
20
20
Example 4
Nickel
[0086] A square shaped contact lead was made by cutting a piece of plane nickel foil (100 μm thick). The contact lead was positioned between the welding fixtures of an ultrasonic welder such that the welding zone was 1 mm from the tab edge. The welding zone was a rectangle (20×6 mm).
[0087] A battery with 9 lithium anodes, each of 100 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The stack of lithium contact tabs was formed and trimmed to produce a flat welding area and to ensure that each of the contact tabs, regardless of its position, in the stack used the minimum quantity of lithium. The trimmed edges of lithium tabs fully covered the welding zone at the nickel foil.
[0088] The stack of lithium contact tabs was then positioned on top of the contact lead, between the welding fixtures of an ultrasonic welder. The welding conditions are listed in Table 4. The welder is a NewPower Ultrasonic Electronic Equipment CO., LTD 40 kHz ultrasonic welder. A single weld was performed. Each of the 9 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the nickel contact lead. This join had been tested per peel test procedure.
[0000]
TABLE 4
Frequency
40 kHz
Welding Time sectors:
Delay
0.15 s
Welding
0.18 s
Take off
0.20 s
Amplitude
50% (of 10 μm)
Pressure
0.21 MPa
Power
350 W
Energy
350 J
Example 5
Copper
[0089] A square shaped contact lead was made by cutting a piece of plane copper foil (100 μm thick). The contact lead was positioned between the welding fixtures of an ultrasonic welder such that the welding zone was placed 1 mm from the tab edge. The welding zone was a rectangle (20×6 mm).
[0090] A battery with 9 lithium anodes, each of 100 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The stack of lithium contact tabs was formed and trimmed to produce a flat welding area and to ensure that each of the contact tabs, regardless of its position, in the stack used the minimum quantity of lithium. The trimmed edges of lithium tabs fully covered the welding zone at the copper foil.
[0091] The stack of lithium contact tabs was then positioned on top of the contact lead, between the welding fixtures of an ultrasonic welder. The welding conditions are listed in Table 5. The welder is a NewPower Ultrasonic Electronic Equipment CO., LTD 40 kHz ultrasonic welder. A single weld was then performed. Each of the 9 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the copper contact lead. This join had been tested per peel test procedure.
[0000]
TABLE 5
Frequency
40 kHz
Welding Time sectors:
Delay
0.15 s
Welding
0.16 s
Take off
0.20 s
Amplitude
50% (of 10 μm)
Pressure
0.20 MPa
Power
300 W
Energy
300 J
Example 6
Stainless Steel, 316
[0092] A square shaped contact lead was made by cutting a piece of plane stainless steel foil (58 μm thick). The contact lead was positioned between the welding fixtures of an ultrasonic welder such that the welding zone was placed 1 mm from the tab edge. The welding zone was a rectangle (20×6 mm).
[0093] A battery with 9 lithium anodes, each of 100 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The stack of lithium contact tabs was formed and trimmed to produce a flat welding area and to ensure that each of the contact tabs, regardless of its position, in the stack used the minimum quantity of lithium. The trimmed edges of lithium tabs fully covered the welding zone at the stainless steel foil.
[0094] The stack of lithium contact tabs was then positioned on top of the contact lead, between the welding fixtures of an ultrasonic welder. The welding conditions are listed in Table 6, were then entered into the NewPower Ultrasonic Electronic Equipment CO., LTD 40 kHz ultrasonic welder. A single weld was then performed. Each of the 9 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the stainless steel contact lead. This join had been tested per peel test procedure.
[0000]
TABLE 6
Frequency
40 kHz
Welding Time sectors:
Delay
0.15 s
Welding
0.18 s
Take off
0.20 s
Amplitude
80% (of 10 μm)
Pressure
0.21 MPa
Power
350 W
Energy
350 J
[0095] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.
[0096] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
[0097] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. | There is disclosed a method of connecting a lithium electrode to a contact lead in a rechargeable battery. The electrode comprises a sheet or foil of lithium or lithium alloy with a tab protruding from an edge of the sheet or foil. The contact lead comprises an electrically conductive lead with an end portion made of a second metal that does not alloy with lithium and has a plurality of through holes. The end portion of the contact lead and the tab of the electrode are positioned so that there is substantial overlap between the end portion and the tab. The metal of the tab is then caused, for example by pressing and welding, to penetrate through the through holes of the end portion so as to join the electrode to the contact lead. A combination electrode/contact lead assembly made by this method is also disclosed. | 51,396 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to fire-fighting equipment, and more specifically to equipment coupled to a fire hose or pipeline for integrating an additive to a water stream.
[0002] Fire fighting systems typically include a fire truck, such as truck T in FIG. 1 , which includes a pumping unit P that pumps water under high pressure from a tanker truck or a nearby fire hydrant, through a fire hose H 1 , H 2 and nozzle N. While water alone is sufficient for most fires, some fires cannot be efficiently controlled or extinguished by water alone. In this case, certain chemical additives are introduced into the water line to be discharged onto the particular type of fire. Incidents involving flammable liquids or hazardous materials often require the use of a foam that is spread over the fire to starve the fire of oxygen or to suppress noxious vapors. For instance, Class A foam concentrates are used for wildland, rural and urban fire suppression on Class A fuels, such as wood, paper and other solid materials. Class B foam concentrates are primarily intended for Class B materials, such as flammable liquids containing hydrocarbons or polar solvents, and can be used for vapor suppression or extinguishment.
[0003] There are numerous approaches to introducing chemical additives or foam concentrates into the flow through firefighting water lines. Some systems utilize additive pumps for forced injection of the chemical into the water line. Such systems are generally complicated and are not portable. On the other hand, portable systems rely upon the movement of water through the fire hose to educe the chemical. In the context of the present invention, educe or induct means that liquid is drawn into the system, such as by the flow of another liquid. In one typical arrangement, a foam bucket F contains a liquid foam concentrate that is induced into the fire hose H 2 by a foam eductor valve E. This typical eductor valve E relies upon venturi flow to draw the foam concentrate from the foam bucket F into the water stream passing through the eductor E.
[0004] The chemical additives or foam concentrates are often corrosive and usually expensive. Thus, the typical eductor valve E includes a check valve system to prevent backflow of water into the chemical supply. For instance, the by-pass eductor described in U.S. Pat. No. 5,960,887, includes a ball check valve integrated into a foam concentrate metering valve.
[0005] While the check valve is important to prevent water backflow, it can be problematic with respect to cleaning the eductor valve E. In fire-fighting equipment back-flow typically occurs when the discharge nozzle N is shut off or when the hose H 2 is kinked so that fluid discharge is terminated. Without cleaning, the chemicals passing through the valve may congeal and foul the valve or the metering orifice used to control the quantity of chemical introduced into the water stream. In an extreme case, the valve may be stuck open or closed. Prior devices require disengaging the eductor valve from the water line, connecting the water supply hose H 1 to the chemical inlet of the eductor valve E, and flushing the valve with water. This process is cumbersome, but perhaps more significantly this approach can be hazardous. In particular, disengaging a eductor valve filled with a chemical additive of foam concentrate will necessarily result in a chemical spill.
[0006] What is needed is an eductor valve apparatus that satisfies all of the necessary functions of an eductor, but that is easy and safe to clean. Such an apparatus would allow controlled flushing so that the chemicals can be safely collected without risk of spilling. A further need is the ability to readily determine the position of the check valve and to manually alter it.
SUMMARY OF THE INVENTION
[0007] To address this unmet need, the present invention contemplates a system for preventing actuation of a check valve within an eductor assembly. In one embodiment, the present invention contemplates an eductor assembly for use with firefighting equipment that comprises an eductor body defining a fluid inlet connectable to a source of a firefighting fluid (e.g., high pressure water), a fluid outlet for dispensing fluid therefrom in fluid communication with the fluid inlet, and an additive inlet connectable to a source of an additive to the firefighting fluid and in fluid communication with the fluid outlet. The additive can be, for example, a foam concentrate that is educed to mix with the high pressure water under venturi flow.
[0008] The eductor assembly further comprises a check valve disposed between the additive inlet and the fluid outlet that is moveable, in response to a flow of water through the fluid inlet, between a first position operable to prevent back flow of water through the additive inlet and a second position to permit flow of additive through the additive inlet to the fluid outlet. In other words, the check valve is open to permit the eduction of the additive under proper venturi conditions, but otherwise closes the additive inlet.
[0009] In one important feature of the invention, means are provided for holding the check valve in its open position while allowing water back flow through the additive inlet. This feature allows the additive fluid circuit to be back flushed and thus cleaned after use. In one embodiment, this means includes an actuator operable from outside the eductor body to move the check valve to the second position. In a more specific embodiment, this actuator is an elongated pin having a proximal end manually accessible outside the eductor body and an opposite working end engageable with the check valve to move the check valve to the second position. The actuator preferably includes a push button mounted to the proximal end of the pin to facilitate manual operation of the actuator.
[0010] Preferably, the actuator pin is sized so that it does not contact the check valve in its non-actuated position. In the preferred embodiment, means are provided for biasing the pin to this non-actuated position away from engagement with the check valve. When the push button is manually pressed, the pin moves against this biasing means to contact and push the check valve to its open position.
[0011] The eductor assembly further comprises a metering head in fluid communication with the additive inlet, in which the metering head includes a metering inlet connectable to the source of the additive and an adjustable metering element disposed between the metering inlet and the additive inlet. The actuator is supported by the metering head to engage the check valve to move the check valve to the second position. Where the actuator is an elongated pin, the pin is slidably disposed within the metering head and has a proximal end manually accessible outside the metering head and an opposite working end engageable with the check valve to move the check valve to the second position.
[0012] In one embodiment, the metering element is connected to a proportioning knob movably mounted to the metering head, and the knob defines a recess for receiving the push button and a bore communicating with the recess slidably receiving the pin therethrough. In a further feature, the eductor assembly includes a mating assembly between the metering head and the additive inlet of the eductor body for removably coupling the metering head thereto. This mating assembly allows removal of not only the additive metering components, but also the actuator pin and push button.
[0013] Preferably, the actuator includes a spring between the push button and the proportioning knob within the recess. The spring is arranged to bias the pin away from engagement with the check valve. In certain embodiments, the pin extends through the metering element, which can comprise a hollow proportioning ball defining a plurality of differently sized metering openings arranged to be selectively aligned with the metering inlet, and a hollow stem coupled to the proportioning ball and defining a passageway to slidingly receive the pin. A fluid sealing element or seal ring may be disposed between the pin and the hollow stem.
[0014] In the preferred embodiment, the check valve includes a valve disc sized to close the additive inlet in the first position and a number of alignment wings projecting from the valve disc into the additive inlet when the check valve is in either of the first and second positions. Thus, the wings maintain the position of the check valve as it moves between its open and closed positions. The wings are sufficiently dispersed to allow substantially unimpeded flow of additive of water back flow through the additive inlet. In a specific embodiment, the number of wings defines a hub arranged to be engaged by the actuator pin when the actuator is operated to move the check valve to the second position.
[0015] The invention further contemplates a method of cleaning an eductor assembly used to introduce an additive to a flow of water through a venturi nozzle. The eductor assembly includes an eductor body defining the venturi nozzle, an additive inlet in fluid communication with the venturi nozzle and a check valve disposed between the additive inlet and the venturi nozzle that is open when the venturi nozzle produces suction to educe additive through the additive inlet, and is otherwise closed to prevent back flow through the additive inlet of water passing through the venturi nozzle. The preferred embodiment of the method comprises the steps of moving the check valve to its open position, holding the check valve in that position and then flowing water through the venturi with the check valve open to produce back flow of water through the additive inlet. Preferably, the holding step includes manually depressing an actuator pin slidably disposed within the eductor assembly to push the check valve into its open position.
[0016] It is one object of the present invention to provide a system and method for cleaning an eductor assembly that is used for introducing a chemical additive, such as foam concentrate, into a flow of water used to battle a fire.
[0017] One benefit of the invention is that the inventive eductor valve apparatus satisfies all of the necessary functions of an eductor, but is easy and safe to clean. A further benefit of the apparatus is that it allows controlled flushing so that the chemicals can be safely collected without risk of spilling. Yet another benefit is provided by the ability to readily determine the position of the check valve and to manually alter it.
[0018] Other objects and benefits of the invention will become apparent upon consideration of the following written description, taken together with the accompanying figures.
DESCRIPTION OF THE FIGURES
[0019] FIG. 1 is a pictorial representation of a fire truck equipped for dispensing a foam for fire or vapor suppression or extinguishment.
[0020] FIG. 2 is a perspective view of the components of an eductor assembly in accordance with one embodiment of the invention.
[0021] FIG. 3 is an exploded view of the eductor assembly depicted in FIG. 2 .
[0022] FIG. 4 is a side partial cross-sectional view of the eductor assembly shown in FIGS. 2-3 .
[0023] FIG. 5 is an enlarged perspective view of a check valve for use in one embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.
[0025] In accordance with one embodiment of the invention, the eductor valve E shown in FIG. 1 includes an eductor assembly 10 , as illustrated in FIG. 2 . This assembly includes a main body 11 having a water inlet 13 and an outlet 15 . A foam inlet 17 intersects the inlet and outlet and is configured to mate with a metering head 20 . The metering head 20 is connected to a suction hose 22 that terminates in a wand 23 . The wand 23 is configured to engage the foam bucket F ( FIG. 1 ) in a conventional manner to draw foam concentrate from the bucket by venturi flow of water through the main body 11 . The metering head 20 includes a mating ring assembly 27 that is configured for quick connect and disconnect to the foam inlet 17 . A proportioning knob 25 can be rotated to adjust the quantity of chemical additive fed through the metering head 20 into the main body 11 .
[0026] As shown in the detail view of FIGS. 3 and 4 , the eductor assembly as thus far described is of known construction. For instance, the main body 11 is hollow and defines a plenum 12 ( FIG. 4 ) into which the chemical or foam additive is drawn. A blending tube 35 is situated at the inlet 13 of the body 11 , terminating in a nozzle end 37 within the plenum 12 . A coupling assembly 39 mounts the blending tube 35 within the body and provides an interface for engagement to a fire hose H 1 ( FIG. 1 ). The coupling assembly 39 can be of known construction, including, for instance, a ball bearing mounted threaded coupling ring sized to mate with a 1½ inch fire hose connection. The coupling assembly 39 facilitates ready removal and replacement of the blending tube 35 to substitute a tube sized for different water flow rates.
[0027] At the outlet 15 , the body 11 mates with a discharge nozzle 42 . The nozzle 42 terminates in a nozzle end 44 within the plenum 12 and is arranged to receive water or a water/chemical mixture when water is supplied under pressure at the inlet 13 . The discharge nozzle 42 includes a coupling end 45 that is configured in a known manner for engagement to a hose H 2 or nozzle N. The discharge nozzle 42 is configured for threaded engagement within the main body 11 . Different discharge nozzles can be provided with differently sized outlets 15 to achieve selectable exit flow rates. In addition, the size of the inlet 13 to the eductor is preferably correlated to the discharge nozzle outlet size to achieve these flow rates.
[0028] The metering head 20 mates with the additive or foam inlet conduit 47 of the main body 11 . The mating ring assembly 27 can be configured in a known manner to provide a quick connect/disconnect fitting arrangement, as depicted in FIG. 3 . The mating ring assembly 27 allows a number of metering heads to be engaged to an eductor body depending upon the desired chemical/foam flow rate.
[0029] The metering head 20 includes a metering body 50 that defines a foam inlet 52 . A fitting assembly 24 connects the suction hose 22 to the metering body in a known manner. The metering body defines a cavity 51 that communicates with the inlet 52 . A proportioning ball 54 resides in and is rotatable within the cavity to align a plurality of differently sized metering orifices 56 with the inlet 52 . In a specific example, the proportioning ball includes five orifices of different sizes and shapes to correspond to different proportional settings for foam consumption, as well as a no flow or “off” setting in which the foam inlet 52 is blocked. In this specific example, the orifices correspond to ¼%, 1 / 2 %, 1%, 3% and 6% ratios of foam concentrate to water volume. The two smaller settings correspond to small orifice diameters and are typically better suited for Class A foams. The larger settings are typically better suited for Class B foams.
[0030] The proportioning ball 54 includes a stem 60 that extends through a bore 53 in the metering body. The stem 60 is connected to the proportioning knob 25 to rotate with the knob. In a specific embodiment, the stem 60 extends through a bore 76 in the knob and includes a notch 61 that can interlock with a rib (not shown) within the bore so that the two components rotate together. An O-ring 58 between the proportioning ball 54 and the metering body helps prevent leakage through the bore 53 . As best seen in FIG. 4 , the metering ball 54 provides a fluid path from the foam inlet 52 through a selected metering orifice 56 and into the cavity 51 of the metering body. The knob preferably includes indicia corresponding to the position of the proportioning ball 54 relative to the foam inlet 52 .
[0031] When the metering head 20 is mounted on the eductor main body 11 , the metering cavity 51 communicates with the plenum 12 through a passageway 49 defined in the additive inlet conduit 47 . As is known in the art, water flowing from the nozzle end 37 of the blending tube 35 into the nozzle end 44 of the discharge nozzle 42 causes a pressure drop within the plenum. This pressure drop pulls or educts fluid from the foam bucket F through the wand 23 , creating a high speed flow of the chemical additive or foam concentrate. This educed fluid mixes with the water as it is discharged through the discharge nozzle 42 .
[0032] In order to prevent unwanted backflow of water from the plenum into the metering head 20 , a check valve 30 is provided within the foam inlet conduit 47 , as shown in FIGS. 3-4 . In a preferred embodiment of the invention, the check valve 30 includes a valve disc 85 that has a diameter greater than the diameter of the passageway 49 defined in the inlet conduit 47 . More specifically, the valve disc 85 is sized to engage a valve seat 49 a to completely close the passageway 49 to prevent the backflow of water into the inlet conduit and metering head.
[0033] The check valve 30 includes an arrangement of wings 87 projecting upward from the disc 85 into the passageway 49 . The wings are configured to constrain and guide the check valve so that it translates along the axis of the passageway and so that the valve disc 85 seats flush with the valve seat 49 a in the main body 11 to close the passageway 49 . The upper surface of the disc 85 can include a resilient seal ring 91 to improve the sealing capability of the check valve. Alternatively, the disc itself can be formed of a resilient material that deforms slightly under fluid pressure to form a tight seal against the main body. In the preferred embodiment, the check valve, including the disc 85 and wings 87 , is formed of a plastic material.
[0034] The wings 87 have a height calibrated so that the wings remain substantially disposed within the passageway even when the valve disc 85 is in contact with one or both of the nozzle ends 37 , 44 . Under normal operating conditions, the valve disc 85 will remain trapped between the nozzle ends and the additive inlet as the venturi suction pulls the disc downward and induces chemical fluid flow through the metering head 20 . However, once the venturi suction falls below a threshold value, or when no fluid is flowing through the metering head, the inlet water pressure will push the check valve upward until the valve disc seals against the main body and closes the inlet passageway 49 . This condition will occur in response to a termination of the flow downstream, such as when the nozzle N is shut off or when the hose H 2 is kinked. Under normal operating conditions, the check valve will remain closed (preventing backflow into the metering head) when the fire hose nozzle N ( FIG. 1 ) is off, since there is no flow through the eductor to produce venturi suction. However, once the nozzle is opened, water flow commences and the check valve opens to draw the chemical additive or foam concentrate into the plenum 12 .
[0035] As thus far described, the check valve 30 presents the same problem experienced by the prior eductor valves with respect to cleaning the eductor assembly 10 . In order to alleviate this problem, the present invention contemplates a system for holding the check valve 30 in an open position—i.e., with the valve disc 30 unseated or offset from the eductor body, leaving the passageway 49 substantially unobstructed even under water pressure. In order to achieve this objective, the preferred embodiment of the invention includes a back flush pin 65 ( FIGS. 3-4 ) that bears against a contact hub 89 defined at the peak of the wings 87 (see FIG. 5 ). The pin 65 is slidably disposed within a passageway 62 defined in the stem 60 of the proportioning ball 54 . Thus, while the proportioning ball is fixed in translation along the cavity 51 , the pin 65 is free to move vertically downward into contact with the hub 89 of the check valve 30 to push the valve downward away from the passageway 49 . For the purposes of the present disclosure, the “vertical” direction is defined as along the axis of the metering body 50 , and “downward” is movement toward the eductor body 11 .
[0036] In the illustrated embodiment, the proportioning knob 25 defines a recess 75 within the metering body 50 that communicates with the bore 76 . As explained above, the stem 60 of the proportioning ball 54 interlocks with the knob 25 within this bore. 0 -ring 58 provides a fluid tight seal between stem 60 and metering body 50 . A cross pin 69 passes through a bore 68 ( FIG. 3 ) in the back flush pin to set an upper limit for the travel of the pin. An O-ring 73 is mounted within a seal ring groove 74 in the pin 65 to provide a fluid-tight seal between the pin and the passageway 62 as the pin translates within the bore.
[0037] A push button 79 is threaded onto the end of the back flush pin 65 , trapping a return spring 77 within the recess 75 . The top end of the back flush pin 65 defines an internally threaded bore 71 to receive a locking screw 81 for fixing the back flush pin 65 to the push button 79 . The push button 79 is accessible above the proportioning knob 25 so that the button can be manually depressed when it is desired to clean the eductor assembly 10 . When the button is pushed, the back flush pin 65 is driven downward to push against the check valve 30 . With the button 79 fully depressed, the check valve is clear of the passageway, creating a back flush flow path from the water inlet 13 through the eductor assembly 10 . The eductor assembly does not need to be disconnected from the water supply, but instead remains connected as it was during the firefighting action. Water from the pumping unit P of the fire truck T, through fire hose H 1 , can be supplied directly to the eductor assembly to flush all of the chemicals out of the assembly components. The flushed liquid is discharged through the suction hose 22 and wand 23 , which means that the wand can be placed within an appropriate receptacle to receive the back flush liquid waste.
[0038] In a typically cleaning process after use, the wand is removed from the foam supply F and optionally placed in a discharge container. The water flow through the supply hose H 1 is significantly reduced from the typical fire-fighting water pressure and flow rate. In a specific embodiment, the back flush water pressure is reduced to below 45 psi (as compared to a typical operating pressure of about 200 psi). With the nozzle N closed (to prevent water flow through the hose H 2 ), the back flush button 79 is depressed to release the check valve 30 and allow the water to flow back through the metering body 50 , suction hose 22 and suction wand 23 . The proportioning knob 25 rotated as the water continues to back flush so that water passes through every foam metering orifice 56 in the proportioning ball 54 . Back flushing continues at each metering setting until there is no visible foam in the flush water. At that point, the water supply is stopped and the metering head 20 is removed from the main body 11 by manipulating the mating ring assembly 27 . The residual water within the metering body 50 and main body 11 can be gravity drained.
[0039] Under certain conditions, the check valve 30 may not properly engage the valve seat 49 a ( FIG. 4 ) to fully close the passageway 49 . In order to ensure a proper sealing engagement, the check valve 30 may be provided with a return element 100 , as shown in FIG. 5 . The return element 100 includes a ring 102 that defines an opening that is preferably larger than the flow path through the outlet 15 so as not to impede the flow of fluid through the eductor 10 . A base 104 is provided on the ring to bear against the wall of the plenum 12 .
[0040] The element 100 further includes an elongated stem 106 projecting upward from the ring 102 . The stem passes through a bore 107 defined in the hub 89 of the check valve 30 . In the preferred embodiment, the stem 106 is long enough to pass completely through the check valve bore 107 .
[0041] The ring 102 is formed of a corrosion resistant material that is flexible and resilient. In a preferred embodiment, the ring is formed of a thermoplastic elastomer, such as ALCRYN®. When the back flush pin 65 is depressed, the check valve 30 bears against the ring 102 to deform the ring. In a preferred embodiment, the ring 102 is circular in its installed shape, and becomes generally oval as it is deformed under pressure from downward movement of the check valve. The return element is configured so that it can be deformed when the check valve opens under venturi pressure. In the preferred embodiment, the opening force due to venturi pressure is about ½ ounce. In addition, when the back flush pin 65 is depressed, the check valve 30 bears against the ring 102 to deform the ring. When the back flush pin is release, the ring 102 seeks its neutral shape so that it springs back to its original oval shape. In so doing, the ring 102 pushes the check valve 30 upward into engagement with the valve seat 49 a. Moreover, as the ring 102 pushes the valve upward, the stem 106 keeps the check valve in proper alignment so the disc 85 bears fully against the valve seat.
[0042] In certain embodiments, the ring 102 is sized so that in its neutral or un-deformed shape the base 104 contacts the wall of the plenum 12 while the top of the ring is also in contact with the disc 85 of the check valve. Alternatively, the ring may be sized so that the top of the ring 102 is slightly offset from the disc 85 so as not to impede the downward movement of the check valve under venturi pressure only. However, in this alternative, the ring is sized so that the ring may be deformed when the back flush pin 65 is fully depressed.
[0043] In the preferred embodiment, the return element is in the form of a ring so that the return spring force produced by the element 100 will be directed substantially along the axis of the elongated stem 106 . Other forms of the return element may be contemplated provided that the element does not interfere with the flow of fluid through the eductor and that the element operates to accurately return the check valve to the valve seat. For example, in lieu of the complete ring 102 , the return element 100 may include a pair of resilient legs extending downward and outward from the check valve to contact the side walls of the plenum 12 .
[0044] The internal components of the eductor assembly 10 are formed of materials that are compatible with the types of chemical additives or foam concentrates flowing through the assembly. The component materials are preferably non-reactive with the chemicals and resistant to the corrosive effects of these chemicals. In a specific embodiment, the wand 23 and the back flush pin 65 , and ancillary hardware are formed of stainless steel, as is the back flush pin 65 . On the other hand, the blending tube 35 can be formed of a high density plastic. Preferably, all the other components are formed of a metal, such as aluminum that has been hard anodized. The proportioning ball 54 and integral stem 60 are also preferably formed of a high density plastic, which beneficially provides a smooth sliding surface for the O-ring 73 as the back flush pin 65 reciprocates within the passageway 62 .
[0045] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
[0046] For instance, while the illustrated embodiment of the check valve contemplates a disc valve, other one-way valves can be utilized. For instance, a ball valve can be situated within the plenum 12 so that the ball seals against the passageway 49 . A cage may contain the ball in alignment with the passageway. The same back flush pin 65 described above can be arranged to bear against the check ball to prevent it from seating over the passageway. In this instance, the pin 65 and inlet conduit 47 would be commensurately sized so that the pin is clear of the ball valve during normal use but is capable of extension into contact with the ball when it is desired to back flush the eductor assembly.
[0047] Similarly, the check valve can be a resilient valve, such as a duckbill valve. With this type of valve, the working end of the back flush pin can be modified to hold open the duckbill when the pin is pushed through the valve.
[0048] As a further example, the illustrated embodiment contemplates a push button feature for actuating the back flush pin 65 . Other means and mechanisms for actuating the pin are contemplated by the present invention. For instance, a pivoting or sliding lever can be integrated into the side wall of the metering body so that manipulation of the lever will push the check valve to its open position. Non-contact actuation is also contemplated, such as a magnetically coupled valve. | An eductor assembly includes an inlet connectable to a high pressure water source useful in firefighting, an outlet connectable to a fire hose and/or nozzle, and a venturi therebetween. An additive inlet communicates with the venturi so that a chemical additive, such as a foam concentrate, is educed into the output stream. A check valve is positioned at the additive inlet to open under venturi flow conditions and remain closed otherwise. An actuator is provided that holds the check valve in its open position while water flows through the eductor assembly under non-venturi conditions to produce a back flow through the additive inlet and ultimately through the additive fluid circuit, including the additive metering valve components. A return element may be disposed within the eductor body to return the check valve to its closed position when the back flow ceases. | 31,148 |
CROSS-REFERENCES TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to liquid product filling heads, more particularly, to a pneumatic control unit for automatically shutting off a liquid product filling head filling a container upon sensing that the container is full.
2. Description of the Related Art
There are a number of automatic container filling machines in the art wherein a sensing tube extends into a container to be filled and when the lower end of the tube is blocked by the product in the container, back pressure through the tube actuates a control device to stop the flow of product into the container. In particular, U.S. Pat. No. 5,161,586 discloses a pneumatic control unit that responds to a sensed back pressure to shut off liquid to the filling container. The shortcomings of the disclosed design are discussed in detail below relative to the present invention.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a pneumatic control unit for a liquid filling head that is easier and less expensive to manufacture and that is easier to maintain than pneumatic control units of the prior art.
The present invention is a pneumatic control head for controlling the supply of a product into a container via a filling head with a sensing tube that extends into the container. The control head has a manifold with several air inputs. A main air input receives main air at an operating pressure, typically at about 60 psi. A blow down air input receives blow down air for cleaning the filling head as needed. A filling head output connects to the sensing tube. A cylinder for operating the filling head attaches to the manifold.
The majority of the control unit is built in a manifold. The manifold has a pilot air duct for conducting pilot air at a pressure near that of the main air operating pressure. A start valve takes in the main air and outputs it to the pilot air duct when actuated by a mechanical switch. The switch includes a ball bearing captured by a collar whereby the switch is actuated when the ball bearing is pressed into the collar.
A pilot valve in the manifold takes in the main air and allows it into a cylinder air duct to activate the cylinder in response to air pressure in the pilot air duct. Optionally, there is a no container switch that exhausts air from the pilot air duct in the event that there is no container under the filling head.
A flow regulator mounted to the manifold receives sensing air and outputs regulated sensing air at a sensing pressure. Optionally, a sensing air shut off valve precedes the flow regulator. The sensing air shut off valve is controlled by the main air to the cylinder so that if the cylinder is not actuated, there is no sensing air to cause the filling product to bubble.
The regulated sensing air passes through a filling head source valve to a filling head output. Normally the filling head source valve routs the regulated sensing air to the filling head output. The filling head source valve routs blow-down air to the filling head output in response to main air from a blow down valve. The blow down valve takes in the main air and outputs it to a switch the filling head source valve when actuated by a mechanical switch. The switch is of the same design as that of the start valve.
An overpressure valve mounted to the manifold exhausts the pilot air duct in response to the regulated sensing air having a pressure higher than normal. When the product fills the container to the point that the product nearly contacts the sensing tube, a back pressure is created that causes the overpressure sensor valve to trip.
Physically, the control unit includes a manifold within which are cut holes for valves and channels for ducts. A top plate houses the flow regulator and provides a mount for the overpressure sensor valve.
The start and blow down valve switches are improvements over those of the control units of the prior art. Each switch is a ball bearing captured by a collar. An external cam pushes the ball bearing into the collar, causing the ball bearing to push the start valve. Friction is reduced because the ball bearing rotates within the collar as the cam slides by. The improvement includes significantly fewer moving parts that substantially reduces both the initial manufacturing and the periodic maintenance costs.
Another improvement over the prior art is the means by which two of the ducts are routed to their respective valves. The pilot and filling head source valves fit into openings in the manifold. The appropriate duct exits at an aperture adjacent to the valve. A single machined plate has a depression that overlaps the aperture and the valve opening. An o-ring fits into a groove surrounding the depression and valve opening. The o-ring provides a seal between the plate and the manifold when installed.
Other objects of the present invention will become apparent in light of the following drawings and detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and object of the present invention, reference is made to the accompanying drawings, wherein:
FIG. 1 is an front perspective view of the pneumatic control unit of the present invention;
FIG. 2 is a rear perspective view of the pneumatic control unit of the present invention;
FIG. 3 is a side view of an assembly of the control unit of the present invention and a filling head;
FIG. 4 is a schematic diagram of the control unit of the present invention;
FIG. 5 is an exploded view of the start switch mechanism of the control unit of FIG. 1; and
FIG. 6 is an exploded view of the pilot valve at the rear of the control unit of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
The pneumatic control unit 10 of the present invention, shown in FIGS. 1-3 and schematically in FIG. 4, has three inlets for external air supplies. The main air inlet 12 accepts the main control air, typically at a pressure of about 60 psi. The sensing air inlet 14 accepts the sensing air, typically at a pressure of about 5 psi This pressure is chosen to be low to avoid bubbling the liquid 95 in the top of a container 97 being filled while being high enough to reliably build a back pressure when the liquid 95 fills the container 97 . The blow down air inlet 16 accepts the blow down air at a pressure typically in the range of about 20-40 psi. The purpose of the blow down air is to clean the filling head 96 as needed, so the pressure is set accordingly for the thickness of the filling liquid.
The air cylinder 20 for operating the filling head extends from the bottom of the control unit 10 . The air cylinder piston 90 extends downwardly under controlled air pressure to open the filling head 94 .
Refer now to FIG. 4 . The start switch 22 mechanically actuates a start valve 24 . The start valve 24 receives the main air and is normally closed, blocking the main air from the pilot air duct 46 . When actuated, the start valve 24 opens, permitting the main air into the pilot air duct 46 . The air in the pilot air duct 46 is referred to as the pilot air. The high pressure pilot air is routed into a no container safety valve 36 of well-known design. Essentially, when there is no container to fill, a mechanical switch 18 actuates the no container safety valve 36 , which exhausts the pilot air from the pilot air duct 46 , as at 37 , preventing it from causing the actuation of the air cylinder 20 . A flow restrictor 30 prevents an excess of main air pressure from exceeding the capacity of the no container safety valve 36 .
The pilot air is routed to a pilot valve 32 and to an overpressure sensor valve 34 . When the start switch 22 is actuated, the pilot air actuates the pilot valve 32 thereby permitting the main air into a cylinder air duct 33 , actuating the air cylinder 20 . Preferably, the pilot valve 32 has a compensating orifice which opens into a passageway into the pilot air chamber of the pilot valve 32 . When the pilot valve 32 is actuated, a portion of the main air passes through the compensating orifice into the pilot air chamber to help hold the pilot valve 32 actuated in order to compensate for any pilot system leaks. For example, some air is bled out of the pilot air duct 46 through a small bleed orifice in the overpressure sensor valve 34 , as described below. A drop in the pilot air pressure will deactuate the pilot valve 32 . Once closing begins, the air from the cylinder air duct 33 is exhausted through the pilot valve exhaust port 38 . In this way the pilot valve 32 reacts quickly to a drop in pilot pressure to stop the liquid filling operation.
The overpressure sensor valve 34 quickly triggers the shut off of the liquid filling operation in response to back pressure from the container 97 being filled. The sensing air is applied to a diaphragm and is allowed to escape through a bleed orifice 49 . When the pressure on the diaphragm increases such that the diaphragm flexes, the flexing diaphragm covers the bleed orifice 49 , causing a build up of pressure which triggers the valve 34 to open. When the overpressure sensor valve 34 opens, the pilot air is exhausted out through the valve 34 , as at 48 , causing the air cylinder piston 90 to retract, halting the liquid filling operation.
The sensing air inlet 14 provides the sensing air control signal to the overpressure sensor valve 34 . Optionally, the sensing air is routed through a sensing air shutoff valve 40 that is controlled by the main air to the cylinder 20 . By shutting off the sensing air when the fill is complete, bubbling of the filling liquid by the sensing air is avoided.
A flow regulator 42 permits accurate regulation of the pressure of the sensing air, providing a means to adjust the control unit 10 for the height of the liquid fill. If the flow regulator 42 is of a variable type, two or more control units 10 may be employed in a mass production filling machine by adjusting the sensing air to fill all containers to the same height.
The sensing air from the flow regulator 42 passes through a filling head source valve 44 to a filling head output 43 . The normal state of the filling head source valve 44 routs the sensing air to the filling head output 43 . The switched state of the filling head source valve 44 routs blow-down air to the filling head output 43 , as described below.
The filling head output 43 is connected, via a hose 96 , to a sensing tube 93 at the end of the filling head 92 . The sensing air easily passes out of the sensing tube opening 94 until the filling liquid 95 contacts or nearly contacts the opening 94 . When this occurs, a back pressure is created that causes the overpressure sensor valve 34 to trip, shutting off the filling operation.
The blow down operation clears the sensing tube 93 . A blow down switch 26 mechanically actuates the blow down valve 28 , allowing main air into a filling head source control duct 45 , which directs the filling head source valve 44 to rout the blow down air from the blow down air inlet 16 to the filling head output 43 . The blow down-operation is momentary, that is, it only operates as long as the blow down switch 26 is activated. When the blow down switch is not actuated, the main air is exhausted from the filling head source control duct 45 by the blow down valve 28 , as at 41 .
The majority of the control unit 10 is formed in a manifold 50 , preferably a block of aluminum. Holes are drilled and channels are cut in the manifold 50 to accommodate the valves and to form the passages between those valves, all in a manner well-known in the art.
A top plate 51 is mounted to the top of the manifold 50 . The top plate 51 provides a housing for the flow regulator 42 and a connection to the manifold 50 for the overpressure sensor valve 34 . The flow regulator control knob 52 extends vertically from the top of the top plate 51 . The sensing air shutoff valve 40 extends rearwardly from the top plate 51 . It receives its connection to the pilot air duct 33 by a hose 53 from the manifold 50 . The output 43 of the filling head source valve 44 is located on the bottom of the manifold 50 and is connected to the filling head 92 by a hose 96 .
The start valve 24 and blow down valve 28 are located on the same side of the manifold 50 . In the prior art, the start switch 22 and blow down switch 26 are rather complicated mechanisms. The appropriate valve is actuated by a leaf spring that is pushed by a pivoting arm. At the free end of the arm is a roller that is pushed by an external cam. The reason for the roller is so that friction is kept to a minimum as the external cam slides by. The various moving parts require regular maintenance to keep operating properly.
The present invention replaces each roller/arm mechanism with a simple ball bearing 57 inside a collar 58 . As can be seen in FIG. 5, the front surface 56 of the manifold 50 is covered by a front plate 59 . The front plate 59 includes a clearance hole 60 for the collar 58 . The collar 58 is a short tube with a flange 62 at the inner end. The inside diameter of the tube is slightly larger than the ball bearing 57 so that the ball bearing 57 slides easily within the tube. An internal lip 64 at the outer end of the collar 58 as an inside diameter slightly smaller than the ball bearing 57 so that the ball bearing 57 is retained in the collar 58 when installed. The plate 59 is typically removably secured by screws 65 sandwiching the collar 58 by the flange 62 between the manifold front surface 56 and the front plate 59 . The ball bearing 54 extends outwardly from the collar 58 at least the length of travel of the start valve 24 . As the control unit 10 moves past the start cam, the cam pushes the ball bearing 57 into the collar 58 , causing the ball bearing 57 to push the start valve 24 , initiating the fill operation. Friction is reduced between the start switch 22 and the cam because the ball bearing 57 rotates within the collar 58 as the cam slides by. The blow down 26 switch is implemented in the same way.
The ball bearing design is an improvement over the design of the prior art. The numerous moving parts, including the roller, the arm, and the leaf spring, are replace by a single moving part, the ball bearing 57 . The reduction in the number of parts substantially reduces both the initial manufacturing cost and the periodic maintenance cost of the control unit 10 .
The rear of the control unit 10 is shown in FIGS. 2 and 6. As can be seen, the filling head source valve 44 fits into a cylindrical opening 70 in the manifold 50 leaving the actuator 72 free. The filling head source control duct 45 exits at an aperture 74 in the rear wall 76 and must be routed to the filling head source valve 44 . The pilot valve 32 and the pilot air duct 46 have the same arrangement. In the prior art, a gasket with a groove fits over the rear wall of the manifold such that one end of the groove is positioned over the valve and the other end of the groove is positioned over the aperture. A metal plate is placed over the gasket and secured to the rear wall. The groove provides the connecting duct and the gasket prevents leaks. Since the rear of the control unit of the prior art has two valves and an air inlet, there are a number of components, including three plates, three gaskets, and a handful of screws, making the manifold relatively costly to manufacture and assemble.
The present invention replaces the piecemeal design of the prior art with the design of FIG. 6 . The multiple plates and gaskets are replaced by a single machined plate 78 and o-rings 80 . A depression 82 that overlaps both the aperture 74 and part of the valve opening 70 is machined in the surface 84 of the plate 78 . The shape of the depression 82 is unimportant, as long as it overlaps both the aperture 74 and the valve opening 70 . In the present embodiment, the depression 82 is cylindrical for ease in machining. A groove 86 surrounding the depression 82 and valve opening 70 is machined in the plate surface 84 . An o-ring 80 seats in the groove 86 and provides a seal between the plate 78 and the manifold rear wall 76 when the plate 78 is secured to the rear wall 76 , typically by screws 88 . In the present embodiment, the groove 86 is eccentric because of the dimensions of the plate 78 and manifold 50 . However, the shape of the groove 86 is unimportant as long as it provides a seat for the o-ring 80 as required. Since there are actually two valves and ducts that need to be connected, the control unit 10 of the present invention has two depressions 82 , two grooves 86 , and two 0 -rings 80 , one each for the pilot valve and the filling head source valve 44 .
Thus it has been shown and described a pneumatic control unit which satisfies the objects set forth above.
Since certain changes may be made in the present disclosure without departing from the scope of the present invention, it is intended that all matter described in the foregoing specification and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. | A pneumatic control head for controlling the supply of a product into a container via a filling head. A manifold has a pilot air duct. A start valve outputs main air to the pilot air duct when actuated by a mechanical switch. A pilot valve activates a cylinder using the main air in response to air pressure in the pilot air duct. A filling head source valve routs either sensing air or blow down air to a filling head output in response to the condition of a blow down valve actuated by a mechanical switch. An overpressure valve exhausts the pilot air duct in response to the sensing air having a pressure higher than normal. The switches each includes a ball bearing captured by a collar. An external cam pushes the ball bearing into the collar, causing the ball bearing to actuate the respective valve. Duct connections to valves are implemented by a single machined plate with a depression that overlaps the duct aperture and valve opening. An o-ring fits into a groove surrounding the depression and valve opening and provides a seal between the plate and the manifold. | 17,892 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to sealing ("stopping-off") ducts or pipes for example during repair of maintenance operations. The most common example of a duct or pipe on which this is done is a distribution duct for main gas supplies.
We are primarily concerned in this invention with the stopping-off of large ducts, say up to about 120 cm diameter, where the pressure to be resisted may be comparatively high, perhaps up to about 2 bar.
2. Description of the Prior Art
To stop-off systems which are working at that sort of pressure, primary sealing is achieved by a so-called iris-stop system. In this, an expansible disc is introduced into the duct through a hole in its wall and opened out to occupy most of its cross-section. A so-called primary bag is introduced into the duct at the upstream side of the disc. Once it is positioned inside the duct it is inflated and thereby forms a seal across the duct. The end of the bag remote from its point of inflation is supported by the disc. This therefore both prevents sliding of the bag along the duct under the high pressure encountered and reduces the general stresses on the primary bag.
A secondary bag is introduced into the duct downstream of the primary bag. The secondary bag acts as a further seal for gas seeping past the first bag. It is also desirable for the secondary bag to act as a safety device, maintaining the seal on the duct if the primary bag fails. The secondary bags currently in use do not perform this back-up safety function very well. Because it is a back-up system the secondary bag has to be designed to meet pressure differentials greater than those which were withstood by the primary system and to meet them in conditions where there has been a sudden collapse of the primary bag, which can result in a substantial shock effect. Because it has to meet anticipated higher pressures it will itself have to be inflated to substantial pressures if it is to seal effectively and so it will, even while the primary bag is still acting, be subjected to considerable stress.
In order to provide some support for the secondary bag, a support member (usually a steel tube) is inserted into the duct through the same hole as is used for insertion of the bag. The support member is placed downstream of the bag. The bag is normally inflated through its downstream end, and the pipe carrying the inflation fluid normally runs from the hole in the duct to the inflation point on the bag through the support member. This support member is much less effective than the iris disc supporting the primary bag, but it is a much simpler structure and does not require a separate insertion hole in the duct, while providing at least a degree of support for the secondary bag. The inflation fluid is in practice always compressed air or another gas, nitrogen is often used.
SUMMARY OF THE INVENTION
We have identified one problem with existing secondary bags as a danger that dislodgement of the bag along the duct by shock or pressure may, if it goes over too great a distance, unduly stress the bag in the region of its inflation connection which is mechanically fixed in relation to the duct because the inflation pipe is held by the support tube.
In particular, the bag usually has a sleeve-like neck at this connection for egress of the mouth of an inflation bladder. The neck tends not to move, and as the remainder of bag moves the bag material may be flexed and bent back at the point where the neck joins the remainder of the bag. Accordingly in the present invention the length of the neck, the dimensions of the inflation pipe, the dimensions of the support member and their dispositions in use are such that if the bag moves until its downstream end presses against the support member, the point where the neck meets the remainder of the bag is not substantially upstream of the upstream side of the support member. In this way, the material cannot be bent back at this point when the bag slips, greatly reducing the risk of bag failure. If the support member is a tube, and the inflation pipe runs within the tube to the connection on the bag, then this condition can become that when the inflation pipe runs in contact with the inside of the support tube at its downstream side, the point where the neck meets the rest of the bag is not substantially upstream of the outside of the tube at its upstream side. Roughly speaking, this means that the length of the neck including its connector for the inflation pipe should be less than the diameter of the tube.
Although a support tube is currently used in practice, other support members are possible.
Another problem which we have identified is that it is not easy to provide the prior art bags with sufficient frictional grip against the duct, to avoid slippage. Accordingly we have increased the length to width ratio of the bag. In the prior art the length over which the inflated bag contacted the duct was about 0.5 of the bag diameter. According to the present invention the length is at least 0.7, preferably between 0.75 and 1.0, more preferably between 0.8 and 0.9 of the bag diameter. This increased length gives an increased contact area and therefore an increased frictional grip for a given contact pressure.
In practice very long bags are not highly advantageous. As the contact length to diameter ratio increases past 1 the bags become less practical, with 1.5 representing the practical limit in the present state of the art. The very long bags have a number of problems. First, the longer the bag the longer the section of duct which needs to be excavated, and the greater the spacing between the iris disc and the secondary support member. Second, it becomes difficult to arrange the uninflated bag correctly in the duct before inflation. Third, the longer bag takes longer to inflate and deflate, especially if it has a large diameter. Last, the preferred bag materials are available in fixed widths, currently of about 1 meter, and it may require more expensive tailoring to make long bags.
Usually a bag and to some degree it associated apparatus are designed to be used in blocking off a duct of a predetermined diameter against a fluid flow in the duct at a predetermined pressure. In order to grip the duct with sufficient force, we find that the pressure differential between the inflation fluid in the bag and the fluid in the pipe should be about 5 p.s.i. (about 1/3 bar). Therefore the bag should be inflated to a pressure of about 21/3 bar if it is to block a duct against a fluid flow at 2 bar. However, since the bag is a secondary bag, it is not subjected to fluid pressure in the duct unless and until the primary system fails. Consequently the bag must be able to support the full differential pressure of 21/3 bar. This will be called the operating pressure in the following discussion.
Current safety requirements include that the bag should be able to withstand inflation to four times its operating pressure. Therefore the bag discussed above must be able to withstand 91/3 bar. If the bag is short, and has a small contact area, its frictional grip on the duct can be improved by inflating it to a higher pressure differential. However, in this case it becomes difficult to meet the safety requirements, as the maximum pressure to be withstood will increase by four times the increase the operating pressure. If the bag is made stronger, to meet this safety requirement then it will be bulkier when uninflated and thus require a bigger insertion hole in the side of the duct.
If a short bag is not inflated to a high pressure, but operated at a pressure giving reduced frictional grip on the duct, nothing adverse will happen for as long as the primary bag does not fail. If the primary bag fails, then the secondary bag is subjected to the full pressure of the fluid in the duct. It is also subjected initially to a shock. Further, the increase of applied pressure in the duct will tend to compress the inflation gas in the bag. At this moment the bag will tend to slip back, and also distort, pressing the downstream end against the support member. (This is the moment when the bag is stressed at the upstream end of the neck if it protrudes past the upstream side of the support member). All bags will tend to slip and distort at this moment, but if the bag's grip on the duct is insufficient it will move so far that the downstream end begins to wrap around the support member. This will pull away from the duct wall part of the duct-contacting surface of the bag. This surface consequently loses the support of the duct wall which it had previously enjoyed, and is therefore exposed to an increased risk of failure. Once again, this can be counter-acted by strengthening the bag, but this will tend to increase its uninflated bulk.
The features of the present invention discussed above are aimed at reducing stress, so that the bag can operate satisfactory and meet the safety requirements without being disadvantageously bulky. Current conventional secondary bags are manufactured in double envelope form mainly because the outer skin acts as an anti-scuffing layer in the event of bag slip. In order to obtain double strength from the two layer construction the tailoring must be exact or one layer will experience greater stress than the other. The general elongation of the nylon material is some 15% maximum and thus a small inner can be supported by the outer if sizing is not too far out. If, however, the inner is larger than the outer only the outer skin is stressed. If this fails then the inner skin of the same material will also fail.
As mentioned above, the part of the bag which is in contact with the duct is substantially relieved of stress by the duct. However, the end faces of the bag must be able to withstand the full operating pressure. Therefore we prefer to make the ends of the bag stronger than the duct-contacting portion, avoiding unnecessary bulk in the latter. In fact, the unsupported parts of the bag are not all stressed to the same degree. The tension in a surface restraining a given pressure depends on the radius of curvature of that surface, the smaller the radius the less the tension. If the bag has a generally cylindrical shape, then at the point where the bag surface leaves the duct wall the stress is relatively low. It is highest over the centre of the end faces. Thus it does not matter if the stronger end surfaces do not reach quite to the wall of the duct.
Preferably the secondary stopping-off bag is constructed as a hollow cylinder of fabric with end closures constructed of a double layer of fabric the warps of the respective layers in a given end closure being at an angle to each other, the end closure being secured to the cylinder by means of folded-over end flaps of the layer. The angle between the warps of the layers in the end closures is optimally 90°. The sleeve-like neck in one end closure of the bag for egress of the mouth of the inflation bladder is made as short as possible and preferably also of a double layer of fabric, each layer having end flaps to be folded over and be secured to the end closures. The flaps radiate from the sleeve with end flaps originating from one layer of the neck being angularly offset from and overlapping the flaps originating from the other.
A seam of the cylinder is axial and is aligned to lie within the convergence of the warps of the layers of the end closures; furthermore when a gas connector is fitted to the neck it should be aligned generally with a continuation of the direction of the seam.
To minimise strength loss during stitching of the fabric it is desirable to use so-called "delta" needles, which have a rounded point and a triangular-section tip portion.
The invention also includes the method of making a secondary bag.
BRIEF DESCRIPTION OF THE DRAWINGS
A particular embodiment of the invention, given by way of example, will now be described with reference to the accompanying drawings in which:
FIG. 1 shows the conventional layout of an iris-stop primary bag system and a secondary bag system in a duct, seen in cross-section;
FIG. 2 shows the secondary bag embodying the present invention in position in the duct;
FIGS. 3a, 3b, 3c, 3d and 3e show various stages in the formation of a neck piece of the present bag;
FIG. 4 shows an end closure of the bag;
FIG. 5 shows the cylinder of the bag;
FIG. 6 shows an assembly stage;
FIG. 7 shows a further assembly stage;
FIG. 8 shows a completed assembly;
FIG. 9 shows a partial cross-section through the assembly as positioned in a duct; and
FIG. 10 is a similar cross-section but of a modified embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a duct 1 of a mains gas pipe in which the gas flows from left to right is being temporarily stopped-off by a primary sealing bag 2 introduced by known means through a hole 3 formed in the wall of the duct. Downstream of the hole 3 a second hole 4 is formed, through which is introduced the support 5 of a spreadable iris-disc 6. The bag 2 having been guided to lie downstream of its insertion position by a skid 7, can be inflated to occupy the duct with its base resting against the iris-disc 6. Downstream of the iris-disc a further hole 9 is formed and a secondary bag (which here is a conventional secondary bag 11) is introduced through it and positioned in the duct upstream of it. A hollow support column 10 is also introduced through the hole 9 and positioned downstream of the secondary bag 11. The secondary bag is inflated through a gas connector 12 connected to a neck 13 of the bag. As can be seen the total length of the gas connector 12 and the neck 13 is greater than the cross-sectional width of the hollow column 10 so that when the bag 11 is inflated its rear end is substantially spaced out from the column. If, however, the primary bag were to fail the secondary bag might be forced back down the duct towards the position shown in dotted lines 11' at which it can be seen that its rear end closure is substantially flexed and stressed around the neck. The secondary bag 11 contacts the duct over a length which is about one half of the duct diameter.
FIG. 2 shows a bag 20 embodying the invention in use. The column 10 may be identical but the total length of the connector 12' and neck 13' is not greater than the cross-sectional dimension of the column. Thus in a normal position shown in full lines the rear end of the bag 20 is supported by the column. This secondary bag 20 contacts the duct over a length which is at least 0.7 times the duct diameter, preferably between 0.8 and 0.9 times the duct diameter. As compared with the conventional bag 11 the increased contact length makes the bag 20 less likely to slip along the duct. Even if it is somewhat dislodged by sudden pressure, to the position 20', there is substantially less flexion and stress in the region of the neck (slight overlapping past the column 10 is possible but only beyond each side of the column).
The bag 20 embodying the invention is made up as follows.
A neck portion of the bag is made up as seen in FIG. 3. Two parts 23 and 24 each having a plurality of tongues 25 and 26 at one of their edges are placed so that the tongues are in staggered relationship and are tacked together by a line of stitching 27, FIG. 3a. They are then brought around as shown in FIG. 3b and seamed along one edge as far as the line of the root of the tongues. This seam 28 results in the formation of the sleeve portion 29. This sleeve is pushed through a central aperture in a planar annulus 30 of fabric seen in FIG. 3d and the tongues 25, 26 are turned outwardly from the sleeve to be radiated upon the face of the annulus 30 and are then stitched down onto that by a circular row of stitching 31. The placing of a cylindrical former inside the sleeve portion 29 as this is being done, is helpful.
In the final step of the formation the sleeve portion 29 is pulled through so that the hem is now inside it, FIG. 3e.
The next step to be described is making end closures of the bag. Each end closure consists of two polygonal sheets of fabric of coincident outline laid upon each other so that the warp direction W1 of one of the sheets 32 lies at an angle which is preferably 90° to the warp direction W2 of the other sheet 31. The two layers thus formed are stitched together along radial lines of stitching 33 into the corners of the polygon. In the end closure seen in FIG. 4, which is that which is going to receive the neck assembly, both layers 31,32 have a central aperture 34 which is surrounded by a reinforcing annulus of fabric 35 which is stitched to the layers by a circle of stitching 36. In the end closure which is to form the other end of the bag (the one to be remote from the column 10) the fabric layers 31,32 are uninterrupted by any aperture.
After the two layers have been attached together in that way, the neck assembly is mounted on them by having the sleeve portion 29, in the condition seen in FIG. 3e, inserted through the aperture 34 from that face of the end closure which is to be innermost in use. The annulus 35 on the interrupted end closure face is on the layer which is to be outermost in use.
The tongues 25,26 are therefore entrapped between the reinforcing annulus 30 and the inner of the two layers of the end closure. The neck assembly is then stitched to the end closure by a ring of stitching 37, FIG. 6, through to the reinforcing annulus 35.
Meanwhile, a hollow cylinder has been prepared from a rectangular blank of fabric 38 having at each major edge extensions which are to form flaps 39. The ends of the blank are brought round together and are overlapped to form a seam 42 and are tacked together at 40, at their end portions only. The sleeve thus formed is next secured to the end closures. In a first step a continuous line of stitching 41 (FIG. 6) is formed parallel to the polygonal edges of the end closure and along the line joining the roots of the end flaps 39 of the cylinder. It is important to note that the securing of the cylinder to the end closures is done in such a way that the seam 42 of the cylinder occurs within the angle between the two warps W1,W2. That is it could either be to the corner marked F or to the corner marked G in FIG. 6, or perhaps between those corners. The same disposition of warps W1,W2 is followed when securing the other of the end closures.
In a second stage of securing of the end closures the end flaps 39 are folded over the end closure and are stitched down onto it by a line of stitching 43 parallel to the edges of the end flaps spaced slightly in from those edges. It is very important that the folded over end flaps 39 shall be at the same tension as the underlying layers 31,32 of fabric of the end closure, so that all layers of fabric secured between the lines 41 and 43 of stitching are in equal tension and equally share any stresses to be experienced.
In a final stage of assembly the bag so formed is turned inside-out by eversion through the gap left along the seam 42 between the tackings 40 and its bladder is inserted into it through the same gap. The inflation neck of the bladder is brought out through the sleeve 29 which is now projecting outside the bag as a whole and is there united by means of standard fitments both with the sleeve and with a gas connector 44 having an inlet 45 which is at right angles to the axis of the bag in the sleeve. It is important that this inlet is orientated generally toward the seam 42 in the cylindrical sleeve, that is to be directed to within the angle formed between the warps W1 and W2 of the end closure.
Finally, the seam 42 is closed either by bonding or stitching. The dimensions of the bag are, of course, chosen in accordance with expected pressures in the duct and the diameter of the duct to be stopped-off and the dimension of the projecting neck and gas connector are selected in relation to the column 10 as has already been noted in connection with FIG. 2.
The fabric used for most of the structural parts is a plain nylon fabric but for the reinforcing annuli such as 30, 35 and also for one of the two parts 23, 24 polyurethane coated nylon is used. The stitching is found to involve least loss of strength if it is performed with round pointed "delta needles", that is to say needles of which at least the tip of the end portion is of triangular section.
FIG. 9 shows the conformation of the bag in use, at the important region where it parts from the wall 1 of the duct. The construction is as previously described except that an additional row of stitching 46 is shown which may advantageously be applied. This method of assembling the single bag 38 to the double end wall 31, 32 is preferred because of its manufacturing advantage but it does leave a region where only a single layer of fabric is resisting, unsupported, the pressures in the bag. This single layer region can usually be tolerated, as the radius of curvature of the fabric is high here and so the stresses induced are relatively low.
An alternative method of construction is shown in FIG. 10 where inner panel 31' is extended at the region 48 to underlie the bag 38 and is secured by a row of stitching 47. This has the advantage of doubling the fabric at the critical area but it is a much more complex method of fabrication.
It is possible for the bag to be inflated not with gas but with liquid, which is advantageous because of the incompressability of the liquid (leading to lower pressure stress in the free standing normal mode of the secondary bag before failure of the primary bag) and because of its high mass leading to high mechanical inertia of the bag. | In an iris-stop arrangement for stopping-off a duct the secondary bag has a contact length with the duct of at least 0.7 times its diameter. The apparatus is such that the point where the inflation neck of the bag meets the remainder of the bag can adopt a position not substantially in front of the secondary bag support member. Thus the bag has improved functional grip on the duct and does not suffer severe flexing at the neck when it moves back to rest against the support member. Preferably the portion of the bag which contacts the duct in use is a single layer of fabric thick while the ends of the bag, which have to withstand the bag inflation pressure unsupported, are two layers thick. In this way the bag can have good performance characteristics while only needing a relatively small insertion hole in the side of the duct. | 22,138 |
RELATED APPLICATION
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 11/716,138, entitled “Low Pass Filter Semiconductor Structures For Use in Transducers For Measuring Low Dynamic Pressures In The Presence of High Static Pressures,” filed Mar. 9, 2007, which is a continuation of U.S. patent application Ser. No. 11/100,652, now U.S. Pat. No. 7,188,528, entitled “Low Pass Filter Semiconductor Structures For Use In Transducers For Measuring Low Dynamic Pressures In The Presence Of High Static Pressures,” filed Apr. 7, 2005, which is a continuation-in-part of U.S. patent application Ser. No. 10/830,796, now U.S. Pat. No. 7,107,853, entitled “Pressure Transducer for Measuring Low Dynamic Pressures in the Presence of High Static Pressures,” filed Apr. 23, 2004, all of which are hereby incorporated by reference as being set forth in its entirety herein.
FIELD OF THE INVENTION
[0002] The invention relates to pressure transducers for measuring low dynamic pressures in the presence of high static pressures, and more particularly to improved low pass filter structures employed with such transducers.
BACKGROUND
[0003] During the testing of jet engines and in many other environments, it is often desirable to measure both the static pressure and the dynamic pressure. The static pressure, in most instances, is usually very high and the dynamic pressure is much lower. The dynamic pressure is also associated with a distinct frequency which occurs at a relatively high rate, for example 5000 cycles/second or greater. In this manner, the dynamic pressure may typically be 20 times less than the static pressure. Hence, to measure static pressure, one requires a transducer with a relatively thick diaphragm so that it can stand the high static pressure. On other hand, such thick diaphragms have a poor response to low pressure. Therefore, to measure static pressure and dynamic pressure is extremely difficult unless one uses a thick diaphragm in conjunction with a thin diaphragm. However, if one uses a thin diaphragm, then this diaphragm will rupture upon application of the high static pressure which also contains the dynamic pressure. One can think of the dynamic pressure as a relatively high frequency fluctuation on top of a relatively high constant static pressure. Thus, as one can ascertain, using a thick diaphragm to measure dynamic and static pressure is not a viable solution.
[0004] U.S. Pat. No. 6,642,594 ('594 patent) entitled, “Single Chip Multiple Range Pressure Transducer Device”, which issued on Nov. 4, 2003 to A. D. Kurtz, the inventor herein and is assigned to Kulite Semiconductor Products, Inc., the assignee herein, discloses problems with transducers responsive to large pressures utilized to measure low pressures. Thus, pressure transducer adapted to measure relatively large pressures typically suffer relatively poor resolution or sensitivity when measuring relatively low pressures. This is because, as a span of the sensor increases, the resolution or sensitivity of that sensor at the low end of the span decreases. An example of various piezoresistive sensors are indicated in the aforementioned '594 patent wherein different transducers have thinned regions having the same thickness, but different planar dimensions. In this manner, the thinned regions will deflect a different amount upon application of a common pressure thereto, whereby when excited each of the circuits provides an output indicative of the common pressure of a different operating range.
[0005] As indicated above, during the testing of jet engines there is a very high static pressure which, for example, may be 100 psi. Present with the static pressure is a low dynamic pressure, which may exhibit frequencies in the range of 5000 Hz and above. As indicated, using a high pressure sensor to measure the static pressure will yield an extremely poor response to the dynamic pressure because of the small magnitude of dynamic pressure which can be, for example, about 5 psi. Therefore, it is desirable to use a relatively rugged pressure transducer having a thick diaphragm to measure static pressure and to utilize another transducer on the same chip having a thinned diaphragm to measure dynamic pressure. Because the thinned transducer is exposed to static pressure both on the top and bottom sides, the static pressure cancels out and does not, in any manner, cause the thinned diaphragm to deflect. As described herein, both static and a dynamic pressure may be applied to the rear side of the diaphragm by a reference tube of substantial length. This reference tube, as will be explained, is a helical structure and has a low resonant frequency. In this manner, when a small dynamic pressure is applied because of the low internal frequency of the tube, the sensor will respond to the static pressure only. The thinned diaphragm should be stopped for pressures in excess of 25 psi, or some higher number than the desired dynamic pressure. The long reference tube can be made by taking a tubular structure and wrapping it such that it looks like a coil or spring. One end would be inserted into the transducer and other end would be exposed to pressure. In this manner, one can implement a transducer for simultaneously measuring a low dynamic pressure in the presence of a high static pressure. Alternative transducer structures and methods for measuring low dynamic pressure in the presence of high static pressure are also desired.
SUMMARY
[0006] A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. The filter receives both a high and relatively low frequency static pressure attendant with a high frequency low dynamic pressure at one end, and operates to filter the high frequency dynamic pressure to provide only the static pressure at the other filter end. A differential transducer receives both dynamic and static pressure at one input port and receives the filtered static pressure at the other port where the transducer provides an output solely indicative of dynamic pressure. The filter in one embodiment has a series of etched channels directed from an input end to an output end. The channels are etched pores of extremely small diameter and operate to attenuate or filter the dynamic pressure. In another embodiment, a spiral tubular groove is formed between a silicon wafer and a glass cover wafer. An input port of the groove receives both the static and dynamic pressure with an output port of the groove providing only static pressure. The groove filters attenuate dynamic pressure to enable the differential transducer to provide an output only indicative of dynamic pressure by cancellation of the static pressure.
BRIEF DESCRIPTION OF THE FIGURES
[0007] FIG. 1 is a partial cross sectional view of a pressure transducer for measuring low dynamic pressures in the presence of high static pressures.
[0008] FIG. 2 is a partial cross sectional view of a pressure transducer for measuring low dynamic pressures in the presence of high static pressures employing a semiconductor attenuator according to an embodiment of the present invention.
[0009] FIG. 3 is a series of top views showing alternate pore configurations useful for the semiconductor attenuator of FIG. 2 .
[0010] FIG. 4 is a partial cross sectional view of a pressure transducer responding to dynamic and static pressures employing a semiconductor helical structure operating as an attenuator.
[0011] FIG. 5A shows a top view of the semiconductor attenuator utilized in FIG. 4 ; and FIG. 5B shows a cross sectional view of the semiconductor attenuator utilized in FIG. 4 taken through line B-B of FIG. 5A .
DETAILED DESCRIPTION
[0012] Referring to FIG. 1 , there is shown a pressure transducer which basically consists of two leadless peizoresistive sensors 20 and 21 mounted on header pins in accordance with the methods disclosed in Kulite U.S. Pat. No. 5,955,771 entitled, “Sensors for Use in High Vibrational Applications and Methods for Fabricating the Same” which issued on Sep. 21, 1999 to A. D. Kurtz et al, the inventor herein and assigned to Kulite Semiconductor Products, Inc., the assignee herein. This patent is incorporated herein by reference.
[0013] Shown in FIG. 1 are two separate transducers 20 and 21 which are fabricated by the same process as according to the teachings of the above-noted co-pending application and patent. The difference between the two transducer or sensor structures is that the sensor structure on the left has a diaphragm 20 which is thicker than the diaphragm 21 of the sensor structure on the right. Both sensors receive on their top surfaces a pressure indicative of the static pressure (P s ) plus the dynamic pressure (P d ) (P s +P d ). As indicated, the static pressure (P s ) may be of a relatively high value and, for example, could be 100 psi or more. The dynamic pressure (P d ) appears as a ripple on top of the static pressure (P s ) and is characterized by a relatively high frequency on the order of magnitude of 5000 Hz and above and a low value of 5 psi or less. Both sensors receive the combination of the static plus the dynamic pressure shown in FIG. 1 . Sensor 20 , as indicated, has a thicker diaphragm and responds mainly to the static pressure to produce at the output pins ( 15 , 16 ) associated therewith, a voltage proportional to the static pressure. This voltage would indicate a static pressure of 100 psi or greater, whatever the case may be.
[0014] While the output of transducer 20 is also responsive to the dynamic pressure (P d ), the dynamic pressure (P d ) is an extremely small percentage of the total static pressure (P s ) and may, as indicated, be on the order of 5 psi or less. The thin diaphragm associated with the transducer 21 will respond only to the dynamic pressure (P d ), as will be explained. As seen in the Figure, transducer 21 has the static plus the dynamic pressure applied to the top surface and is indicated again by P s +P d . Coupled to the bottom surface of the diaphragm is a tube or reference tube of an exceedingly long length, designated by reference numeral 18 . The tube 18 is coupled to the bottom surface of the diaphragm. Essentially, the tube 18 receives at an inlet both the static and dynamic pressure, which is P s +P d .
[0015] The tube, as shown, is in helical form. It is well known that the resonant frequency f of such a tube, as, for example, an organ pipe, is given by f=c/(41), where c is the speed of sound, and 1 is the length of the tube. For instance, in air, where the speed of sound is approximately 1200 feet per second, a tube length of 2½ feet will give a resonant frequency of 120 Hz. Thus, tube 18 acts as a low pass filter and will only pass frequencies which are below 120 Hz. In this manner, the dynamic frequency, which is 5000 Hz or greater, will not pass through the tube 18 . Therefore, the underside of the diaphragm associated with transducer 21 only receives the status pressure (P s ). The static pressure (P s ) subtracted from the static pressure plus the dynamic pressure (P s +P d ) supplied to the top surface of the diaphragm such that the output of the differential unit 21 provides a pressure equal to the differential pressure (P d ). As seen, there is a stop member associated with diaphragm 21 . The stop member 25 assures that the diaphragm 21 will not deflect in a downward direction for pressures in excess of 25 psi, or some number higher than the desired dynamic pressure. The reference tube is fabricated by taking a tubular structure, which may be metal or some other material, and wrapping it such that it looks like a coil or a spring where one end is inserted into the transducer, as shown, and the other end is exposed to the static and dynamic pressure. Reference is made to U.S. Pat. No. 6,642,594 entitled, “Single Chip Multiple Range Pressure Transducer Device” issued on Nov. 4, 2003 to A. D. Kurtz, the inventor herein and assigned to the assignee herein, the entire disclosure of which is hereby incorporated by reference herein as well.
[0016] Therefore, the diaphragm associated with sensor 20 is intended for accurately measuring static pressure. The sensor unit 21 will measure dynamic pressure because of the differential operation of the sensor 21 and because of the tube. These dynamic pressures have relatively high frequencies measured primarily by the first assembly 21 , with the second assembly 20 measuring the steady state pressure, which is a large pressure. The fabrication of stops, such as 25 for transducers, is well known in the art. See, for example, U.S. Pat. No. 4,040,172 entitled, “Method of Manufacturing Integral Transducer Assemblies Employing Built-In Pressure Limiting” issued on Aug. 9, 1997 to A. D. Kurtz et al and is assigned to the assignee herein. See also U.S. Pat. No. 4,063,209 entitled, “Integral Transducer Assemblies Employing Built-In Pressure Limiting” issued on Dec. 13, 1997 to A. D. Kurtz et al. and assigned to the assignee herein. The entire disclosures of U.S. Pat. Nos. 4,040,172 and 4,063,209 are also incorporated by reference herein.
[0017] See also U.S. Pat. No. 6,595,066 issued on Jul. 22, 2003 to A. D. Kurtz et al. and is assigned to the assignee herein and entitled, “Stopped Leadless Differential Sensor”. This patent describes a leadless device which is similar to the devices utilized in FIG. 1 which has a stop apparatus associated therewith. The sensor depicted in the '066 patent also operates as a differential sensor with a Wheatstone bridge sensor array. The output provides a difference between a pressure applied to the top side of the sensor with respect to the force applied to the bottom side of the sensor. This sensor acts as the sensor 21 associated and seen in FIG. 1 . U.S. Pat. No. 6,595,066 is incorporated herein.
[0018] See also U.S. Pat. No. 6,588,281 issued on Jul. 8, 2003 entitled, “Double Stop Structure for a Pressure Transducer” issued to A. D. Kurtz et al. and assigned to the assignee herein. That patent shows a stop device in both first and second directions. As one can ascertain from FIG. 1 , a stop 25 is only required in the down direction. This is so, as the large pressure P s +P d , as applied to the top surface, could rupture the thin diaphragm if the pressure applied to the bottom surface momentarily is interrupted. In this manner, the diaphragm of the sensor 21 will impinge upon the stop 25 to prevent the fracture of the diaphragm. The interruption of the pressure applied to the bottom surface of the diaphragm could occur during pressure build-up or when the pressure source is first turned on or off. U.S. Pat. No. 6,588,281 is also incorporated herein.
[0019] Referring now to FIG. 2 , there is shown a transducer structure in which the helical tube 18 of FIG. 1 is eliminated. As the tube or organ pipe illustrated in FIG. 1 may be expensive and/or difficult to fabricate and incorporate, the semiconductor structure of FIG. 2 operates to emulate the characteristics of the helical tube, including for example, frequency response, without providing such a helical tube.
[0020] FIG. 2 utilizes the same reference numerals as FIG. 1 for corresponding parts. It is seen that there are again two sensor diaphragms 20 and 21 , each having piezoresistors located thereon and each receiving a pressure at a top surface which is the static plus dynamic pressure designated as P s +P d .
[0021] A reference tube 25 is shown which receives the pressure P s +P d at the inlet. Disposed between the back surface of transducer 21 and the input of the reference tube 25 is a silicon wafer 26 .
[0022] The wafer 26 has a plurality of holes or through channels, each having a diameter of less than about 0.001 inches and formed by etching or micromachining, for example. In this case, as indicated in FIG. 2 , the small diameter holes or apertures serve to attenuate any high frequency components of the pressure caused by viscosity of the gas flowing through the apertures. The pressure and attenuation provided is determined by the diameter of the holes, the number of holes, as well as by the cavity volume on the underside of the sensing diaphragm.
[0023] The hole diameter, number of holes on the silicon wafer 26 , and the cavity size are selected such that a desired filtering frequency can be obtained utilizing the formula:
[0000]
τ
=
32
γ
vVL
AD
2
c
2
[0000] where
τ=attenuation and γ represents the ratio of specific heats; for air γ=1.4; v represents the kinematic viscosity; for air v=14.5 m 2 /s or 0.0225 in 2 /s; V represents the volume of the cavity or wafer; L represents length of the pipe; A represents the total area of feeding pipes or apertures; D represents the diameter of feeding pipe or apertures; and c represents the speed of sound, which is about 1120 ft/s at room temperatures.
For example; to achieve a cut-off frequency of 100 Hz, or a time constant of 10 milli-seconds, the following parameters can be selected:
D=0.0002 inch A=0.000625 inch 2 assuming 25% pososity and a 0.050″ chip c=1120 ft/s=13400 inch/2 L=0.005 V=0.001 in 3 .
[0037] As one can see, attenuation is determined by the diameter of the hole as well as the number of holes. The wafer having the silicon holes acts as a single hole of considerably longer length. The fabrication of holes in silicon is well understood and can be accurately controlled. See for example, an article entitled “Porous Silicon/A New Material for MEMs” published in the IEEE 1996 by V. Lehmann of Siemens Ag Munchen, Germany, which describes a technique for the formation of pores or holes in silicon with high aspect ratios utilizing electrochemical etching of n-type silicon wafers in hydrofluoric acid.
[0038] The wafer as shown in FIG. 2 is an n-type silicon wafer. As the article indicates, porous silicon has been used for many years and may be formed on a silicon substrate during anodization in a hydrofluoric acid electrolyte. Pore formation is present for anodic densities below a critical current density. The pore geometry can be controlled, as can the pore cross section. The pore cross section can vary between a circle and a forearm star depending on the formation conditions. Subsequent to the electrochemical pore formation, the cross section of the pores can be made more circular by oxidation steps or can be made more square shaped by anisotropic chemical etching for example using aqueous HF.
[0039] Referring to FIG. 3 , there is shown a series of pore cross sections, all of which shapes can be formed during the etching process, and which shapes have been described in the above-identified article. While circular shapes may be preferred, the pores can be of a square or any other suitable configuration represented by shapes designated A through E in FIG. 3 .
[0040] While the above-identified article describes process steps which are standard techniques in microelectronic manufacturing, such techniques may be used to develop pore configurations in a silicon substrate which enable communication between the bottom surface of the substrate to the top surface of the substrate.
[0041] Based on the diameter of the pores and based on the width of the silicon wafer, one can therefore obtain the same frequency characteristics as are available by a helical tube. The bottom surface of wafer diaphragm 21 thus receives only the static pressure (P.sub.s), whereby the higher frequency dynamic pressure is completely suppressed by the semiconductor wafer 26 having pores of configurations A-E as shown in FIG. 3 .
[0042] The pore configurations A to E have various cross sections and will extend from the top surface of the wafer to the bottom surface of the wafer.
[0043] Referring now to FIG. 4 there is shown an alternate embodiment of a semiconductor arrangement that emulates the helical tube illustrated in FIG. 1 and that functions in a manner similar to the apertured wafer structure 26 illustrated in FIG. 2 . FIG. 4 illustrates transducer diaphragms 20 and 21 arranged in a housing whereby the static plus dynamic pressure (P s +P d ) is applied to the top surface. The reference tube 25 again receives the static and dynamic pressure, which now is applied to the bottom surface of a semiconductor wafer 28 . The semiconductor wafer 28 has an input aperture 30 which is directed into a coiled hollow helical structure fabricated on the surface of the semiconductor substrate. The helical structure has an output aperture 31 communicating with the underside of the diaphragm 21 .
[0044] Thus, the underside of the diaphragm 21 receives the static and dynamic pressure and because of the helical structure fabricated on the semiconductor wafer 28 , the dynamic pressure frequencies are again suppressed.
[0045] Referring to FIG. 5 , there is shown a top view of the wafer 28 . The wafer 28 as shown in a cross sectional view of FIG. 5 b has a bottom silicon wafer 33 with a glass cover wafer 32 . The silicon wafer is first processed to provide a helical structure 40 on a top surface. The helical structure 40 is fabricated at a given depth. The helical structure communicates with an aperture 30 as shown in FIG. 4 to enable the static plus the dynamic pressure to be applied to aperture 30 .
[0046] The pressure is then circulated within the helical structure as covered by the glass cover member 32 and at the output aperture 31 the pressure P s which is the static pressure now applied to the underside of the diaphragm.
[0047] It is understood that there are numerous ways of fabricating helical structures in semiconductor material. These can be fabricated by utilizing stacking layers whereby a spiral coil is fabricated between these layers and effectively constitutes a helical semiconductor structure which manifests itself in having the same diameter and length as the helical tube shown in FIG. 1 . In this case, the length of the spiral determines the frequency of operation according to the following formula
[0000]
f
=
c
4
L
1
-
(
4
v
D
2
c
4
L
)
2
[0000] where
c=speed of sound, about 1120 ft/s L=length of pipe or spiral; D=diameter of pipe or spiral; v=kinematic viscosity: for air, v is about 14.5 m 2 /s or 0.0225 in 2 /s.
In an exemplary configuration, a spiral of 0.005 inch diameter and 1 inch in length achieves a filtering frequency f of 100 Hz.
[0052] By varying lengths and diameters of the holes, as for example concerning the embodiment depicted in FIG. 2 , one can tailor the frequency attenuation to desired value. According to an aspect of the present invention, such frequency attenuation can be attained in an exceedingly small space. The structures as described herein can be mounted directly behind a deflecting diagram and beyond the header, as shown in FIG. 2 and FIG. 4 , for example.
[0053] It should be noted that after using standard micromachining techniques, a significant number of these structures could be made simultaneously within a relatively small size (of silicon, for example). The processing techniques, as indicated above, will enable such structures to be produced, and hence produce reliable semiconductor attenuators or semiconductor filters for use in static and dynamic pressure measurements.
[0054] While it is understood that the figures and descriptions herein illustrate a dual transducer structure, it is understood that a single transducer can be utilized, whereby static and dynamic pressure applied to one surface and static and dynamic pressure are applied to the bottom surface or the opposing surface via a semiconductor attenuator such as a semiconductor wafer having through pores from the top to the bottom surface. Alternately, a semiconductor helical arrangement having a hollow passageway from an input port which receives the static and dynamic pressure to an output port which will only allow the static pressure to pass due to the length and diameter of the helix can be employed.
[0055] It is therefore understood that the above-noted semiconductor structures may replace the mechanical helical design in a more efficient and compact structure while enabling a great number of applications to be provided. While the above noted exemplary embodiments are preferred, it is also understood that alternative embodiments can be employed according to the teachings of this invention.
[0056] For example, a single transducer such as that depicted by reference numeral 21 can be utilized to produce an output indicative of dynamic pressure and whereby the static pressure would be cancelled. These and alternate embodiments can be ascertained by one skilled in the art and are deemed to be encompassed with the spirit and scope of the claims appended hereto. | A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. The filter receives a high and very low frequency static pressure attendant with a high frequency low dynamic pressure at one end, the filter operates to filter said high frequency dynamic pressure to provide only the static pressure at the other filter end. A differential transducer receives both dynamic and static pressure at one input port and receives said filtered static pressure at the other port where said transducer provides an output solely indicative of dynamic pressure. The filter in one embodiment has a series of etched channels directed from an input end to an output end. The channels are etched pores of extremely small diameter and operate to attenuate or filter the dynamic pressure. In another embodiment, a spiral tubular groove is found between a silicon wafer and a glass cover wafer, an input port of the groove receives both the static and dynamic pressure with an output port of the groove providing only static pressure. The groove filters attenuate dynamic pressure to enable the differential transducer to provide an output only indicative of dynamic pressure by cancellation of the static pressure. | 27,700 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to passive seatbelt systems and more particularly to passive seatbelt systems which automatically fasten a restrictive webbing about a passenger after the passenger has seated himself in the motor vehicle.
2. Prior Art
Seatbelt devices are designed to protect passengers in a motor vehicle by holding them with restrictive seatbelts during vehicular emergencies and preventing collision with dangerous objects within the motor vehicle to thereby greatly increase the safety of such passengers. However, because of the complexity, etc. fastening such seatbelts, the percentage of use is very low. For this reason, passive seatbelts which automatically fasten themselves about the passenger after the passenger has been seated, have been proposed. These passive seatbelt devices or systems consist of a restrictive seatbelt whose outer end is fastened on the door or roof side and is movable forward and backward. This outer end is connected to and moved by a motor connected to the vehicle's power supply and may be moved forward or backward to cause the seatbelt to approach or move away from the passenger seat.
Therefore, after the passenger seats himself, the seatbelt would automatically move rearward to fasten itself and to close the gap between the seatbelt and the seat.
However, in such present passive seatbelt systems, since the stopping point of the outer end of the seatbelt is a constant, it is not possible for the seatbelt device to fit passengers of different physiques and therefore the passenger's freedom is restricted after the seatbelt is fastened and the passenger is uncomfortable.
SUMMARY OF THE INVENTION
Accordingly, it is the general object of the present invention to provide a passive seatbelt system which automatically fastens the seatbelt appropriately about passengers of different physiques after the passengers enter the vehicle.
It is still another object of the present invention to provide a passive seatbelt system which guarantees the safety of the passenger by restricting them during vehicular emergencies but does not interfere with the passenger's freedom under normal vehicular operating conditions.
In keeping with the principles of the present invention, the objects are accomplished by a unique passive seatbelt system including a passenger restrictive seatbelt of which an inner end is attached to a roller mechanism fastened to a center of the motor vehicle and an outer end which is fastened to a moving plate, the moving plate is fastened to a roof side of the motor vehicle and constrained to forward and rearward motion, a narrow belt is attached to the moving plate at one end and to a winding roller located to the rear of the roof side for winding up the narrow belt, the narrow belt winding roller being arranged and configured such that it permits free unwinding to accomodate passengers of different physique except at times of a vehicular emergency wherein the unwinding of the narrow belt is stopped by an emergency locking retractor.
BRIEF DESCRIPTION OF THE DRAWINGS
The above mentioned features and objects of the present invention will become more apparent with reference to the following description taken in conjunction with the accompanying drawings wherein like reference numerals denote like elements, and in which:
FIG. 1 is a side view illustrating one embodiment of a passive seatbelt system in accordance with the teachings of the present invention;
FIG. 2 is a front view of the vehicle of FIG. 1;
FIG. 3 is an expanded view of a part of FIG. 1;
FIG. 4 is a cross sectional along the line IV--IV of FIG. 3;
FIG. 5 is a close-up of a thick tape;
FIG. 6 is a cross sectional along the line VI--VI of FIG. 1;
FIG. 7 is a cross sectional along the line VII--VII in FIG. 1;
FIG. 8 is a close-up of a front pillar showing a sprocket wheel;
FIG. 9 is a cross sectional along the line IX--IX of FIG. 8;
FIG. 10 is a side view showing a second embodiment of a passive seatbelt system in accordance with the teachings of the present invention;
FIG. 11 is an expanded view of part of FIG. 10;
FIG. 12 is a cross sectional view along the line XII--XII of FIG. 10; and
FIG. 13 is a cross sectional view along the line XIII--XIII of FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
Referring more particularly to the drawings, shown in FIG. 1 is a first embodiment of a passive seatbelt system in accordance with the teachings of the present invention. In FIGS. 1 and 2, the inner end 12 of the passenger restraining belt 10 is wound onto a self-winding roller 14 which is fastened to the vehicle floor 15. The winding roller 14 is fastened to the center of the vehicle facing left and right.
The outer end 16 of the belt 10 is fastened to a truck 18 which is fastened to the roof side member 20 and may be moved forward and backward. By this forward and backward motion, the belt 10 approaches and moves away from the passenger seat 22. Therefore, a passenger seated in the seat 22 may be automatically fastened in or released by the belt 10. The truck 18, as shown in FIGS. 3 and 4, includes a moving plate 20 and an extension 26 which protrudes toward the floor of the vehicle. The extension 26 is provided with a slot 28 onto which the other end of the belt 10 is secured. Also, the moving plate 24 has four axles 30 which are provided so as to be mutually parallel. On each of the axles 30, as shown in FIG. 4, is provided wheels 32 whose diameter at the center is smaller than the diameter at the edge. The wheels 32, as shown in FIG. 4, ride within a guide wheel 34 which is C-shaped in cross section and may be moved along the axis of the guide rail 34, that is forward and backward along the vehicle.
The guide rail 34 is fastened by several fastening screws 36 through the central part of the C-shaped cross section to the inside of roof side member 20 and the open part is arranged so as to face toward the inside of the vehicle.
The top of guide rail 34 is formed into a flange 38 and the flange 38 is attached by fastening screws 44 to flange 42 which is provided on slide rail 40. Accordingly, guide rail 34 and slide rail 40 are kept parallel. The central part of slide rail 40 is provided with a rectangular groove 46 along its axis and midway down the rectangular groove 46, slide grooves 48 widen the width of the groove 46. A thick tape 50, shown in FIG. 5, is provided in the slide grooves 48 and can slide along the long axis of the slide rail 40.
The thick tape 50, as shown in FIG. 5, is a rectangular cross section and many holes are provided in the thick tape 50 at uniform intervals. Also, the rectangular cross section of the thick tape 50 is a tight fit in the slide grooves 48 of the slide rail 40 when inserted such that while an extension force is naturally transmitted, a compression force can also be transmitted. Furthermore, it is desirable that the material of the tape 50 be made from a synthetic resin with an appropriate flexibility so that the tape 50 may be bent with a small radius of curvature. One end of the tape 50 is fastened by four rivets 52 to a sliding block 54.
Projection 56 of sliding block 54 disengageably engages with projection 58 of movable plate 24 which projects in the direction of the thick tape 50 from the rear. Furthermore, when sliding block 54 is moved toward the front of the vehicle by thick tape 50, the movable plate 24 which has the projection 58 is also caused to move toward the front of the vehicle. In contrast, movable plate 24 may move toward the rear of vehicle by itself. By this means, when a passenger wearing the belt 10 changes his driving position, the movable plate 24 unwinds the narrow belt 62 and moves toward the front of the vehicle thereby increasing the passenger's freedom. Also, if the passenger grabs the belt 10 causing the outer end 16 to move while the outer end 16 is being moved by the thick tape 50 or when the passenger's body is being moved around during an accident, truck 18 can separate from sliding block 54 to prevent damage to the parts of the mechanism.
The end of movable plate 24 at the rear of the motor vehicle has a slot 60 provided in it and one end of a narrow belt 62 is secured to this slot 60. The other end of the narrow belt 62 is wound on roller 68 of winding roller 66 which is held by a fastening bolt 64 to a roof side member 20 at the rear end of guide rail 34. The winding roller 66 is a winding roller of construction similar to winding roller or retractor 14 onto which the inner end 12 of belt 10 is wound. Furthermore, the winding roller 66 is provided with a well known emergency locking retractor for preventing extension of the belt 62 during a vehicular emergency. Under normal circumstances belt 62 is wound up by a spring-powered winder 70. Thus, movable plate 24 which is connected by belt 62 to winding rollers 66 is pulled toward the rear of the vehicle by the force of the spring winder 70. In a vehicular emergency, by movement of the inertia locking device, a pawl can engage ratchet wheel 71 which is fastened to roller 68 to prevent the belt 62 from unwinding. Accordingly, the outer end 16 of the passenger restrictive belt 10 is effectively fastened to the roof side member 20.
From the slide rail 40, as shown in FIG. 4, in a direction opposite to flange 42, that is toward the floor of the vehicle, is provided another flange 72 and the interior roof lining 74 is held by fastening screws 75 to the flange 72. The guide rail 40 is, as shown in FIGS. 6 and 7 held with fastening screws 44 to the inner side of the vehicular front pillar 79 and descends along this front pillar 79. The lower end of the slide rail 40 is, as shown in FIG. 8, fastened to a sprocket housing 82. The sprocket housing 82, as shown in FIG. 9, is fastened to the center pillar 79 by fastening screws 106. The holes 51 of the thick tape 50 engage with the sprocket wheel 84 and are guided through a groove receiver portion provided in the sprocket housing 82. The sprocket wheel 84 is rotated by a reversible motor 112 such that the thick tape 50, which is held by sprocket 84, is caused to move along its long axis. The motor 112 is arranged such that when the passenger door is opened, it turns counterclockwise in FIG. 8; and when the door is closed it turns clockwise. In each instance, the motor 112 turns a fixed predetermined number of revolutions.
In operation, initially in FIG. 1 the passenger is shown in the vehicle equipped with belt 10 in the operational position. Truck 18 has moved as far as possible to the rear of the vehicle along the guide rail 34 and the passenger is held in by the belt 10. Since the inner end 12 of the webbing 10 is held by winding roller or retractor 14 and the outer end 16 is coupled to movable plate 24 and narrow belt 62 and each of these move, the passenger may freely alter his seated position. When the movable plate 24 moves toward the front of the vehicle, projection 58 separates from projection 56 and thick tape 50 does not move.
When a vehicular emergency such as a collision occurs, the inertia locking devices within rollers 14 and 66 completely stop the unwinding of belt 10 and narrow belt 62. Accordingly whatever position truck 18 and belt 10 are in, the outer end 16 of belt 10 is held at that position to the roof side member 20 and the passenger is restrained and his safety is guaranteed.
Now, when the passenger begins to leave the vehicle and opens the door, motor 112, rotating in a counterclockwise direction in FIG. 1, turns sprocket wheel 84 to pull thick tape 50 and moves the tape 50 in the direction indicated by arrow A. The result is that sliding block 54 moves truck 18 along guide rail 34 toward the front of the vehicle. Therefore, the outer end 16 of the belt 10 moves substantially toward the front of the vehicle to a position shown by the dotted lines in the Figures. Next, when the passenger has reboarded the vehicle, after seating himself and closing the door, motor 112 reverses and exerts a compressive force on the thick tape 50 moving it in a direction opposite to that given by arrow A. As a result, sliding block 54 moves toward the winding rollers 66 and the winding rollers 66 exerts a force on the narrow belt 62 which is attached to truck 18 and moves it toward the rear of the vehicle. By this means, the belt fastened condition of FIG. 1 may be achieved.
From the above description, it is apparent that since the truck 18 follows the movement of the body of the passenger and its stopping point is fixed by the sliding block 56, the extent of the unwinding of the narrow belt 62 from the winding rollers 66 changes with the passenger's body movements and that no matter how far the narrow belt 62 has extended from the winding roller 66, as long as the inertia locking device can still operate, this system can still restrain the passenger in a vehicular emergency.
Referring now to FIGS. 10 through 13, shown therein is a second embodiment of a passive seatbelt system in accordance with the teachings of the present invention. This example differs from the previous example in that a wire 150 is used to transmit the pulling force of the motor 112 to the truck 18 instead of the wide tape 50. This wire 150 is naturally capable of transmitting a tensile force along its axis but also may transmit a compressive force. One end is, as shown in FIGS. 11 and 12, clamped to sliding block 54A, while the middle portion is inserted into a slide groove 48A of almost circular cross-section which is provided in slide rail 40 and the wire 150 moves in this slide groove 48A.
The other end of wire 150 is wound onto a wire capstan 152 which is fastened to roof side member 20 at the front end of guide rail 34. The wire capstan 152 has, as shown in FIG. 13, a dish-shaped base 154 which is fastend to roof side member 20 by fastening bolt 156 and axle 156 is provided in the center of the base 154. A worm wheel 160 is provided on the axle 158 and engages with worm 162 mounted on the base 154. The worm 162 is rotated by a motor 112 which is fastened by a bracket (not shown) to roof side member 20. Also, on the axle 158 is provided a circular pressure plate 164 and a pressure coil spring 170 is fitted between the circular pressure plate 164 and a ring 168 which is in turn secured by a C-ring 166. Furthermore, the pressure plate 164 is pressed against worm wheel 160 by a spring 170 and is thus caused by friction to turn with worm wheel 160.
A thin rotatable plate 174, containing a circumferential groove of U-shaped cross-section is fastened to pressure plate 164. The bottom of the circumferential groove 172 is fastened one side of capstan 176 and the space between groove 162 and the outer edge rotatable plate 174 is formed into a wire receiver 178 of tapered cross-section. Here a U-shaped wire guide 180 is formed in base 154. Wire groove 182, adjacent wire guide 180, matches the greatest diameter 178A of circular wire receiver 178 and wire receiver 178 communicates with slide groove 48A of slide rail 40. One end of wire 150 is fastend to capstan 176 at its smallest diameter 178B.
In this construction, capstan 176 is rotated by motor 112. Winding wire 150 on the point of smallest diameter 178B pulls sliding block 54 toward the front of the vehicle when motor 112 is normally operated. When motor 112 is reversed, wire 150 is unwound from the point of greatest diameter and compression of wire 150 causes sliding block 54 to move to the rear of the vehicle. The remainder of the elements of this second embodiment are similar to those described above and are given like reference numerals and the description of their operation and interconnection is omitted.
From the above description, it is apparent that with the present invention, it is possible to provide a passive seatbelt fastening device which can be used with passengers of different physiques and provide freedom of movement for the passengers.
It should be apprent to one skilled in the art that the above described embodiments are merely illustrative but a few of the many possible specific embodiments which represent the application of the principles of the present invention. Numerous and varied other arrangements can be readily devised by those skilled in the art without departing from the spirit and scope of the invention. | A passive seatbelt system including a passenger restrictive seatbelt of which an inner end is attached to a roller mechanism fastened to a center of the motor vehicle and an outer end which is fastened to a moving plate, the moving plate is fastened to a roof side of the motor vehicle and constrained to forward and rearward motion, a narrow belt is attached to the moving plate at one end and to a winding roller located to the rear of the roof side for winding up the narrow belt, the narrow belt and winding roller being arranged and configured such that it permits free unwinding to accommodate passengers of different physique except at times of a vehicular emergency wherein the unwinding of the narrow belt is stopped by an emergency locking retractor. | 16,679 |
RELATED APPLICATIONS
[0001] This Application is a regular utility application based on Provisional Patent Application Ser. No. 62/309,927 entitled “VEHICLE SAFETY RAILROAD CROSSING” by Frank J. Bartolotti filed Mar. 17, 2016, which is incorporated by reference herein in its entirety and claims any and all benefits to which it is entitled therefrom.
FIELD OF THE INVENTION
[0002] The present invention is a vehicle safety railroad crossing system comprising a system for preventing collisions between trains and motor vehicles at all railroad crossings. Designed to save both lives and property, the vehicle safety railroad crossing system functions to alert the train's engineer and brakeman of the vehicle ahead obstructing the tracks, and automatically apply the train's brakes to prevent a collision.
BACKGROUND OF THE INVENTION
[0003] The United States railroad system consists of over 750 railroads running on 140,000 miles of track. Every day trains travel across more than 212,000 highway/rail so-called grade crossings. A grade crossing is a location where a public highway, road, street, or private roadway, including associated sidewalks, and pathways, crosses railroad tracks at grade, i.e., at the same level as the street. There are also more than 38,000 locations were railroad tracks and roadways cross at different levels.
[0004] According to the Federal Railroad Administration (FRA), there are about 270 deaths a year at public and private grade crossings. These deaths include pedestrians, but are predominantly due to train-versus-vehicle collisions. Largely through the FRA's safety programs, the number of fatalities has gone down by 54 percent over the last two decades. According to the FRA, trespassing along railroad rights-of-way is the leading cause of rail-related pedestrian deaths in America. Nationally, more than 431 trespass fatalities occur each year, and nearly as many injuries, the vast majority of which are preventable. Whether in a vehicle at a rail-crossing or as a pedestrian walking in the railroad right-of way, the reality is that nearly every 180 minutes in America, someone is hit by a train. Combined, highway/rail-crossing and trespasser deaths account for 95 percent of all rail-related deaths and most of these deaths are avoidable. Being struck by a train almost always means death for the motorist, but that can often be only the beginning of a larger, cascading disaster as the locomotive and cars of the train, one after another, derail. Regardless of whether the train in question is carrying crude oil, chlorine, or passengers, the effects of that initial collision continue long after that impact. What is needed is some more-effective means of preventing such collisions from occurring in the first place. The present invention prevents trains from colliding with vehicles at all rail crossings equipped with a sensor scale triggered to brake the approaching train.
[0005] Several references in the prior art show train safety systems. U.S. Pat. Nos. 5,554,982, 5,699,986 and 5,864,304 all show various systems which try to alert a train engineer of a vehicle, person, or blockage on the railroad tracks and try to allow time for train stoppage before collision. However, none of these patents teaches the vehicle safety railroad crossing system of the present invention.
[0006] Here in the United States and World Wide there are three (3) basic types of railroad crossings. These three types are as follows:
[0007] A. The first type of crossing is a sign with no lights or no bells. The sign simply states “Railroad Crossing” or uses an abbreviation such as “RR Crossing” or similar.
[0008] B. The second type of crossing is a pole with a sign, as above, but also with a flashing red light and/or a ringing bell to signify that a train is approaching.
[0009] C. The third type of railroad crossing is the gate system where gates come down and block the crossing, along with flashing lights and ringing bells to alert on-comers that a train is approaching.
[0010] For all 3 types of crossings there must be some type of a ramp to get over the tracks. Otherwise the vehicle will always get stuck in the tracks. A solar panel can be used for power in areas where there is no electric power line available. This is useful in condition type A, mentioned above. It will be understood that in conditions B and C, an electrical hook up at the crossing to power the gates and bells is always necessary. At a point down the track about a half of a mile or more, the train reaches a certain point and trips a switch that powers the gates to go down and activates the bells and lights to signal to cars or trucks of the oncoming train. Theoretically, vehicles cannot enter the crossing once the gates are down. Sometimes, however, vehicles get stuck at the crossing while the gates are down. There is nothing in the prior art that detects a vehicle or other object located in the middle of an intersection on top of the tracks at a rail crossing and trips the brakes of the train before the train collides with the vehicle stuck in the railroad crossing.
SUMMARY OF INVENTION AND ADVANTAGES
[0011] The vehicle safety railroad crossing system of the present invention would equip the nation's railroad crossings with a unique technological innovation designed to save lives and property: a system that would sense the presence of a motor vehicle in the crossing as a train approaches, act to alert the train's engineer and brakeman, and automatically apply the train's brakes.
[0012] The beneficiaries of the vehicle safety railroad crossing system of the present invention, or those who would most benefit from its installation at railroad crossing, would not only be the owners and operators of the trains that travel the rails but also owners and operators of motor vehicles, i.e., the so-called automotive aftermarket. This automotive aftermarket might also include professional drivers, such as the operators of long-haul trucks, and tax and limousine services.
[0013] While the most obvious beneficiaries of the vehicle safety railroad crossing system would be motorists, the system itself would likely be installed at crossings by the railroad companies. As was noted previously, the U.S. railroad system consists of hundreds of railroads running on thousands of miles of track. It is an object and advantage of the present invention to enhance safety at the large number of U.S. grade and other rail crossings.
[0014] One object of the present invention is to provide an efficient and economical way to reduce traffic accidents caused by stalled vehicles stuck on a railroad track at a railroad crossing.
[0015] Another object and advantage of the present invention is to provide a fail-safe system whereby sensors located adjacent a railroad track at a railroad crossing that detect the presence of any large stationary object transmit a signal to a point distal to the railroad crossing such that an eminently approaching train will be braked and stopped by activation of an electronic or mechanical trip-switch.
[0016] Yet another object and advantage of the present invention is to provide a system that brakes and stops a train automatically, such as in the absence or unavailability of brakeman/operator intervention.
[0017] Yet a another object and advantage of the present invention is to provide a vehicle safety railroad crossing system that has a predetermined minimum vehicle weight requirement for activation.
[0018] Yet a another object and advantage of the present invention is to provide a vehicle safety railroad crossing system that has weight sensors built into the ramps leading up to and across the railroad tracks.
[0019] Yet a another object and advantage of the present invention is to provide a vehicle safety railroad crossing system in which the presence of transitory vehicles or other objects is distinguished and differentiated from the presence of stationary, non-moving vehicles or other objects resting upon the railroad tracks at the crossing that pose risk of being struck by an eminently passing train.
[0020] Yet a another object and advantage of the present invention is to provide a vehicle safety railroad crossing system which not only prevents damage to vehicles and trains, but also reduces the incidence of road and rail closures for repair, medical treatment of injured persons and collision investigations, which in turn reduced traffic congestion, commuter trains delays, etc.
[0021] Benefits and features of the invention are made more apparent with the following detailed description of a presently preferred embodiment thereof in connection with the accompanying drawings, wherein like reference numerals are applied to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 (prior art) shows a representative typical railroad crossing 90 .
[0023] FIG. 2A is a representative top view of the vehicle safety railroad crossing system 100 of the present invention.
[0024] FIG. 2B is a representative section view of the vehicle safety railroad crossing system 100 shown in FIG. 2A taken at A-A.
[0025] FIG. 2C is representative top detail view D of the vehicle safety railroad crossing system 100 shown in FIG. 2A .
[0026] FIG. 3A is a representative side view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having moving gate arms 300 , looking in a direction parallel to the railroad tracks 70 .
[0027] FIG. 3B is a representative side view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having moving gate arms 300 , looking in a direction perpendicular to the railroad tracks 70 .
[0028] FIG. 3C is a representative perspective view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having lights 320 .
[0029] FIG. 3D is a representative perspective view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having conventional railroad crossing verbiage or symbols 350 .
[0030] FIG. 4 is a representative top view of the vehicle safety railroad crossing system 100 of the present invention illustrating a method of use of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] The description that follows is presented to enable one skilled in the art to make and use the present invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principals discussed below may be applied to other embodiments and applications without departing from the scope and spirit of the invention. Therefore, the invention is not intended to be limited to the embodiments disclosed, but the invention is to be given the largest possible scope which is consistent with the principals and features described herein.
[0032] FIG. 1 (prior art) shows a representative typical railroad crossing 90 . As is well known, the typical railroad crossing 90 consists of a road with 1 or more lanes 80 and a location or intersection 76 where a set of railroad tracks 70 cross the road 80 . In a typical railroad crossing 90 in which the railroad crossing is indicated by a system in which an audible, illuminated sign or moving gate arms (not shown), there is an electrical connection, such as wire enclosed in conduit, that communicates from the intersection 76 to a distal point 78 . When an eminently approaching train 88 passes the distal point 78 , an electrical or mechanical-type of trip switch 60 transmits an electrical signal to the railroad crossing lights, bells and optionally gate arms, thereby activating the railroad crossing 90 lights, alarm, bell and/or moving gate arms. When the railroad crossing 90 is activated, the operator of an approaching car or other motor vehicle 98 will be advised of the dangers of proceeding through the intersection 76 , or will actually be prevented from passing there through by moving gate arms.
[0033] FIG. 2A is a representative top view of the vehicle safety railroad crossing system 100 of the present invention. FIG. 2B is a representative section view of the vehicle safety railroad crossing system 100 shown in FIG. 2A taken at A-A. FIG. 2C is representative top detail view D of the vehicle safety railroad crossing system 100 shown in FIG. 2A . The vehicle safety railroad crossing system-enhanced railroad crossing 100 of the present invention comprises a set of railroad tracks 70 that in general run perpendicular or essentially perpendicular to a one or more lane street, road or highway 80 . It will be understood that the vehicle safety railroad crossing system-enhanced railroad crossing 100 of the present invention can be installed at intersections 100 in which the railroad tracks 70 run at an angle to the road 80 . In either case, ramp portions 102 are installed in the intersection 100 at both sides of the railroad tracks 70 such that as a vehicle 98 approaches the crossing area 104 of the intersection 100 , the ramp portions 102 raise the vehicle off the grade level 104 to allow the vehicle 98 to clear the elevated rails 72 .
[0034] In order to sense the presence of a stalled or otherwise stationary vehicle 98 at risk or in danger of being struck by a passing train 88 , weight sensors 110 are installed adjacent the rails 72 of the railroad track 70 underneath the ramp portions 102 on either one side or both sides of the railroad tracks 72 within the crossing area 104 of the intersection 100 . The weight sensors 110 are placed at a location underneath or within the ramp portions 102 adjacent the railroad tracks 72 . If a stalled or stationary vehicle 98 is detected by the weight sensor 110 , and the system 100 determines that the vehicle 98 is not moving, then a signal is sent to trip switch 120 . This notifies approaching train 88 a sufficient distance from the crossing area 104 intersection such that the approaching train 88 can stop before striking the vehicle 98 .
[0035] FIG. 3A is a representative side view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having moving gate arms 320 , looking in a direction parallel to the railroad tracks 70 . FIG. 3B is a representative side view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having moving gate arms 300 , looking in a direction perpendicular to the railroad tracks 70 . The improved railroad crossing system 100 of the present invention can be used in locations where a conventional railroad crossing with gate arms 300 is used. Such railroad crossings comprise a base portion 312 that supports a center mast 310 , with gate arms 300 and counterweights 302 , flashing lights 320 and a crossbuck sign 310 mounted thereon.
[0036] FIG. 3C is a representative perspective view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having only lights 320 .
[0037] FIG. 3D is a representative perspective view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having conventional railroad crossing verbiage or symbols 350 .
[0038] FIG. 4 is a representative top view of the vehicle safety railroad crossing system 100 of the present invention illustrating a method of use of the present invention. As described above, in the event a vehicle 98 stops or is unable to proceed out of the cross-walk 76 zone of danger, the vehicle weight is detected by scales or weight sensor 110 . The scales or sensors 110 trigger a switch 120 , such as by transmitting a signal along wire 122 or transmitted signal which is able to communicate with oncoming train 88 . Thus, the train will be notified and the brakes can automatically be activated, thus stopping the train 88 long before it collides with the vehicle 98 stopped in the intersection 76 .
[0039] Railroad Crossing Safety Feature for all 3 Types of Crossings
[0040] The present invention 100 is a retrofit assembly that is installed under the ramps 102 that lead over the railroad tracks 70 at virtually all railroad crossings. An installed weight sensor or scale 110 only gets activated when substantial weight up to 1,000 pounds or more stays on the tracks 72 at the crossing 100 for 30 seconds or more. The precise parameters including weight range and timing can be adjusted by the railroad companies or other users of the system 100 . The stopping feature must be wired with the gates and signal devices down the tracks about a mile or more. The distances between devices can be adjusted by the railroad companies or other users of the system. Thus, if a car or truck gets stuck on the crossing, the weight will activate the scale that will send a signal down the tracks to the trip switch. The trip switch will then apply the brakes to the trains and stop the train automatically.
[0041] Thus, the present invention requires a group of scales wired to a sensor wired to a trip switch. As suggested above, crossing type A would need to have solar panels installed to provide the electric to the scales, devices and switches. The scale would indicate that there is a vehicle on the tracks, which would then send a signal to the trip switch to stop the train. Even in an event where the motormen would be unable to stop the train, this system will work automatically.
[0042] The wiring, scales, sensor and distance to the trip switch can all be adjusted by the railroad companies operating the system to suit their conditions. This system can be used world wide and is cheaper to retrofit than building overpasses or underpasses.
[0043] The vehicle safety railroad crossing system would work on double gate crossings, crossings with bells and lights, and crossings with just signs. As a train travels down the track, a sensor is triggered and the gates go down, or crossing signals are activated. The vehicle safety railroad crossing system would affordably install scales under the ramps at each railroad crossing. The scales would detect weights up to and in excess of 1000 lbs which either linger on the tracks for more than 30 seconds (or another amount of time designated by the Railroad system), or are on the tracks as the train is approaching. When tripped, this system would send an alert signal to the approaching train that a vehicle is stopped on the tracks. The train's engineer and brakeman can then stop the train before a collision occurs, or the safety trigger alert could stop the train automatically when a signal is received, or if the brakeman fails to stop the train. The details are to be determined, however, the alert could be issued to any train within a 1 mile or more range. Electrical conduit would be used, and solar panels would serve to supply power to the scales, devices, and switches. It will be understood that the physical wiring, scales, sensors, and distance settings can all be installed, adjusted and maintained by the various railroad companies that use them. Among the benefits and advantages of the vehicle safety railroad crossing system, the most important is the increase in safety—for both motorists and trains—that it would provide. And the vehicle safety railroad crossing system would operate automatically to brake a train approaching an imminent collision. Less expensive than building overpasses and underpasses to avoid railroad crossings, the vehicle safety railroad crossing system should have a strong appeal for the nation's railroads—and provide far greater safety not only for the nation's motorists, but for its railroads as well.
[0044] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Although any methods and materials similar or equivalent to those described can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications and patent documents referenced in the present invention are incorporated herein by reference.
[0045] While the principles of the invention have been made clear in illustrative embodiments, there will be immediately obvious to those skilled in the art many modifications of structure, arrangement, proportions, the elements, materials, and components used in the practice of the invention, and otherwise, which are particularly adapted to specific environments and operative requirements without departing from those principles. The appended claims are intended to cover and embrace any and all such modifications, with the limits only of the true purview, spirit and scope of the invention. | A vehicle safety railroad crossing system comprising a system for preventing collisions between trains and motor vehicles at railroad crossings. The vehicle safety railroad crossing system functions to alert the train's engineer and brakeman of the vehicle ahead obstructing the tracks, and automatically apply the train's brakes to prevent a collision. | 22,030 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 62/329,535, filed on Apr. 29, 2016, and U.S. Provisional Application No. 62/329,586, filed on Apr. 29, 2016. The entire disclosures of the applications referenced above are incorporated herein by reference.
FIELD
[0002] The present disclosure relates to co-fluids for use with carbon dioxide refrigerant in heating, ventilation, air conditioning and refrigeration (HVAC&R) systems.
BACKGROUND
[0003] This section provides background information related to the present disclosure which is not necessarily prior art.
[0004] Because carbon dioxide (R744) has a low global warming potential (GWP) of only 1 and no ozone-depleting potential at all (ODP of zero), it makes an excellent environmentally friendly refrigerant as compared to hydrofluorocarbons, hydrofluoroolefins, and other less environmentally sound refrigerants. However, the pressures required to liquefy carbon dioxide prove to be too high for use in conventional heating and cooling systems. To avoid high pressures in a refrigeration cycle, carbon dioxide can be used along with a so-called co-fluid or mixture of co-fluids.
[0005] In operation of an HVAC&R system using carbon dioxide and a co-fluid, carbon dioxide refrigerant is absorbed into and desorbed out of the co-fluid. For example, carbon dioxide is absorbed and the pressure lowered during compression and flow through a condenser or absorber. Subsequent flow through an expansion device and evaporator requires a desirable release (desorption) of a portion of the carbon dioxide refrigerant.
[0006] It has generally been observed that rates of absorption tend to be faster than rates of desorption in co-fluid systems using carbon dioxide as refrigerant. This rate inequality can potentially lead to problems in operating the heating and cooling system. There may not be enough time for proper heat flow to the evaporator needed for cooling. And there could be an accumulation of carbon dioxide in the co-fluid due to the rate difference, causing the system to be inefficient or even inoperable. There is a continuing need for co-fluids that provide a higher rate of desorption to improve operation in cooling systems.
SUMMARY
[0007] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
[0008] A carbon dioxide/co-fluid mixture is provided for use in a refrigeration cycle in which the carbon dioxide is alternately absorbed and desorbed from the co-fluid. The mixture includes from 50% to 99% by weight co-fluid and 1% to 50% by weight carbon dioxide. Suitable co-fluids are selected from the class of alkoxylated carboxylic amides, wherein the amides are cyclic or non-cyclic. It has been discovered that N-2,5,8,11-tetraoxadodecyl-2-pyrrolidinone and its homologs exhibit an advantageous property of a high rate of desorption at lower temperatures.
[0009] Pumps or compressors containing the co-fluid as a lubricant are provided for use in a system that includes in sequence a compressor, an absorber (or resorber), an expansion device (or expander), and a desorber. A method of operating a refrigeration system involves circulating the co-fluid and refrigerant around such a system.
[0010] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0011] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
[0012] FIG. 1 is a schematic representation of a climate-control system according to the principles of the present disclosure;
[0013] FIG. 2 is a schematic representation of an exemplary desorber that can be incorporated into the system of FIG. 1 ;
[0014] FIG. 3 is a schematic representation of another climate-control system according to the principles of the present disclosure;
[0015] FIG. 4 is a schematic representation of yet another climate-control system according to the principles of the present disclosure;
[0016] FIG. 5 is a schematic representation of a generator that can be incorporated into the system of FIG. 4 ;
[0017] FIG. 6 compares desorption rates among lubricants;
[0018] FIGS. 7-11 show comparative desorption rates of co-fluids;
[0019] FIG. 12 illustrates carbon dioxide desorption of co-fluids; and
[0020] FIG. 13 compares desorption rates to those of co-fluids.
[0021] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0022] Example embodiments will now be described more fully with reference to the accompanying drawings.
[0023] Co-fluids are provided for use in co-fluid systems where carbon dioxide is used as refrigerant. The co-fluid is an absorbent capable of absorbing and desorbing the carbon dioxide refrigerant. Use of the co-fluids eliminates the need for high system pressures otherwise required to change the phase of the refrigerant carbon dioxide.
[0024] Co-fluids are selected from those with the following generic formulae:
[0000]
[0000] where m is 1 to 10; R is alkyl, alkenyl, or aryl with 1 to 26 carbon atoms; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where m is 1 to 10; p is 1 to 3; R is alkyl, alkenyl, or aryl with 1 to 26 carbon atoms; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where x is 1 to 4; n is 1 to 10; R′ is H or optionally substituted C 1-6 alkyl-; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where y is 1 to 4; n is 1 to 10; p is 1 to 3; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where z is 1 to 4; n is 1 to 10; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where z is 1 to 4; n is 1 to 10; p is 1 to 3; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H.
[0025] Although the invention is not to be limited by any scientific hypothesis or theory of operation, the compounds of formulae (I)-(VI) share chemical features that are believed to contribute to their general usefulness as co-fluids for use with carbon dioxide refrigerant. It is believed that the carboxylic amide (cyclic or open chain) and the polyoxyalkylene moiety combine to provide compositions that desorb carbon dioxide at a high rate, a rate that is higher than homologous compounds without those features, even though the homologous compounds are considered part of the described invention to the extent they have not yet been disclosed as co-fluids. Generally speaking, species with high desorption rates are preferred as co-fluids in carbon dioxide refrigeration systems, because of the operational advantages expected to flow from having high desorption.
[0026] The compounds of formulae (I)-(VI) are characterized by a “side chain” that has a polyoxyalkylene structure denoted by the repeat units of m or n in the formulae. If both of R″ and R′″ are hydrogen (H), the chain is polyoxyethylene; if one of them is methyl (the other being H), the chain is polyoxypropylene; if one of them is ethyl, the chain is polyoxybutylene. Because the repeat units m and n range from 1 to 10, it is also possible to provide so-called heteric polyoxyalkylene chains containing a combination of polyoxyethylene, polyoxypropylene, and polyoxybutylene. That is to say, the formulae should be interpreted as permitting up to 10 repeat units, where each repeat unit is independently based on ethylene-, propylene-, or butylene oxide.
[0027] The non-cyclic amide “alkoxylates” of formulae (I) and (II) are based on carboxylic amides with at least two and up to 27 carbon atoms (since R has 1 to 26 carbon atoms). The nature of the R group (size, level of branching, presence or not of unsaturation) is expected to affect the equivalent weight of and the viscosity of the co-fluid. These are design factors than can be taken into account.
[0028] In all formulae, the terminal hydroxyl of the polyoxyalkylene chain is in the alternative capped with an alkyl group (preferably methyl for ease of synthesis) that is optionally substituted. Although part of the invention, the hydroxyl compounds (R′ ═H) are less preferred in some embodiments because the hydroxyl could contribute to undesirable reactivity, high viscosity, or even corrosion. Capping takes the hydroxyl group out of play. Substitutions on R′ are allowed to the extent they do not spoil the operation of the compound as a co-fluid. In a particular embodiment, the alkyl group R′ is substituted with a carboxylic amide group as shown in the description below and in the examples. Thus, R′ in any of the above can be C 1-6 alkyl substituted with alkylcarbamido or alkenylcarbamido, represented by the following structures where R is alkyl or alkenyl:
[0000]
[0029] The compounds of formulae (I)-(VI) are formally alkoxylates of the carboxylic amide or -imide shown. The compounds of (I), (III), and (V) can be synthesized by direct alkoxylation of the amide/imide starting group, because the amide/imide group is reactive and can open the oxirane ring of the corresponding alkylene oxides. The compounds of (II), (IV), and (VI) on the other hand, can be made by alkoxylating the free hydroxyl group of a starting material that contains an alkylol moiety attached to the amide or imide. Depending on whether p in the formulae is 1, 2, or 3, the group is a methylol, ethylol, or propylol group.
[0030] Compounds with n (or m) from 1 to 10 can be made by reacting the starting material with n or m equivalents of oxide and reacting to a polydisperse mixture containing an average of n oxide units per amide group. Alternatively, they can be synthesized with a goal of producing a molecular weight distribution where the peak is at a species with n oxide units. Various fractions can be physically separated to provide other distributions of alkoxylation.
[0031] But especially for the lower molecular weight compounds, it can be simpler not to form the compounds by alkoxylation, but instead by reacting a pre-formed monodisperse compound containing n repeat units with the reactive amide nitrogen (or with the hydroxyl of an alkylol group added to the amide, for example by reaction with formaldehyde). This is illustrated by reacting a starting material N-methylolpyrrolidone (N-hydroxymethyl-2-pyrrolidone) with triethylene glycol monomethyl ether in a conventional Williamson ether synthesis.
[0032] In various embodiments, the co-fluids of formulae (I)-(VI) are further characterized by one or any combination of the following: the parameters x and y have a value of either 2 or 4; the parameter z has a value of 2 (meaning the structure is based on a succinimide derivative); the variables n and m are 1 to 4; R′ is methyl; R″ and R′″ are both H; R′ is C 1-3 alkyl substituted with alkylcarbamido. Particular embodiments include the following:
[0000]
[0033] In operation, the co-fluid acts as lubricant as well a carrier fluid for the refrigerant carbon dioxide. A compressor for use in the cooling circuits described herein contains any of the described co-fluids as a lubricant.
[0034] In operation, the co-fluids absorb (resorb) and desorb refrigerant carbon dioxide as they circulate around a refrigeration or cooling circuit. At various points in the circuit, a cooling composition comprises from 50% to 99% by weight co-fluid and 1% to 50% by weight carbon dioxide.
[0035] Preferred co-fluids have the chemical structures disclosed herein. In various embodiments, performance also relies on a co-fluid having advantageous physical properties as well. Naturally, preferred co-fluids readily absorb and desorb carbon dioxide used as refrigerant. An instantaneous rate (rate essentially at time zero) as well as amount desorbed at 1 minute and at 2 minutes are measured. The results can be used to screen potential candidates.
[0036] The co-fluid also needs to have suitable viscosity. In various embodiments, viscosity is in the range of 1 to 50 centistokes (cSt); 1 to 20 cSt; 3 to 20 cSt; 5 to 20 cSt; 1 to 10 cSt; 3 to 10 cSt. Some good candidates have a viscosity of fairly close to 10 cSt. The viscosity is advantageously in a range of 5 to 15 CSt, 8 to 12 cSt, or 9 to 11 cSt, in various embodiments. Too high a viscosity and fluid flow around the cooling circuit can be impeded. If the viscosity is too low, there could be leakage past seals in the system. A non-limiting illustration of use of the co-fluids follows.
Use of the Co Fluids in Refrigeration Methods
[0037] A representative refrigeration cycle based on carbon dioxide as refrigerant (“vapor”) operates as follows. A combination of vapor and liquid (co-fluid) is compressed in a compressor, raising the pressure and forcing some of the vapor into the liquid phase. Heat is rejected in a resorber (absorber) downstream of the compressor. This cools the mixture and causes more of the vapor to be absorbed. The remaining CO 2 vapor and co-fluid are further cooled in an internal heat exchanger. The cool, fully liquefied mixture is then passed through an expansion device, decreasing the pressure, dropping the temperature further, and releasing some of the CO 2 into the vapor phase. Heat is extracted from the refrigerated space into a desorber as the temperature of the mixture rises and further CO 2 escapes from the liquid phase. Finally, the fluids are further warmed in an internal heat exchanger, completing the cycle.
Binary-Cycle Climate-Control System
[0038] With reference to FIG. 1 , a binary-cycle climate-control system 10 is provided that may include a compressor 12 , a liquid-vapor separator 13 , an agitation vessel (e.g., a stirring and/or shaking vessel) 15 , an absorber (or resorber) 14 , an internal heat exchanger 16 , an expansion device 18 , and a desorber 20 . The compressor 12 can be any suitable type of compressor, such as a scroll, rotary or reciprocating compressor, for example. The compressor 12 may include a shell 22 , a compression mechanism 24 disposed within the shell 22 , and a motor 26 (e.g., a fixed-speed or variable-speed motor) that drives the compression mechanism 24 via a crankshaft 28 . The compressor 12 can be a fixed-capacity or variable-capacity compressor. The compressor 12 may compress a mixture of a refrigerant (e.g., carbon dioxide, hydrofluorocarbons, ammonia, bromide, etc.) and a co-fluid (e.g., oil, water, polyalkylene glycol, polyol ester, polyvinyl ether, etc.) and circulate the mixture throughout the system 10 . The co-fluid may be an absorbent capable of absorbing a refrigerant. Compressing the mixture of refrigerant and co-fluid raises the pressure and temperature of the mixture and causes some refrigerant to be absorbed into the co-fluid.
[0039] The liquid-vapor separator 13 may include an inlet 17 , a first outlet (e.g., a gas outlet) 19 , and a second outlet (e.g., a liquid outlet) 21 . The inlet 17 may be fluidly coupled with an outlet 34 of the compressor 12 such that the liquid-vapor separator 13 receives the compressed mixture of refrigerant and co-fluid (e.g., the compressed mixture of refrigerant vapor and liquid co-fluid containing some dissolved refrigerant gas) from the compressor 12 . The liquid co-fluid (which may contain some dissolved refrigerant gas) may settle to the bottom of the liquid-vapor separator 13 , and the undissolved refrigerant vapor may remain at the top (or rise to the top) of the liquid-vapor separator 13 (i.e., above the surface of the liquid co-fluid). The liquid co-fluid may exit the liquid-vapor separator 13 through the second outlet 21 (which may be located below the surface of the liquid in the separator 13 ), and the refrigerant vapor may exit the liquid-vapor separator 13 through the first outlet 19 (which may be located above the surface of the liquid in the separator 13 ).
[0040] The agitation vessel 15 may include a first inlet 23 , a second inlet 25 , a first outlet 27 , a second outlet 29 , and an agitator 31 . The first inlet 23 may be disposed at or generally near a top end of the vessel 15 and may be fluidly coupled with the second outlet 21 of the separator 13 such that liquid co-fluid from the separator 13 enters the vessel 15 through the first inlet 23 . The liquid co-fluid entering the separator 13 through the first inlet 23 may fall to the bottom of the vessel 15 . The second inlet 25 may be below the surface of the liquid co-fluid in the vessel 15 and may be fluidly coupled with the first outlet 19 of the separator 13 such that refrigerant vapor from the separator 13 enters the vessel 15 through the second inlet 25 . In this manner, the refrigerant vapor enters the vessel 15 below the surface of the liquid co-fluid, which causes some of the refrigerant vapor entering the vessel 15 to be absorbed (or dissolved) into the liquid co-fluid.
[0041] The agitator 31 can be or include an impeller (e.g., one or rotating paddles or blades) and/or a shaker, for example, disposed below the surface of the liquid co-fluid in the vessel 15 . The agitator 31 may be driven by a motor 33 and may stir or agitate the liquid co-fluid in the vessel 15 to further promote absorption of the refrigerant vapor into the liquid co-fluid.
[0042] The first outlet 27 of the vessel 15 may be disposed below the surface of the liquid co-fluid such that refrigerant vapor exits the vessel 15 through the first outlet 27 . The second outlet 29 of the vessel 15 may be disposed above the surface of the liquid co-fluid such that liquid co-fluid (with refrigerant vapor dissolved therein) exits the vessel 15 through the second outlet 29 . The first and second outlets 27 , 29 may both be in communication with a conduit 35 such that the liquid co-fluid from the first outlet 27 and refrigerant vapor from the second outlet 29 are combined and mix with each other (further promoting absorption of the refrigerant vapor into the liquid co-fluid) in the conduit 35 .
[0043] The absorber 14 may be a heat exchanger that may be fluidly coupled with the conduit 35 and may receive the compressed mixture of the refrigerant and co-fluid from the conduit 35 . In configurations of the system 10 that do not include the separator 13 and vessel 15 , the absorber 14 may receive the compressed mixture of the refrigerant and co-fluid directly from the compressor 12 . Within the absorber 14 , heat from the mixture of the refrigerant and co-fluid may be rejected to air or water for example, or some other medium. In the particular configuration shown in FIG. 1 , a fan 36 may force air across the absorber 14 to cool the mixture of the refrigerant and co-fluid within the absorber 14 . As the mixture of the refrigerant and co-fluid cools within the absorber 14 , more refrigerant is absorbed into the co-fluid.
[0044] The internal heat exchanger 16 may include a first coil 38 and a second coil 40 . The first and second coils 38 , 40 are in a heat transfer relationship with each other. The first coil 38 may be fluidly coupled with the outlet 32 of the absorber 14 such that the mixture of the refrigerant and co-fluid may flow from the outlet 32 of the absorber 14 to the first coil 38 . Heat from the mixture of the refrigerant and co-fluid flowing through the first coil 38 may be transferred to the mixture of the refrigerant and co-fluid flowing through the second coil 40 . More refrigerant may be absorbed into the co-fluid as the mixture flows through the first coil 38 .
[0045] The expansion device 18 may be an expansion valve (e.g., a thermal expansion valve or an electronic expansion valve) or a capillary tube, for example. The expansion device 18 may be in fluid communication with the first coil 38 and the desorber 20 . That is, the expansion device 18 may receive the mixture of the refrigerant and co-fluid that has exited downstream of the first coil 38 and upstream of the desorber 20 . As the mixture of the refrigerant and co-fluid flows through the expansion device 18 , the temperature and pressure of the mixture decreases.
[0046] The desorber 20 may be a heat exchanger that receives the mixture of the refrigerant and co-fluid from the expansion device 18 . Within the desorber 20 , the mixture of the refrigerant and co-fluid may absorb heat from air or water, for example. In the particular configuration shown in FIG. 1 , a fan 42 may force air from a space (i.e., a room or space to be cooled by the system 10 ) across the desorber 20 to cool the air. As the mixture of the refrigerant and co-fluid is heated within the desorber 20 , refrigerant is desorbed from the co-fluid. From an outlet 53 of the desorber 20 , the mixture of refrigerant and co-fluid may flow through the second coil 40 and back to the compressor 12 to complete the cycle.
[0047] One or more ultrasonic transducers (i.e., vibration transducers) 44 may be attached to the desorber 20 . As shown in FIG. 1 , the ultrasonic transducers 44 may be mounted to an exterior surface 46 of the desorber 20 . In some configurations, the ultrasonic transducers 44 are disposed inside of the desorber 20 and in contact with the mixture of refrigerant and co-fluid (as shown in FIG. 2 ). The ultrasonic transducers 44 can be any suitable type of transducer that produces vibrations (e.g., ultrasonic vibrations) in response to receipt of electrical current. For example, the ultrasonic transducers 44 could be piezoelectric transducers, capacitive transducers, or magnetorestrictive transducers. For example, the ultrasonic transducers 44 may have an output frequency in the range of about 20-150 kHz (kilohertz). The ultrasonic transducers 44 may (directly or indirectly) apply or transmit vibration to the mixture of refrigerant and co-fluid flowing through the desorber 20 to increase a rate of desorption of the refrigerant from the co-fluid.
[0048] The ultrasonic transducers 44 can have any suitable shape or design. For example, the ultrasonic transducers 44 may have a long and narrow shape, a flat disc shape, etc., and can be flexible or rigid. In configurations in which the ultrasonic transducers 44 are mounted to the exterior surface 46 of the desorber 20 , it may be beneficial for the desorber 20 to have a minimal wall thickness at the location at which the ultrasonic transducers 44 are mounted in order to minimize attenuation of the ultrasonic vibration. Furthermore, it may be beneficial to apply the ultrasonic vibration to the mixture of the refrigerant and co-fluid at a location at which the mixture of the refrigerant and co-fluid is static or at a location of reduced or minimal flow rate of the mixture of the refrigerant and co-fluid, because fluids flowing at high rates can be more difficult to excite with ultrasonic energy.
[0049] A control module (or controller) 48 may be in communication (e.g., wired or wireless communication) with the ultrasonic transducers 44 and may control operation of the ultrasonic transducers 44 . The control module 48 can control the frequency and amplitude of electrical current supplied to the ultrasonic transducers 44 (e.g., electrical current supplied to the ultrasonic transducers 44 by a battery and/or other electrical power source) to control the frequency and amplitude of the vibration that the ultrasonic transducers 44 produce. The control module 48 may also be in communication with and control operation of the motor 26 of the compressor 12 , the expansion device 18 , the motor 33 of the agitator 31 , the fans 36 , 42 , and/or other components or subsystems.
[0050] As described above, applying ultrasonic vibration to the mixture of refrigerant and co-fluid increases the desorption rate. The control module 48 may control operation of the ultrasonic transducers 44 to control the desorption rate. For example, the control module 48 may control the frequency, amplitude, runtime (e.g., pulse-width-modulation cycle time), etc. of the motor 33 , fans 36 , 42 , and/or the ultrasonic transducers 44 such that the desorption rate matches or nearly matches a rate of absorption of the refrigerant into the co-fluid that occurs upstream of the expansion device 18 (e.g., in the absorber 14 and vessel 15 ).
[0051] Without any excitation of the mixture of refrigeration and co-fluid, the absorption rate may be substantially greater than the desorption rate. The absorption rate may vary depending on a variety of operating parameters of the system 10 (e.g., pressure, compressor capacity, fan speed, thermal load on the system 10 , type of refrigerant, type of co-fluid, etc.). In some configurations, a first sensor 50 and a second sensor 52 may be in communication with the control module 48 and may measure parameters that are indicative of absorption rate and desorption rate. For example, the first sensor 50 can be a pressure or temperature sensor that measures the pressure or temperature of the mixture of refrigerant and co-fluid within the absorber 14 , and the second sensor 52 can be a pressure or temperature sensor that measures the pressure or temperature of the mixture of refrigerant and co-fluid within the desorber 20 . The pressures and/or temperatures measured by the sensors 50 , 52 may be indicative of absorption rate and desorption rate.
[0052] The sensors 50 , 52 may communicate the pressure or temperature data to the control module 48 , and the control module 48 may determine a concentration of refrigerant in the co-fluid based on the pressure or temperature data (e.g., using a lookup table or equations). The control module 48 can include an internal clock (or be in communication with an external clock) and can determine the absorption rate and desorption rate based on changes in the concentration of refrigerant in the co-fluid over a period of time. The control module 48 may control operation of the ultrasonic transducers 44 based on the absorption rate and/or the desorption rate. The control module 48 may also control operation of the compressor 12 , the fans 36 , 42 and/or the expansion device 18 based on the absorption and/or desorption rates and/or to control the absorption and/or desorption rates. In some configurations, the control module 48 may control the ultrasonic transducers 44 based on data from additional or alternative sensors and/or additional or alternative operating parameters.
[0053] Because the absorption rate of many refrigerants into many co-fluids is significantly faster than the desorption rate, the rate of desorption may substantially limit the capacity of the system 10 . Applying ultrasonic energy (e.g., via the ultrasonic transducers 44 ) to the mixture of refrigerant and co-fluid unexpectedly solves the problem of slow desorption rates. It can be shown that desorption rates may increase by about 100%-900% (depending on the refrigerant type and co-fluid type) by exciting the mixture of refrigerant and co-fluid with ultrasonic energy (e.g., using one or more ultrasonic transducers 44 ) as compared to stirring the mixture with a propeller at 400 revolutions per minute. This increase in the desorption rate surpassed reasonable expectations of success.
[0054] Referring now to FIG. 3 , another binary-cycle climate-control system 100 is provided that may include a compressor 112 , a pump 111 , a liquid-vapor separator 113 , an agitation vessel (e.g., a stirring and/or shaking vessel) 115 , an absorber 114 , an internal heat exchanger 116 , an expansion device 118 , a desorber 120 , a receiver 121 , one or more ultrasonic transducers 144 and a control module 148 . The structure and function of the compressor 112 , liquid-vapor separator 113 , agitation vessel 115 , absorber 114 , internal heat exchanger 116 , expansion device 118 , desorber 120 , ultrasonic transducers 144 and control module 148 may be similar or identical to that of the compressor 12 , liquid-vapor separator 13 , agitation vessel 15 , absorber 14 , internal heat exchanger 16 , expansion device 18 , desorber 20 , ultrasonic transducers 44 and control module 48 described above (apart from any exceptions described below). Therefore, similar features may not be described again in detail.
[0055] The receiver 121 may be fluidly coupled with the internal heat exchanger 116 (e.g., a second coil 140 of the internal heat exchanger 116 ), the compressor 112 , and the pump 111 . The receiver 121 may include an inlet 154 , a refrigerant outlet 156 , and a co-fluid outlet 158 . The inlet 154 may receive the mixture of refrigerant and co-fluid from the second coil 140 . Inside of the receiver 121 , gaseous refrigerant may be separated from liquid co-fluid. That is, the co-fluid accumulates in a lower portion 162 of the receiver 121 , and the refrigerant may accumulate in an upper portion 160 of the receiver 121 . The refrigerant may exit the receiver 121 through the refrigerant outlet 156 , and the co-fluid may exit the receiver 121 through the co-fluid outlet 158 . The refrigerant outlet 156 may be fluidly coupled with a suction fitting 164 of the compressor 112 such that refrigerant is drawn into the compressor 112 for compression therein. The co-fluid outlet 158 may be fluidly coupled with an inlet 166 of the pump 111 so that the co-fluid is drawn into the pump 111 . Outlets 168 , 170 of the compressor 112 and pump 111 , respectively, are fluidly coupled with an inlet 117 of the separator 113 via a conduit 172 or with an inlet of the absorber 114 such that refrigerant discharged from the compressor 112 and co-fluid discharged from the pump 111 can be recombine in the vessel 115 , in the absorber 114 and/or in the conduit 172 that feeds the separator 113 or the absorber 114 .
[0056] With reference to FIG. 4 , an absorption-cycle climate-control system 200 is provided that may include a vessel 212 (e.g., a generator), a condenser 214 , a first expansion device 216 , an evaporator 218 , an absorber 220 , an internal heat exchanger 222 , a second expansion device 224 , and a pump 226 . The vessel 212 may include an inlet 228 , a refrigerant outlet 230 , and a co-fluid outlet 232 . The inlet 228 may receive a mixture of refrigerant and co-fluid (i.e., with the refrigerant absorbed into the co-fluid).
[0057] The vessel 212 may be heated by any available heat source (e.g., a burner, boiler or waste heat from another system or machine)(not shown). In some configurations, the vessel 212 may absorb heat from a space to be cooled (e.g., the space to be cooled within a refrigerator, freezer, etc.). As heat is transferred to the mixture of refrigerant and co-fluid within the vessel 212 , the vapor refrigerant desorbs from the co-fluid so that the refrigerant can separate from the co-fluid. The refrigerant may exit the vessel 212 through the refrigerant outlet 230 , and the co-fluid may exit the vessel 212 through the co-fluid outlet 232 .
[0058] One or more ultrasonic transducers 244 may be attached to the vessel 212 . As shown in FIG. 4 , the ultrasonic transducers 244 may be mounted to an exterior surface 234 of the vessel 212 . In some configurations, the ultrasonic transducers 244 are disposed inside of the vessel 212 and in contact with the mixture of refrigerant and co-fluid (as shown in FIG. 5 ). The structure and function of the ultrasonic transducers 244 may be similar or identical to that of the ultrasonic transducers 44 described above. As described above, the ultrasonic transducers 244 produce ultrasonic vibration that is transmitted to the mixture of refrigerant and co-fluid to increase the desorption rate of the refrigerant from the co-fluid. In some configurations, ultrasonic vibration may be used to produce a desired amount of desorption without adding heat from another source. In some configurations, ultrasonic vibration and the addition of heat may further accelerate the desorption rate.
[0059] As described above, a control module 248 may be in communication with and control operation of the ultrasonic transducers 244 to increase the desorption rate to a desired level (e.g., to a level matching a rate of absorption). The structure and function of the control module 248 may be similar or identical to that of the control module 48 . The control module 248 may be in communication with sensors 250 , 252 and may control operation of the ultrasonic transducers 244 based on pressure and/or temperature data received from the sensors 250 , 252 . The sensor 250 may be disposed within the vessel 212 and may measure a pressure or temperature of the mixture of refrigerant and co-fluid therein. The sensor 252 may be disposed within the absorber 220 and may measure a pressure or temperature of the mixture of refrigerant and co-fluid therein. The control module 248 may also be in communication with and control operation of the pump 226 , the expansion devices 216 , 224 and/or fans 254 , 256 , 257 .
[0060] The condenser 214 is a heat exchanger that receives refrigerant from the refrigerant outlet 230 of the vessel 212 . Within the condenser 214 , heat from the refrigerant may be rejected to air or water for example, or some other medium. In the particular configuration shown in FIG. 4 , the fan 254 may force air across the condenser 214 to cool the refrigerant within the condenser 214 .
[0061] The expansion devices 216 , 224 may be expansion valves (e.g., thermal expansion valves or electronic expansion valves) or capillary tubes, for example. The first expansion device 216 may be in fluid communication with the condenser 214 and the evaporator 218 . The evaporator 218 may receive expanded refrigerant from the expansion device 216 . Within the evaporator 218 , the refrigerant may absorb heat from air or water, for example. In the particular configuration shown in FIG. 4 , the fan 256 may force air from a space (i.e., a room or space to be cooled by the system 200 ) across the evaporator 218 to cool the air.
[0062] The absorber 220 may include a refrigerant inlet 258 , a co-fluid inlet 260 , and an outlet 262 . The refrigerant inlet 258 may receive refrigerant from the evaporator 218 . The co-fluid inlet 260 may receive co-fluid from the second expansion device 224 . Refrigerant may absorb into the co-fluid within the absorber 220 . The fan 257 may force air across the absorber 220 to cool the mixture of refrigerant and co-fluid and facilitate absorption.
[0063] Like the internal heat exchanger 16 , the internal heat exchanger 222 may include a first coil 264 and a second coil 266 . The first coil 264 may receive co-fluid from the co-fluid outlet 232 of the vessel 212 . The co-fluid may flow from the first coil 264 through the second expansion device 224 and then into the absorber 220 through the co-fluid inlet 260 .
[0064] The mixture of refrigerant and co-fluid may exit the absorber 220 through the outlet 262 , and the pump 226 may pump the mixture through the second coil 266 . The mixture of refrigerant and co-fluid flowing through the second coil 266 may absorb heat from the co-fluid flowing through the first coil 264 . From the second coil 266 , the mixture of refrigerant and co-fluid may flow back into the vessel 212 through the inlet 228 .
[0065] It will be appreciated that the climate-control systems 10 , 100 , 200 can be used to perform a cooling function (e.g., refrigeration or air conditioning) or a heating function (e.g., heat pump).
EXAMPLES
Example 1—Comparison to Known Co Fluids
[0066] Several commercial lubricants were compared to a co-fluid of the current teachings. MinOil is mineral oil. POE is polyol ester. PAG is polyalkylene glycol. NMP is N-methylpyrrolidone. PVE is polyvinyl ether. Comparison of their desorption rates at 32° F. under the same initial pressure load, initial desorption pressure and agitation rate is plotted in FIG. 6 and compared with N-2,5,8,11-tetraoxadodecyl-2-pyrrolidone (abbreviated: Pyrr(EO)3Me) shown here:
[0000]
[0000] In FIG. 6 , each value represents the pressure increase in one minute's time and the values are an average of three trials.
[0067] Pyrr(EO)3Me also shows a rate inversion with temperature. Generally, desorption rates are expected to be faster at higher temperatures and slower at lower temperatures. But the plot in FIG. 7 shows that desorption is actually faster at the lower temperature.
Example 2—Comparison of Analog Compounds
[0068] A) Comparison of Aliphatic Side Chain and Polyoxyalkylene Side Chain
[0069] Pyrr(EO)3Me has a 12 atom chain attached to the nitrogen. A saturated analog, N-dodecyl-2-pyrrolidone (Abbreviated: NDDPy), also has a 12-atom chain. They have similar viscosities (NDDPy at 40° C.=9.29 cSt, Pyrr(EO)3Me at 40° C.=9.06 cSt) and are close in molecular weight. NDDPy had to be evaluated at a higher temperature due to it solidifying at 5° C. Pyrr(EO)3Me has a faster desorption rate, as shown in FIG. 8 .
[0000]
[0070] B) Comparison of Carboxylic Amide to Carboxylic Ester
[0071] Pyrr(EO3Me) was compared to a corresponding ester compound IsoV(EO)3Me. Although the comparison ester had a lower viscosity than Pyrr(EO)3Me (which would provide a faster desorption rate, all things equal), the Pyrr(EO)3Me had a faster desorption rate. Data are shown in FIG. 9 .
[0000]
[0072] C) Comparison to a Compound without the Cyclic Carboxylic Amide
[0073] Pyrr(EO)3Me was also compared with triethylene glycol dimethyl ether to show that a low viscosity, low molecular weight polyalkylene glycol would not have the same or better desorption rates. Data are shown in FIG. 10 , demonstrating Pyrr(EO)3Me has a faster desorption rate. The “dimethyl glycol ether” of FIG. 10 is triethylene glycol dimethyl ether.
[0000]
[0074] D) N-2,5,8,11-Tetraoxadodecyl-Caprolactam Shows the Same Temperature Rate Inversion as Pyrr(EO)3Me.
[0075] N-2,5,8,11-Tetraoxadodecyl-Caprolactam has a 7-membered lactam ring rather than the five-membered ring on Pyrr(EO)3Me. It shows a temperature rate inversion, with the data shown in FIG. 11 . The analog's structure is:
[0000]
[0076] E) Effect of Ethylene Oxide Chain Length on the Rate of Carbon Dioxide Desorption.
[0077] The graph in FIG. 12 shows instantaneous rates (rates at time zero) of desorption for a series of compounds with no, 1, 2, or 3 ethylene oxides added to N-hydroxymethyl-2-pyrrolidone, as shown here:
[0000]
[0078] F) Desorption Rates of Eight Atom Chain Co-Fluids Double Capped with 2-Pyrrolidone Rings.
[0079] The following two compounds were compared at 40° C. This temperature was chosen due to solidification of one of the compounds at 0° C.
[0000]
[0000] As with the single pyrrolidone capped material (methyl cap at the other end), the compound having both ethylene oxide and pyrrolidone functions desorbs carbon dioxide faster under comparable conditions. This can be seen in the graph in FIG. 13 .
Example 3—Synthesis of Co Fluids
Preparation of N-Hydroxymethyl-2-Pyrrolidone
[0080] (This preparation is a slight modification of U.S. Pat. No. 3,073,843)
[0081] To a 250 mL two necked round bottom flask, equipped with a thermometer, magnetic stirrer, and reflux condenser, was added 53.3 g (0.63 moles) 2-pyrrolidone, 19.1 g (0.64 moles) paraformaldehyde, and 0.2 g KOH all at once. The mixture was stirred and heated to 80-90° C. for ˜2.5 hours. Afterwards, 100 mL of hot toluene was added. The solution was then filtered and allowed to cool to room temperature. The resulting crystals were filtered and washed with cold toluene to give 64.5 g (89% yield) of 2-hydroxymethyl-2-pyrrolidone. H NMR and FTIR confirmed the structure.
Preparation of N-Hydroxymethyl-2-Caprolactam
[0082] (This preparation is essentially that of U.S. Pat. No. 4,769,454.)
[0083] To a 500 mL round bottom flask equipped with a magnetic stirrer, thermometer, and reflux condenser was added 113.2 g (1.00 mole) of caprolactam, The caprolactam was heated to liquid at which time 31 g (1.0 mole) of paraformaldehyde and 0.7 g of K 2 CO 3 were added at once. A slight exotherm raised the temperature to 97° C., however the reaction mixture was maintained between 70° C. and 95° C. for 2.5 hours. Afterwards, a seed crystal was added at 57° C. and the mixture held at 50° C. for 18 hours. White crystals resulted with a small amount of liquid. The liquid was decanted away from the white crystals to give 138 g (96% yield) of N-hydroxymethyl-2-caprolactam. H NMR and FTIR confirmed the structure.
Synthesis of N-2,5,8,11-Tetraoxadodecyl-2-Pyrrolidone
[0084] (See U.S. Pat. No. 3,853,910—hereby incorporated by reference—for hydroxymethyl-2-pyrrolidone ethers of alkyl, aryl, alkenyl, groups etc.)
[0085] To a 500 mL two-necked round bottom flask equipped with a magnetic stirrer, thermometer, and reflux condenser was added 58 g (0.50 moles) of N-hydroxymethyl-2-pyrrolidone and 246 g (1.5 moles) of triethylene glycol monomethyl ether at once. The mixture was cooled to ca. 10° C. and 21 mL of 12N HCl was added in 5 to 10 minutes while maintaining the temperature around 10° C. during the addition. Afterwards, the mixture was warmed to room temperature and was held at this temperature for 2 hours while stirring. Addition of 40 g of 25% NaOH to the mixture between 15° C. and 25° C., followed by stirring for 0.5 hours produced a mixture of NaCl and product. The salt was filtered off and the mixture subjected to vacuum distillation to remove water (27° C. at 0.12 Torr). More salt precipitated out and the distillation stopped and the salt filtered off. The resultant oil was distilled three times through a 6×¾ inch Vigreux Column under vacuum. The final cut distilled at 156° C. at 0.11 Torr to give 71.6 g (55% yield) of N-2,5,8,11-tetraoxadodecyl-2-pyrrolidone. H NMR and FTIR confirmed the structure.
Synthesis of N-2,5,8,11-Tetraoxadodecyl-Caprolactam
[0086] To a 500 mL two necked round bottom flask equipped with a magnetic stirrer, thermometer, and reflux condenser was added 71.6 g (0.50 moles) of N-hydroxymethyl-caprolactam and 246 g (1.5 moles) of triethylene glycol monomethyl ether at once. The mixture was cooled to ca. 4° C. and 21 mL of 12N HCl was added in ca. 15 minutes while maintaining the temperature around 10° C. during the addition. Afterwards, the mixture was warmed to room temperature and was held at this temperature for 2.5 hours while stirring. Addition of 40 g of 25% NaOH to the mixture between 15° C. and 25° C., followed by stirring for 0.5 hours produced a mixture of NaCl and product. The mixture was subjected to rotoevaporation to remove water. The resultant salt was filtered off and the mixture subjected to straight take over vacuum distillation collecting a top cut between 82° C. and 84° C. More salt precipitated out and the distillation stopped and the salt filtered off. The resultant oil was distilled through a 6×¾ inch Vigreux column under vacuum. The main cut distilled between 159° C. and 169° C. at 0.2 Torr to give 80.1 g (55% yield) of N-2,5,8,11-tetraoxadodecyl-2-caprolactam. H NMR and FTIR confirmed the structure.
Synthesis of 1,8-bis-(Pyrrolidon-1-yl)-3,6-dioxaoctane
[0087] To a single necked 500 mL round bottom flask was added 134 g (1.56 mole) gamma-Butyrolactone and 109.5 g (0.74 mole) 1,8-diamino-3,6-dioxaoctane at once. The flask was fitted with a magnetic stir bar, H-Trap and a condenser. At the top of the condenser a nitrogen source was attached via a Firestone Valve. A vacuum was pulled while heating the mixture to melt any resultant solids. This was followed by a vacuum then nitrogen purge three times. While under nitrogen, the mixture was heated and after 26 mL of water was collected in the H-Trap, the reaction mixture was cooled and subjected to straight take-over vacuum distillation. The material was distilled twice and the final product cut distilled between 196° C. and 214° C. at 0.11 Torr to give 124 g of product. H NMR and FTIR confirmed the structure.
Synthesis of 1,8-bis-(pyrrolidon-1-yl)octane
[0088] To a single necked 500 mL round bottom flask was added 134 g (1.56 mole) gamma-butyrolactone and 106 g (0.74 mole) 1,8-diaminooctane at once. The flask was fitted with a magnetic stir bar, Dean-Stark Trap and a condenser. At the top of the condenser a nitrogen source was attached via a Firestone Valve. A vacuum was pulled while heating the mixture to melt any resultant solids. This was followed by a vacuum then nitrogen purge four times. While under nitrogen, the mixture was heated and after 27 mL of water was collected in the Dean-Stark Trap, the reaction mixture was cooled and subjected to vacuum distillation. The material was distilled twice and the final product cut distilled between 200° C. and 208° C. at 0.2 Torr to give 166 g (81% yield) of product. H NMR and FTIR confirmed the structure.
Synthesis of 3,6,9-trioxadecyl isovalerate
[0089] To a 500 mL single necked round bottom flask equipped with a magnetic stir bar and a Dean-Stark Trap was added 53.7 g (0.526 mole) isovaleric Acid, 81.6 g (0.50 mole) triethylene glycol monomethyl ether, 0.3 g p-toluenesulfonic acid and 200 mL of toluene at once. The mixture was heated under reflux till 8.5 mL of water was collected. After cooling to room temperature, the toluene solution was washed with 200 mL of 5% aqueous NaOH, 200 mL of saturated salt solution and dried over sodium sulfate. The mixture was filtered and subjected to rotoevaporation. Straight take-over distillation gave 91.7 g (73% yield). The product cut was at 107° C. and 115° C. at 1.0 Torr. FTIR confirmed the structure.
Example 4—Measuring Carbon Dioxide Desorption Rate
[0090] A co-fluid (50 g) is added to a 300 mL Parr reactor and the reactor is evacuated to ca. 0.21 Torr while stirring and at the temperature being studied. The stirring is stopped, and the co-fluid allowed to settle for 1 minute. CO 2 is bled in to the reactor at the required pressure, which is 300 psia unless indicated otherwise. The CO 2 is introduced as quietly as possible, with minimal co-fluid agitation. Stirring is then started (400 rpms), time is marked 0 minutes and pressure rate recorded. Equilibrium is recorded generally after 15 minutes of stirring. Note that the equilibrium is reached prior to this.
[0091] Afterwards the stirring is stopped and the co-fluid allowed to settle for 1 minute. The pressure is then rapidly but “quietly” dropped to 50 psi. Stirring is resumed and the pressure rise (indicating release of CO 2 from the co-fluid) is recorded for a period of time. Instantaneous rates are determined by taking measurements for the first 20 seconds and fitting a straight line curve through the data.
[0092] All data points represent at least 3 experimental runs.
[0093] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. | A carbon dioxide/co-fluid mixture is provided for use in a refrigeration cycle in which the carbon dioxide is alternately absorbed and desorbed from the co-fluid. Suitable co-fluids are selected from the class of alkoxylated carboxylic amides, wherein the amides are cyclic or non-cyclic. It has been discovered that N-2,5,8,11-tetraoxadodecyl-2-pyrrolidinone and its homologs exhibit an advantageous property of a high rate of desorption at lower temperatures. | 51,445 |
BACKGROUND OF THE INVENTION
This invention relates to a barometer for measuring gas pressure around a quartz oscillator using the quartz oscillator.
There is an urgent need in industrial applications to measure continuously gas pressure ranging from ambient pressure to 10 -3 Torr with a single sensor.
A quartz barometer which utilizes the phenomenon that the frequency at resonance of a quartz oscillator increases with a decreasing gas pressure surrounding the oscillator satisfies to some extent the industrial requirement described above. However, this barometer involves a critical problem in that the lower limit of measurement is about 10 Torr. Though a heat conduction vacuum gauge such as the Pirani gauge has a lower limit value of measurement of about 10 -4 to 10 -3 Torr, it is not free from the same problem as that of the quartz type barometer because its upper limit of measurement is about 10 Torr.
It has been shown recently that the resonance resistance of a quartz oscillator depends upon ambient gas pressure over an extremely wide range, and that a barometer which can continuously measure pressure ranging from ambient atmospheric pressure to 10 -3 Torr can be realized by utilizing this property. This is reported, for example, in "Development of Ultra-Miniature Vacuum Sensor Using Quartz Oscillator" in the magazine "Instrumentation", 1984, Vol. 27, No. 7.
However, in a quartz barometer having the prior art construction which utilizes the temperature depedence of the resistance of a quartz oscillator at resonance described above, a problem has been left unsolved in that precision measurement can not be readily effected because the resistance of the quartz oscillator at resonance varies markedly with temperature, particularly in the low pressure range of roughly 10 -3 to 10 -2 Torr.
SUMMARY OF THE INVENTION
To eliminate this problem, in a quartz barometer utilizing the temperature dependence of the resistance of a quartz oscillator at resonance, the present invention is directed to provide means which compensate for the temperature change of the resistance at resonance by connecting a temperature-dependent resistor in series with a quartz oscillator thereby enabling said quartz barometer to measure gas pressure much more accurately.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the relation between the characteristic values (resistance at resonance, current at resonance, resonant frequency) of a quartz oscillator and ambient gas pressure;
FIG. 2 is a block diagram of a quartz barometer electronic circuit in accordance with the present invention;
FIG. 3 is a diagram showing the relation between the meter driving voltage and ambient pressure;
FIG. 4 is a diagram showing the temperature characteristics of the resistance of the quartz oscillator at resonance;
FIG. 5 is a circuit diagram showing one embodiment of the present invention; and
FIG. 6 is a diagram showing the temperature characterstics of the embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Hereinafter, the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram showing the relation between gas pressure and the characteristic values (resistance at resonance, current at resonance and resonant frequency) of a quartz oscillator. The resonant frequency starts changing when pressure exceeds 10 Torr, but the sensitivity to pressure is virtually nil below 10 Torr. However, the resistance of a quartz oscillator at resonance is sensitive to pressure ranging from ambient atmospheric pressure to 10 -3 Torr. When this quartz oscillator is driven at a constant voltage, a resonance current-v-gas pressure curve can be obtained as represented by symbol i o in the diagram. It is sensitive to pressure ranging from ambient atmospheric pressure to 10 -3 Torr in the same say as the resistance at resonance described above. Therefore, it is easier to measure the current at resonance or the voltage at resonance than to measure the resistance at resonance.
FIG. 2 is a block diagram of a quartz barometer electronic circuit to which the present invention is directed. Its principal components are a PLL circuit, a display conversion circuit and a display. The PLL circuit consists of a variable frequency oscillator 1 which is controlled by a voltage or a current, an amplifier 2 which amplifies the current of a quartz oscillator 5 at resonance as a voltage, a phase comparator 3 which compares the phase of the output signal of the amplifier 2 with that of the output signal of the variable frequency oscillator 1 and produces a signal proportional to the phase difference, and a low-pass filter 4 which converts the pulse-like output signal of the phase comparator 3 to a d.c. voltage. The output voltage of the low-pass filter 4 controls the oscillation frequency of the variable frequency oscillator 1. The pressure-sensitive quartz oscillator 5 is connected to the output terminal of the variable frequency oscillator 1 and the input terminal of the amplifier 2.
The principle of operation of the PLL circuit is well known already, it is not described herein. The output signal of the variable frequency oscillator 1 is always controlled such that the phase difference between the output signal of the variable frequency oscillator 1, that is, the driving voltage of the quartz oscillator 5, and the output signal of the amplifier 2, that is, the current flowing through the quartz oscillator 5, is zero. Therefore the quartz oscillator 5 is always driven at its resonance frequency. This is a significant factor in practical application of a quartz barometer since the resonant frequency of the quartz oscillator varies with pressure as shown in FIG. 1.
Next, the display conversion circuit portion consists of a main amplifier 6 which further amplifies the signal from the amplifier 2, a rectifier 7 which changes the output signal of the main amplifier 6 to d.c. an inverter 8 which inverts the polarity of the output viltage of the rectifier 7, and a buffer 9 which biases the output voltage of the inverter 8. The bias level can be controlled by a variable resistor 9a. The display may be either digital or analog. In this embodiment, it consists of a meter 10; pressure is read from the deflection angle of said meter.
The pressure characteristics of the resonant current of the quartz oscillator are such that said current increases as ambient pressure decreases, as shown in FIG. 1. Therefore, if the current at resonance is amplified as a voltage and is changed to d.c. to drive the meter, the deflection angle of the meter will increase with decreasing pressure; consequently, the display will be the opposite of the detected pressure. This is obviously undesirable from the common sense point of view; therefore, the inverter 8 inverts the polarity of the d.c. voltage, and the buffer 9 then applies the bias voltage so that the meter dirving voltage shown in FIG. 3 can be obtained. In the embodiment shown in FIG. 3, the bias quantity is adjusted so that the meter driving voltage is 10 V at ambient atmospheric pressure. In this manner, a conventional pressure display can be effected in which the meter indicator angle of deflection increases as ambient atmospheric pressure increases and decreases as ambient atmospheric pressure decreses.
FIG. 4 shows the temperature characteristics of the resistance of the quartz oscillator at resonance. The degree of change of the resistance at resonance due to temperature is great in vacuum, and the resistance at resonance increases with as temperature increases. Since most of the resistance at resonance in the ambient atmosphere is frictional resistance, the resistance at resonance does not vary greatly with temperature. As a result, the prior art technique involves the problem that the effect of temperature increases markedly as gas pressure decreases, thereby introducing an error into the measured value.
The present invention provides means for minimizing the error just described.
FIG. 5 shows one embodiment of the present invention. Component 5 is a quartz osoillator, 11 is a thermistor and 12 is a resistor. In FIG. 6, a is the curve of the temperature characteristics of the resistance at resonance of the quartz oscillator at resonance, b is the curve of the temperature characteristics of the combined resistance of the thermistor and the resistor, and c is the curve of the temperature characteristics of the combined resistance of the quartz oscillator, the thermistor and the resistor. The resistance of the quartz oscillator at resonance has a positive temperature coefficient, whereas the resistance of the thermistor has a negative temperature coefficient. If they are connected in series, therefore, the combined resistance value becomes a curve which has a valley with respect to temperature. The resistor described above is a variable resistor so that the temperature range of the valley is that of room temperature (20°-30° C.).
The resistance of the thermistor is not affected by the gas pressure around it; hence, it can compensate for temperature without regard to pressure. In the prior art technique in which the thermistor does not compensate for temperature, the measured value of 1×10 -2 Torr at 25° C. varies to a maximum of 4×10 -2 Torr if the ambient temperature varies from 10° C. to 40° C. If the thermistor compensates for temperature, the measured value of 1×10 -2 Torr at 25° C. will fall within the range of a maximum of 2×10 -2 Torr. Thus, the measurement error due to temperature can be reduced by half. The practical temperature range in the environment of measurement is roughly 25°±5° C. Since the embodiment of the present invention can easily set the minimal point of the resistance value relative to the temperature to 25° C., measurement error due to varying temperature can be drastically reduced in practice.
As described above, the present invention can minimize the adverse effect of varying temperature upon the resistance of the quartz oscillator at resonance by extremely simple means, and can improve accuracy, particularly, in the low pressure range. Since the barometer of the present invention is simply constructed, any increase in the production costs will be minimal.
Though the embodiment described above uses the thermistor as a device to compensate for temperature characteristics of resistance of a quartz oscillator at resonance, devices other than the thermistor can be of course employed if they have a temperature coefficient opposite to that of the resonance of the quartz oscillator at resistance. | In a quartz barometer untilizing the temperature dependence of the resistance of a quartz oscillator at resonance, the present invention is directed to provide a circuit which compensates for the temperature change of the resistance at resonance by connecting a temperature-dependent resistor in series with a quartz oscillator thereby enabling said quartz barometer to measure gas pressure much more accurately. | 10,854 |
This application is a Continuation of application Ser. No. 08/287,567, filed Aug. 9, 1994 now abandoned.
FIELD OF THE INVENTION
This invention generally relates to semiconductor electronic devices, and more specifically to heterojunction bipolar transistors having improved current gain and reliability.
BACKGROUND OF THE INVENTION
Heterojunction bipolar transistors (HBTs) exhibit desirable features such as high current gain and an extremely high cut-off frequency for switching applications, and high power gain and power density for microwave amplifier applications. Even so, as with other types of semiconductor devices there is demand for ever higher operating frequencies or switching speeds from HBTs. Efforts to accomplish this increased performance invariably lead to a scaling down of transistor size. However, as the emitter in an HBT is scaled down, the current gain of the transistor is also dramatically reduced. This effect threatens to limit the level of integration and circuit complexity that can be realized with HBT technology, and has implications for the reliability of HBT power transistors as well.
The reduction in current gain is related to the ratio of the HBT's emitter perimeter-to-area ratio. A cross-sectional diagram of a typical npn HBT is shown in FIG. 1 (the base layer thickness relative it) the other layers is highly exaggerated). In operation, a flow of electrons is established from the emitter, through the base, and into the collector. This electron current is modulated by holes injected into the base from the base contacts. These holes recombine with some of the electrons from the emitter and therefore result in finite current gain. One limitation on current gain is the high density of carrier traps which exists at an exposed semiconductor surface. The trap density is typically large enough to create an electric field near the surface that extends some distance into the base layer. Electrons injected near the edge of the emitter mesa are drawn to the surface of the base layer by this electric field where they recombine in the abundance of traps present at the surface. Hence, the total minority carrier current from the emitter has a desirable component, i.e. the carriers that transit the base to the collector; and an undesirable component, i.e. the carriers that recombine at the surface of the base layer. Unfortunately, the desirable current scales with the area of the emitter, while the undesirable current scales with the perimeter. Consequently, as the emitter dimensions are reduced, the perimeter current becomes a larger percentage of the total emitter current. This results in a decrease of the current gain of the transistor.
Past efforts at solving the problem of surface recombination at the extrinsic base surface have included physical and chemical passivation treatments. Sputtered SiN, depleted AlGaAs passivation ledges, and sulfide-base coatings have been reported. See O. Nakajima, et al., "Emitter-Base Junction Size Effect on Current Gain H fc of AlGaAs/GaAs Heterojunction Bipolar Transistors", Japanese Journal of Applied Physics, Vol. 24, No. 8, pp. L596-L598, Aug. 1985; R. J. Malik, et al., "Submicron Scaling of AlGaAs/GaAs Self-aligned Thin Emitter Heterojunction Bipolar Transistors with Current Gain Independent of Emitter Area", Electronics Letters, Vol. 25, No. 17, pp. 1175-1177, Aug. 17, 1989; S. Tiwari, et al., "Surface Recombination in GaAlAs/GaAs Heterostructure Bipolar Transistors", Journal of Applied Physics, Vol. 64, No. 10, pp. 5009-5012, Nov. 15, 1988. However, these solutions have drawbacks such as process complexity and performance shortcomings that prevent them from offering a complete answer to the problem of extrinsic base surface recombination. For example, depleted AlGaAs passivation ledges, shown in FIG. 2, while effective in reducing the effects of surface states, require that the spacing between the base contact 10 and the active emitter 12 be large enough to accommodate a passivation ledge 14 extending between the active emitter 12 and the base contact 10. High frequency operation demands a lower base resistance and base-collector junction capacitance than is generally possible with such a technique. In addition, the passivation ledge structure does not lend itself to the self-aligned fabrication techniques necessary for economical volume production.
Another prior art approach to passivating the base surface is shown in FIG. 3 and is described in Malik, supra at 1176. It is a modification of the ledge passivation approach. The surface of the GaAs base layer 20 is completely covered by a thin AlGaAs emitter layer 22, in contrast to the ledge structure described above. As in the ledge approach the thin AlGaAs layer 22 extending between the emitter mesa 24 and the base contacts 26 is fully depleted. It serves to passivate the surface states at the surface of the base layer and therefore minimizes surface recombination. In this particular prior art structure, the base layer is primarily GaAs, but contains a small mole fraction of aluminum. The aluminum content is graded from 0% at the base-collector interface to 6% at the base-emitter interface. This sets up a quasi-electric field that helps to keep the minority carriers from migrating to the surface to recombine. However, a problem with this approach is that the base contacts are formed on the emitter layer. Metal from the contacts spikes through the emitter layer and into the base layer upon being alloyed. Since the base layer is typically very thin (approximately 600 Å), it is difficult to alloy the contacts such that metal 27 extends into the base layer 20 without also extending into the underlying collector layer 28. A structure that relies on such alloyed contacts suffers from process uncertainty and has been shown to be unreliable in production. The present invention is intended to address the reliability problems of this prior art structure and the process limitations of the ledge structure.
SUMMARY OF THE INVENTION
The invention includes a passivating layer of material in the base structure of an HBT that serves to cover the extrinsic base region of the transistor. The passivating layer is formed of a material having a wider bandgap than the base layer, and is heavily doped with the same doping type (n or p) as the base layer. This has advantages in that the base contacts of the device are made directly to the passivating layer and are not in direct contact with the base layer or the emitter layer. This eliminates the need for alloyed contacts and the concomitant reliability problems associated with spiking contacts. In addition, this is completely compatible with self-aligned production techniques, and can result in small self-aligned devices that have substantially the same current gain as very large devices not produced by self-alignment.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a cross-sectional view of a prior art heterojunction polar transistor;
FIG. 2 is a cross-sectional view of a prior an heterojunction bipolar transistor which incorporates ledge passivation;
FIG. 3 is a cross-sectional view of a prior an heterojunction bipolar transistor which uses a thin emitter layer to passivate the extrinsic base;
FIG. 4 is a cross-sectional view of a preferred embodiment of the invention;
FIG. 5a is an energy band diagram showing the conduction and valence bands of an extrinsic base region of a prior art unpassivated HBT;
FIG. 5b is an energy band diagram showing the conduction and valence bands of an extrinsic base region with a surface passivation consisting of a wide bandgap material;
FIG. 6 is an energy band diagram showing the emitter-base heterojunction;
FIG. 7 is a cross-sectional diagram of a preferred embodiment material structure from which a preferred embodiment of the invention may be fabricated:
FIGS. 8-13 are diagrams showing a preferred embodiment method of processing; and
FIGS. 14 and 15 are diagrams showing a second preferred embodiment method of processing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In a first preferred embodiment shown in FIG. 4, a thin AlGaAs passivation layer 40 is included within the base structure 42 of an npn HBT adjacent to the emitter layer 46. Passivation layer 40 suppresses the recombination of electrons from the emitter at the surface of the base layer surrounding the emitter mesa 50. FIG. 5a shows the effect of surface states on the conduction and valence bands of an exposed base layer without a passivation layer. Electrons entering the base layer from the emitter are drawn to the surface of the base layer because of the electric field established by the presence of surface states. This is reflected in FIG. 5a by the band bending. FIG. 5b shows the band diagram of the preferred embodiment base layer with an overlying passivation layer. It is apparent from this diagram that electrons in the base layer will be inhibited from reaching the high density of carrier traps at the surface by the conduction band discontinuity between the base layer and the exposed surface. The discontinuity is a result of the interface between the wider bandgap passivation layer 40 and the narrower bandgap base layer 44. This is not true in FIG. 5a, where there is nothing between electrons in the base and the high density of carrier traps at the surface of the base.
The band diagrams of FIGS. 5a and 5b refer to the effect of the preferred embodiment passivation layer 40 over the portion of the base layer that lies between the base contact (48 in FIG. 4) and the emitter mesa 50. It is also important that the passivation layer 40 not interfere with the functioning of the emitter-base junction, which is critical to the operation of the transistor. It is an essential aspect of the functioning of an HBT that the emitter bandgap is larger than that of the base in order to create a barrier in the valence band at the interface between the emitter and base. This barrier prevents holes injected into the base from an external source from being injected into the emitter. A band diagram illustrating this point is shown in FIG. 6. In FIG. 6 a GaAs base and Ga 0 .52 In 0 .48 P emitter are separated by an Al 0 .17 Ga 0 .83 As passivation layer. Note that the valence band has the necessary offset and that the discontinuity in the conduction band may easily be overcome by electrons when the emitter-base junction is forward-biased. The choice of aluminum mole fraction is important in achieving the simultaneous goals of passivating the exposed, or extrinsic, base and of providing a functional emitter-base junction. The aluminum mole fraction that fulfills these requirements is typically in the range of approximately 4% to 30%, with approximately 17% being preferable.
The doping of the AlGaAs layer 40 is of the same type (n or p) as that of the GaAs base layer 44. The carrier concentration in the passivating layer varies according to the desired performance of the transistor, but will typically be within the range from approximately 5×10 18 cm -3 to approximately 1×10 20 cm -3 . For transistors requiring base doping below approximately 5×10 18 cm -3 , recombination is generally not a dominant problem, but for higher concentrations it is more critical. In order for the passivation to be effective, it is important that the entire thickness of the passivation layer not be depleted of carriers. Therefore, the choice of layer thickness depends directly upon the doping concentration in the passivation layer, which in turn is dependent upon the desired operating frequency of the transistor. For example, for L-band operation the preferred concentration is approximately 1.5×10 19 cm -3 ; for X-band operation the preferred concentration is approximately 4×10 19 cm -3 ; for K-band operation the preferred concentration is approximately 7×10 19 cm -3 . The surface depletion region depth varies in approximate proportion to the square root of the doping concentration. Thus, the depletion thickness ranges from approximately 85 Å to approximately 20 Å over the doping concentration range of 5×10 18 cm -3 to 1×10 20 cm - . To ensure that the passivation layer is not completely depleted, the layer thickness is typically chosen to be in the range of 50 to 300 Å, with the particular thickness being determined by the base doping. For an X-band transistor the passivation layer thickness is approximately 100 Å, and is roughly twice the thickness of the depletion region.
The first embodiment structure has numerous advantages over the prior art devices. For example, in the prior an device shown in FIG. 3, the emitter layer 30 extends from the emitter mesa out underneath the base contacts 26. The emitter layer is thin enough to be depleted, but it has been shown that such a structure establishes a leakage path between the emitter mesa and the base contacts. Electrons injected laterally into the depleted surface layer travel a very short distance before recombining at the base contacts 26. Typically, such a layer will allow leakage of several milliamps before the base-emitter junction becomes forward biased. This results in a reduction of current gain.
Additionally, in order for the base contacts 26 to make contact with the base layer 20, the contact must be alloyed. Aside from the difficulties involved in stopping the contact from spiking through the base layer and into the collector 28, the metal that enters the base in the alloying procedure creates an interface that introduces carrier traps. Metal that extends into the collector forms a Schottky diode between the base and collector. This increases the emitter-collector offset voltage, which is undesirable for power amplifier applications. Any disturbance of the semiconductor lattice in the base layer, whether it is an exposed surface, or a metal contact, creates a high density of mid-bandgap states that increases the amount of undesirable recombination in the base layer. So, while the prior an minimizes the carrier traps at the base layer surface by providing an overlying depleted emitter layer, it essentially counters that advantage by introducing traps at the base contact-to-base layer interface. It has been estimated that the surface passivation provides two or three orders of magnitude improvement on the recombination velocity in the base layer, but that the introduction of alloyed metal contacts to the base layer reduces that improvement to less than one order of magnitude.
The first preferred embodiment of the invention shown in FIG. 4 retains the advantages of surface passivation, while eliminating the need for alloyed contacts to the base. Forming the passivation layer of a material doped with the same type (n or p) of dopant as the base layer, rather than that of the emitter, allows the base contact to be made directly to the passivation layer. There is no need for alloying the base contact. This eliminates the leakage path between the emitter mesa and the base contact that plagues the prior art device, while retaining the full benefit of the reduction in base layer recombination.
In a second preferred embodiment of the invention, an Al 0 .35 Ga 0 .65 As emitter is used instead of the GaInP used in the first preferred embodiment. The 35% mole fraction of aluminum provides an emitter layer with a wider bandgap than the 17% aluminum passivation layer. Therefore, the band diagram of the second preferred embodiment structure is almost identical to that for the first preferred embodiment structure shown in FIG. 6. A difference between the two emitter materials is the processing involved in forming the emitter mesa shown in FIG. 4. It should be noted that the invention described with reference to these embodiments is completely compatible with self-aligned processes. This is in contrast to the prior art ledge passivation technique (FIG. 2) which requires a considerable space between the emitter mesa 12 and the base contacts 10, and other prior art techniques which suffer from high emitter-base leakage current if self-alignment is used.
A process to fabricate the first preferred embodiment may begin with the structure shown in FIG. 7 and fully described in Tables I and II. The commonly used etchants for GaAs and AlGaAs do not etch GaInP. Therefore, the processes described hereinbelow have been developed to take advantage of this selectivity. In the first approach, an emitter contact 120 of a suitable material (e.g. Ti/Pt/Au in respective thicknesses of 300/250/3000 Angstroms, for example) is deposited on GaAs layer 106, as shown in FIG. 8. The entire structure is then placed in the reaction chamber of a Reactive Ion Etching (RIE) apparatus. With BCl 3 +SF 6 , CCl 4 , or other commonly used chlorofluorocarbons as the reactant. GaAs layer 106 is anisotropically dry-etched from areas not covered by masking pattern 120. The etch is allowed to continue for approximately 1 minute after the GaInP layer 108 is exposed.
The GaInP is not etched because a residual layer of unknown composition 122, shown in FIG. 9, forms at the surface of GaInP layer 108. Thus, BCl 3 is an etchant that selectively etches GaAs, but not GaInP. Unfortunately, the residual layer 122 is not easily etched using the compositions known to wet etch GaInP, particularly HCl and HCl:H 3 PO 4 (3:1 by volume).
Thus, the BCl 3 apparently reacts with the GaInP to form a composition which is not readily etchable by either normal GaInP wet etchants or by the normal GaAs dry etchant. Therefore, in this embodiment the residual layer 122 is ion milled by placing the structure in an asher at approximately 300 Watts for approximately 10 minutes. O 2 and Ar 124 form the active species liar the milling, depicted in FIG. 10. One can also use a commercially available ion mill apparatus. Immediately alter ion milling, the structure is immersed in a solution containing HF and NH 4 F for approximately 1 minute. The structure is then immersed in a solution of H 2 SO 4 :H 2 O 2 :H 2 O (1:8:160 by volume) for 10 seconds. This prepares the GaInP for removal with an HCl solution. The structure is then immersed in static (unstirred) HCl for 5 seconds, and then immersed in a stirred HCl solution for approximately 1 minute intervals. After each interval two probes are placed on the etched surface to test for breakdown voltage. The process typically requires two 1 minute intervals to etch through the GaInP and results in a structure as shown in FIG. 11. Thus, this process combines the anisotropic, yet selective, reactive ion etching technique with the unselective ion milling and wet etch techniques. This allows the formation of an emitter having a smaller size than would be possible with a wet etch alone.
TABLE I______________________________________ Preferred ApproximateElement # Generic Name Material Thicknesses______________________________________106 Emitter Cop GaAs 2000 Å108 Emitter GaInP 700 Å110 Passivation layer AlGaAs 100 Å112 Base GaAs 800 Å114 Collector GaAs 7000 Å116 Subcollector GaAs 1 μm______________________________________
TABLE II______________________________________ Examples Approximate ofElement Generic Doping Preferred Alternative# Name Concentration Dopant Dopants______________________________________106 Emitter 1 × 10.sup.19 cm.sup.-3 Si Sn Cap108 Emitter 5 × 10.sup.17 cm.sup.-3 Si Sn110 Passivation 3 × 10.sup.19 cm.sup.-3 C Be layer112 Base 3 × 10.sup.19 cm.sup.-3 C Be114 Collector 3 × 10.sup.16 cm.sup.-3 Si Sn116 Subcollector 2 × 10.sup.18 cm.sup.-3 Si Sn______________________________________
Once the emitter mesa (50 in FIG. 4) is formed, base contacts 48 may be formed by spinning on and patterning a layer of photoresist (not shown) to define the location of the contacts on the base passivation layer 40. A metal composition such as Ti/Pt/Au, for example in thicknesses of approximately 500, 250, and 1500 Angstroms, respectively is deposited. The photoresist is then lifted off to leave the base contacts 48 as shown in FIG. 4. Unlike the prior art structure shown in FIG. 3, the first preferred embodiment structure of FIG. 4 does not require alloying of the base contacts 48. The passivation layer 40 is a part of the base structure, rather than the emitter as in the prior art.
After the base contacts are formed, the base mesa may be formed by removing layers 40, 42, 44, and the collector layer 52 to expose the subcollector layer 54. A solution of H 2 SO 4 :H 2 O 2 :H 2 O in the ratio of 1:8:160 (by volume), for example, may be used to remove the layers. Photoresist (not shown) is then deposited and patterned to define the collector contacts 56. AuGe/Ni/Au is then evaporated onto the water to thicknesses of, for example, 500/140/2000 Angstroms, respectively, to form the contact 56. The photoresist layer is then stripped, which lifts off all excess metallization. This results in the structure of FIG. 4. The structure is then heated to 430° C. for approximately 1 minute to alloy the collector contacts.
In a second preferred embodiment process, the structure of FIG. 8 is again etched using the RIE technique described above, but the etch is stopped before GaAs layer 106 is completely etched away. This leaves a thin layer 126 of GaAs, as shown in FIG. 11 (instead of forming the residual layer 122 of FIG. 9). This thin layer of GaAs is removed using a solution of H 2 SO 4 :H 2 O 2 :H 2 O (1:8:160 by volume). The H 2 SO 4 solution stops on the GaInP layer 108, leaving the structure shown in FIG. 13.
In another preferred embodiment process of the invention, the material structure is altered to include an Al x Ga 1-x As (where x is approximately 0.3) layer 128 between GaInP layer 108 and GaAs layer 106. The structure shown in FIG. 14. The AlGaAs layer serves as an etch stop in that the BCl 3 dry etch described in the abovementioned embodiments, when combined with SF 6 , for example, stops on AlGaAs. Hence, after deposition of a masking pattern 120, shown in FIG. 15, the dry BCl 3 etch is performed until GaAs layer 106 is removed. AlGaAs layer 128 is removed with a solution of H 2 SO 4 :H 2 O 2 :H 2 O (1:8:160 by volume) for example, in a timed etch. GaInP layer 108 is then removed with HCl:H 3 PO 4 (3:1 by volume) for example. Though 3:1 does not appreciably etch the AlGaAs base layer 110, the timing in this etch is monitored to avoid substantial undercutting. The structure shown in FIG. 15 results from this process.
Yet another preferred embodiment process is similar to the first except that an InGaAs layer is deposited (by MBE, MOCVD, or other suitable technique) on GaAs layer 106. The InGaAs layer facilitates the formation of an ohmic contact to the material structure. A transistor otherwise may be formed with the process described as the first preferred embodiment. In general, the transistor of FIG. 4 may be obtained with standard processing techniques after one of the above described processes is performed.
A few preferred embodiments have been described in detail hereinabove. It is to be understood that the scope of the invention also comprehends embodiments different from those described, yet within the scope of the claims.
Internal and external connections can be ohmic, capacitive, inductive, direct or indirect, via intervening circuits or otherwise. Implementation is contemplated in discrete components or fully integrated circuits in silicon, gallium arsenide, or other electronic materials families, as well as in optical-based or other technology-based forms and embodiments.
While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the an upon reference to the description. For example, though AlGaAs was used as the wide bandgap passivation layer in the above embodiments, it may be appreciated that other materials having a bandgap wider than the layer being passivated in addition to having a lattice constant relatively close to the layer being passivated may be used. Also, though only GaInP and AlGaAs were mentioned above as emitter materials, it may be appreciated that other semiconductors producing an offset in the valence band between the emitter and base layers may be used. It is therefore intended that the appended claims encompass any such modifications or embodiments. | A bipolar transistor includes a passivating layer of material 40 in the base structure 42 that serves to cover the extrinsic base region of the transistor. The passivating layer 40 is formed of a material having a wider bandgap than the base layer 44, and is heavily doped with the same doping type (n or p) as the base layer. The invention is advantageous in that the base contacts 48 of the device are made directly to the passivating layer 40 and are not in direct contact with the base layer 44. This eliminates the need for alloyed contacts and the concomitant reliability problems associated with spiking contacts. In addition, the invention is completely compatible with self-aligned production techniques. | 25,399 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2011-267539, filed on Dec. 7, 2011, the entire contents of which are incorporated herein by reference.
FIELD
[0002] The embodiments discussed herein are related to an amplifier.
BACKGROUND
[0003] The number of frequency bands utilized in a mobile communication system has been increased. Recently, in the mobile communication system, a service is provided in multiple bands (multiband). More specifically, the service is provided in a 700 MHz band, an 800 MHz band, a 1.5 GHz band, a 1.7 GHz band, a 2.1 GHz band, and a 2.5 GHz band in the mobile communication system.
[0004] An amplifier used for a base station in the mobile communication system is requested to have a high efficiency performance. To satisfy the request of the high efficiency performance, the Doherty amplifier is adopted in many cases. The Doherty amplifier includes a carrier-amplifier and a peak-amplifier arranged in parallel. The carrier-amplifier regularly operates, and the peak-amplifier operates only at the time of a high output.
[0005] In the base station, an amplifier is prepared for each frequency band. However, the preparation of the amplifier for each frequency band is not preferable from viewpoints of a design, a cost, and an amount of resources. Therefore, a Doherty amplifier that can cope with the multiband by a single amplifier is desired.
[0006] A technique for achieving the high efficiency performance with respect to the multiband by switching, using a switch, an electrical length of an output power combining circuit of the Doherty amplifier in accordance with the frequency band is proposed (for example, see Japanese Laid-open Patent Publication No. 2006-345341).
SUMMARY
[0007] According to an aspect of the invention, an amplifier includes a first amplification element configured to amplify a first signal in one of a first operation class and a second operation class, a second amplification element configured to amplify a second signal in one of a first operation class and a second operation class, a first transmission line through which the amplified first signal is transferred, and a coupler configured to couple the first signal transferred through the first transmission line and the amplified second signal so as to transfer the coupled signal to a second transmission line, wherein the first amplification element amplifies the first signal in the first operation class and the second amplification element amplifies the second signal in the second operation class, when the first signal and the second signal have a first frequency band, and wherein the first amplification element amplifies the first signal in the second operation class and the second amplification element amplifies the second signal in the first operation class, when the first signal and the second signal have a second frequency band.
[0008] The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 illustrates a base station according to a first embodiment;
[0011] FIG. 2 illustrates another base station according to the first embodiment;
[0012] FIG. 3 illustrates a transmission unit according to the first embodiment;
[0013] FIG. 4 illustrates an amplifier according to the first embodiment;
[0014] FIG. 5 is a Smith chart illustrating an example of an impedance matching by input matching circuits;
[0015] FIG. 6 is a Smith chart illustrating an example of an impedance matching by output matching circuits;
[0016] FIG. 7 is a flowchart of an operation by the amplifier according to the first embodiment;
[0017] FIG. 8 illustrates a transmission unit according to a second embodiment;
[0018] FIG. 9 illustrates an amplifier according to the second embodiment; and
[0019] FIG. 10 is a flowchart of an operation by the amplifier according to the second embodiment.
DESCRIPTION OF EMBODIMENTS
[0020] Hereinafter, embodiments will be described based on the drawings. In all the drawings for describing the embodiments, the same reference sign is used for elements having the same function, and a repeated description thereof will be omitted.
First Embodiment
<Base Station 100 >
[0021] FIG. 1 illustrates a base station 100 according to an embodiment. The base station 100 includes amplification units 102 ( 102 1 to 102 6 ), modulation units 104 ( 104 1 to 104 6 ), control units 106 ( 106 1 to 106 6 ), and power units 108 ( 108 1 to 108 6 ). A base station may be configured by including units represented by the same suffix.
[0022] FIG. 1 illustrates a case in which the base station 100 includes six amplification units 102 1 to 102 6 . However, the number of the amplification units 102 is not limited to six, and one or two to five amplification units, or seven or more amplification units may be included. FIG. 1 illustrates a case in which the base station 100 includes six modulation units 104 1 to 104 6 . However, the number of the modulation units 104 is not limited to six, and one or two to five modulation units, or seven or more modulation units may be included. FIG. 1 illustrates a case in which the base station 100 includes six control units 106 1 to 106 6 . However, the number of the control units 106 is not limited to six, and one or two to five control units, or seven or more control units may be included. FIG. 1 illustrates a case in which the base station 100 includes six power units 108 1 to 108 6 . However, the number of the power units 108 is not limited to six, and one or two to five power units, or seven or more power units may be included.
[0023] For example, the amplification units 102 1 to 102 6 , the modulation units 104 1 to 104 6 , the control units 106 1 to 106 6 , and the power units 108 1 to 108 6 may have a card-like shape. The base station is configured by storing the respective units in a casing of the base station.
<Base Station 200 >
[0024] FIG. 2 illustrates a base station 200 according to the embodiment. The base station 200 includes Remote Radio Heads (RRHs) 202 ( 202 1 to 202 3 ) and a Base Band Unit (BBU) 208 . FIG. 2 illustrates a case in which the base station 200 includes three RRHs 202 1 to 202 3 . The number of the RRH 202 is not limited to three, and one or two, or four or more remote radio heads may be included.
[0025] The RRH 202 is a wireless unit of the base station. More specifically, the RRH 202 includes modulation units 206 ( 206 1 to 206 3 ) configured to perform modulation processing on transmission data. The RRH 202 also includes amplification units 204 ( 204 1 to 204 3 ) configured to amplify a signal on which the modulation processing is performed by the modulation unit 206 . The BBU 208 is configured to perform base band signal processing.
<Transmission Unit 300 >
[0026] FIG. 3 illustrates a transmission unit 300 according to the embodiment. The transmission unit 300 may be mainly included in the amplification unit 102 , the modulation unit 104 in the base station 100 illustrated in FIG. 1 and the RRH 202 in the base station 200 illustrated in FIG. 2 .
[0027] The transmission unit 300 includes modulation circuits 302 1 and 302 2 , digital-to-analog (D/A) converters 304 1 and 304 2 , preamplifiers 306 1 and 306 2 , an amplifier 308 , a filter 310 , an antenna 312 , and a phase conversion circuit 314 . The amplifier 308 is achieved by the Doherty amplifier.
[0028] The modulation circuits 302 1 and 302 2 are configured to modulate the transmission signal. The modulation circuit 302 1 sends out the modulated transmission signal to the D/A converter 304 1 . The modulation circuit 302 2 sends out the modulated transmission signal to the D/A converter 304 2 .
[0029] The D/A converters 304 1 and 304 2 are respectively connected to the modulation circuits 302 1 and 302 2 . The D/A converters 304 1 and 304 2 convert the modulated transmission signal from a digital signal to an analog signal. The D/A converter 304 1 sends out the signal converted into the analog signal to the preamplifier 306 1 . The D/A converter 304 2 sends out the signal converted into the analog signal to the preamplifier 306 2 .
[0030] The preamplifiers 306 1 and 306 2 are respectively connected to the D/A converters 304 1 and 304 2 . The preamplifiers 306 1 and 306 2 amplify the analog signals from the D/A converters 304 1 and 304 2 . The preamplifier 306 1 sends out the amplified analog signal to the amplifier 308 . The preamplifier 306 2 sends out the amplified analog signal to the phase conversion circuit 314 .
[0031] The phase conversion circuit 314 is connected to the preamplifier 306 2 . The phase conversion circuit 314 shifts a phase of the signal from the preamplifier 306 2 by 90 degrees. The phase conversion circuit 314 sends out the signal from the preamplifier 306 2 the phase of which is shifted by 90 degrees to the amplifier 308 . Specifically, the phase conversion circuit 314 delays the phase of the signal from the preamplifier 306 2 by 90 degrees. The phase of the signal from the preamplifier 306 2 is delayed by 90 degrees because the signal from a carrier-amplifier and the signal from a peak-amplifier are coupled to each other at a phase difference by 90 degrees in the Doherty amplifier.
[0032] The amplifier 308 is connected to the preamplifier 306 1 and the phase conversion circuit 314 . The amplifier 308 utilizes the signal from the preamplifier 306 1 and the signal from the phase conversion circuit 314 to amplify the power up to an average power level by the carrier-amplifier and operate the peak-amplifier from a point in the middle of the power elevation. The amplifier 308 synthesizes the signal amplified by the carrier-amplifier with the signal amplified by the peak-amplifier. With the amplification by the carrier-amplifier, it is possible to improve the amplification efficiency. With the operation by the peak-amplifier, it is also possible to obtain the maximum power. The amplifier 308 sends out the amplified signal obtained by utilizing the signal from the preamplifier 306 1 and the signal from the phase conversion circuit 314 to the filter 310 .
[0033] The filter 310 is connected to the amplifier 308 . The filter 310 performs a band limitation on the signal from the amplifier 308 and sends out the signal to the antenna 312 .
[0034] The antenna 312 is connected to the filter 310 . The antenna 312 wirelessly transmits the signal on which the filter 310 performs the band limitation.
<Amplifier 308 >
[0035] FIG. 4 illustrates the amplifier 308 according to the embodiment. The amplifier 308 operates corresponding to plural bands, that is, multiband. Specifically, the amplifier 308 operates corresponding to the 700 MHz band, the 800 MHz band, the 1.5 GHz band, the 1.7 GHz band, the 2.1 GHz band, and the 2.5 GHz band.
[0036] A case will be described in which the amplifier 308 according to the embodiment operates corresponding to the 700 MHz band and the 2.1 GHz band among the plural bands. The present embodiment can also similarly be applied to a case in which the amplifier 308 operates corresponding to other frequencies without a limitation on the case in which the amplifier 308 operates corresponding to 700 MHz band and the 2.1 GHz band.
[0037] The amplifier 308 includes input matching circuits 402 1 and 402 2 , amplification elements 404 1 and 404 2 , the output matching circuits 406 1 and 406 2 , and transmission lines 408 and 410 . For example, the amplification elements 404 1 and 404 2 may be a semiconductor device such as an LD-MOS (Lateral Double-Diffused MOS), a GaAs-FET, an HEMT, or an HBT.
[0038] In the amplifier 308 , between a bias voltage operating in Class AB and a bias voltage operating in Class C, voltages applied to the amplification elements 404 1 and 404 2 are switched. More specifically, in a case where the input signal is a signal in the 700 MHz band, the bias voltage to operate in Class AB is applied to the amplification element 404 1 , and the bias voltage to operate in Class C is applied to the amplification element 404 2 . Since the amplification element 404 1 receives the bias voltage to operate in Class AB, the amplification element 404 1 functions as the carrier-amplifier of the Doherty amplifier. Since the amplification element 404 2 receives the bias voltage to operate in Class C, the amplification element 404 2 functions as the peak-amplifier of the Doherty amplifier. The input signals are the signals from the preamplifier 306 1 and the phase conversion circuit 314 .
[0039] Further, in a case where the input signal is a signal in the 2.1 GHz band, the bias voltage to operate in Class C is applied to the amplification element 404 1 , and the bias voltage to operate in Class AB is applied to the amplification element 404 2 . Since the amplification element 404 1 receives the bias voltage to operate in Class C, the amplification element 404 1 functions as the peak-amplifier of the Doherty amplifier. Since the amplification element 404 2 receives the bias voltage to operate in Class AB, the amplification element 404 2 functions as the carrier-amplifier.
[0040] By switching the bias voltages to be applied to the amplification elements 404 1 and 404 2 , the amplification elements 404 1 and 404 2 can switch the functions between the function as the carrier-amplifier and the function as the peak-amplifier of the Doherty amplifier.
[0041] The input matching circuit 402 1 is connected to the preamplifier 306 1 . The input matching circuit 402 1 converts an impedance of the signal from the preamplifier 306 1 to be matched with an input impedance of the amplification element 404 1 . The input matching circuit 402 1 sends out the impedance-converted signal to the amplification element 404 1 .
[0042] The amplification element 404 1 is connected to the input matching circuit 402 1 . The amplification element 404 1 is an amplification element configured to amplify the signal. The amplification element 404 1 is biased to Class AB or Class C. That is, the amplification element 404 1 receives, as the bias voltage, the voltage that is applied for operating the amplification element 404 1 in Class AB or the voltage that is applied for operating the amplification element 404 1 in Class C. Since the amplification element 404 1 receives the voltage to an extent where the operation class is changed, the amplification element 404 1 can be operated as the Class AB amplifier or the Class C amplifier. The amplification element 404 1 sends out the amplified signal to the output matching circuit 406 1 .
[0043] The output matching circuit 406 1 is connected to the amplification element 404 1 . The output matching circuit 406 1 including the transmission line 408 converts a load impedance of the signal from the amplification element 404 1 .
[0044] The input matching circuit 402 2 is connected to the phase conversion circuit 314 . The input matching circuit 402 2 converts the impedance of the signal from the phase conversion circuit 314 to be matched with the input impedance of the amplification element 404 2 . The input matching circuit 402 2 sends out the impedance-converted signal to the amplification element 404 2 .
[0045] The amplification element 404 2 is connected to the input matching circuit 402 2 . The amplification element 404 2 is an amplification element configured to amplify the signal. The amplification element 404 2 is biased to Class AB or Class C. That is, the amplification element 404 2 receives, as the bias voltage, the voltage that is applied for operating the amplification element 404 2 in Class AB or the voltage that is applied for operating the amplification element 404 2 in Class C. Since the amplification element 404 2 receives the voltage to an extent where the operation class is changed, the amplification element 404 2 can be operated as the Class AB amplifier or the Class C amplifier. The amplification element 404 2 sends out the amplified signal to the output matching circuit 406 2 .
[0046] The output matching circuit 406 2 is connected to the amplification element 404 2 . The output matching circuit 406 2 converts a load impedance of the signal from the amplification element 404 2 .
[0047] The transmission line 408 is connected to the output matching circuit 406 1 . The transmission line 408 is a transmission line configured to carry out the impedance conversion of the signal from the output matching circuit 406 1 . More specifically, in the transmission line 408 , an impedance conversion is carried out based on an electrical length of λ/4 with respect to a frequency of the signal that is input to the amplifier 308 . The signal input to the amplifier 308 is the signal from the preamplifier 306 1 . Herein, the electrical length regulates the length of the transmission line while a wavelength (λ) in the transmission line is set as a reference. With the regulation while the wavelength in the transmission line is set as a reference, it is possible to take a line constant into account. The line constant includes a specific inductive capacity of a dielectric or the like. By carrying out the impedance conversion of the signal from the output matching circuit 406 1 based on the electrical length of λ/4 with respect to the frequency of the signal that is input to the amplifier 308 , it is possible to ensure the matching with the signal from the output matching circuit 406 2 .
[0048] The transmission line 410 is connected to the transmission line 408 and the output matching circuit 406 2 . In the transmission line 410 , the impedance conversion is carried out on the signal obtained by synthesizing the signal from the transmission line 408 with the signal from the output matching circuit 406 2 . A point where the signal from the transmission line 408 is coupled to the signal from the output matching circuit 406 2 is set as a coupling part A. The signal from the transmission line 408 is synthesized with the signal from the output matching circuit 406 2 at the coupling part A. More specifically, in the transmission line 410 , the impedance conversion is carried out based on the electrical length of λ/4 with respect to the frequency of the signal that is input to the amplifier 308 . By carrying out the impedance conversion based on the electrical length of λ/4 with respect to the frequency of the signal that is input to the amplifier 308 , it is possible to ensure the matching with the filter 310 .
<Input Matching Circuits 402 1 and 402 2 >
[0049] Under the condition for matching the impedance between the devices, an impedance point at which the efficiency is optimized may be different from an impedance point at which the electric power is maximized in some cases. Depending on the frequency of the input signal, also, an impedance point at which the efficiency is optimized may be different from an impedance point at which the electric power is maximized in some cases.
[0050] An amplifier that operates corresponding to plural frequency bands will be described. For example, the amplifier can be used for input signals in two frequency bands. In the above-mentioned amplifier, it may be difficult, in some cases, to obtain a matching circuit that can ensure the impedance matching so that the efficiency is optimized in both frequency bands of a frequency band f 1 and a frequency band f 2 . Herein, the frequency band f 1 may be the 700 MHz band, and the frequency band f 2 may be the 2.1 GHz band. According to the present embodiment, the amplifier is designed so that the matching can be ensured to optimize the efficiency in the frequency band f 1 and the matching can be ensured to maximize the electric power in the frequency band f 2 . The impedance matching point at which the efficiency is optimized may be different from the impedance matching point at which the electric power is maximized. In the amplifier 308 , since the two types of impedance points can be selected, it is possible to increase the impedance points that can be selected at the time of designing.
[0051] FIG. 5 is a Smith chart illustrating an example of an impedance matching by the input matching circuits 402 1 and 402 2 .
[0052] In FIG. 5 , “Pf 1 AB” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “Pf 1 C” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class C. “γf 1 AB” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “γf 1 C” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class C.
[0053] Further, “Pf 2 AB” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “Pf 2 C” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class C. “γf 2 AB” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “γf 2 C” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class C.
[0054] In the example illustrated in FIG. 5 , “Pf 1 AB” as the impedance matching point at which the electric power is maximized in the frequency band f 1 or “γf 1 AB” as the impedance matching point at which the efficiency is optimized in the frequency band f 1 can be set in the input matching circuit 402 1 . Furthermore, in accordance with the impedance matching point set in the input matching circuit 402 1 , it is possible to set the impedance matching point in the input matching circuit 402 2 . More specifically, “γf 1 C” as the impedance matching point at which the efficiency is optimized in the frequency band f 1 or “Pf 1 C” as the impedance matching point at which the electric power is maximized in the frequency band f 1 can be set in the input matching circuit 402 2 .
[0055] Further, “Pf 2 AB” as the impedance matching point at which the electric power is maximized in the frequency band f 2 or “γf 2 AB” as the impedance matching point at which the efficiency is optimized in the frequency band f 2 can be set in the input matching circuit 402 1 . Furthermore, in accordance with the impedance matching point set in the input matching circuit 402 1 , it is possible to set the impedance matching point in the input matching circuit 402 2 . More specifically, “γf 2 C” as the impedance matching point at which the efficiency is optimized in the frequency band f 2 or “Pf 2 C” as the impedance matching point at which the electric power is maximized in the frequency band f 2 can be set in the input matching circuit 402 2 . Accordingly, when the multiband of the amplifier is to be achieved, it is possible to improve the degree of freedom in the design of the matching circuit.
<Output Matching Circuits 406 1 and 406 2 >
[0056] With regard to the output matching circuits 406 1 and 406 2 , similarly as in the input matching circuits 402 1 and 402 2 , under the condition for matching the impedance between the devices, an impedance point at which the efficiency is optimized may be different from an impedance point at which the electric power is maximized in some cases. Depending on the frequency of the input signal, also, an impedance point at which the efficiency is optimized is different from an impedance point at which the electric power is maximized.
[0057] For example, in the amplifier that operates corresponding to the plural frequency bands, in both the frequency of the frequency band f 1 and the frequency band f 2 , it may be difficult to achieve a matching circuit that can ensure the impedance matching so that the efficiency is optimized in some cases. In this case, the design is made such that the matching can be ensured to optimize the efficiency in the frequency band f 1 and the matching can be ensured to maximize the electric power in the frequency band f 2 . The impedance matching point at which the efficiency is optimized may be different from the impedance matching point at which the electric power is maximized. In the amplifier 308 , since the two types of impedance points can be selected, it is possible to increase the impedance points that can be selected at the time of designing.
[0058] FIG. 6 is a Smith chart illustrating an example of an impedance matching by the output matching circuits 406 1 and 406 2 .
[0059] In FIG. 6 , “Pf 1 AB” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “Pf 1 C” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class C. “γf 1 AB” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “γf 1 C” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class C.
[0060] Further, “Pf 2 AB” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “Pf 2 C” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class C. “γf 2 AB” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “γf 2 C” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class C.
[0061] In the example illustrated in FIG. 6 , “Pf 1 AB” as the impedance matching point at which the electric power is maximized in the frequency band f 1 or “γf 1 AB” as the impedance matching point at which the efficiency is optimized in the frequency band f 1 can be set in the output matching circuit 406 1 . Furthermore, in accordance with the impedance matching point set in the output matching circuit 406 1 , it is possible to set the impedance matching point in the output matching circuit 406 2 . More specifically, “γf 1 C” as the impedance matching point at which the efficiency is optimized in the frequency band f 1 or “Pf 1 C” as the impedance matching point at which the electric power is maximized in the frequency band f 1 can be set in the output matching circuit 406 2 .
[0062] Further, “Pf 2 AB” as the impedance matching point at which the electric power is maximized in the frequency band f 2 or “γf 2 AB” as the impedance matching point at which the efficiency is optimized in the frequency band f 2 can be set in the output matching circuit 406 1 . Furthermore, in accordance with the impedance matching point set in the output matching circuit 406 1 , it is possible to set the impedance matching point in the output matching circuit 406 2 . More specifically, “γf 2 C” as the impedance matching point at which the efficiency is optimized in the frequency band f 2 or “Pf 2 C” as the impedance matching point at which the electric power is maximized in the frequency band f 2 can be set in the output matching circuit 406 2 . Accordingly, when the multiband of the amplifier is to be achieved, it is possible to improve the degree of freedom in the design of the matching circuit.
<Operation by the Amplifier 308 >
[0063] FIG. 7 is a flowchart of an operation by the amplifier 308 according to the embodiment. Herein, a case where the switching is conducted so that the signal in the 700 MHz band is amplified and a case where the switching is conducted so that the signal in the 2.1 GHz band is amplified will be described.
[0000] <Case where Switching is Conducted so that Signal in 700 MHz band is Amplified>
[0064] The switching is conducted to cause the amplifier 308 that has been set to amplify the signal in the 2.1 GHz band to amplify the signal in the 700 MHz band.
[0065] The matching condition is set in the amplifier 308 (step S 702 ). More specifically, in the input matching circuit 402 1 , the impedance matching point at which the efficiency is optimized at 700 MHz is set. Also, in the output matching circuit 406 1 , the impedance matching point at which the efficiency is optimized at 700 MHz is set.
[0066] On the other hand, in the input matching circuit 402 2 , the impedance matching point at which the electric power is maximized at 700 MHz is set. Also, in the output matching circuit 406 2 , the impedance matching point at which the electric power is maximized at 700 MHz is set.
[0067] The bias voltage is applied to the amplifier 308 (step S 704 ). More specifically, the amplification element 404 1 receives the bias voltage to operate in Class AB. On the other hand, the amplification element 404 2 receives the bias voltage to operate in Class C.
[0000] <Case where Switching is Conducted so that Signal in 2.1 GHz Band is Amplified>
[0068] The switching is conducted to cause the amplifier 308 that has been set to amplify the signal in the 700 MHz band to amplify the signal in the 2.1 GHz band.
[0069] The matching condition is set in the amplifier 308 (step S 702 ). More specifically, in the input matching circuit 402 1 , the impedance matching point at which the electric power is maximized at 2.1 GHz is set. Also, in the output matching circuit 406 1 , the impedance matching point at which the electric power is maximized at 2.1 GHz is set.
[0070] On the other hand, in the input matching circuit 402 2 , the impedance matching point at which the efficiency is optimized at 2.1 GHz is set. Also, in the output matching circuit 406 2 , the impedance matching point at which the efficiency is optimized at 2.1 GHz is set.
[0071] The bias voltage is applied to the amplifier 308 (step S 704 ). More specifically, the amplification element 404 1 receives the bias voltage to operate in Class C. On the other hand, the amplification element 404 2 receives the bias voltage to operate in Class AB.
[0072] According to the present embodiment, when the multiband of the Doherty amplifier is to be achieved, it is possible to improve the degree of freedom in the design of the matching circuit. That is, it is possible to select the impedance matching point to be set from the plural impedance matching points. Since the impedance matching point can be selected from the plural impedance matching points, it is possible to easily achieve the multiband of the Doherty amplifier. Also, without switching the transmission lines or the like, it is possible to achieve the multiband of the Doherty amplifier.
[0073] Further, in the amplifier that operates corresponding to the 700 MHz band and the 2.1 GHz band, as described above, the transmission lines 408 and 410 can be achieved by the lines of λ/4.
[0074] In the Doherty amplifier, the signal from the carrier-amplifier and the signal from the peak-amplifier are to be coupled to each other at a phase difference of 90 degrees. In the amplifier 308 illustrated in FIG. 4 , the signal from the carrier-amplifier and the signal from the peak-amplifier can be coupled to each other at the phase difference of 90 degrees by the transmission line 408 .
[0075] Further, at the time of the operation by the peak-amplifier, since the carrier-amplifier and the peak-amplifier are operated in parallel, the impedance conversion is to be conducted on the signal obtained by synthesizing the signal from the peak-amplifier with the signal from the carrier-amplifier. In the amplifier 308 illustrated in FIG. 4 , the impedance conversion is conducted by the transmission line 410 on the signal obtained by synthesizing the signal from the peak-amplifier with the signal from the carrier-amplifier.
[0076] For example, the transmission lines 408 and 410 can be replaced by lines of 90 degrees (λ/4). However, since the line has a frequency characteristic, a case of a certain frequency corresponds to the phase of 90 degrees.
[0077] According to the present embodiment, the amplifier 308 is set to correspond to the 700 MHz band and the 2.1 GHz band that is three times as high as 700 MHz. With the settings for corresponding to the 700 MHz band and the 2.1 GHz band, the transmission lines 408 and 410 can be used in common with the λ/4 line at the low frequency, that is, 700 MHz. Since the transmission lines can be used in common with the λ/4 line at 700 MHz, it is possible to avoid the switching of the line on the output side.
Second Embodiment
<Base Station>
[0078] The base station 100 and the base station 200 according to a second embodiment are similar to those in FIG. 1 and FIG. 2 .
<Transmission Unit 300 >
[0079] FIG. 8 illustrates the transmission unit 300 according to the second embodiment. The transmission unit 300 according to the second embodiment is different from the transmission unit described with reference to FIG. 3 in that the transmission unit 300 according to the second embodiment includes a phase conversion circuit 316 .
[0080] The phase conversion circuit 316 is connected to the preamplifier 306 1 . The phase conversion circuit 316 shifts the phase of the signal from the preamplifier 306 1 . The phase conversion circuit 316 sends out the signal from the preamplifier 306 1 the phase of which is shifted to the amplifier 308 . More specifically, the phase conversion circuit 316 delays the phase of the signal from the preamplifier 306 1 .
[0081] Further, the phase conversion circuit 314 adds 90 degrees and more to shift the phase of the signal from the preamplifier 306 2 . The phase conversion circuit 314 sends out the signal from the preamplifier 306 2 the phase of which is shifted by being added with 90 degrees and more to the amplifier 308 . More specifically, the phase conversion circuit 316 shifts the phase of the signal from the preamplifier 306 1 by 90 degrees and further delays the phase. <Amplifier 308 >
[0082] FIG. 9 illustrates the amplifier 308 according to the embodiment. The amplifier 308 according to the second embodiment is different from the amplifier 308 described with reference to FIG. 4 in that the amplifier 308 according to the second embodiment includes phase compensation lines 412 and 414 .
[0083] A signal from the phase conversion circuit 316 is input to the input matching circuit 402 1 .
[0084] The phase compensation line 412 is connected to the output matching circuit 406 1 . The phase compensation line 412 is a transmission line configured to compensate for a shift of the phase generated by the amplification element 404 1 .
[0085] Specifically, in a case where the signal in the 700 MHz band is amplified, the phase compensation line 412 compensates the signal from the output matching circuit 406 1 by a phase θ 1 . The phase θ 1 is a shift of the phase supposed to be generated by the amplification element 404 1 when the signal in the 700 MHz band is amplified. The signal the phase of which is compensated by the phase compensation line 412 is input to the transmission line 408 .
[0086] Further, in a case where the signal in the 2.1 GHz band is amplified, the phase compensation line 412 compensates the signal from the output matching circuit 406 1 by a phase θ 3 . The phase θ 3 is a shift of the phase supposed to be generated by the amplification element 404 1 when the signal in the 2.1 GHz band is amplified. The signal the phase of which is compensated by the phase compensation line 412 is input to the transmission line 408 .
[0087] The phase compensation line 414 is connected to the output matching circuit 406 2 . The phase compensation line 414 is a transmission line configured to compensate for a shift of the phase generated by the amplification element 404 2 .
[0088] Specifically, in a case where the signal in the 700 MHz band is amplified, the phase compensation line 414 compensates the signal from the output matching circuit 406 2 by a phase θ 2 . The phase θ 2 is a shift of the phase supposed to be generated by the amplification element 404 2 when the signal in the 700 MHz band is amplified. The signal the phase of which is compensated by the phase compensation line 414 is synthesized with the signal from the transmission line 408 at the coupling part A to be input to the transmission line 410 .
[0089] Further, in a case where the signal in the 2.1 GHz band is amplified, the phase compensation line 414 compensates the signal from the output matching circuit 406 2 by a phase θ 4 . The phase θ 4 is a shift of the phase supposed to be generated by the amplification element 404 2 when the signal in the 2.1 GHz band is amplified. The signal the phase of which is compensated by the phase compensation line 414 is synthesized with the signal from the transmission line 408 at the coupling part A to be input to the transmission line 410 .
[0090] In the Doherty amplifier, the signal from the carrier-amplifier and the signal from the peak-amplifier are to be coupled to each other at a phase difference of 90 degrees. However, since the bias conditions and the matching conditions vary between the carrier-amplifier and the peak-amplifier, the signal that is output from the carrier-amplifier and the signal that is output from the peak-amplifier do not have a same passing phase. Accordingly, on the output side of the output matching circuits 406 1 and 406 2 , the phase compensation lines 412 and 414 are respectively provided, so that the lines configured to compensate the passing phase are inserted.
[0091] However, if the frequency for achieving the multiband is changed, the phase shift amounts are not the same. To compensate for the phase shift amounts supposed to fluctuate in response to the change in the frequency, the phase shift amounts are individually set in the carrier-amplifier and the peak-amplifier.
[0092] More specifically, in a case where the signal in the 700 MHz band is amplified, the phase conversion circuit 316 sets an amount of shifting the phase of the signal from the preamplifier 306 1 as Δθ 1 , and the phase conversion circuit 314 sets an amount of shifting the phase of the signal from the preamplifier 306 2 as Δθ 2 .
[0093] Further, in a case where the signal in the 2.1 GHz band is amplified, the phase conversion circuit 316 sets an amount of shifting the phase of the signal from the preamplifier 306 1 as Δθ 3 , and the phase conversion circuit 314 sets an amount of shifting the phase of the signal from the preamplifier 306 2 as Δθ 4 .
[0094] With this configuration, for achieving the multiband, even in a case where the frequency of the input signal is changed, it is possible to compensate for the phase shift amount that fluctuates when the frequency is changed.
<Operation by the Amplifier 308 >
[0095] FIG. 10 is a flowchart of an operation by the amplifier 308 according to the embodiment. Herein, a case will be described where the switching is conducted so that the signal in the 700 MHz band is amplified and a case will be described where the switching is conducted so that the signal in the 2.1 GHz band is amplified.
[0000] <Case where Switching is Conducted so that Signal in 700 MHz Band is Amplified>
[0096] The switching is conducted to cause the amplifier 308 that has been set to amplify the signal in the 2.1 GHz band to amplify the signal in the 700 MHz band.
[0097] The matching condition is set in the amplifier 308 (step S 1002 ). Specifically, in the input matching circuit 402 1 , the impedance matching point at which the efficiency is optimized at 700 MHz is set. Also, in the output matching circuit 406 1 , the impedance matching point at which the efficiency is optimized at 700 MHz is set.
[0098] On the other hand, in the input matching circuit 402 2 , the impedance matching point at which the electric power is maximized at 700 MHz is set. Also, in the output matching circuit 406 2 , the impedance matching point at which the electric power is maximized at 700 MHz is set.
[0099] The phase is set (step S 1004 ). More specifically, Δθ 1 is set as the phase shift amount in the phase conversion circuit 316 , and Δθ 2 is set as the phase shift amount in the phase conversion circuit 314 . Also, the phase compensation line 412 is set to compensate the phase of the signal from the output matching circuit 406 1 by the phase θ 1 . Also, the phase compensation line 414 is set to compensate the phase of the signal from the output matching circuit 406 2 by the phase θ 2 .
[0100] The bias voltage is applied to the amplifier 308 (step S 1006 ). More specifically, the amplification element 404 1 receives the bias voltage to operate in Class AB. On the other hand, the amplification element 404 2 receives the bias voltage to operate in Class C.
[0000] <Case where Switching is Conducted so that Signal in 2.1 GHz Band is Amplified>
[0101] The switching is conducted to cause the amplifier 308 that has been set to amplify the signal in the 700 MHz band to amplify the signal in the 2.1 GHz band.
[0102] The matching condition is set in the amplifier 308 (step S 1002 ). More specifically, in the input matching circuit 402 1 , the impedance matching point at which the electric power is maximized at 2.1 GHz is set. Also, in the output matching circuit 406 1 , the impedance matching point at which the electric power is maximized at 2.1 GHz is set.
[0103] On the other hand, in the input matching circuit 402 2 , the impedance matching point at which the efficiency is optimized at 2.1 GHz is set. Also, in the output matching circuit 406 2 , the impedance matching point at which the efficiency is optimized at 2.1 GHz is set.
[0104] The phase is set (step S 1004 ). More specifically, Δθ 3 is set as the phase shift amount in the phase conversion circuit 316 , and Δθ 4 is set as the phase shift amount in the phase conversion circuit 314 . Also, the phase compensation line 412 is set to compensate the phase of the signal from the output matching circuit 406 1 by the phase θ 3 . The phase compensation line 414 is set to compensate the phase of the signal from the output matching circuit 406 2 by the phase θ 4 .
[0105] The bias voltage is applied to the amplifier 308 (step S 1006 ). More specifically, the amplification element 404 1 receives the bias voltage to operate in Class C. On the other hand, the amplification element 404 2 receives the bias voltage to operate in Class AB.
[0106] According to the present embodiment, when the multiband of the Doherty amplifier is to be achieved, it is possible to improve the degree of freedom in the design of the matching circuit. That is, it is possible to select the impedance matching point to be set from the plural impedance matching points. Since the impedance matching point can be selected from the plural impedance matching points, it is possible to easily achieve the multiband of the Doherty amplifier. Also, without switching the transmission lines or the like, it is possible to achieve the multiband of the Doherty amplifier.
[0107] Further, in the amplifier that operates corresponding to the 700 MHz band and the 2.1 GHz band, as described above, the transmission lines 408 and 410 can be achieved by the lines of λ/4.
[0108] In the Doherty amplifier, the signal from the carrier-amplifier and the signal from the peak-amplifier are to be coupled to each other at a phase difference of 90 degrees. In the amplifier 308 illustrated in FIG. 9 , the signal from the carrier-amplifier and the signal from the peak-amplifier can be coupled to each other at the phase difference of 90 degrees by the transmission line 408 .
[0109] Further, at the time of the operation by the peak-amplifier, since the carrier-amplifier and the peak-amplifier are operated in parallel, the impedance conversion is to be conducted on the signal obtained by synthesizing the signal from the peak-amplifier with the signal from the carrier-amplifier. In the amplifier 308 illustrated in FIG. 9 , the impedance conversion is conducted by the transmission line 410 on the signal obtained by synthesizing the signal from the peak-amplifier with the signal from the carrier-amplifier.
[0110] For example, the transmission lines 408 and 410 can be replaced by lines of 90 degrees (λ/4). However, since the line has a frequency characteristic, a case of a certain frequency corresponds to the phase of 90 degrees.
[0111] According to the present embodiment, the amplifier 308 is set to correspond to the 700 MHz band and the 2.1 GHz band that is three times as high as 700 MHz. With the setting for corresponding to the 700 MHz band and the 2.1 GHz band, the transmission lines 408 and 410 can be used in common with the λ/4 line at the low frequency, that is, 700 MHz. Since the transmission lines can be used in common with the λ/4 line at 700 MHz, it is possible to avoid the switching of the line on the output side.
[0112] Further, according to the present embodiment, since the shift of the passing phases between the signal from the carrier-amplifier and the signal from the peak-amplifier can be compensated for, the shifts of the synthesis points between the signal from the carrier-amplifier and the signal from the peak-amplifier can be reduced. Since the shifts of the synthesis points between the signal from the carrier-amplifier and the signal from the peak-amplifier can be reduced, it is possible to improve the amplification characteristic at a time when the maximum power is obtained, in particular.
[0113] Further, without carrying out the physical switching of the lines or the like when the frequency bands are switched, it is possible to adjust the shift of the phase generated by the frequency characteristic that is different for each amplification element by controlling the phase of the input signal.
[0114] According to the above-mentioned embodiment, the operation classes of the amplification elements 404 1 and 404 2 may be switched between Class AB and Class B and may also be switched between Class A and Class B. Also, the operation classes of the amplification elements 404 1 and 404 2 may be switched between Class AB and Class C and may also be switched between Class A and Class C.
[0115] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. | An amplifier includes a first amplification element configured to amplify a first signal in one of first and second operation classes, a second amplification element configured to amplify a second signal in one of first and second operation classes, a first transmission line through which the amplified first signal is transferred, and a coupler configured to couple the transferred first signal and the amplified second signal, wherein the first amplification element amplifies the first signal in the first operation class and the second amplification element amplifies the second signal in the second operation class, when the first signal and the second signal have a first frequency band, and wherein the first amplification element amplifies the first signal in the second operation class and the second amplification element amplifies the second signal in the first operation class, when the first signal and the second signal have a second frequency band. | 51,782 |
FIELD OF THE INVENTION
The instant invention pertains to those numerous instances wherein it is desired to operate a solenoid coil or other device which experiences the same benefits in steady state conditions at reduced power. The goal is to reduce energy consumption by controlling the net wattage of the solenoid coil. Use of an alternating or direct current power supply for inputting power to the solenoid coil is achieved by the instant invention. The preferred embodiment is shown with respect to the coils powered by DC. However, the inventive concepts will apply equally well to AC powered coils.
BACKGROUND OF THE INVENTION
The problem is not new. The power to initially actuate a solenoid coil is much higher than that necessary to maintain the solenoid in the latched position. The magnetic circuit is different in these two conditions.
Some devices employ a power circuit having a pulsed square wave or rectified sine wave output. These devices lower the net RMS voltage and power to approximately 20% but they experience significant DC ripple which can cause the plunger within the solenoid to drop out. They also suffer from potential reliability problems because they are polarity sensitive. The input voltage tolerance to these devices is +/-10% and the DC ripple can be as much as 20% peak to peak. The input voltage tolerance is narrow because these devices do not have any output voltage sensing apparatus.
SUMMARY OF THE INVENTION
The instant invention reduces power consumption of the solenoid coil by 80 to 90%. Coil life is extended by virtue of lower power consumption by the coil. A rectifying bridge is employed in the preferred embodiment so that either AC or DC power sources may be used. The bridge is not polarity sensitive so the orientation of the positive and negative power leads in the case of the DC power source does not matter.
A power circuit for controlling the amount of power delivered to a solenoid coil is disclosed in the preferred embodiment. The initial voltage applied to the coil may be chosen to be higher than the steady state rating, for example 24 volts applied to a 12 volt coil, to ensure quick and reliable pull in. Thereafter the voltage is reduced to prevent heating etc. A current mode pulse width modulated controller is employed to control the flow of current through a power branch of the circuit. A rectifying bridge enables use of the power circuit with either AC or DC power sources. The power circuit includes a novel startup current source for initially energizing the pulse width modulation controller. Two feedback circuits, one representing a compensated current through a power branch of the power circuit and one representing the output voltage of the power circuit are processed by the pulse width modulation controller (PWMC). The PWMC outputs pulses of varying duration at a constant frequency to a field effect transistor in the power branch of the power circuit. The opening of the field effect transistor interrupts the flow of current in the power branch of the circuit. The shorter the duration of the pulses the less time the field effect transistor in the power branch of the power circuit is closed and the less power is delivered to the output of the power circuit for a given input voltage. The longer the duration of the pulses the more time the field effect transistor in the power branch is closed and more power is delivered to the output of the power circuit.
Two inductors are used. A coupling capacitor is interposed between the first inductor and the second inductor. Control of the output voltage and output current of the circuit are effected by two feedback circuits (in the preferred embodiment voltages) inputted to the current mode pulse width modulation controller. The power branch of the circuit containing the field effect transistor is at a node located between the first inductor and the current coupling capacitor. The voltage and current at this node are constantly changing in value due to the operation of the field effect transistor in the power branch of the power circuit.
Accordingly, it is an object of the present invention to provide a circuit to control the output power in the steady state energized condition thereof to 10 to 20% of the rated wattage of the coil.
It is a further object of the present invention to provide a power circuit capable of delivering high output power to the solenoid coil during initial energization thereof.
It is a further object of the present invention to provide a power circuit capable of delivering high output power to the solenoid coil for 0.3-0.5 seconds after initial energization thereof.
It is a further object of the present invention to use the energy stored in the magnetic fields of two inductors to supply output power to the solenoid coil.
It is a further object of the present invention to provide a pulse width modulation controller to gate a field effect transistor allowing different amounts of current to flow through the power branch of the circuit containing the field effect transistor.
It is a further object of the present invention to provide a branch of the circuit in parallel with the output of the circuit which branch contains a resistor and a capacitor for operating a junction field effect transistor. The junction field effect transistor is in series with a resistor which is in parallel with another resistor to develop a feedback voltage representative of the voltage output of the power circuit.
It is a further object of the present invention to provide a current sensing circuit, (or first feedback voltage sensing circuit) for sensing the current (inferred by a voltage measurement) in the power branch of the circuit containing the field effect transistor.
It is a further object of the present invention to provide a current sensing circuit, (or first feedback voltage sensing circuit) for sensing the current (inferred by a voltage measurement) in the solenoid.
It is a further object of the present invention to provide a compensated current sensing circuit for use by the current mode pulse width modulation controller.
It is a further object of the present invention to provide a voltage sensing circuit which senses the solenoid voltage. The voltage sensing circuit includes two parallel resistors. During normal low power output of the power circuit, the second feedback voltage is sensed across one of the resistors to ground. When the solenoid coil is first being energized, the second feedback voltage is sensed across two resistors in parallel to ground. The second resistor is in the circuit by means of a closed, junction field effect transistor which is in series with the second resistor. The normally closed junction field effect transistor is no longer gated, or closed, when the voltage applied to its gate reaches approximately 3.0 VDC. The voltage applied to the gate of the junction field effect transistor is sensed across a capacitor to ground in a resistor-capacitor branch of the circuit measured across the output of the power circuit. The time constant of the circuit together with the ramping of the voltage across the output of the power circuit provides a 0.3 to 0.5 second delay before the junction field effect transistor opens (is not gated). This 0.3 to 0.5 second delay has been found to be a sufficient delay for initially energizing the solenoid coil (load) rated at 24 volts, 15 watts. Other time consultants can be used to provide longer or shorter energizing power to other solenoid coils as will become apparent from the present teachings.
It is a further object of the present invention to provide a startup current means for supplying power to the pulse width modulation controller.
It is a further object of the present invention to include a resistor and a capacitor as part of the current sensing circuit. The capacitor provides a smooth voltage which is input to the pulse width modulation controller together with a clocked compensated signal.
It is a further object of the present invention to provide a startup current source for initially powering the current mode pulse with modulation controller which includes a metal oxide semiconductor field effect transistor, an amplifier (voltage regulator), a transistor, resistors and diode which allow 10 VDC power to pass to the PWMC.
It is a further object of the present invention to provide a power circuit for energizing a solenoid coil which is operable with DC voltage sources and is not polarity sensitive.
It is a further object of the present invention to provide a power circuit for powering a solenoid coil which is operable with AC power sources in the range of 40-140 VAC at either 50 or 60 hz or DC power sources in the range of 10.8-140 VDC.
It is a further object of the present invention to eliminate AC buzz of solenoid coils.
It is a further object of the instant invention to provide a power circuit that has no DC ripple on the output of the power circuit.
It is a further object of the present invention to provide a power circuit which eliminates AC solenoid coil buzz and AC coil burn out.
The objects of the invention will be better understood when taken in conjunction with the Brief Description of the Drawings, the Detailed Description of the Invention and the Claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of the power circuit;
FIG. 2 is a schematic drawing of the startup current source.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, current mode pulse width modulation controller 1 is an integrated circuit, a Unitrode UC 3843AD. The pulse width modulation controller has a first input which senses the voltage across resistor 24. Resistor 24 is a 0.22 Ω resistor. Resistor 25 is a 49.9 Ω resistor. Capacitor 34 is a 220 pF capacitor yielding a very short time constant. Reference numeral 37 is a 5 VDC reference output by the pulse width modulation controller 1. Resistor 31 is a 10 kΩ resistor and capacitor 32 is a 0.001 μF capacitor. Together, resistor 31 and capacitor 32 set the clock input 39 of the pulse width modulation controller at 100 kHz.
Reference numeral 39 is a clock input to the PWMC 1. Input 39 reaches approximately 3 VDC and then resets at 1 VDC. Capacitor 32 discharges when clock input 39 resets.
The cycling of the clock applies and removes voltage from the base 46 of the transistor 45. Capacitor 44 is a 0.1 μF capacitor which stabilizes the 5 VDC reference voltage at output 37. Transistor 45 conducts more current when voltage is applied to the base 46 thereof Resistor 56 is a 3.01 kΩ resistor. A sawtooth wave is generated at the clock 39 which follows the charging of capacitor 32. Current flows to the junction of the resistor 25 and capacitor 34 via transistor 45.
The currents flowing through resistors 25 and 56 are summed into a voltage across capacitor 34. The current flowing through resistor 56 is a slope compensation current and is summed with the current through resistor 25.
Zener diode 29 and capacitor 30, a 10 μF capacitor, regulate and stabilize respectively, the input voltage applied to power input 10 of the PWMC.
Reference numeral 38 indicates a ground on the PWMC. Reference numeral 10 is the power input to the PWMC which is connected to resistors 8 and 33. Reference numeral 14 is the second (voltage) input of the PWMC. A feedback voltage is applied to second input 14. Capacitor 41 is a 0.1μF capacitor in series with 42, a 5.11 kΩ resistor. Capacitor 41 and resistor 42 provide high frequency compensation of the voltage feedback from the output of the power circuit. Reference numeral 40 is the compensating input to the PWMC.
It will be apparent to those skilled in the art that the PWMC is being employed as a current mode PWMC. Reference numeral 11 is the output of the PWMC which is buffered by resistor 13, a 10 Ω resistor. The output 11 of the PWMC controls the field effect transistor 12.
A supply voltage input is applied at the terminals denoted by reference numeral 15 in FIG. 1. A metal oxide varistor 4 is applied across the input terminals for surge protection. Fuse 3 provides overpower protection. Rectifying bridge 5 converts alternating current to direct current. The input voltage may be in the range of 10 to 140 VDC or 40 to 140 VAC at either 50 or 60 Hz. A 10 μF power supply filtering capacitor 7 is used to stabilize the input voltage. One side of the bridge is connected to a ground 2. Node 2 is either a common voltage or ground. A common voltage may be impressed on the node 2 shown in FIG. 1.
Inductor 9 is a 100 μH inductor. This inductor is known as a boost to those skilled in the art. Capacitor 26 is an AC current coupling capacitor between the inductor 9 and the output. The voltage at the node between inductor 20 and capacitor 26 is switching due to the field effect transistor 12 switching the current in the power branch 59 of the power circuit. Inductor 20 is a 100 μH inductor. Inductor 20 once energized, supplies power to the output of the power circuit when field effect transistor 12 closes and current flows through the power branch 59 of the power circuit. When the current mode PWMC outputs a voltage to the field effect transistor 12 it closes for the duration of the pulse width. The pulse width is operating at 100 kHz and the duration of the pulses vary. The amount of current that flows through the power branch 59 of the power circuit beginning at the node connecting inductor 9 and capacitor 26 and terminating at node 2 and passing through resistor 24 is a function of the input voltage at the output of the rectifying bridge 5, the time that the inductor 9 has charged and the amount of charge held in the field of inductor 9, the discharge of capacitor 26 (a 2.2 μF current coupling capacitor), and the amount of time that field effect transistor 12 is closed, and the resistance of the field effect transistor 12, as is known in the art.
The startup current source 6 necessary to power 1 and associated circuitry is shown in FIG. 2. Resistor 8 (FIG. 1) is a 220 Ω resistor and it drops a voltage as current flows out of the current source 6. Current source 6 is used during the startup of the circuit. Once power is established to the inductor 9 and the capacitor 26 for a sufficient amount of time, diode 28 passes current through resistor 33 to power PWMC 1 and its circuitry. This reduces the power dissipation in 6 which may otherwise be considerable if the maximum input voltage is applied to 15. Resistor 33 is a 49.9 Ω resistor.
Referring to FIG. 2, reference numeral 48 indicates incoming voltage (and current) applied to the current source 6 from bridge rectifier 5. Reference numeral 47 illustrates ground or common. Resistors 49 and 50 are 100 kΩ resistors. Metal oxide semiconductor field effect transistor (MOSFET) 51 is in series with incoming power on line 48. Reference numeral 52 is a transistor. Reference numeral 54 is a 10 volt zener diode. Reference numeral 55 is a 10 kΩ resistor and reference numeral 53 is a voltage regulator (amplifier). Metal oxide semiconductor field effect transistor 51 is a variable linear impedance. The larger the voltage on the gate of MOSFET 51 the more current flows from the drain to the source. The drain is the side of the MOSFET 51 near the input power source 48 and the source is the other side. Transistor 52 shunts voltage across gate resistor 55 and zener diode 55 establishes the feedback for zener diode 53 to the source when sufficient voltage is applied to the source of MOSFET 51. Zener diode 54 permits current to flow when the output 60 of the current source 6 exceeds 10 VDC either due to current flow through 51 or resistors 33 and 8. MOSFET 51 is a variable impedance and drops voltage when, for example, 24 VDC is applied to input power source 48. The drop across MOSFET 51 will be 14 VDC in this example. Linear regulator 53 acts as a variable impedance. The current of the circuit of FIG. 2 is reduced after the start of current flow in diode 28 and resistor 33. The circuit of FIG. 2, just described, is a linear regulator.
Referring again to FIG. 1 and in particular referring to the right most or output portion of the figure, resistor 17 is a 48.7 kΩ resistor and resistor 18 is a 14.7 kΩ resistor. Reference numeral 27 indicates a diode through which power passes to the output 16 of the circuit. The output voltage across terminals 16 changes as a function of the feedback voltage. The feedback voltage is the voltage across resistor 18. The maximum power output of the circuit on terminals 16 is nominally 24 VDC at 1.5 A and the normal power output of the circuit is nominally 10.8 VDC at approximately 0.28 A. Load 70 is a solenoid coil which includes a plunger.
Reference numeral 19 is a 5.11 kΩ resistor in series with a junction field effect transistor 23. The transistor 23 is normally closed and opens when its base voltage is approximately 3.0 VDC. It takes approximately 0.3 to 0.5 seconds after initial energization of the power circuit to charge capacitor 22 to approximately 3 VDC. It will be understood by those skilled in the art that the voltage at the output of diode 27 is a dynamic voltage from the standpoint that it does not instantaneously reach 24 VDC upon initial energization of the power circuit. Rather, the voltage ramps up to approximately 24 VDC upon initial energization of the power circuit. The higher power output is necessary to initially energize the solenoid coil. Because the voltage on 22 is the integral of current through resistor 21 which in turn is proportional to the voltage at 16, the voltage on 22 may be thought of as a measure of, or proportional to, the current passed through the solenoid at initial energization. The charging of capacitor 22 may be thought of as a time delay.
The junction field effect transistor 23 is controlled by the RC circuit made up of resistor 21 and capacitor 22. Resistor 21 is a 2 MΩ resistor and capacitor 22 is a 0.47 μF capacitor. This RC branch of the circuit is across the output of the power circuit.
The voltage across resistor 18 changes depending whether or not resistor 18 is in parallel with resistor 19. When resistors 18 and 19 are in parallel the voltage across them will decrease and the voltage sensed at the second input 14 to the PWMC 1 will also decrease.
The output 11 of the PWMC is dependent upon the voltage applied to the first input 36 and second input 14 of the PWMC. The voltage applied to the first input 36 is the voltage across capacitor 34 which is created by the currents flowing through resistors 25 and 56. Ignoring resistor 56, the current flowing through the resistor 25 will charge capacitor 34 to the voltage across resistor 24. The current flowing through resistor 56 will add additional charge to capacitor 34. The current through resistor 56 is from the slope compensating network. The slope compensating network is comprised of resistor 56 and transistor 45. Resistor 31 and capacitor 32 are the RC components for the PWMC clock. This slope compensating network combines a voltage which is representative of the primary current through resistor 24. The Unitrode current mode pulse width modulation controller 1 processes the feedback voltage from the output circuit which is impressed on the second input 14 to the controller together with the compensated current input which is impressed on the first input 36 to form pulses of sufficient duration to maintain the desired voltage across resistor 18 which in turn maintains the desired voltage at 16.
Output 11 clocks pulses of varying widths at 100 kHz. The maximum pulse width is typically 97%. When the pulse widths are at their maximum the power circuit is in a current limiting mode meaning that the amount of power being transferred to the output circuit through the current coupling capacitor 26 and diode 27 is limited. The circuit is thus protected against shorts to ground (or other problems) on the output side. The maximum current through the solenoid is also limited. The maximum pulse widths occur when the voltage applied to the first input 36 exceeds 1 VDC. The PWMC acts to control the current through the resistor 24 and thus the corresponding solenoid current, by forcing it to follow the error between voltage applied to second input 14 and an internal voltage (2.5 VDC) of the PWMC.
The output across terminals 16 is filtered by capacitor 35 which is a 47 μF capacitor.
Simplistically described, it will be recognized that upon initial excitation of the circuit by application of voltage at 15, that the output voltage 16 will quickly ramp up to a maximum of 24 volts at which time the voltage at 14 which is determined by the resistor divider comprised of resistor 17 in series with the parallel combination of resistors 18 and 19 causes the PWMC 1 to begin to limit and maintain the output voltage at terminal 16 to approximately 24 volts.
Simultaneously the current through current sense resistor 24 begins to charge capacitor 34, and the voltage at 16 causes current to flow through resistor 21 to charge capacitor 22. Current through the solenoid coil will increase as determined by its electrical characteristics toward a steady state value which would otherwise be limited only by the coil's resistance.
The electrical characteristics affecting the rate at which the solenoid's current increases include the series resistance, inductance and stray capacitance of the coil. The inductance is affected by the position of the plunger and current in the coil and all of the parameters are normally affected by temperature. Without other control, the pull in time of the solenoid will vary depending on temperature, and the mechanical condition (dirt, wear, etc.) of the solenoid.
When the current in resistor 24 reaches a value which corresponds to the solenoid coil minimum plunger pull current out of terminal 16, the pulse width at 11 is caused to be changed to limit the terminal 16 current to that value. This effectively causes the buildup of magnetic field in the solenoid to occur at a predictable and steady rate which is mostly insensitive to the previously mentioned variables. This limitation allows fairly accurate determination of the total magnetic field in the solenoid, and thus a related knowledge of the position of the solenoid plunger. In other words this provides a method of determining when the plunger is assured of being fully pulled in by either elapsed time or by the integral of the current through resistor 21, without undue effects of the variables mentioned above. In addition, it provides some control on the speed at which the plunger is pulled in, as that speed is somewhat proportional to coil current.
At a time thereafter which is determined by the integral of the current through 21, the values of resistor 21 and capacitor 22, transistor 23 is turned off. The turn off of 23 removes the effect of resistor 19, causing a rapid increase of the voltage at 14, thus causing PWMC 1 to limit the voltage at 16 to a new and lower value. This lower value is selected to be high enough to reliably maintain the solenoid in an energized state while not being so high as to cause unwanted or excessive heating and other effects as previously described.
The values of resistor 21 and capacitor 22 may be chosen to create a simple time delay, causing 23 to turnoff a known time after the appearance of a certain voltage at 16, or may be chosen to represent the integral of the current through resistor 21 which in turn is a measure of the current flowing in the solenoid, which in turn is a measure of the magnetic field and thus the position of the plunger of the solenoid.
It is possible to first limit the solenoid current and then afterward to reduce the current to a hold in value by one of the described methods, or to simply use the current limit as a failure safety feature and merely use either a time delay or a measure of the of coil current to reduce the hold in current as desired to meet particular requirements when utilizing the present invention.
From the teachings herein, one of ordinary skill in the art will be able to adjust the values of the various components for optimum performance, for example, R24 and C34 to control the maximum current and the response timing of the current limitation, capacitor 41 and resistor 42 for the response timing of the output voltage on 16, resistor 21 and capacitor 22 to control either timing or measure of solenoid parameters as discussed above, as well as the values of resistors 17, 18, and 19 to control the pull in and hold in currents of the solenoid. Such adjustments may be made to allow optimization of the invention for use in particular applications where one parameter may be more desirable than another.
It will be recognized by those skilled in the art that the present invention has been disclosed by way of example only and the invention shall not be limited to the embodiment disclosed. Further, those skilled in the art will recognize that many changes may be made to the present invention without departing from the scope of the appended claims. | A power circuit for controlling the amount of power delivered to a solenoid coil is disclosed. A current mode pulse width modulation controller is employed to interrupt the flow of current through a power branch of the circuit. A rectifying bridge enables use of the power circuit with either AC or DC power sources. The power circuit includes a startup current source for initially energizing the pulse width modulation controller. Two feedback voltages, one representing the compensated current through the power branch of the circuit and one representing the output voltage of the power circuit are used by the pulse width modulation controller to output pulses of varying duration at constant frequency to a field effect transistor. The opening of the field effect transistor interrupts the flow of current in the power branch of the circuit. | 25,488 |
RELATED APPLICATIONS
[0001] This application is a divisional of copending application Ser. No. 09/059,796, filed April 13, which is a divisional of application Ser. No. 08/788,786, filed Jan. 23, 1997, now U.S. Pat. No. 6,235,043, which is a continuation of application Ser. No. 08/188,244, filed on Jan. 26, 1994 (now abandoned).
FIELD OF THE INVENTION
[0002] This invention relates to improvements in the surgical treatment of bone conditions of the human and other animal bone systems and, more particularly, to an inflatable balloon-like device for use in treating such bone conditions. Osteoporosis, avascular necrosis and bone cancer are diseases of bone that predispose the bone to fracture or collapse. There are 2 million fractures each year in the United States, of which about 1.3 million are caused by osteoporosis. Avascular necrosis and bone cancers are more rare but can cause bone problems that are currently poorly addressed.
BACKGROUND OF THE INVENTION
[0003] In U.S. Pat. Nos. 4,969,888 and 5,108,404, an apparatus and method are disclosed for the fixation of fractures or other conditions of human and other animal bone systems, both osteoporotic and non-osteoporotic. The apparatus and method are especially suitable for use in the fixation of, but not limited to, vertebral body compression fractures, Colles fractures and fractures of the proximal humerus.
[0004] The method disclosed in these two patents includes a series of steps which a surgeon or health care provider can perform to form a cavity in pathological bone (including but not limited to osteoporotic bone, osteoporotic fractured metaphyseal and epiphyseal bone, osteoporotic vertebral bodies, fractured osteoporotic vertebral bodies, fractures of vertebral bodies due to tumors especially round cell tumors, avascular necrosis of the epiphyses of long bones, especially avascular necrosis of the proximal femur, distal femur and proximal humerus and defects arising from endocrine conditions).
[0005] The method further includes an incision in the skin (usually one incision, but a second small incision may also be required if a suction egress is used) followed by the placement of a guide pin which is passed through the soft tissue down to and into the bone.
[0006] The method further includes drilling the bone to be treated to form a cavity or passage in the bone, following which an inflatable balloon-like device is inserted into the cavity or passage and inflated. The inflation of the inflatable device causes a compacting of the cancellous bone and bone marrow against the inner surface of the cortical wall of the bone to further enlarge the cavity or passage. The inflatable device is then deflated and then is completely removed from the bone. A smaller inflatable device (a starter balloon) can be used initially, if needed, to initiate the compacting of the bone marrow and to commence the formation of the cavity or passage in the cancellous bone and marrow. After this has occurred, a larger, inflatable device is inserted into the cavity or passage to further compact the bone marrow in all directions.
[0007] A flowable biocompatible filling material, such as methylmethacrylate cement or a synthetic bone substitute, is then directed into the cavity or passage and allowed to set to a hardened condition to provide structural support for the bone. Following this latter step, the insertion instruments are removed from the body and the incision in the skin is covered with a bandage.
[0008] While the apparatus and method of the above patents provide an adequate protocol for the fixation of bone, it has been found that the compacting of the bone marrow and/or the trabecular bone and/or cancellous bone against the inner surface of the cortical wall of the bone to be treated can be significantly improved with the use of inflatable devices that incorporate additional engineering features not heretofore described and not properly controlled with prior inflatable devices in such patents. A need has therefore arisen for improvements in the shape, construction and size of inflatable devices for use with the foregoing apparatus and method, and the present invention satisfies such need.
[0009] Prior Techniques for the Manufacture of Balloons for In-Patient Use
[0010] A review of the prior art relating to the manufacture of balloons shows that a fair amount of background information has been amassed in the formation of guiding catheters which are introduced into cardiovascular systems of patients through the brachial or femoral arteries. However, there is a scarcity of disclosures relating to inflatable devices used in bone, and none for compacting bone marrow in vertebral bodies and long bones.
[0011] In a dilatation catheter, the catheter is advanced into a patient until a balloon is properly positioned across a lesion to be treated. The balloon is inflated with a radiopaque liquid at pressures above four atmospheres to compress the plaque of the lesion to thereby dilate the lumen of the artery. The balloon can then be deflated, then removed from the artery so that the blood flow can be restored through the dilated artery.
[0012] A discussion of such catheter usage technique is found and clearly disclosed in U.S. Pat. No. 5,163,989. Other details of angioplasty catheter procedures, and details of balloons used in such procedures can be found in U.S. Pat. Nos. 4,323,071, 4,332,254, 4,439,185, 4,168,224, 4,516,672, 4,538,622, 4,554,929, and 4,616,652.
[0013] Extrusions have also been made to form prism shaped balloons using molds which require very accurate machining of the interior surface thereof to form acceptable balloons for angioplastic catheters. However, this technique of extrusion forms parting lines in the balloon product which parting lines are limiting in the sense of providing a weak wall for the balloon itself.
[0014] U.S. Pat. No. 5,163,989 discloses a mold and technique for molding dilatation catheters in which the balloon of the catheter is free of parting lines. The technique involves inflating a plastic member of tubular shape so as to press it against the inner molding surface which is heated. Inflatable devices are molded into the desired size and shape, then cooled and deflated to remove it from the mold. The patent states that, while the balloon of the present invention is especially suitable for forming prism-like balloons, it can also be used for forming balloons of a wide variety of sizes and shapes.
[0015] A particular improvement in the catheter art with respect to this patent, namely U.S. Pat. No. 54,706,670, is the use of a coaxial catheter with inner and outer tubing formed and reinforced by continuous helical filaments. Such filaments cross each other causing the shaft of the balloon to become shorter in length while the moving portion of the shank becomes longer in length. By suitably balancing the lengths and the angle of the weave of the balloon and moving portions of the filaments, changes in length can be made to offset each other. Thus, the position of the inner and outer tubing can be adjusted as needed to keep the balloon in a desired position in the blood vessel.
[0016] Other disclosures relating to the insertion of inflatable devices for treating the skeleton of patients include the following:
[0017] U.S. Pat. No. 4,313,434 relates to the fixation of a long bone by inserting a deflated flexible bladder into a medullary cavity, inflating the balloon bladder, sealing the interior of the long bone until healing has occurred, then removing the bladder and filling the opening through which the bladder emerges from the long bone.
[0018] U.S. Pat. No. 5,102,413 discloses the way in which an inflatable bladder is used to anchor a metal rod for the fixation of a fractured long bone.
[0019] Other references which disclose the use of balloons and cement for anchoring of a prosthesis include U.S. Pat. Nos. 5,147,366, 4,892,550, 4,697,584, 4,562,598, and 4,399,814.
[0020] A Dutch patent, NL 901858, discloses a means for fracture repair with a cement-impregnated bag which is inflated into a preformed cavity and allowed to harden.
[0021] It can be concluded from the foregoing review of the prior art that there is little or no substantive information on inflatable devices used to create cavities in bone. It does not teach the shape of the balloon which creates a cavity that best supports the bone when appropriately filled. It does not teach how to prevent balloons from being spherical when inflated, when this is desired. Current medical balloons can compress bone but are too small and generally have the wrong configuration and are generally not strong enough to accomplish adequate cavity formation in either the vertebral bodies or long bones of the body.
[0022] U.S. Pat. Nos. 4,969,888 and 5,108,404 disclose a checker-shaped balloon for compressing cancellous bone, but does not provide information on how this balloon remains in its shape when inflated.
[0023] Thus, the need continues for an improved inflatable device for use with pathological bones and the treatment thereof.
SUMMARY OF THE INVENTION
[0024] The present invention is directed to a balloon-like inflatable device or balloon for use in carrying out the apparatus and method of the above-mentioned U.S. Pat. Nos. 4,969,888 and 5,108,404. Such inflatable devices, hereinafter sometimes referred to as balloons, have shapes for compressing cancellous bone and marrow (also known as medullary bone or trabecular bone) against the inner cortex of bones whether the bones are fractured or not.
[0025] In particular, the present invention is directed to a balloon for use in treating a bone predisposed to fracture or to collapse. The balloon comprises an inflatable, non-expandable balloon body for insertion into said bone. The body has a predetermined shape and size when substantially inflated sufficient to compress at least a portion of the inner cancellous bone to create a cavity in the cancellous bone and to restore the original position of the outer cortical bone, if fractured or collapsed. The balloon body is restrained to create said predetermined shape and size so that the fully inflated balloon body is prevented from applying substantial pressure to the inner surface of the outer cortical bone if said bone is unfractured or uncollapsed.
[0026] In addition to the shape of the inflatable device itself, another aspect of importance is the construction of the wall or walls of the balloon such that proper inflation the balloon body is achieved to provide for optimum compression of all the bone marrow. The material of the balloon is also desirably chosen so as to be able to fold the balloon so that it can be inserted quickly and easily into a bone using a guide pin and a cannula, yet can also withstand high pressures when inflated. The balloon can also include optional ridges or indentations which are left in the cavity after the balloon has been removed, to enhance the stability of the filler. Also, the inflatable device can be made to have an optional, built-in suction catheter. This is used to remove any fat or fluid extruded from the bone during balloon inflation in the bone. Also, the balloon body can be protected from puncture by the cortical bone or canula by being covered while inside the canula with an optional protective sleeve of suitable material, such as Kevlar or PET or other polymer or substance that can protect the balloon. The main purpose of the inflatable device, therefore, is the forming or enlarging of a cavity or passage in a bone, especially in, but not limited to, vertebral bodies.
[0027] The primary object of the present invention is to provide an improved balloon-like inflatable device for use in carrying out a surgical protocol of cavity formation in bones to enhance the efficiency of the protocol, to minimize the time prior to performing the surgery for which the protocol is designed and to improve the clinical outcome. These balloons approximate the inner shape of the bone they are inside of in order to maximally compress cancellous bone. They have additional design elements to achieve specific clinical goals. Preferably, they are made of inelastic material and kept in their defined configurations when inflated, by various restraints, including (but not limited to) use of inelastic materials in the balloon body, seams in the balloon body created by bonding or fusing separate pieces of material together, or by fusing or bonding together opposing sides of the balloon body, woven material bonded inside or outside the balloon body, strings or bands placed at selected points in the balloon body, and stacking balloons of similar or different sizes or shapes on top of each other by gluing or by heat fusing them together. Optional ridges or indentations created by the foregoing structures, or added on by bonding additional material, increases stability of the filler. Optional suction devices, preferably placed so that if at least one hole is in the lowest point of the cavity being formed, will allow the cavity to be cleaned before filling.
[0028] Among the various embodiments of the present invention are the following:
[0029] 1. A doughnut (or torus) shaped balloon with an optional built-in suction catheter to remove fat and other products extruded during balloon expansion.
[0030] 2. A balloon with a spherical outer shape surrounded by a ring-shaped balloon segment for body cavity formation.
[0031] 3. A balloon which is kidney bean shaped in configuration. Such a balloon can be constructed in a single layer, or several layers stacked on top of each other.
[0032] 4. A spherically shaped balloon approximating the size of the head of the femur (i.e. the proximal femoral epiphysis). Such a balloon can also be a hemisphere.
[0033] 5. A balloon in the shape of a humpbacked banana or a modified pyramid shape approximating the configuration of the distal end of the radius (i.e. the distal radial epiphysis and metaphysis).
[0034] 6. A balloon in the shape of a cylindrical ellipse to approximate the configuration of either the medial half or the lateral half of the proximal tibial epiphysis. Such a balloon can also be constructed to approximate the configuration of both halves of the proximal tibial epiphysis.
[0035] 7. A balloon in the shape of sphere on a base to approximate the shape of the proximal humeral epiphysis and metaphysis with a plug to compress cancellous bone into the diaphysis, sealing it off.
[0036] 8. A balloon device with optional suction device.
[0037] 9. Protective sheaths to act as puncture guard members optionally covering each balloon inside its catheter.
[0038] The present invention, therefore, provides improved, inflatable devices for creating or enlarging a cavity or passage in a bone wherein the devices are inserted into the bone. The configuration of each device is defined by the surrounding cortical bone and adjacent internal structures, and is designed to occupy about 70-90% of the volume of the inside of the bone, although balloons that are as small as about 40% and as large as about 99% are workable for fractures. In certain cases, usually avascular necrosis, the balloon size may be as small as 10 % of the cancellous bone volume of the area of bone being treated, due to the localized nature of the fracture or collapse. The fully expanded size and shape of the balloon is limited by additional material in selected portions of the balloon body whose extra thickness creates a restraint as well as by either internal or external restraints formed in the device including, but not limited to, mesh work, a winding or spooling of material laminated to portions of the balloon body, continuous or non-continuous strings across the inside held in place at specific locations by glue inside or by threading them through to the outside and seams in the balloon body created by bonding two pieces of body together or by bonding opposing sides of a body through glue or heat. Spherical portions of balloons may be restrained by using inelastic materials in the construction of the balloon body, or may be additionally restrained as just described. The material of the balloon is preferably a non-elastic material, such as polyethylene tetraphthalate (PET), Kevlar or other patented medical balloon materials. It can also be made of semi-elastic materials, such as silicone or elastic material such as latex, if appropriate restraints are incorporated. The restraints can be made of a flexible, inelastic high tensile strength material including, but not limited, to those described in U.S. Pat. No. 4,706,670. The thickness of the balloon wall is typically in the range of 2/1000 ths to 25/1000 ths of an inch, or other thicknesses that can withstand pressures of up to 250-400 psi.
[0039] A primary goal of percutaneous vertebral body augmentation of the present invention is to provide a balloon which can create a cavity inside the vertebral body whose configuration is optimal for supporting the bone. Another important goal is to move the top of the vertebral body back into place to retain height where possible, however, both of these objectives must be achieved without fracturing the cortical wall of the vertebral body. This feature could push vertebral bone toward the spinal cord, a condition which is not to be desired.
[0040] The present invention satisfies these goals through the design of inflatable devices to be described. Inflating such a device compresses the calcium-containing soft cancellous bone into a thin shell that lines the inside of the hard cortical bone creating a large cavity.
[0041] At the same time, the biological components (red blood cells, bone progenitor cells) within the soft bone are pressed out and removed by rinsing during the procedure. The body recreates the shape of the inside of an unfractured vertebral body, but optimally stops at approximately 70 to 90% of the inner volume. The balloons of the present invention are inelastic, so maximally inflating them can only recreate the predetermined shape and size. However, conventional balloons become spherical when inflated. Spherical shapes will not allow the hardened bone cement to support the spine adequately, because they make single points of contact on each vertebral body surface (the equivalent of a circle inside a square, or a sphere inside a cylinder). The balloons of the present invention recreate the flat surfaces of the vertebral body by including restraints that keep the balloon in the desired shape. This maximizes the contacts between the vertebral body surfaces and the bone cement, which strengthens the spine. In addition, the volume of bone cement that fills these cavities creates a thick mantle of cement (4 mm or greater), which is required for appropriate compressive strength. Another useful feature, although not required, are ridges in the balloons which leave their imprint in the lining of compressed cancellous bone. The resulting bone cement “fingers” provide enhanced stability.
[0042] The balloons which optimally compress cancellous bone in vertebral bodies are the balloons listed as balloon types 1, 2 and 3 above. These balloons are configured to approximate the shape of the vertebral body. Since the balloon is chosen to occupy 70 to 90% of the inner volume, it will not exert undue pressure on the sides of the vertebral body, thus the vertebral body will not expand beyond its normal size (fractured or unfractured). However, since the balloon has the height of an unfractured vertebral body, it can move the top, which has collapsed, back to its original position.
[0043] One aspect of the invention provides a device for insertion into a vertebral body to apply a force capable of compacting cancellous bone and moving fractured cortical bone. The device includes a catheter extending along an axis and having a distal end sized and configured for insertion through a cannula into the vertebral body. The catheter carries near its distal end an inflatable body having a wall sized and configured for passage within the cannula into the vertebral body when the inflatable body is in a collapsed condition. The wall is further sized and configured to apply the in response to expansion of the inflatable body within the vertebral body. The wall includes, when inflated, opposed side surfaces extending along an elongated longitudinal axis that is substantially aligned with the axis of the catheter. The inflatable body has a height of approximately 0.5 cm to 3.5 cm, an anterior to posterior dimension of approximately 0.5 cm to 3.5 cm, and a side to side dimension of approximately 0.5 cm to 5.0 cm.
[0044] In a representative embodiment, the inflatable body comprises a balloon and the cannula is a percutaneious cannula.
[0045] In another aspect of the invention, the wall includes changes in wall thickness which restrain the opposed sided surfaces from expanding beyond a substantially flat condition.
[0046] According to another aspect of the invention, the wall includes an internal restraint which restrains the opposed side surfaces from expanding beyond a substantially flat condition. The internal restraint may include a mesh material, a string material, a woven material, a seam, or an essentially non-elastic material.
[0047] In yet another aspect of the invention, the wall includes an external restraint which restrains the opposed side surfaces from expanding beyond a substantially flat condition. The internal restraint may include a mesh material, a string material, a woven material, a seam, or an essentially non-elastic material.
[0048] A primary goal of percutaneous proximal humeral augmentation is to create a cavity inside the proximal humerus whose configuration is optimal for supporting the proximal humerus. Another important goal is to help realign the humeral head with the shaft of the humerus when they are separated by a fracture. Both of these goals must be achieved by exerting pressure primarily on the cancellous bone, and not the cortical bone. Undue pressure against the cortical bone could conceivably cause a worsening of a shoulder fracture by causing cortical bone fractures.
[0049] The present invention satisfies these goals through the design of the inflatable devices to be described. Inflating such a device compresses the cancellous bone against the cortical walls of the epiphysis and metaphysis of the proximal humerus thereby creating a cavity. In some cases, depending on the fracture location, the balloon or inflatable device may be used to extend the cavity into the proximal part of the humeral diaphysis.
[0050] Due to the design of the “sphere on a stand” balloon (described as number 7 above), the cavity made by this balloon recreates or approximates the shape of the inside cortical wall of the proximal humerus. The approximate volume of the cavity made by the “spherical on a stand balloon” is 70 to 90% that of the proximal humeral epiphysis and metaphysis, primarily, but not necessarily exclusive of, part of the diaphysis. The shape approximates the shape of the humeral head. The “base” is designed to compress the trabecular bone into a “plug” of bone in the distal metaphysis or proximal diaphysis. This plug of bone will prevent the flow of injectable material into the shaft of the humerus, improving the clinical outcome. The sphere can also be used without a base.
[0051] A primary goal of percutaneous distal radius augmentation is to create a cavity inside the distal radius whose configuration is optimal for supporting the distal radius. Another important goal is to help fine tune fracture realignment after the fracture has been partially realigned by finger traps. Both of these goals must be achieved by exerting pressure primarily on the cancellous bone and not on the cortical bone. Excessive pressure against the cortical bone could conceivably cause cortical bone fractures, thus worsening the condition.
[0052] The present invention satisfies these goals through the design,of inflatable devices either already described or to be described.
[0053] The design of the “humpbacked banana”, or modified pyramid design (as described as number 5 above), approximates the shape of the distal radius and therefore, the cavity made by this balloon approximates the shape of the distal radius as well. The approximate volume of the cavity to be made by this humpbacked banana shaped balloon is 70 to 90% that of the distal radial epiphysis and metaphysis primarily of, but not necessarily exclusive of, some part of the distal radial diaphysis. Inflating such a device compresses the cancellous bone against the cortical walls of the epiphysis and metaphysis of the distal radius in order to create a cavity. In some cases, depending on the fracture location, the osseous balloon or inflatable device may be used to extend the cavity into the distal part of the radial diaphysis.
[0054] A primary goal of percutaneous femoral head (or humeral head) augmentation is to create a cavity inside the femoral head (or humeral head) whose configuration is optimal for supporting the femoral head. Another important goal is to help compress avascular (or aseptic) necrotic bone or support avascular necrotic bone is the femoral head. This goal may include the realignment of avascular bone back into the position it previously occupied in the femoral head in order to improve the spherical shape of the femoral head. These goals must be achieved by exerting pressure primarily on the cancellous bone inside the femoral head.
[0055] The present invention satisfied these goals through the design of inflatable devices either already described or to be described.
[0056] The design of the spherical osseous balloon (described as balloon type 4 above) approximates the shape of the femoral head and therefore creates a cavity which approximates the shape of the femoral head as well. (It should be noted that the spherical shape of this inflatable device also approximates the shape of the humeral head and would, in fact, be appropriate for cavity formation in this osseous location as well.) Inflating such a device compresses the cancellous bone of the femoral head against its inner cortical walls in order to create a cavity. In some cases, depending upon the extent of the avascular necrosis, a smaller or larger cavity inside the femoral head will be formed. In some cases, if the area of avascular necrosis is small, a small balloon will be utilized which might create a cavity only 10 to 15% of the total volume of the femoral head. If larger areas of the femoral head are involved with the avascular necrosis, then a larger balloon would be utilized which might create a much larger cavity, approaching 80 to 90% of the volume of the femoral head.
[0057] The hemispherical balloon approximates the shape of the top half of the femoral (and humeral) head, and provides a means for compacting cancellous bone in an area of avascular necrosis or small fracture without disturbing the rest of the head. This makes it easier to do a future total joint replacement if required.
[0058] A primary goal of percutaneous proximal tibial augmentation is to create a cavity inside the proximal tibia whose configuration is optimal for supporting either the medial or lateral tibial plateaus. Another important goal is to help realign the fracture fragments of tibial plateau fractures, particularly those features with fragments depressed below (or inferior to) their usual location. Both of these objectives must be achieved by exerting pressure on primarily the cancellous bone and not the cortical bone. Pressure on the cortical bone could conceivably cause worsening of the tibial plateau fracture.
[0059] The present invention satisfies these goals through the design of the inflatable devices to be described. Inflating such a device compresses the cancellous bone against the cortical walls of the medial or lateral tibial plateau in order to create a cavity.
[0060] Due to the design of the “elliptical cylinder” balloon (described as balloon type 6 above) the cavity made by this balloon recreates or approximates the shape of the cortical walls of either the medial or lateral tibial plateaus. The approximate volume of the cavity to be made by the appropriate elliptical cylindrical balloon is 50 to 90% of the proximal epiphyseal bone of either the medial half or the lateral half of the tibial.
[0061] Other objects of the present invention will become apparent as the following specification progresses, reference being had to the accompanying drawings for an illustration of the invention.
DESCRIPTION OF THE DRAWINGS
[0062] [0062]FIG. 1 is a perspective view of a first embodiment of the balloon of the present invention, the embodiment being in the shape of a stacked doughnut assembly.
[0063] [0063]FIG. 2 is a vertical section through the balloon of FIG. 1 showing the way in which the doughnut portions of the balloon of FIG. 1, fit into a cavity of a vertebral body.
[0064] [0064]FIG. 3 is a schematic view of another embodiment of the balloon of the present invention showing three stacked balloons and string-like restraints for limiting the expansion of the balloon in directions of inflation.
[0065] [0065]FIG. 4 is a top plan view of a spherical balloon having a cylindrical ring surrounding the balloon.
[0066] [0066]FIG. 5 is a vertical section through the spherical balloon and ring of FIG. 4.
[0067] [0067]FIG. 6 shows an oblong-shaped balloon with a catheter extending into the central portion of the balloon.
[0068] [0068]FIG. 6A is a perspective view of the way in which a catheter is arranged relative to the inner tubes for inflating the balloon of FIG. 6.
[0069] [0069]FIG. 7 is a suction tube and a contrast injection tube for carrying out the inflation of the balloon and removal of debris caused by expansion from the balloon itself.
[0070] [0070]FIG. 8 is a vertical section through a balloon after it has been deflated and as it is being inserted into the vertebral body of a human.
[0071] [0071]FIGS. 9 and 9A are side elevational views of a cannula showing how the protective sleeve or guard member expands when leaving the cannula.
[0072] [0072]FIG. 9B is a vertical section through a vertebral bone into which an access hole has been drilled.
[0073] [0073]FIG. 10 is a perspective view of another embodiment of the balloon of the present invention formed in the shape of a kidney bean.
[0074] [0074]FIG. 11 is a perspective view of the vertebral bone showing the kidney shaped balloon of FIG. 10 inserted in the bone and expanded.
[0075] [0075]FIG. 12 is a top view of a kidney shaped balloon formed of several compartments by a heating element or branding tool.
[0076] [0076]FIG. 13 is a cross-sectional view taken along line 13 - 13 of FIG. 12 but with two kidney shaped balloons that have been stacked.
[0077] [0077]FIG. 14 is a view similar to FIG. 11 but showing the stacked kidney shaped balloon of FIG. 13 in the vertebral bone.
[0078] [0078]FIG. 15 is a top view of a kidney balloon showing outer tufts holding inner strings in place interconnecting the top and bottom walls of the balloon.
[0079] [0079]FIG. 16 is a cross sectional view taken along lines 16 - 16 of FIG. 15.
[0080] [0080]FIG. 17A is a dorsal view of a humpback banana balloon in a right distal radius.
[0081] [0081]FIG. 17B is a cross sectional view of FIG. 17A taken along line 17 B- 17 B of FIG. 17A.
[0082] [0082]FIG. 18 is a spherical balloon with a base in a proximal humerus viewed from the front (anterior) of the left proximal humerus.
[0083] [0083]FIG. 19A is the front (anterior) view of the proximal tibia with the elliptical cylinder balloon introduced beneath the medial tibial plateau.
[0084] [0084]FIG. 19B is a three quarter view of the balloon of FIG. 19A.
[0085] [0085]FIG. 19C is a side elevational view of the balloon of FIG. 19A.
[0086] [0086]FIG. 19D is a top plan view of the balloon of FIG. 19A.
[0087] [0087]FIG. 20 is a spherically shaped balloon for treating avascular necrosis of the head of the femur (or humerus) as seen from the front (anterior) of the left hip.
[0088] [0088]FIG. 20A is a side view of a hemispherically shaped balloon for treating avascular necrosis of the head of the femur (or humerus).
DETAILED DESCRIPTION
[0089] Ballons For Vertebral Bodies
[0090] A first embodiment of the balloon (FIG. 1) of the present invention is broadly denoted by the numeral 10 and includes a balloon body 11 having a pair of hollow, inflatable, non-expandable parts 12 and 14 of flexible material, such as PET or Kevlar. Parts 12 and 14 have a suction tube 16 therebetween for drawing fats and other debris by suction into tube 16 for transfer to a remote disposal location. Catheter 16 has one or more suction holes so that suction may be applied to the open end of tube 16 from a suction source (not shown).
[0091] The parts 12 and 14 are connected together by an adhesive which can be of any suitable type. Parts 12 and 14 are doughnut-shaped as shown in FIG. 1 and have tubes 18 and 20 which communicate with and extend away from the parts 12 and 14 , respectively, to a source of inflating liquid under pressure (not shown). The liquid can be any sterile biocompatible solution. The liquid inflates the balloon 10 , particularly parts 12 and 14 thereof after the balloon has been inserted in a collapsed condition (FIG. 8) into a bone to be treated, such as a vertebral bone 22 in FIG. 2. The above-mentioned U.S. Pat. Nos. 4,969,888 and 5,108,404 disclose the use of a guide pin and cannula for inserting the balloon into bone to be treated when the balloon is deflated and has been inserted into a tube and driven by the catheter into the cortical bone where the balloon is inflated.
[0092] [0092]FIG. 8 shows a deflated balloon 10 being inserted through a cannula 26 into bone. The balloon in cannula 26 is deflated and is forced through the cannula by exerting manual force on the catheter 21 which extends into a passage 28 extending into the interior of the bone. The catheter is slightly flexible but is sufficiently rigid to allow the balloon to be forced into the interior of the bone where the balloon is then inflated by directing fluid into tube 88 whose outlet ends are coupled to respective parts 12 and 14 .
[0093] In use, balloon 10 is initially deflated and, after the bone to be filled with the balloon has been prepared to receive the balloon with drilling, the deflated balloon is forced into the bone in a collapsed condition through cannula 26 . The bone is shown in FIG. 2. The balloon is oriented preferably in the bone such that it allows minimum pressure to be exerted on the bone marrow and/or cancellous bone if there is no fracture or collapse of the bone. Such pressure will compress the bone marrow and/or cancellous bone against the inner wall of the cortical bone, thereby compacting the bone marrow of the bone to be treated and to further enlarge the cavity in which the bone marrow is to be replaced by a biocompatible, flowable bone material.
[0094] The balloon is then inflated to compact the bone marrow and/or cancellous bone in the cavity and, after compaction of the bone marrow and/or cancellous bone, the balloon is deflated and removed from the cavity. While inflation of the balloon and compaction occurs, fats and other debris are sucked out of the space between and around parts 12 and 14 by applying a suction force to catheter tube 16 . Following this, and following the compaction of the bone marrow, the balloon is deflated and pulled out of the cavity by applying a manual pulling force to the catheter tube 21 .
[0095] The second embodiment of the inflatable device of the present invention is broadly denoted by the numeral 60 and is shown in FIGS. 4 and 5. Balloon 60 includes a central spherical part 62 which is hollow and which receives an inflating liquid under pressure through a tube 64 . The spherical part is provided with a spherical outer surface 66 and has an outer periphery which is surrounded substantially by a ring shaped part 68 having tube segments 70 for inflation of part 68 . A pair of passages 69 interconnect parts 62 and 68 . A suction tube segment 72 draws liquid and debris from the bone cavity being formed by the balloon 60 .
[0096] Provision can be made for a balloon sleeve 71 for balloon 60 and for all balloons disclosed herein. A balloon sleeve 71 (FIG. 9) is shiftably mounted in an outer tube 71 a and can be used to insert the balloon 60 when deflated into a cortical bone. The sleeve 71 has resilient fingers 71 b which bear against the interior of the entrance opening 71 c of the vertebral bone 22 (FIG. 9A) to prevent tearing of the balloon. Upon removal of the balloon sleeve, liquid under pressure will be directed into tube 64 which will inflate parts 62 and 68 so as to compact the bone marrow within the cortical bone. Following this, balloon 60 is deflated and removed from the bone cavity.
[0097] [0097]FIGS. 6 and 6A show several views of a modified doughnut shape balloon 80 of the type shown in FIGS. 1 and 2, except the doughnut shapes of balloon 80 are not stitched onto one another. In FIG. 6, balloon 80 has a pear-shaped outer convex surface 82 which is made up of a first hollow part 84 and a second hollow part 85 . A tube 88 is provided for directing liquid into the two parts along branches 90 and 92 to inflate the parts after the parts have been inserted into the medullary cavity of a bone. A catheter tube 16 is inserted into the space 96 between two parts of the balloon 80 . An adhesive bonds the two parts 84 and 85 together at the interface thereof.
[0098] [0098]FIG. 6A shows the way in which the catheter tube 16 is inserted into the space or opening 96 between the two parts of the balloon 80 .
[0099] [0099]FIG. 7 shows tube 88 of which, after directing inflating liquid into the balloon 80 , can inject contrast material into the balloon 80 so that x-rays can be taken of the balloon with the inflating material therewithin to determine the proper placement of the balloon. Tube 16 is also shown in FIG. 6, it being attached in some suitable manner to the outer side wall surface of tube 88 .
[0100] Still another embodiment of the invention is shown in FIG. 3 which is similar to FIG. 1 except that it is round and not a doughnut and includes an inflatable device 109 having three balloon units 110 , 112 and 114 which are inflatable and which have string-like restraints 117 which limit the expansion of the balloon units in a direction transverse to the longitudinal axes of the balloon units. The restraints are made of the same or similar material as that of the balloon so that they have some resilience but substantially no expansion capability.
[0101] A tube system 115 is provided to direct liquid under pressure into balloon units 110 , 112 and 114 so that liquid can be used to inflate the balloon units when placed inside the bone in a deflated state. Following the proper inflation and compaction of the bone marrow, the balloon can be removed by deflating it and pulling it outwardly of the bone being treated. The restraints keep the opposed sides 77 and 79 substantially flat and parallel with each other.
[0102] In FIG. 10, another embodiment of the inflatable balloon is shown. The device is a kidney shaped balloon body 130 having a pair of opposed kidney shaped side walls 132 which are adapted to be collapsed and to cooperate with a continuous end wall 134 so that the balloon 130 can be forced into a bone 136 shown in FIG. 11. A tube 138 is used to direct inflating liquid into the balloon to inflate the balloon and cause it to assume the dimensions and location shown vertebral body 136 in FIG. 11. Device 130 will compress the cancellous bone if there is no fracture or collapse of the cancellous bone. The restraints for this action are due to the side and end walls of the balloon.
[0103] [0103]FIG. 12 shows a balloon 140 which is also kidney shaped and has a tube 142 for directing an inflatable liquid into the tube for inflating the balloon. The balloon is initially a single chamber bladder but the bladder can be branded along curved lines or strips 141 to form attachment lines 144 which take the shape of side-by-side compartments 146 which are kidney shaped as shown in FIG. 13. The branding causes a welding of the two sides of the bladder to occur since the material is standard medical balloon material, which is similar to plastic and can be formed by heat.
[0104] [0104]FIG. 14 is a perspective view of a vertebral body 147 containing the balloon of FIG. 12, showing a double stacked balloon 140 when it is inserted in vertebral bone 147 .
[0105] [0105]FIG. 15 is a view similar to FIG. 10 except that tufts 155 , which are string-like restraints, extend between and are connected to the side walls 152 of inflatable device 150 and limit the expansion of the side walls with respect to each other, thus rendering the side walls generally parallel with each other. Tube 88 is used to fill the kidney shaped balloon with an inflating liquid in the manner described above.
[0106] The dimensions for the vertebral body balloon will vary across a broad range. The heights (H, FIG. 11) of the vertebral body balloon for both lumbar and thoracic vertebral bodies typically range from 0.5 cm to 3.5 cm. The anterior to posterior (A, FIG. 11) vertebral body balloon dimensions for both lumbar and thoracic vertebral bodies range from 0.5 cm to 3.5 cm. The side to side (L, FIG. 11) vertebral body dimensions for thoracic vertebral bodies will range from 0.5 cm to 3.5 cm. The side to side vertebral body dimensions for lumbar vertebral bodies will range from 0.5 cm to 5.0 cm.
[0107] The eventual selection of the appropriate balloon for, for instance, a given vertebral body is based upon several factors. The anterior-posterior (A-P) balloon dimension for a given vertebral body is selected from the CT scan or plain film x-ray views of the vertebral body. The A-P dimension is measured from the internal cortical wall of the anterior cortex to the internal cortical wall of the posterior cortex of the vertebral body. In general, the appropriate A-P balloon dimension is 5 to 7 millimeters less than this measurement.
[0108] The appropriate side to side balloon dimensions for a given vertebral body is selected from the CT scan or from a plain film x-ray view of the vertebral body to be treated. The side to side distance is measured from the internal cortical walls of the side of the vertebral bone. In general, the appropriate side to side balloon dimension is 5 to 7 millimeters less than this measurement by the addition of the lumbar vertebral body tends to be much wider than side to side dimension then their A-P dimension. In thoracic vertebral bodies, the side to side dimension and their A-P dimensions are almost equal.
[0109] The height dimensions of the appropriate vertebral body balloon for a given vertebral body is chosen by the CT scan or x-ray views of the vertebral bodies above and below the vertebral body to be treated. The height of the vertebral bodies above and below the vertebral body to be treated are measured and averaged. This average is used to determine the appropriate height dimension of the chosen vertebral body balloon.
[0110] Ballons for Long Bones
[0111] Long bones which can be treated with the use of balloons of the present invention include distal radius (larger arm bone at the wrist), proximal tibial plateau (leg bone just below the knee), proximal humerus (upper end of the arm at the shoulder), and proximal femoral head (leg bone in the hip).
[0112] Distal Radius Balloon
[0113] For the distal radius, a balloon 160 is shown in the distal radius 152 and the balloon has a shape which approximates a pyramid but more closely can be considered the shape of a humpbacked banana in that it substantially fills the interior of the space of the distal radius to force cancellous bone 154 lightly against the inner surface 156 of cortical bone 158 .
[0114] The balloon 160 has a lower, conical portion 159 which extends downwardly into the hollow space of the distal radius 152 , and this conical portion 159 increases in cross section as a central distal portion 161 is approached. The cross section of the balloon 160 is shown at a central location (FIG. 17B) and this location is near the widest location of the balloon. The upper end of the balloon, denoted by the numeral 162 , converges to the catheter 88 for directing a liquid into the balloon for inflating the same to force the cancellous bone against the inner surface of the cortical bone. The shape of the balloon 160 is determined and restrained by tufts formed by string restraints 165 . These restraints are optional and provide additional strength to the balloon body 160 , but are not required to achieve the desired configuration. The balloon is placed into and taken out of the distal radius in the same manner as that described above with respect to the vertebral bone.
[0115] The dimensions of the distal radius balloon vary as follows:
[0116] The proximal end of the balloon (i.e. the part nearest the elbow) is cylindrical in shape and will vary from 0.5.times.0.5 cm to 1.8.times.1.8 cm.
[0117] The length of the distal radius balloon will vary from 1.0 cm to 12.0 cm.
[0118] The widest medial to lateral dimension of the distal radius balloon, which occurs at or near the distal radio-ulnar joint, will measure from 1.0 cm to 2.5 cm.
[0119] The distal anterior-posterior dimension of the distal radius balloon will vary from 0.5 to 3.0 cm.
[0120] Proximal Humerus Fracture Balloon
[0121] The selection of the appropriate balloon size to treat a given fracture of the distal radius will depend on the radiological size of the distal radius and the location of the fracture.
[0122] In the case of the proximal humerus 169 , a balloon 166 shown in FIG. 18 is spherical and has a base design. It compacts the cancellous bone 168 in a proximal humerus 169 . A mesh 170 , embedded or laminated and/or winding, may be used to form a neck 172 on the balloon 166 , and second mesh 170 a may be used to conform the bottom of the base 172 a to the shape of the inner cortical wall at the start of the shaft. These restraints provide additional strength to the balloon body, but the configuration can be achieved through molding of the balloon body. This is so that the cancellous bone will be as shown in the compacted region surrounding the balloon 166 as shown in FIG. 18. The cortical bone 173 is relatively wide at the base 174 and is thin-walled at the upper end 175 . The balloon 166 has a feed tube 177 into which liquid under pressure is forced into the balloon to inflate it to lightly compact the cancellous bone in the proximal humerus. The balloon is inserted into and taken out of the proximal humerus in the same manner as that described above with respect to the vertebral bone.
[0123] The dimensions of the proximal humerus fracture balloon vary as follows:
[0124] The spherical end of the balloon will vary from 1.0.times.1.0 cm to 3.0.times.3.0 cm.
[0125] The neck of the proximal humeral fracture balloon will vary from 0.8.times.0.8 cm to 3.0.times.3.0 cm.
[0126] The width of the base portion or distal portion of the proximal numeral fracture balloon will vary from 0.5.times.0.5 cm to 2.5.times.2.5 cm.
[0127] The length of the balloon will vary from 4.0 cm to 14.0 cm.
[0128] The selection of the appropriate balloon to treat a given proximal humeral fracture depends on the radiologic size of the proximal humerus and the location of the fracture.
[0129] Proximal Tibial Plauteau Fracture Balloon
[0130] The tibial fracture is shown in FIG. 19A in which a balloon 180 is placed in one side 182 of a tibia 183 . The balloon, when inflated, compacts the cancellous bone in the layer 184 surrounding the balloon 180 . A cross section of the balloon is shown in FIG. 19C wherein the balloon has a pair of opposed sides 185 and 187 which are interconnected by restraints 188 which can be in the form of strings or flexible members of any suitable construction. The main purpose of the restraints is to make the sides 185 and 187 substantially parallel with each other and non-spherical. A tube 190 is coupled to the balloon 180 to direct liquid into and out of the balloon. The ends of the restraints are shown in FIGS. 19B and 19D and denoted by the numeral 191 . The balloon is inserted into and taken out of the tibia in the same manner as that described above with respect to the vertebral bone. FIG. 19B shows a substantially circular configuration for the balloon; whereas, FIG. 19D shows a substantially elliptical version of the balloon.
[0131] The dimensions of the proximal tibial plateau fracture balloon vary as follows:
[0132] The thickness or height of the balloon will vary from 0.5 cm to 5.0 cm.
[0133] The anterior/posterior (front to back) dimension will vary from 1.0 cm to 6.0 cm.
[0134] The side to side (medial to lateral) dimension will vary from 1.0 cm to 6.0 cm.
[0135] The selection of the appropriate balloon to treat a given tibial plateau fracture will depend on the radiological size of the proximal tibial and the location of the fracture.
[0136] Femoral Head Balloon
[0137] In the case of the femoral head, a balloon 200 is shown as having been inserted inside the cortical bone 202 of the femoral head which is thin at the outer end 204 of the femur and which can increase in thickness at the lower end 206 of the femur. The cortical bone surrounds the cancellous bone 207 and this bone is compacted by the inflation of balloon 200 . The tube for directing liquid for inflation purposes into the balloon is denoted by the numeral 209 . It extends along the femoral neck and is directed into the femoral head which is generally spherical in configuration. FIG. 20A shows that the balloon, denoted by the numeral 200 a , can be hemispherical as well as spherical, as shown in FIG. 20. The balloon 200 is inserted into and taken out of the femoral head in the same manner as that described with respect to the vertebral bone. The hemispherical shape is maintained in this example by bonding overlapping portions of the bottom, creating pleats 200 b as shown in FIG. 20A.
[0138] The dimensions of the femoral head balloon vary as follows:
[0139] The diameter of the femoral head balloon will vary from 1.0 cm to up to 4.5 cm. The appropriate size of the femoral head balloon to be chosen depends on the radiological or CT scan size of the head of the femur and the location and size of the avascular necrotic bone. The dimensions of the hemispherical balloon are the same as the those of the spherical balloon, except that approximately one half is provided. | A balloon for use in compressing cancellous bone and marrow (also known as medullary bone or trabecular bone) against the inner cortex of bones whether the bones are fractured or not. The balloon comprises an inflatable, non-expandable balloon body for insertion into said bone. The body has a shape and size to compress at least a portion of the cancellous bone to form a cavity in the cancellous bone and to restore the original position of the outer cortical bone, if fractured or collapsed. The balloon is prevented from applying excessive pressure to the outer cortical bone. The wall or walls of the balloon are such that proper inflation the balloon body is achieved to provide for optimum compression of all the bone marrow. The balloon is able to be folded so that it can be inserted quickly into a bone. The balloon can be made to have a suction catheter. The main purpose of the balloon is the forming or enlarging of a cavity or passage in a bone, especially in, but not limited to, vertebral bodies. | 53,261 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a detector of quantity of electricity for detecting a value of amplitude of quantity of electricity of AC voltage, AC current and the like, particularly to improvement of frequency characteristics thereof.
2. Description of Related Art
FIG. 1 is a figure explaining a principle of a conventional digital processing apparatus of a quantity of AC electricity disclosed in Japanese Patent Application No. 62-333434, the value of amplitude being determined by using three data which have been sampled with electrical angle 90° of AC current being sampling cycle T. In the figure, assuming that a sampling value 1 of an appropriate time is i(O), a sampling value 2 preceding one cycle (T) being i(T), a sampling value 3 preceding two cycles (2T) being i(2T), sampling values 1˜3 are squared, by square operating means 5˜7 respectively, and only the result of the square operating means 6 is doubled by a double operating means 29.
The results obtained at aforesaid square operating means 5 and 7 are added to the result of aforesaid double operating means 29 by an adder means 11 so as to obtain the sum. The sum is divided by 2 by a divide operating means 30 and the square root is calculated by a square root operating means 13 to obtain, at a terminal 14, the output Fn thereof, being the value of amplitude of AC current.
Next, explanation will be given on the operation. For the convenience sake of the explanation, the quantity of AC electricity is assumed to be AC current, maximum value I, instantaneous magnitude i, fundamental blade frequency fo, and the sampling cycle T whose cycle is made to be 1/4 of the fundamental blade frequency fo. And in order to distinguish data at a sampling time, assuming that nT (where n =0, 1, 2, . . . , and n=0 being this time) is suffix, the sampling value of the appropriate time are expressed to be i(O), the sampling value preceding one cycle from the appropriate time to be i(T), and the sampling value preceding two cycles from the appropriate time to be i(2T). . . respectively.
When output Fn is expressed in any formula, the following first formula is obtained. ##EQU1##
The sampling cycle T is fixed to 1/4 cycle relative to where the fundamental frequency of the AC current, that is, a time period which corresponds to electrical angle 90°, however, where the frequency of the sampling time is f, the sampling cycle T is expressed as in the second formula. ##EQU2##
For example, the frequency of the AC current is f=fo =50 Hz, the sampling cycle T=90° is established.
Generally, as an electric power system is operated by rated frequency fo, in formula (1), Fn=I is obtained, thereby the amplitude value of the current can be calculated, which, for example, is used for such as an AC excess current protection relay and a control apparatus. But, for the protection relay for detecting accidents being happened in the electric power system and for the control apparatus for detecting the quantity of electricity for controlling an operation apparatus, there are many cases where the frequency of the electric power system has changed from fo. But, even if there is some dislocation of frequency of the electric power system, there is a need to determine the value of amplitude accurately. Generally, in order to cope with the change of ±5% of the frequency, it is necessary to lessen errors as much as possible.
Now, assuming that the frequency f=52.5 Hz (increase of 5% of 50 Hz), formula T=94.5° is obtained. When it is substituted in formula (1), the following formula is established:
Fn=I{1-0.0062cos(2θ-189°)}.sup.1/2 ( 3).
Such result is obtained as that the constant value is degenerated by the amplitude waveform of double cycle. Since cos(2θ-189°) can be changed from +1.0 to -1.0, the formula (3) becomes as
Fn=0.997I˜1.003I (4),
thereby, the error of -0.3% to 0.3% is created compared with that of the operation of the amplitude value at the time when the rated frequency is 50 Hz.
Because the conventional detector of quantity of electricity is so constructed as above, there is a problem that the calculation of error of amplitude value is relatively larger in the case where the frequency varies to the extent of about ±5%.
SUMMARY OF THE INVENTION
The present invention has been devised to solve such a problem as mentioned above.
The primary object of the invention is to provide a detector of quantity of electricity which is capable of lessen the detected error of the amplitude value of quantity of AC electricity on the basis of four sampling values of quality of AC electricity.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing showing a conception of detecting principle of the conventional detector of quantity of electricity.
FIG. 2 is a block diagram showing a construction of the detector of quantity of electricity.
FIG. 3 is a drawing showing a conception of detecting principle of the detector of quantity of electricity of the present invention, and
FIG. 4 is a graph which compares the detected accuracy of the conventional detector of quantity of electricity with the one that of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An explanation will now be given on an embodiment of the present invention referring to the drawings.
FIG. 2 is a block diagram showing a hardware construction of the detector of quantity of electricity 28 for executing aforesaid calculation of amplication value. In the figure, reference numeral 15 is a potential transformer, 16 being a current transformer, 17 and 18 being input transformers for converting the values of voltage and current of the electric power system so that they can be processed easily, and reference numerals 19 and 20 being filters for removing frequency at more than a half of the sampling frequency out of such high frequency as included in the voltage and current, as well known. Numerals 21 and 22 are sample-and-hold circuits for holding the sampling value until the next sampling cycle. Numeral 23 is a multiplexer for sequentially switching the outputs of the sample-and-hold circuits so as to transmit them to an analog-digital converter 24. Numeral 25 is a microprocessor for executing calculation by using the program being previously stored in a memory 26, the result thereof being outputted to an output circuit 27.
FIG. 3 is a conceptual diagram showing a principle of detecting the quantity of electricity by the detector of quantity of electricity 28. The sampling values 1˜4, at the time t-nt (n=0, 1, 2, 3) which is separated cycles being required for obtaining the predetermined sampling number n according to the time t, are assumed to be i(O), i(T), i(2T), and i(3T), and the sampling values 1˜4 are squared by the square calculating means 5˜8, respectively, only the result of the square calculating means 6 and 7 being tripled by triple calculating means 9 and 10.
The result being obtained by aforesaid square calculating means 5 and 8, are added to the result of aforesaid triple calculating means 9 and 10 by the adding means 11 so as to obtain the sum. Then the sum is divided by 4 by a division calculating means 12 so as to obtain the square root by a square root calculating means 13. The result is obtained to be as the output Fn at a terminal 14.
The above operation is expressed in such formula (5) as follows: ##EQU3## At the sampling time, in the case where the frequency f=52.5 Hz (increase of 5% of 50 Hz), such formula as T=94.5° is obtained. When this is substituted into the formula (5), the following formula (6) is obtained:
Fn=I[1-cos.sup.3 (94.5°)·cos(2θ-3×94.5°)].sup.1/2 =I[1+4.83×10.sup.-4 cos(2θ-283.5°)].sup.1/2(6)
This formula expresses that the amplitude relative to I is to be as 4.83×10 -4 and the amplitude wave form of double frequency is degenerated. Since cos(2θ-283.5°) can be changed from +1.0 to -1.0, the following formula is established:
Fn=0.99976I˜1.00024I (7)
When this is compared with the calculation of amplitude value at 50 Hz of the rated frequency, the error is to be such minimum value as -0.024% to +0.024%.
The result of calculation of the amplitude value Fn obtained here (not shown) is compared with the predetermined value (also called setting value) by a comparison calculating means so as to compare which is larger, thereby detecting accidents to the electric power system by the digital protection relay. And according to the obtained Fn, the control apparatus (not shown) is used for such as on-off control of a static capacitor and the like.
In addition, the above explanation has made on such arrangement as that the output of the adding means 11 is processed by the division calculating means 12 and the square root calculating means 13, however, aforesaid square calculating means 13 is dispensable, if the preset values of the digital protection relay and the control apparatus are set at the values which have been obtained by squaring the predetermined value (setting value). And, if the preset value is set at the value which has been obtained by squaring the predetermined value (setting value) and then quadrupling, aforesaid division calculating means 12 and aforesaid square root calculating means 13 become dispensable.
In addition, in aforesaid embodiment, the outputs of the square calculating means 6 and 7 are adapted to be tripled by triple calculating means 9 and 10 respectively, however, such change of the well-known operation law as to calculate the sum of the square calculating means 6 and 7 and then triple the sum, is not restricted in any way.
Next will be explained the change status of Fn being the result of calculation of the amplitude value in the case where the frequency is varied.
When the ratio of the frequency f after the change to the rated frequency fo is expressed as the formula m=f/fo, formula (8) is obtained from formulas (2) and (5).
Fn=I[1-cos.sup.3 (T)·cos(2θ-3T)].sup.1/2 =I[1-cos.sup.3 (90° m)·cos(2θ-3×90° m)].sup.1/2(8)
When m in the formula (8) is varied and displayed, which is shown in the portion of oblique lines in FIG. 4, and in the vicinity of m=1 (f=fo), the change of the size of the portion is scarcely to be seen, thereby it can be clear that the error of the calculated result of the amplitude value becomes minimum.
In the same way, formula (9) is obtained by expressing the conventional formula (1) with such formula of m as described above, and dotted lines in FIG. 4 show that the calculation processing of the present invention obviously has less error.
Fn=I[1-cos.sup.2 (90° m)·cos(2θ-2×90° m)].sup.1/2 (9)
In addition, since the sampling value used in the calculation of amplitude value is realized with four sampling values including that at the predetermined time, the result can be obtained with the time period corresponding to 90°×4=360°, thereby the present invention can realize to obtain the result at a high speed practically the same as that in the conventional apparatus, and also generally the same quantity of memory necessary for calculation processing can be realized.
Furthermore, explanation has been given on the embodiment above mentioned in order to calculate the amplitude value of the AC current. The AC current at that time is the same as a phase current and a line-to-line current of the electric power system, or a symmetrical component obtained from aforesaid phase current and line-to-line current, that is, a positive phase current, a negative current or a zero phase current.
Moreover, the AC voltage can also has the same effect by applying it in the same way.
As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the meets and bounds of the claims, or equivalence of such meets and bounds thereof are therefore intended to be embraced by the claims. | A detector of quantity of electricity of the invention for detecting an amplitude value from the quantity of AC electricity, comprising sampling means for sampling the quantity of AC electricity at a cycle T which is 1/4 of the rated cycle of quantity of AC electricity, and operating means for operating the amplitude value on the basis of the sampling values, operates with the following formula:
y(o).sup.2 +3·{y(T).sup.2 +y(2T).sup.2 }+y(3T).sup.2
where, y(t-nT) is expressed as y(nT). | 12,738 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to Provisional Serial No. 60/046,006, filed May 9, 1997, under 35 U.S.C. Section 119(e).
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
This invention was supported in part by the National Science Foundation under Grant No. ECD-8907068. The United States Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed generally to high density magnetic recording sequence detectors, and, more particularly, to correlation-sensitive sequence detectors.
2. Description of the Background
In recent years, there has been a major shift in the design of signal detectors in magnetic recording. Traditional peak detectors (PD), such as those described in Nakagawa et al., “A Study of Detection Methods of NRZ Recording”, IEEE Trans. Magn., vol. 16, pp. 1041-110, Jan. 1980, have been replaced by Viterbi-like detectors in the form of partial response maximum likelihood (PRML) schemes or hybrids between tree/trellis detectors and decision feedback equalizers (DFE), such as FDTS/DF, MDFE and RAM-RSE. These methods were derived under the assumption that additive white Gausian noise (AWGN) is present in the system. The resulting trellis/tree branch metrics are then computed as Euclidian distances.
It has long been observed that the noise in magnetic recording systems is neither white nor stationary. The nonstationarity of the media noise results from its signal dependent nature. Combating media noise and its signal dependence has thus far been confined to modifying the Euclidian branch metric to account for these effects. Zeng, et al., “Modified Viterbi Algorithm for Jitter-Dominated 1-D 2 Channel,” IEEE Trans. Magn., Vol. MAG-28, pp. 2895-97, Sept. 1992, and Lee et al., “Performance Analysis of the Modified maximum Likelihood Sequence Detector in the Presence of Data-Dependent Noise,” Proceedings 26th Asilomar Conference, pp. 961-64, Oct. 1992 have derived a branch metric computation method for combating the signal-dependent character of media noise. These references ignore the correlation between noise samples. The effectiveness of this method has been demonstrated on real data in Zayad et al., “Comparison of Equalization and Detection for Very High-Density Magnetic Recording,” IEEE INTERMAG Conference, New Orleans, April 1997.
These methods do not take into consideration the correlation between noise samples in the readback signal. These correlations arise due to noise coloring by front-end equalizers, media noise, media nonlinearities, and magnetoresistive (MR) head nonlinearities. This noise coloring causes significant performance degradation at high recording densities. Thus, there is a need for an adaptive correlation-sensitive maximum likelihood sequence detector which derives the maximum likelihood sequence detector (MLSD) without making the usual simplifying assumption that the noise samples are independent random variables.
SUMMARY OF THE INVENTION
In high density magnetic recording, noise samples corresponding to adjacent signal samples are heavily correlated as a result of front-end equalizers, media noise, and signal nonlinearities combined with nonlinear filters to cancel them. This correlation deteriorates significantly the performance of detectors at high densities.
The trellis/tree branch metric computation of the present invention is correlation-sensitive, being both signal-dependent and sensitive to correlations between noise samples. This method is termed the correlation-sensitive maximum likelihood sequence detector (CS-MLSD), or simply correlation-sensitive sequence detector (CS-SD).
Because the noise statistics are non-stationary, the noise sensitive branch metrics are adaptively computed by estimating the noise covariance matrices from the read-back data. These covariance matrices are different for each branch of the tree/trellis due to the signal dependent structure of the media noise. Because the channel characteristics in magnetic recording vary from track to track, these matrices are tracked on-the-fly, recursively using past samples and previously made detector decisions.
The present invention represents a substantial advance over prior sequence detectors. Because the present invention takes into account the correlation between noise samples in the readback signal, the detected data sequence is detected with a higher degree of accuracy. Those advantages and benefits of the present invention, and others, will become apparent from the Detailed Description of the Invention hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
For the present invention to be clearly understood and readily practiced, the present invention will be described in conjunction with the following figures wherein:
FIG. 1 is an illustration of a magnetic recording system;
FIG. 2 is an illustration of a CS-MLSD detector circuit of a preferred embodiment of the present invention;
FIG. 3 is an illustration of a sample signal waveform, its samples, and written symbols;
FIG. 3A is an illustration of a branch metric computation module;
FIG. 3B is an illustration of an implementation of a portion of the branch metric computation module of FIG. 3A;
FIG. 4 is an illustration of one cell of a PR4 trellis;
FIG. 5 is an illustration of a detected path in a PR4 trellis;
FIG. 6 is a block diagram of a preferred embodiment of a method for signal detection;
FIG. 7 is an illustration of PR4 detection results at a 4.4 a/symbol;
FIG. 8 is an illustration of EPR4 detection results at a 4.4 a/symbol;
FIG. 9 is an illustration of PR4 detection results at a 3.5 a/symbol;
FIG. 10 is an illustration of EPR4 detection results at a 3.5 a/symbol;
FIG. 11 is an illustration of S(AWG)NR margins needed for error rate of 10 −5 with EPR4 detectors;
FIG. 12 is an illustration of PR4 detection results at a 2.9 a/symbol; and
FIG. 13 is an illustration of EPR 4 detection results at a 2.9 a/symbol.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a magnetic recording system 10 . A data source 12 supplies data to a write signal processing circuit 14 . The signal processing circuit 14 converts the input data into signals with a format suitable for storage on a magnetic medium 16 . The medium 16 is typically a rotating disk, a “floppy” disk, or a tape with magnetic coatings. A write head 18 stores the signals on the medium 16 as a series of variations in the magnetic flux of the medium 16 . The write head 18 is controlled by a write control circuit 20 , which supplies signals to the write head 18 to control its position with respect to the medium 16 .
A read head 22 retrieves the variations in the magnetic flux that are stored on the medium 16 . A read control circuit 24 supplies signals to the read head 22 to control its position with respect to the medium 16 . The read head 22 provides a stream of data to a detector circuit 26 . The detector circuit 26 detects the data from the data stream and outputs the data. The detector 26 must be able to detect the data in the presence of intersymbol interference (“ISI”) noise. Prior art detector circuits have employed the maximum likelihood sequence (“MLS”) estimation algorithm or peak detection techniques. The MLS algorithm analyzes a sequence of consecutive data and determines the output data based on the sequence. Peak detection techniques identify analog peaks in a sequence of data and determine the output data based on the peaks.
A block diagram of a CS-MLSD detector circuit 28 is shown in FIG. 2 . The CS-MLSD detector circuit 28 is a part of the detector circuit 26 of FIG. 1 . The detector circuit 28 has a feedback circuit 32 which feeds back into a Viterbi-like detector 30 . The outputs of the detector 30 are decisions and delayed signal samples, which are used by the feedback circuit 32 . A noise statistics tracker circuit 34 uses the delayed samples and detector decisions to update the noise statistics, i.e., to update the noise covariance matrices. A metric computation update circuit 36 uses the updated statistics to calculate the branch metrics needed in the Viterbi-like algorithm. The algorithm does not require replacing current detectors. It simply adds two new blocks in the feedback loop to adaptively estimate the branch metrics used in the Viterbi-like detector 30 .
The Viterbi-like detector 30 typically has a delay associated with it. Until the detector circuit 28 is initialized, signals of known values may be input and delayed signals are not output until the detector circuit 28 is initialized. In other types of detectors, the detector may be initialized by having the necessary values set.
The correlation-sensitive maximum likelihood sequence detector (CS-MLSD) 28 is described hereinbelow. Assume that N>1 channel bits (symbols), a 1 , a 2 , . . . , a N , are written on a magnetic medium. The symbols a i , i=1, . . . , N, are drawn from an alphabet of four symbols, a i , ε {+, ⊕, −, ⊖}. The symbols ‘+’ and ‘−’ denote a positive and a negative transition, respectively. The symbol ‘⊕’ denotes a written zero (no transition) whose nearest preceding non-zero symbol is a ‘+’ while ‘⊖’ denotes a written zero whose nearest preceding transition is a negative one, i.e., ‘−’. This notation is used because a simple treatment of transitions as ‘1’s and no transitions as ‘0’s is blind to signal asymmetries (MR head asymmetries and base line drifts), which is inappropriate for the present problem. In FIG. 3 a sample waveform is illustrated. The signal asymmetries and base line shifts are exaggerated in FIG. 3 . FIG. 3 also shows the written symbols a 1 , . . . , a 18 , as well as the samples r 1 , . . . , r 18 of the read-back waveform, sampled at the rate of one sample per symbol interval.
When the written sequence of symbols a i , i=1, . . . , N, is read, the readback waveform is passed through a pulse-shaping equalizer and sampled one sample per symbol, resulting in the sequence of samples r i , i=1, . . . , N. Due to the noise in the system, the samples r i are realizations of random variables. The maximum likelihood detector determines the sequence of symbols a i that has been written, by maximizing the likelihood function, i.e.: { a ^ 1 , … , a ^ N } = arg [ max all a i f ( r 1 , … , r N a 1 , … , a N ) ] . ( 1 )
In (1), the likelihood function f (r 1 , . . . , r N |a 1 , . . . , a N ) is the joint probability density function (pdf) of the signal samples r 1 , . . . , r N , conditioned on the written symbols a, . . . , a N . The maximization in (1) is done over all possible combinations of symbols in the sequence {a 1 , . . . , a N }.
Due to the signal dependent nature of media noise in magnetic recording, the functional form of joint conditional pdf f (r 1 , . . . , r N |a 1 ,. . . , a N ) in (1) is different for different symbol sequences a 1 , . . . , a N . Rather than making this distinction with more complex but cluttered notation, the notation is kept to a minimum by using simply the same symbol f to denote these different functions.
By Bayes rule, the joint conditional pdf (likelihood function) is factored into a product of conditional pdfs: f ( r 1 , … , r N a i , … , a N ) = ∏ i = 1 N f ( r i r i + 1 , … , r N , a 1 , … , a N ) . ( 2 )
To proceed and obtain more concrete results, the nature of the noise and of the intersymbol interference in magnetic recording is exploited.
Finite correlation length. The conditional pdfs in Equation (2) are assumed to be independent of future samples after some length L≧0. L is the correlation length of the noise. This independence leads to:
f ( r i |r i+1 , . . . , r N , a 1 , . . . , a N )= f ( r i |r i+1 , . . . , r i+L , a 1 , . . . , a N ). (3)
Finite intersymbol interference. The conditional pdf is assumed to be independent of symbols that are not in the K-neighborhood of r i , . . . , r i+L . The value of K≧1 is determined by the length of the intersymbol interference (ISI). For example, for PR4, K=2, while for EPR4, K=3. K 1 ≧0 is defined as the length of the leading (anticausal) ISI and K t ≧0 is defined as the length of the trailing (causal) ISI, such that K=K l +K t +1. With this notation the conditional pdf in (3) can be written as:
f ( r i |r i+1 , . . . , r i+L , a 1 , . . . , a N )= f ( r i |r i+1 , . . . r i+L a i−K t ). (4)
Substituting (4) into (2) and applying Bayes rule, the factored form of the likelihood function (conditional pdf) is obtained: ( 5 ) f ( r 1 , … , r N | a i , … , a N ) = ∏ i = 1 N f ( r i r i + 1 , … , r N , a 1 , … , a N ) = ∏ i = 1 N f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) .
The factored form of equation (5) is suitable for applying Viterbi-like dynamic programming detection techniques. Equation (5) assumes anticausal factorization, i.e., it is derived by taking into account the effect of the samples r i+1 , . . . , r i+L , on r i . If only the causal effects are taken into account, the causal equivalent of (5) can be derived as f (r 1 , . . . r N ,|a 1 , . . . , a N )= ∏ i = 1 N f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i + 1 , … , r i + L - 1 a i - K l , … , a i + L + K t )
The causal and anticausal factorization could be combined to find the geometric mean of the two to form a causal-anticausal factorization. Since this only complicates derivations and does not provide further insight, only the anticausal Equation (5) is considered.
Maximizing the likelihood function in (5) is equivalent to minimizing its negative logarithm. Thus, the maximum likelihood detector is now: ( 6 ) { a ^ 1 , … , a ^ N } = arg [ min all a i log ∏ i = 1 N f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) ] = arg [ min all a i ∑ i = 1 N log f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) ] = arg [ min all a i ∑ i = 1 N M i ( r i , r i + 1 , … , r i + L , a i - K l , … , a i + L + K t ) ]
M i represents the branch metric of the trellis/tree in the Viterbi-like algorithm. The metric is a function of the observed samples r i , r i+1 , . . . , r i+L . It is also dependent on the postulated sequence of written symbols a i −K 1 ,. . . , a i +L+K t , which ensures the signal-dependence of the detector. As a consequence, the branch metrics for every branch in the tree/trellis is based on its corresponding signal/noise statistics.
Specific expressions for the branch metrics that result under different assumptions on the noise statistics are next considered.
Euclidian branch metric. In the simplest case, the noise samples are realizations of independent identically distributed Gaussian random variables with zero mean and variance σ 2 . This is a white Gaussian noise assumption. This implies that the correlation distance is L=0 and that the noise pdf s have the same form for all noise samples. The total ISI length is assumed to be K=K l +K t +1, where K l and K t are the leading and trailing ISI lengths, respectively. The conditional signal pdfs are factored as f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) = 2 πσ 2 exp [ ( r i - m i ) 2 2 σ 2 ] ( 7 )
Here the mean signal m i is dependent on the written sequence of symbols. For example, for a PR4 channel, m i ε{−1,0,1}. The branch/tree metric is then the conventional Euclidian distance metric:
M i =N i 2 =(r i −m i ) 2 (8)
Variance dependent branch metric. It is again assumed that the noise samples are samples of independent Gaussian variables, but that their variance depends on the written sequence of symbols. The noise correlation length is still L=0, but the variance of the noise samples is no longer constant for all samples. The variance is σ 2i , where the index i denotes the dependence on the written symbol sequence. As for the Euclidian metric, it is assumed that the total ISI length is K=K l +K t +1. The conditional signal pdf is factored to give: f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) = 2 πσ i 2 exp [ ( r i - m i ) 2 2 σ i 2 ] ( 9 )
The corresponding branch metric is: M i = log σ i 2 + N i 2 σ i 2 = log σ i 2 + ( r i - m i ) 2 σ i 2 ( 10 )
Correlation-sensitive branch metric. In the most general case, the correlation length is L>0. The leading and trailing ISI lengths are K l and K t , respectively. The noise is now considered to be both correlated and signal-dependent. Joint Gaussian noise pdfs are assumed. This assumption is well justified in magnetic recording because the experimental evidence shows that the dominant media noise modes have Gaussian-like histograms. The conditional pdfs do not factor out in this general case, so the general form for the pdf is: f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) = ( 2 π ) L + 1 det C i ( 2 π ) L det c i exp [ N _ i T C i - 1 N _ i ] exp [ n _ i T c i - 1 n _ i ] ( 11 )
The (L+1)×(L+1) matrix C i is the covariance matrix of the data samples r i , r i+1 , . . . , r i+L , when a sequence of symbols a i−Kl , . . . a i+L+Kt is written. The matrix c i in the denominator of (11) is the L×L lower principal submatrix of C i =[c i ]. The (L+1)-dimensional vector N i is the vector of differences between the observed samples and their expected values when the sequence of symbols a i−Kl , . . . , a i+L+Kt is written, i.e.:
N i =[( r i −m i )( r i+1 −m i+1 ) . . . ( r i+L −m i+L )] T (12)
The vector n i collects the last L elements of N i , n i =[(r i+1 −m i+1 ) . . . (r i+L −m i+L )] T .
With this notation, the general correlation-sensitive metric is: M i = log det C i det c i + N _ i T C i - 1 N _ i - n _ i T c i - 1 n _ i ( 13 )
In the derivations of the branch metrics (8), (10) and (13), no assumptions were made on the exact Viterbi-type architecture, that is, the metrics can be applied to any Viterbi-type algorithm such as PRML, FDTS/DF, RAM-RSE, or, MDFE.
FIG. 3A illustrates a block diagram of a branch metric computation circuit 48 that computes the metric M i for a branch of a trellis, as in Equation (13). Each branch of the trellis requires a circuit 48 to compute the metric M i .
A logarithmic circuit 50 computes the first term of the right hand side of (13) ( i . e . log det C i det c i )
and a quadratic circuit 52 computes the second terms of the right hand side of (13) (i.e. N i T C i −1 N i − n i T c i −1 n i ). The arrows through the circuits 50 and 52 represent the adaptive nature of the Virterbi-like detector 30 . A sum circuit 53 computes the sum of the outputs of the circuits 50 and 52 .
As stated above, the covariance matrix is given as: C i = [ α i c _ i c _ i T c i ] . ( 14 )
Using standard techniques of signal processing, it can be shown that: det C i det c i = α i - c _ i T c i - 1 c _ i . ( 15 )
This ratio of determinants is referred to as σ i 2 , i.e.: σ i 2 = det C i det c i = α i - c _ i T c i - 1 c _ i . ( 16 )
It can be shown by using standard techniques of signal processing that the sum of the last two terms of (13), i.e. the output of the circuit 52 , is: Y i = N _ i T C i - 1 N _ i - n _ i T c i - 1 n _ i ( 17 ) = ( w _ i T N _ i ) 2 σ i 2 , ( 18 )
Where the vector w i is (L+1)-dimensional and is given by: w _ i T = [ 1 w i ( 2 ) w i ( 3 ) … ( w i ( L + 1 ) ] ) T ( 19 ) = [ 1 - c i - 1 c _ i ] . ( 20 )
Equations (17), (18) and (16) (the circuit 52 ) can be implemented as a tapped-delay line as illustrated in FIG. 3 B. The circuit 52 has L delay circuits 54 . The tapped-delay line implementation shown in FIGS. 3A and 3B is also referred to as a moving-average, feed-forward, or finite-impulse response filter. The circuit 48 can be implemented using any type of filter as appropriate.
The adaptation of the vector of weights w i and the quantity σ i 2 as new decisions are made is essentially an implementation of the recursive least squares algorithm. Alternatively, the adaptation may be made using the least mean squares algorithm.
The quantities m i that are subtracted from the output of the delay circuits 54 are the target response values, or mean signal values of (12). The arrows across multipliers 56 and across square devices 58 indicate the adaptive nature, i.e., the data dependent nature, of the circuit 52 . The weights w i and the value σ i 2 can be adapted using three methods. First, w i and σ i 2 can be obtained directly from Equations (20) and (16), respectively, once an estimate of the signal-dependent covariance matrix C i is available. Second, w i and σ i 2 can be calculated by performing a Cholesky factorization on the inverse of the covariance matrix C i . For example, in the L i D i −1 L i T Cholesky factorization, w i is the first column of the Cholesky factor L i and σ i 2 is the first element of the diagonal matrix D i . Third, w i and σ i 2 can be computed directly from the data using a recursive least squares-type algorithm. In the first two methods, an estimate of the covariance matrix is obtained by a recursive least squares algorithm.
Computing the branch metrics in (10) or (13) requires knowledge of the signal statistics. These statistics are the mean signal values m i in (12) as well as the covariance matrices C i in (13). In magnetic recording systems, these statistics will generally vary from track to track. For example, the statistics that apply to a track at a certain radius will differ from those for another track at a different radius due to different linear track velocities at those radii. Also, the signal and noise statistics will be different if a head is flying slightly off-track or if it is flying directly over the track. The head skew angle is another factor that contributes to different statistics from track to track. These factors suggest that the system that implements the metric in (13) needs to be flexible to these changes. Storing the statistics for each track separately is very difficult because of the memory span required to accomplish this. A reasonable alternative is to use adaptive filtering techniques to track the needed statistics.
Tracking the mean signal values m i is generally done so that these values fall on prespecified targets. An adaptive front-end equalizer is employed to force the signal sample values to their targets. This is certainly the case with partial response targets used in algorithms like PR4, EPR4, or EEPR4 where the target is prespecified to one of the class-4 partial responses. For example, in a PR4 system, the signal samples, if there is no noise in the system, fall on one of the three target values 1, 0, or −1. Typically this is done with an LMS-class (least mean-squares) algorithm that ensures that the mean of the signal samples is close to these target values. In decision feedback equalization (DFE) based detectors or hybrids between fixed delay tree search and DFE, such as FDTS/DF or MDFE, the target response need not be prespecified. Instead, the target values are chosen on-the-fly by simultaneously updating the coefficients of the front-end and feed-back equalizers with an LMS-type algorithm.
When there are severe nonlinearities in the system (also referred to as nonlinear distortion or nonlinear ISI), a linear equalizer will generally not be able to place the signal samples right on target. Instead, the means of the signal samples will fall at a different value. For example, in a PR4 system, the response to a sequence of written symbols . . . , −,+, ⊕, . . . might result in mean sample target values . . . , 0, 1, 0.9, . . . , while a sequence of written symbols . . . , +, −, ⊖, . . . might result in a sequence of mean sample values . . . , 0.95, −1.05, 0, . . . Clearly, in this example, what should be a target value of 1 becomes either 1, 0.9, or 0.95 depending on the written sequence. Because mean values and not noisy samples are being considered, this deviation is due to nonlinearities in the system. There are two fixes for this problem. The first is to employ a nonlinear filter (neural network or Volterra series filter) that is capable of overcoming these nonlinear distortions. Although recently very popular, such a method introduces further correlation between noise samples due to the nonlinear character of the filter. The second fix is to track the nonlinearities in a feedback loop and use the tracked value in the metric computation. For example, let the response to a written symbol sequence . . . , ⊖, +, ⊕, . . . be consistently . . . , 0, 1, 0.9, . . . Then, rather than using the value 1 in the metric computation for the third target, this behavior can be tracked and the value m i =0.9 can be used.
In the remainder of this discussion, for simplicity, it is assumed that the front-end equalizer is placing the signal samples right on the desired target values and that there is no need for further mean corrections. The focus is shifted to tracking the noise covariance matrices needed in the computation of the branch metrics (13).
Assume that the sequence of samples r i , r i+l . . . , r i+L is observed. Based on these and all other neighboring samples, after an appropriate delay of the Viterbi trellis, a decision is made that the most likely estimate for the sequence of symbols a i−K l , . . . , a i+L+K t is â i−K l , . . . , â i+L+K t . Here L is the noise correlation length and K=K l +K t +1 is the ISI length. Let the current estimate for the (L+1)×(L+1) covariance matrix corresponding to the sequence of symbols â i−K t , . . . , â i+L+K t be Ĉ(â i−K t , . . . , â i+L+K t ).
This symbol is abbreviated with the shorter notation, Ĉ(â). If the estimate is unbiased, the expected value of the estimate is:
EĈ ( â )= E[ N i N i T ] (21)
where N i is the vector of differences between the observed samples and their expected values, as defined in (12).
Note that once the samples r i , r i+1 , . . . , r i+L are observed, and once it is decided that most likely they resulted from a series of written symbols â i−K l , . . . , â i+L+K t , the sequence of target (mean) values m i , m i+1 , . . . , m i+L is known that correspond to these samples. They are used to compute the vector N i , with which the empirical rank-one covariance matrix N i , N T i is formed. In the absence of prior information, this rank-one matrix is an estimate for the covariance matrix for the detected symbols. In a recursive adaptive scheme, this rank-one data covariance estimate is used to update the current estimate of the covariance matrix Ĉ(â). A simple way to achieve this is provided by the recursive least-squares (RLS) algorithm. The RLS computes the next covariance matrix estimate Ĉ′(â) as:
Ĉ ′( â )=β( t ) Ĉ ( â )+[1−β( t )] N i N i T (22)
Here, β(t), 0<β(t)<1, is a forgetting factor. The dependence on t signifies that β is a function of time. Equation (22) can be viewed as a weighted averaging algorithm, where the data sample covariance N i N i T is weighted by the factor [1−β(t)], while the previous estimate is weighted by β(t). The choice of β(t) should reflect the nonstationarity degree of the noise. For example, if the nonstationarity is small, β(t) should be close to 1, while it should drop as the nonstationarity level increases. The forgetting factor is typically taken time-dependent to account for the start-up conditions of the RLS algorithm in (22). As more data is processed, a steady-state is expected to be achieved and β(t) is made to approach a constant value. Initially, β(t) is close to zero, to reflect the lack of a good prior estimate Ĉ(â), and to rely more on the data estimate. With time, β(t) is increased and settles around a value close to 1.
The impact of the initial conditions in (22) decays exponentially fast. Hence, the algorithm (22) can be started with an arbitrary initial guess for the covariance matrix Ĉ(â), with the only constraint being that the matrix be positive semidefinite, e.g, a zero matrix or an identity matrix.
The one-dimensional equivalent of equation (22) is
{circumflex over (σ)} new 2 =β{circumflex over (σ)} old 2 +[1 −β]N i 2 . (23)
This equation can be used in conjunction with the metric in (10).
It is important to point out that, due to the signal-dependent character of the media noise, there will be a different covariance matrix to track for each branch in the tree-trellis of the Viterebi-like detector. Practical considerations of memory requirements, however, limit the dimensions of the matrices to be tracked. Fortunately, simple 2×2 matrices are enough to show substantial improvement in error rate performance.
The following example illustrates how the algorithm in (22) works. Assume a PR4 target response with a simple trellis structure as shown in FIG. 4 Notice that for PR4, the symbols can be equated to the trellis states, as is illustrated in FIG. 4 The number next to each branch in FIG. 4 represents the target value (mean sample value) for the corresponding path between states. The target values in PR4 can be one of three values −1, 0, or 1.
In this example a noise correlation length of L=1 is assumed. It is also assumed that the leading and trailing ISI lengths are K l =0 and K t =1, respectively, to give the total ISI length K=K l +K t +1=2 for the PR4 response. Because L=1, signal covariance matrices of size (L+1)×(L+1)=2×2 need to be tracked. The number of these matrices equals the number of different combinations of two consecutive branches in the trellis. A simple count in FIG. 4 reveals that this number is 16, because there are 4 nodes in the trellis and 2 branches entering and leaving each node.
Assume that, using the branch metric in (13), the Viterbi-like detector decides that the most likely written symbols a i , a i+1 , a i+2 , equal {â i , â i+1 , â i+2 }={⊖, +, −}. This is illustrated in FIG. 5, where the corresponding path through the trellis is highlighted. The noisy signal samples corresponding to the trellis branches are r i =0.9 and r i+1 =−0.2, which deviate slightly from their ideal partial response target values of 1 and 0, respectively.
Suppose that, prior to making the decision {â i , â i+1 , â i+2 }={⊖, +, −}, the estimate for the covariance matrix associated with this sequence of three symbols is C ^ ( ⊖ , + , - ) = [ 0.5 - 0.2 - 0.2 0.8 ] ( 24 )
Let the forgetting factor be B=0.95. To update the covariance matrix the vector is first formed:
N =[( r i −1)( r i+1 −0)] T =[−0.1−0.2] T (25)
The rank-one sample covariance matrix N N T is used to find the covariance matrix update: C ^ ′ ( ⊖ , + , - ) = β C ^ ( ⊖ , + , - ) + ( 1 - β ) N _ N _ T = [ 0.4755 - 0.189 - 0.189 0.7620 ] ( 26 )
The matrix Ĉ′(⊖, +, −) becomes our estimate for the covariance matrix corresponding to this particular symbol sequence (trellis path) and is used to compute the metrics (13) in the subsequent steps of the Viterbi-like algorithm.
FIG. 6 illustrates a flowchart of a method of detecting a sequence of adjacent signal samples stored on a high density magnetic recording device. Viterbi sequence detection is performed using a signal sample at step 38 . The sequence detection produces decisions which are output at step 40 . The signal sample is delayed at step 42 . The past samples and detector decisions are used to update the noise statistics at step 44 . Branch metrics, which are used in the sequence detection step 38 , are calculated at step 46 .
It can be understood by those skilled in the art that the method of FIG. 6 can be performed on a computer. The steps may be coded on the computer as a series of instructions, which, when executed, cause the computer to detect a sequence of adjacent signal samples stored on a high density magnetic recording device. The computer may be, for example, a personal computer, a workstation, or a mainframe computer. The computer may also have a storage device, such as a disk array, for storage of the series of instructions.
Simulation results using two partial response detection algorithms, namely PR4 and EPR4 are now presented. To create realistic waveforms, corrupted by media noise, an efficient stochastic zig-zag model, the TZ-ZT model was used. These waveforms are then passed through the detectors. A Lindholm inductive head is used for both writing and reading. Table 1 presents the recording parameters of the model. These recording parameters are chosen so that with a moderately low symbol density per PW50, a low number of transition widths a per symbol transition separation results. Namely, at 3 symbols/PW50 a transition separation of only 2.9a is present. The transition profile was modeled by an error function, where the transition width a denotes the distance from the transition center to the point where the magnetization equals M r /2.
TABLE 1
Recording parameters used in simulations.
Parameter
Symbol
Value
media remanence
M r
450kA/m
media coercivity
H c
160kA/m
media thickness
δ
0.02 μm
media cross-track correlation width
s
200Å
head-media separation
d
15 nm
head field gradient factor
Q
0.8
had gap length
g
0.135 μm
track width
TW
2 μm
transition width parameter
α
0.019 μm
percolation length
L = 1.4α
0.0266 μm
50% pulse width
PW50
0.167 μm
Table 1: Recording Parameters Used in Simulations
The symbols utilizing the (0,4) run length limited code are written. No error correction is applied, so the obtained error rates are not bit error rates, but (raw) symbol error rates.
Both the PR4 and EPR4 detectors were tested using the following three different metric computation methods: the Euclidian metric (8), the variance dependent metric (10), also referred to as the C1 metric, and the 2×2 correlation sensitive metric (13), named the C2 metric for short. For a PR4 target response, the total ISI length is K=K l +K t +1=2, where the leading and trailing ISI lengths are K l =0 and K t =1, respectively. The noise correlation length for the Euclidian and the C1 metrics is L=0, and for the C2 metric the noise correlation length is L=1. These three PR4 detectors are referred to as PR4(Euc), PR4(C1), and PR4(C2).
Similarly to the PR4 detectors, three EPR4 detectors were tested, EPR4(Euc), EPR4(C1) and EPR4(C2). The only difference between the PR4 detectors and the EPR4 detectors are the target response and the ISI length, which for the EPR4 target response equals K=K l +K t +1=3, with K l =1 and K t =1.
The signal obtained by the TZ-ZT model is already corrupted with media noise. To this signal white Gaussian noise was added to simulate the head and electronics noise in a real system. The power of the additive white Gaussian noise is quoted as the signal to additive white Gaussian noise ratio, S(AWG)NR, which is obtained as: S ( AWG ) NR = 10 log A iso 2 σ n 2 ( 27 )
where A iso is the mean (media noise free) amplitude of an isolated pulse and σ 2 n is the variance of the additive white Gaussian noise. The noise distorted signal is first passed through a low-pass filter to clean out the noise outside the Nyquist band- The signal is then sampled at a rate of one sample per symbol and subsequently passed through a partial response shaping filter, either PR4 or EPR4. The partial response shaping filter is implemented as an adaptive FIR filter whose tap weights are adjusted using the LMS algorithm. Note that both filters add correlation to the noise. For the C1 and C2 metrics in (10) and (13), the RLS algorithms (22) and (23) are used to estimate the noise variances and covariance matrices for the branch metric computations. In both cases, the forgetting factor is set to β=0.95.
All six detection algorithms were tested at three different recording densities.
Symbol separation of 4.4a. This recording density corresponds to a symbol density of 2 symbols/PW50, see Table 1. FIG. 7 shows the symbol error rate performance of the PR4 detectors for different additive noise SNRs. The media noise is embedded in the system, which is why the x-axis on the graph is labeled as S(AWG)NR instead of simply SNR. At this density, the PR4(Euc) and PR4(C1) detectors perform just about the same and the PR4(C2) detector outperforms them both by about 3 dB. The reason for this is that the PR4 shaping filter averages noise samples from different symbols, which masks the signal dependent nature of the media noise. This is why there is not much to gain by using PR4(C1) instead of PR4(Euc). The PR4(C2) detector performs better because it partially removes the effects of noise correlation introduced by the PR4 shaping filter. FIG. 8 shows how the EPR4 detectors perform at this same density (symbol separation 4.4a). The PR4(C2) has the best performance and PR4(Euc) has the worst. The difference in performance at the error rate of 10 −5 is only about 0.5 dB between PR4(Euc) and PR4(C2). This is because the media noise power at this density is low and the signal is well matched to the target so the EPR4 shaping filter does not introduce unnecessary noise correlation.
Symbol separation of 3.5a. This recording density corresponds to a symbol density of 2.5 symbols/PW50. FIG. 9 shows the performance of the PR4 detectors at this density. FIG. 9 is similar to FIG. 7, except that the error rates have increased. This is again due to a mismatch between the original signal and the PR4 target response, which is why the PR4 shaping filter introduces correlation in the noise. PR4(C2) still outperforms the two other algorithms, showing the value of exploiting the correlation across signal samples.
FIG. 10 shows the error rates obtained when using the EPR4 detectors. Due to a higher density, the media noise is higher than in the previous example with symbol separations of 4.4a. This is why the graph in FIG. 10 has moved to the right by 2 dB in comparison to the graph in FIG. 8 . While the required S(AWG)NR increased, the margin between the EPR4(Euc) and EPR4(C2) also increased from about 0.5 dB to about 1 dB, suggesting that the correlation-sensitive metric is more resilient to density increase. This is illustrated in FIG. 11 where the S(AWG)NR required for an error rate of 10 −5 is plotted versus the linear density for the three EPR4 detectors. From FIG. 11 it can be seen that, for example, with an S(AWG)NR of 15 dB, the EPR(Euc) detector operates at a linear density of about 2.2 symbols/PW50 and the EPR4(C2) detector operates at 2.4 symbols/PW50, thus achieving a gain of about 10% of linear density.
Symbol separation of 2.9a. This recording density corresponds to a symbol density of 3 symbols/PW50. Due to a very low number of symbols per a, this is the density where the detectors significantly lose performance due to the percolation of magnetic domains, also referred to as nonlinear amplitude loss or partial signal erasure. FIGS. 12 and 13 show the performance of the PR4 and EPR4 families of detectors at this density. The detectors with the C2 metric outperform the other two metrics. The error rates are quite high in all cases. This is because at the symbol separations of 2.9a, nonlinear effects, such as partial erasure due to percolation of domains, start to dominate. These effects can only be undone with a nonlinear pulse shaping filter, which have not been employed here.
The experimental evidence shows that the correlation sensitive sequence detector outperforms the correlation insensitive detectors. It has also been demonstrated that the performance margin between the correlation sensitive and the correlation insensitive detectors grows with the recording density. In other words, the performance of the correlation insensitive detector deteriorates faster than the performance of the correlation sensitive detector. Quantitatively, this margin depends on the amount of correlation in the noise passed through the system. Qualitatively, the higher the correlation between the noise samples, the greater will be the margin between the CS-SD and its correlation insensitive counter part.
While the present invention has been described in conjunction with preferred embodiments thereof, many modifications and variations will be apparent to those of ordinary skill in the art. For example, the present invention may be used to detect a sequence that exploits the correlation between adjacent signal samples for adaptively detecting a sequence of symbols through a communications channel. The foregoing description and the following claims are intended to cover all such modifications and variations. | The present invention is directed to a method of determining branch metric values for branches of a trellis for a Viterbi-like detector. The method includes the step of selecting a branch metric function for each of the branches at a certain time index. The method also includes the step of applying the selected function to a plurality of time variant signal samples to determine the metric values. | 50,733 |
BACKGROUND OF THE INVENTION
The present invention relates to an electrode structure for nitride III-V compound semiconductor devices and, more particularly, to a Schottky electrode structure having high adhesion strength and good temperature characteristics.
A conventional hetero-junction field effect transistor (hereinafter referred to as “HFET”) made of nitride semiconductor is generally of such a construction as shown in FIG. 9 . As is shown in FIG. 9, the HFET includes a sapphire substrate 101 , a low temperature grown GaN (gallium nitride) buffer layer 102 having a layer thickness of 20 nm, and a GaN buffer layer 103 having a layer thickness of 2 μm and a carrier density of 5×10 16 cm −3 , the latter two layers being sequentially placed on the substrate. Sequentially stacked on the buffer layer 103 are an AlGaN (aluminum gallium nitride) spacer layer 104 having a layer thickness of 20 nm, an AlGaN donor layer 105 having a layer thickness of 20 nm and a carrier density of 1×10 18 cm −3 , and a GaN contact layer 106 having a layer thickness of 10 nm and a carrier density of 2×10 18 cm −3 .
Source/drain electrodes 107 , 107 using an ohmic contact, and a gate electrode 108 using the Schottky junction are formed on the GaN contact layer 106 .
Generally, metals having a large work function, such as nickel (Ni) (Y.-F. Wu et al, IEEE Electron Device Lett. 18 [1997] 290), platinum Pt (W. Kruppa et al, Electronics Lett. 31 [1995] 1951), and gold Au (U.S. Pat. No. 5,192,987), have been used as Schottky electrode materials for gate electrodes. These metals are ohmic electrode materials relative to p-type semiconductors and are, therefore, used as Schottky electrode materials relative to n-type semiconductors.
However, these metals will show relatively weak adhesion to the semiconductor and, at temperatures of 400 ° C. or more, the metals will give rise to the problem of increased current leaks, with the result that the HFET is very much deteriorated in its characteristics.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide an electrode structure for nitride III-V compound semiconductor devices, the electrode structure including a Schottky electrode having a high adhesion to a semiconductor and good temperature characteristics.
In order to solve the above object, present inventors made an extensive research and, as a result, it was found that the electrode structure described below would be effective as a solution. This finding led to the present invention.
That is, in nitride III-V compound semiconductor devices, it was found that a nitride o f a metal having a nitride forming negative free energy could provide a Schottky electrode showing a high adhesion to semiconductors and good temperature characteristics. The reason for this is that the formation of the metallic nitride on a nitride semiconductor leads to the formation of a chemical bond through nitrogen atoms, resulting in a stronger bond than prior art semiconductor/metal interfaces.
Therefore, an electrode structure for nitride III-V compound semiconductor devices in accordance with the present invention is characterized in that a metallic nitride is used as an electrode material, a metallic material of the metallic nitride having a negative nitride formation free energy.
The metallic nitride should show a metallic conductivity in order to play a role of an electrode.
As examples of metals having a negative nitride formation free energy and at the same time forming a metallic nitride showing a metallic conductivity, mention may be made of metals included in the IVa, Va, and VIa groups. Such metals are exemplified by titanium (Ti) and zirconium (Zr) belonging to the IVa group, vanadium (V), niobium (Nb) and tantalum (Ta) belonging to the Va group, and chromium (Cr), molybdenum (Mo), and tungsten (W) belonging to the VIa group. Hafnium (Hf) is an exception and use of this material is undesirable because its nitride formation free energy is positive. As Table 1 given below tells, the tabulated data of metals shown indicates that all of the metals show a negative nitride formation free energy. The larger the formation free energy in the negative direction, the better. The reason for this is that the resulting metallic nitride is more stable and, in particular, Zr, Ti, Ta, and Nb having a formation free energy of not more than −50 kcal/mol are preferred.
TABLE 1
Nitride
Formation
Melting
Melting
Free
Point
Nitride
Point
Energy − *
Metal
(° C.)
Form
(° C.)
(kcal/mol)
Ti
1668
Tin
2950
−74
Zr
1852
ZnN
2980
−87
Hf
2230
HfN
3000
81
V
1887
VN
2050
−35
Nb
2468
NbN
2300
−51
Ta
2996
TaN
3087
−54
Cr
1907
CrN
1500
−24
Mo
2617
Mo 2 N
—
−12
W
3407
W 2 N
—
−11
*“Structure and Properties of Inorganic Solids” by F. S. Galasso (1970), Pergamon Press Inc.
The metal material for these metallic nitrides may be a single metal or a composite metal comprised of two or more kinds of metals. These metals have a high melting point and, accordingly, nitrides of the metals have a high melting point and are thermally stable, being thus able to exhibit good temperature characteristics.
From the standpoint of thermal stability, it is desirable that the melting points of the metals and metallic nitrides be as high as possible, while some correlation can be observed between the melting points of metals and the melting points of metallic nitrides through the formation free energy. That is, in case that even if the melting point of a metal is relatively low, but if its formation free energy is large, the melting point of a nitride of the metal tends to rise. Therefore, from the standpoint of thermal stability, Zr, Ti, Ta, Nb are preferred.
For depositing such a metallic nitride, various methods, such as molecular beam epitaxy using a nitrogen radical and a reactive sputtering method, can be employed.
A suitable thickness range of the metallic nitride layer formed in this way is not less than 10 nm but not more than 200 nm. If the thickness of the metallic nitride is less than 10 nm, the metallic nitride layer does not form a continuous layer, and this poses a problem that no satisfactory reproducibility could be obtained with respect to the characteristics of the metallic nitride layer. On the other hand, the thickness of the metallic nitride which is more than 200 nm will cause a problem of deterioration of the electrical characteristics and crystallinity of a GaN semiconductor layer due to the stress of the metallic nitride layer.
Further, in order to facilitate bonding of lead wire onto the metallic nitride layer, a layer comprised of Au or an Au alloy may be placed on the metallic nitride layer. The Au alloy is not particularly limited; as long as it is superior to Au in hardness, the alloy is acceptable. As a method of depositing Au or an Au alloy, vacuum deposition and sputtering may be mentioned, but are not limitative. By depositing Au or an Au alloy on the metallic nitride, it is possible to reduce the contact resistance of a contact portion between the electrode and the lead wire and hence generation of heat from the contact portion to thereby further improve the characteristics of the electrode.
Thus, a schottky electrode having high film adhesivity and a good temperature characteristic can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a schematic sectional view of a nitride III-V compound semiconductor device having a first embodiment of the electrode structure of the present invention;
FIG. 2 is an I-V characteristic diagram of a ZrN film of the semiconductor device;
FIGS. 3A, 3 B, and 3 C are I-V characteristic diagrams of the semiconductor device after annealing at temperatures of 500° C., 643° C., 800° C., respectively.
FIGS. 4A and 4B are, respectively, an I-V characteristic diagram of a comparative example in relation to a second embodiment after deposition of a Ti film and before annealing, and an I-V characteristic diagram of the second embodiment after deposition of a TiN film and before annealing;
FIGS. 5A and 5B are, respectively, an I-V characteristic diagram of the comparative example after the annealing preceded by the Ti film deposition, and an I-V characteristic diagram of the second embodiment after the annealing preceded by the TiN film deposition;
FIGS. 6A and 6B are, respectively, an I-V characteristic diagram of a metal/semiconductor interface structure of the comparative example after the Ti film deposition but before the annealing, and a metal/semiconductor interface structure after annealing the Ti film deposited structure;
FIGS. 7A and 7B are, respectively, a diagram showing a metal/semiconductor interface structure of the second embodiment after the TiN film deposition but before the annealing, and a diagram showing a metal/semiconductor interface structure after the annealing preceded by the TiN film deposition;
FIG. 8 is a schematic sectional view of a nitride III-V compound semiconductor device having a third embodiment of the electrode structure of the present invention; and
FIG. 9 is a schematic sectional view of the conventional HFET.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings.
First Embodiment
FIG. 1 schematically shows the construction of a semiconductor device having an electrode structure according to a first embodiment of the invention. The semiconductor device has a (0001) sapphire substrate 1 , a low temperature grown AlN (aluminum nitride) buffer layer 2 formed on the substrate 1 and having a thickness of 20 nm, an n-type GaN layer 3 formed on the buffer layer 2 and having a carrier density of 2×10 18 cm −3 and a layer thickness of 1 μm, and ZrN (zirconium nitride) electrodes 4 formed on the n-type GaN layer 3 .
In the electrode structure of the present embodiment, the ZrN electrodes 4 were formed by the reactive sputtering process. This process was carried out in the following way.
First, with zirconium (Zr) used as a target, the flow rate of argon gas and the flow rate of nitrogen gas were set to 30 sccm and 12 sccm respectively, and sputtering was carried out at the power of 70 W. Thus, a ZrN electrode 4 comprised of a ZrN film having a thickness of 100 nm was formed on the n-type GaN layer 3 .
FIG. 2 shows I-V characteristics of the GaN layer 3 after deposition of the ZrN film. As shown in FIG. 2, according to the electrode arrangement of the present embodiment, it is possible to obtain a satisfactory Schottky characteristic of a turn-on voltage on the order of 1.5 V.
FIGS. 3A, 3 B, and 3 C show I-V characteristics at annealing temperatures of 500° C., 643 ° C., and 800° C., respectively. As shown in FIGS. 3A, 3 B, and 3 C., no change was observed among the I-V characteristics at annealing temperatures 500° C., 643° C., and 800° C. (annealing time: 6 minutes each). That is, experiments have proved that the ZrN electrode structure exhibits a thermally stable Schottky characteristic.
Second Embodiment
Next, a second embodiment of the invention will be described. A semiconductor device having an electrode structure of the second embodiment is different from the semiconductor device having the electrode structure of the above described first embodiment only in that the zirconium nitride electrode 4 shown in FIG. 1 was replaced by a titanium nitride (TiN) electrode.
FIG. 4B shows I-V characteristics of the n-type GaN layer 3 of the semiconductor device having a nitride titanium electrode of this second embodiment. The I-V characteristics were measured in the condition of the device prior to annealing, and good Schottky characteristic was witnessed, which showed a turn-on voltage of the order of 1.2 V. FIG. 5B shows I-V characteristic measured after annealing was carried out at 500° C. for 10 minutes. After annealing the n-type GaN layer 3 also showed good Schottky characteristic such that the turn-on voltage was of the order of 1.2 V, which was almost same as the I-V characteristic before annealing.
Whilst, as a comparative example in relation to the foregoing example, in FIG. 4A is shown the I-V characteristic of an n-type GaN layer 3 of a semiconductor device including a titanium (Ti) electrode in place of the titanium nitride (TIN) electrode, and in FIG. 5A is shown the I-V characteristic after annealing at 500° C. for 10 minutes.
Where Ti is deposited on the n-type GaN layer in place of TiN, a characteristic having a slight deviation from an ohmic characteristic was observed in the condition after film deposition, as shown in FIG. 4A, but as FIG. 5A shows, a perfect ohmic characteristic was obtained by annealing.
In contrast, according to the present embodiment, as already mentioned, after film or layer deposition, and even after annealing, nearly same good Schottky characteristics were achieved.
The reason for this is explained hereinbelow.
If Ti is deposited on the n-type GaN layer 3 to form a Ti electrode 61 , as shown in FIG. 6A corresponding to the comparative example, and then annealing process is carried out, an intermediate layer (GatiN) 62 is formed at the interface between the n-type GaN layer 3 and the Ti 61 , as shown in FIG. 6B, in which the composition continuously changes like GaN/GaTiN/TiN/Ti. By virtue of the presence of the intermediate layer (GaTiN) 62 , the ohmic characteristic is obtained.
In contrast to the comparative example, when TiN is deposited on the n-type GaN layer 3 as shown in FIG. 7A to form a TiN electrode 63 according to the second embodiment, a steep interface between GaN and TiN is maintained even after the annealing process, as shown in FIG. 7 B. By virtue of the presence of the steep GaN/TiN interface, good Schottky characteristics are obtained.
Third Embodiment
Next, the electrode structure of the third embodiment of the invention is described with reference to FIG. 8 . The electrode structure of the third embodiment is different from the electrode structure of the first embodiment in that the third embodiment has a layer 5 made of an alloy of gold (Au) on the ZrN film 4 . After deposition of the ZrN film 4 on the n-type GaN layer 3 to the thickness of 100 nm, in succession a gold (Au) alloy (AuCr in the present case) is deposited thereon by sputtering process to form the AuCr layer 5 . By depositing an Au alloy on a metallic nitride (zirconium nitride in the present case), the contact resistance of the electrode and lead wire can be reduced. Thus, it is possible to minimize heat generation at the contact portion therebetween, resulting in further improvement on the characteristics of the electrode. While a gold alloy (AuCr) is deposited on zirconium nitride in the present embodiment, gold (Au) may be deposited on the zirconium nitride. Further, other gold alloys may be used.
In the first, second and third embodiments, for component metals of the metallic nitride, titanium (Ti) and zirconium (Zr) are used, but where other metals belonging to the IVa, Va, and/or VIa groups, such as niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), vanadium (V), and tungsten (W), are used, same effect as in first, second and third embodiments can be obtained.
Test Results
Schottky electrodes were formed using metallic nitrides shown in Table 1 (see the “SUMMARY OF THE INVENTION” column), except Mo and W, and acceleration tests on leak current under reverse bias were carried out. The acceleration tests were conducted under the conditions of 800° C. and 1,000 hours of duration time. Percentages of change in leak current at reverse bias voltage of 50 V are shown in Table 2 below. For the purpose of comparison, percentages of change in the case of Pt and Ni are also shown in Table 2.
TABLE 2
Electrode Material
Change (%)
TiN
0.5
ZrN
0.5
VN
0.9
NbN
0.5
TaN
0.4
CrN
0.9
Pt
400
Ni
800
Percentages of change in leak current of metallic nitrides were all below 1%, and good thermal stability was witnessed. Whilst, in the case of Pt and Ni, the amount of change was very noticeable, showing they are thermally unstable electrode materials.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | In an electrode structure for a nitride III-V compound semiconductor device, a metallic nitride is used as an electrode material. A metallic material of the metallic nitride has a negative nitride formation free energy, and comprises at least one metal selected from a group consisting of IVa-group metals such as titanium and zirconium, Va-group metals such as vanadium, niobium, and tantalum, and VIa-group metals such as chromium, molybdenum, and tungsten. | 21,140 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to devices and method for treating a patient with compression, and in particular, to techniques employing separate shells.
[0003] 2. Description of Related Art Edema is a medical condition that requires careful treatment. Lymphedema, a type of edema, is a swelling of a body part, often the result of the abnormal accumulation in the affected area of protein-rich edema fluid (primarily lymph fluids). Lymphedema is classified as either primary or secondary. Primary lymphedema is the result of lymphatic dysplasia. It may be present at birth but more often develops later in life without obvious cause. Secondary lymphedema is much more common and is the result of surgery or is a side effect of radiation therapy for cancer. Secondary forms may also occur after injury, scarring, trauma, or infection of the lymphatic system. Lymphedema treatment options offered in the United States include surgery, medication, pneumatic compression pump therapy, Manual Lymph Drainage (MLD), and Complete Decongestive Therapy (CDT).
[0004] Surgery and medication have their place, but their success is not guaranteed and comes with risks. The pneumatic compression pump is a mechanical device that “milks” the lymph fluid out of the swollen extremity. The problems with pneumatic pumps are numerous and any results achieved are usually very temporary.
[0005] Lymphedema physical therapy treatment would not be possible without compression therapy employing bandages and elastic compression garments. Elastic compression garments are easily used and sold under the trade names: Solaris, JoviPak, CircAid, Biacare, and Reid Sleeve. Another compression therapy involves bandaging with short stretch bandages and is a highly skilled procedure designed to take advantage of natural pumping pressures.
[0006] Lymph is propelled through the various lymph vessels by muscular activity, breathing, etc. Bandaging/garments improve the efficiency of the muscle and joint pump and also prevents the re-accumulation of evacuated lymph fluid. These techniques will also break up deposits of accumulated scar and connective tissue.
[0007] The nature of compression varies greatly when a comparison is made between short stretch bandages and elastic compression garments. Both are necessary complements to a program of Complete Decongestive Therapy (CDT) when utilized by competent and well-trained therapists. The distinction lies in the working and resting forces generated by these two forms of compression. Elastic compression garments are designed to provide a pressure gradient favoring proximal fluid flow and are comfortable and convenient. However, they tend to produce constant resting pressure without enhanced working pressure. Short stretch compression bandages supports a limb without constant “squeezing” (i.e. will exhibit low resting pressure), but when a limb is exercised produces relatively high working pressure.
[0008] No effective homecare device exists to maintain/reduce lymphedema/edema consistent with the principles of CDT (Complete Decongestive Therapy). Therefore, patients are saddled with the responsibility of life-long lymphedema control, but the task is arduous, tedious and time consuming. When self-applied compression is performed with less than sufficient skill, it can also be painful, counter-therapeutic or even damage the limbs' health.
[0009] Aftermarket compression products have tried alternative solutions to replace multilayered compression bandages. Treatment at joints is most problematical for these products. Even at the limb segments (between joints) the solutions offered utilize unsatisfactory materials and tensioning techniques to generate pressure. As a result these products lack continuous working pressure (cast-like containment) longitudinally as well as structure to prevent buckling and bulging of tissues.
[0010] See also U.S. Pat. Nos. 4,676,233; 5,152,302; 6,526,592; 6,785,905; 7,135,005; and 6,991,612; as well as US Patent Application Publication Nos. 2005/0066412; 2006/0135902; and 2008/0228117.
SUMMARY OF THE INVENTION
[0011] In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a compression device for treating edema. The device includes a plurality of curved shells, each having an internal pad. The device also includes a ligature network routed across the plurality of shells. The network includes a plurality of tensioners. The tensioners are mounted on at least some of the plurality of shells and are operable to separately adjust tension in different portions of the ligature network.
[0012] In accordance with another aspect of the invention, a compression device is provided for treating edema. The device includes a plurality of curved shells, each having an internal pad. The device also includes a ligature network routed across the shells. The ligature network includes a plurality of tensioners mounted on at least some of said plurality of shells. At least at least a portion of the ligature network is releasably mounted and repositionable on the shells to allow spatial adjustment of compression forces produced by said compression device
[0013] In accordance with yet another aspect of the invention, a method is provided for treating edema with a ligature network and a plurality of padded shells. The method includes the step of routing the ligature network across the plurality of shells. Also, with a body part embraced by the padded shells, the method performs the step of separately adjusting tension in different portions of the ligature network to affect the balance of compression forces at spaced positions along the plurality of padded shells.
[0014] In accordance with still yet another aspect of the invention, a method is provided for treating edema with a ligature network and a plurality of padded shells. The method includes the step of adjusting routing of the ligature network across the plurality of shells to provide tailored compression forces at spaced positions along the plurality of padded shells. Also, with a body part embraced by the padded shells, the method performs the step of adjusting tension in the ligature network to adjust compression forces along the plurality of padded shells.
[0015] By employing devices and methods of the foregoing type an improved technique is achieved for treating edema. For example, lymphedema limb areas need not be immobilized and the present device does not function as a cast or an immobilizer. Areas of joint articulation can sustain movement without abrasion or discomfort. The natural muscle and joint pumps will be allowed to activate a natural fluid pumping effect. Allowing movement within a compression device tends to reverse lymphostatic fibrosis.
[0016] A disclosed embodiment is presented for treating the hand, although treatment of other body parts is described. The embodiment for treating the hand employs a pair of padded shells, one placed on the palm and one on the dorsum.
[0017] These padded shells each have a heat-treatable, plastic panel that is relatively stiff, so that the shells can apply transaxial pressure without squeezing the hand laterally. This arrangement cancels out high lateral pressures, and accentuates high dorsal and palmar pressures.
[0018] These panels are fashioned to accommodate the specific body part being treated. For example, an outline of a hand may be applied to plastic panels and used to trim them accordingly, although the final panel outline need not follow the exact outline of the hand. Typically, the panel will be notched to allow articulation of the thumb.
[0019] The panels may be heated to soften and bend them into a curve that accommodates the curves of the hand or other body part under treatment.
[0020] Lymphedema is a staged condition according to disease severity (stages 1, 2, 3). As such it requires modifications in the approach according to the quantity of swelling and tissue integrity. The above noted shells apply the external force, but inner-padding materials must be tailored to modify the force according to the disease severity, desired gradient of pressure, limb girth and abnormal contours if any.
[0021] With this in mind, the inside of the disclosed panels will be fitted with pads; for example, multiple layers of foam material. In one case the layer on the plastic panel is a closed cell foam that readily accommodates transaxial force, while the layer contacting skin tissue is an open cell foam that conforms more closely to the curves of the hand and increases comfort. In some cases one or more of the layers will not be one continuous piece, but will be formed from multiple disjoint segments that are fashioned to tailor the pressure being applied to the body part under treatment.
[0022] Proper treatment requires that skin integrity be preserved to combat any localized immune deficiency. To address this requirement the shells' pads ought to be hypoallergenic, customized to the patient, and hygienic. Moreover, any inner layer in contact with the skin should be exchanged regularly.
[0023] Lymphedema treatment requires that a gradient of pressure be exerted regardless of the contour of the swollen limb. Pressure applied to hypothetical conical shapes will respond according to the “law of Laplace” (P=Tc/R), however swollen limbs are not always conical. To address this anatomical requirement “zones” of pressure are created and padding modified suitably to direct fluid from distal areas towards proximal areas. Limbs that have received treatment in the clinic (e.g., with CDT) become more normally shaped (from columnar to conical again) and readily responsive to the above compression device.
[0024] In order to achieve an appropriate pressure, a disclosed embodiment employs a ligature network that is formed from a number of cords that are routed across the padded shells. Specifically, these cords are routed through guides strategically placed at various locations on the opposing shells. A disclosed network has two circuits that are independently tightened by two tensioners. The disclosed tensioners are cord winders placed in strategic locations on one or more of the shells.
[0025] In this embodiment, the guides and winders are easily repositioned to modify the routing of the cords in the ligature network. Specifically, the guides and winders are attached to the outside of the shells by hook and loop fasteners.
[0026] Devices of this type may be used as an adjunct to, or a follow-up after, professional therapy. Also, after the initial fitting of the device, a user will be able to readily remove the device and later place it back on the body part under treatment without the need for professional assistance. In addition, since the tension in the ligature network is readily adjusted, a user can easily adjust tension throughout the day as needed.
[0027] Devices according to the foregoing principles can achieve high working pressure, and low resting pressure throughout. Such devices are adaptable to the edema reduction process by allowing movement, and normal activity. In the disclosed embodiment, tension is easily adjusted so a user is able to regularly conduct subtle re-tensioning.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
[0029] FIG. 1 is a top view of a compression device in accordance with principles of the present invention;
[0030] FIG. 2 is a bottom view of the compression device of FIG. 1 ;
[0031] FIG. 3 is a side view of the compression device of FIGS. 1 and 2 ;
[0032] FIG. 4 is a sectional view of a fragment of one of the padded shells of the device of FIGS. 1 and 2 ;
[0033] FIG. 5 is a side view of one of the tensioners of FIG. 1 ;
[0034] FIG. 6 is a perspective view of one of the guides of FIGS. 1 and 2 ;
[0035] FIG. 7 is a perspective view of the curved guide of FIG. 2 ;
[0036] FIG. 8 is a fragmentary, perspective view of a tensioner in a ligature network that is an alternate to that shown in FIGS. 1 and 2 ;
[0037] FIG. 9 is an inside view of a padded shell that is an alternate to that shown in FIG. 2 ;
[0038] FIG. 10 is a perspective view of a compression device that is an alternate to that shown in FIGS. 1-3 ;
[0039] FIG. 11 is an end view of the device of FIG. 10 ; and
[0040] FIG. 12 is an end view of a device that is an alternate to that of FIG. 11 .
DETAILED DESCRIPTION
[0041] Referring to FIGS. 1-7 , the illustrated compression device has a palmar shell 10 and a dorsal shell 12 , each designed for right hand H. Each of the shells 10 and 12 have a heat-deformable plastic panel 14 ( FIG. 4 ). Various types of thermoplastics will operate satisfactorily as a panel, and the Aquaplast® moldable sheets from Patterson Medical (1.6 to 3.2 mm thick, perforated) will operate satisfactorily. Panel 14 ought to be relatively stiff in order to transmit compression forces normal to its surface. In this embodiment the opposite faces of panel 14 have a coterminous covering 16 and 18 in the form of a sheet of hook and loop material (loop material prominent) on a breathable plastic substrate.
[0042] FIG. 1 shows the outline of padded shell 12 , it being understood that the right and left edges are rolled about 45°, except at the extension 12 A provided for thumb T. One can establish the outline of shell 12 by tracing the outline of the hand (hand H of FIG. 2 ) on panel 14 and trimming appropriately. The trimmed panel 14 will have additional material for the rolling of the right and left panel edges and will make accommodations for the extended thumb region 12 A.
[0043] Thereafter, panel 14 can be heated by, for example, immersion in hot water. When heated, the right and left edges of panel 14 can be rolled as noted above, while the central region can be given an appropriate curve to accommodate the natural curves of hand H. The outline and curvature of panel 14 may be refined based on the judgment and experience gathered by a properly trained therapist. Also, after an initial shaping, panel 14 can be placed against hand H to determine what areas need correction before possibly trimming and reshaping the panel again.
[0044] FIG. 2 shows the outline of padded shell 10 with the right and left edges again rolled about 45°, except in the vicinity of notch 10 A provided for thumb T. Panel 14 of shell 10 can be trimmed and curved in a manner similar to that described in connection with shell 12 .
[0045] The faces of panels 14 of shells 10 and 12 that face the skin are fitted with an internal pad, shown in FIG. 4 as a pair of resilient layers 20 and 22 . Layers 20 and 22 will be trimmed to be coterminous with their associated shells 10 and 12 .
[0046] Distal layer 20 may be formed of a closed cell foam material of the type typically used in compression therapy for lymphedema patients. Such lymphedema grade foams are available under the trade names Jobst Foam or Komprex Foam. Foams of this type are resilient but still tend to transmit compression forces substantially perpendicular to shell panel 14 . Layer 20 will be secured onto hook and loop material 18 , using, if necessary, an additional hook and loop sheet (hooks prominent).
[0047] It is desirable that proximal layer 22 be more compliant than layer 20 to add to the wearer's comfort. Also, a softer material will tend to feather the compression forces near the edges of the device, thereby avoiding the tendency to apply undesired lateral compression. Open cell foam material has been found satisfactory for this purpose, although other types of resilient materials can be used as well. An acceptable open cell foam material is available from Canal Rubber Supply Co. of New York (light to medium density).
[0048] In this embodiment layer 22 is ½ inch thick (1.3 cm). In other embodiments the layer thickness may be varied, although typically remaining within a range of ¼ to ¾ inch (0.6 to 1.9 cm) thick, with the thickness chosen to accommodate the needs of the patient.
[0049] Padded shells 10 and 12 are pressed together with a ligature network employing nylon cords arranged in a pair of circuits 24 and 26 . Circuit 24 terminates at network tensioner 28 , while circuit 26 terminates at network tensioner 30 . In this embodiment tensioners 28 and 30 are identical, but need not be so. Circuit 24 has cord segment 24 A running atop shell 12 through plastic tube 36 A, which tube is designed to decrease cord friction. Cord segment 24 A traverses the edge of shell 12 and crosses over to run atop shell 10 , as shown by cord segment 24 B.
[0050] Cord segment 24 B is threaded through network guide 32 A, which is releasably secured atop shell 10 . Guide 32 A is shown in FIG. 6 as a slab 32 A- 1 supporting sleeve 32 A- 2 , which has through bore 32 A- 3 for receiving previously mentioned cord segment 24 B. A sheet of hook and loop fastening material 32 A- 4 glued on the underside of slab 32 A- 1 is designed to releasably attach guide 32 A to mating sheet 16 ( FIG. 4 ) on shell 10 . Guide 32 A is identical to guides 32 B, 32 C, 32 D and 32 E shown in FIGS. 1 and 2 (these guides sometimes being referred to as annular implements).
[0051] Cord segment 24 B traverses the edge of shell 10 and passes between forefinger I and middle finger M before running atop shell 12 , as shown by cord segment 24 C. Cord segment 24 C is threaded through guides 32 B and 32 C, which are mounted atop shell 12 . Cord segment 24 B traverses the edge of shell 12 and passes between ring finger A and pinky finger S before running atop shell 10 , as shown by cord segment 24 D. Cord segment 24 D is threaded through guide 32 D, which is releasably secured atop shell 10 . Cord segment 24 D traverses the edge of shell 10 to run atop shell 12 , as shown by cord segment 24 E. Cord segment 24 E passes through friction reducing tube 36 B.
[0052] Referring now to circuit 26 , cord segment 26 A runs atop shell 12 and traverses the edge of shell 12 before running atop shell 10 as shown by cord segment 26 B. Cord segment 26 B is threaded through guide 32 E, which is releasably secured atop shell 10 . Cord segment 26 B traverses the edge of shell 10 before running atop shell 12 , as shown by cord segment 26 C, which passes through friction reducing tube 36 C. Cord segment 26 C traverses the edge of shell 12 before running atop shell 10 , as shown by cord segment 26 D. Cord segment 26 D runs through a channel in network guide 34 , which is releasably secured atop shell 10 .
[0053] In FIG. 7 guide 34 is shown with a platform 34 A having a curved outside edge (approximately a quarter circle curve) and an inside edge leading to a curved wall 34 B (approximately a quarter circle curve). A similarly curved shelf 34 C projecting from atop wall 34 B forms a curved channel 34 D to guide previously mentioned cord segment 26 D. Hook and loop fastener 34 E glued on the underside of platform 34 A will releasably attach guide 34 to hook and loop fastening material 16 atop shell 10 .
[0054] Tensioner 28 is shown in FIG. 5 having a dial 28 A rotatably mounted on body 28 B, which sits atop base 28 C. Cord segment 24 A is shown passing through hole 28 D in body 28 B. It will be appreciated that cord segment 24 E passes through another hole (not shown) on the other side of body 28 B. Tensioner 28 operates as a manually operable winder. Specifically, dial 28 A can be rotated clockwise (counterclockwise) to wind (unwind) cord segments 24 A relative to a reel (not shown) inside winder body 28 B. Cord segment 24 E will not be wound although winding may be implemented in other embodiments. Winders of this type can be obtained from Boa Technology, Inc. of Steamboat Springs, Colo.
[0055] A sheet of hook and loop material 28 E is glued to the underside of winder base 28 C to act as a fastening device that will releasably attach the winder 28 by mating to hook and loop material 16 atop shell 12 ( FIG. 1 ).
[0056] Referring to FIG. 8 , a different type of manually operable winder (tensioner) is illustrated. Components corresponding to those previously described in connection with FIG. 5 have the same reference numeral but increased by 100 . The winder 128 has mounted atop base 128 C a body 128 B containing a winding reel (not shown) that is driven by dial 128 A. Rotation of dial 128 A will wind or unwind band 124 A, which will be part of a ligature network similar to that previously described. However, in this embodiment, winder 128 only works with one end of band 124 A, whose opposite end may either be anchored at another location or connected to another winder. Moreover, band 124 A is not routed in a closed circuit in this embodiment.
[0057] An alternate guide 132 A is shown as a cloth strip stitched into a loop that holds annular implement 133 . Band 124 A is shown routed through implement 133 . Cloth loop 132 A may be attached atop a padded shell by hook and loop fastening means, snaps, mechanical clips, etc.
[0058] Referring to FIG. 9 , palmar shell 10 ′ is designed for left hand H′ and is substantially the mirror image of shell 10 of FIG. 2 . As before, shell 10 ′ has a heat deformable plastic core 14 with the same covering 16 and 18 as mentioned previously. In this embodiment, the layer 20 previously mentioned in FIG. 4 has been replaced with three disjoint segments 120 A, 1208 and 120 C (also referred to as discrete panels). While three segments are shown, in other embodiments a greater or lesser number may be employed instead.
[0059] Segment 120 A is an elongated slab with rounded ends designed to engage the knuckles of hand H′. Segment 120 B has a teardrop shaped outline and is designed to engage the fleshy part of the palm at the base of thumb T′. Segment 120 C is shaped to treat most of the remaining area of the palm of hand H′ and has an outline that is roughly a triangle with rounded corners. Segment 120 C is given some flexibility to bend along one of its edges by a pair of grooves 38 .
[0060] It will be appreciated that the chosen outline, placement, thickness, and materials of segments 120 A- 120 C will be tailored by the therapist that sets up the device, these choices being made to accommodate and best treat hand H′. Also, each of the discrete segments 120 A- 120 C may be formed from the same material as layer 20 of FIG. 4 , but in some cases each of the segments may use a different material with different characteristics adapted to accommodate the hand H′ under treatment.
[0061] Panel segments 120 A- 120 C may be overlaid (face to face) with a full panel (not shown) having an outline substantially the same as that of core panel 14 and made of material similar to panel 22 of FIG. 4 . In other embodiments the roles may be reversed with the layer adjacent to the skin tissue being segmented, and the other layer being continuous.
[0062] Referring to FIG. 10 , the illustrated compression device is designed to treat a different body part, namely forearm F instead of hand H. Components in this Figure corresponding to those of the embodiment of FIGS. 1-7 have the same reference numerals but increased by 200 . Padded shell 212 is shown on the extension side of forearm F and padded shell 210 is shown on the volar side of the forearm. Shells 210 and 212 are roughly semicylindrical and are layered in substantially the same manner as shown in FIG. 4 .
[0063] Mounted on shell 212 are winders 230 and 228 , which each have independently adjustable circuits 224 and 226 , respectively. Winder 228 is shown connected to cord segments 224 A and 224 E of circuit 224 . Winder 230 is shown connected to cord segments 226 A and 226 E of circuit 226 .
[0064] Circuit 224 extends along cord segment 224 E on shell 212 , crossing over to shell 210 to form cord segment 224 D, which passes through guide 232 D before returning to shell 212 to form the cord segment 224 C, passing through guide 232 C. Cord segment 224 C will pass through another guide (not shown) before taking a looping turn on a guide (not shown) on shell 210 , eventually returning as cord segment 224 A. It will be appreciated that circuit 224 has topographically the same routing as circuit 24 of FIGS. 1 and 2 .
[0065] Circuit 226 is topographically the same as circuit 26 of FIGS. 1 and 2 . Specifically, cord segment 226 A crosses from shell 212 to shell 210 where cord segment 226 B passes through guide 232 E on shell 210 before returning to shell 212 to form cord segment 226 C. Cord segment 226 C will make a looping turn on a guide (not shown) on shell 210 before returning as cord segment 226 E. It will be appreciated that circuit 226 has topographically the same routing as circuit 26 of FIGS. 1 and 2 .
[0066] A third winder 40 on shell 212 connects to a third independently adjustable circuit 42 at cord segments 42 A and 42 E. Circuit 42 cooperates with a pair of guides at the proximal corner of shell 212 , one such guide being shown as guide 44 B. Guide 44 A is mounted along the edge of shell 210 and a corresponding guide (not shown) is mounted at the opposite edge of shell 210 at the same longitudinal position.
[0067] Cord segment 42 A extends across shell 212 , crossing over to shell 210 where cord segment 42 B passes through guide 44 A before returning to shell 212 to form cord segment 42 C, which passes through guide 44 B and the complementary guide on the other side of shell 212 . It will be appreciated that cord segment 42 C crosses over to shell 210 and loops back in a manner similar to that shown for cord segment 42 B.
[0068] As before, winders 228 , 230 and 40 are releasably secured to shell 212 to allow a therapist to adjust the position of each. Similarly positionable are the guides (e.g., illustrated guides 232 C- 232 E and 44 A- 44 B).
[0069] As shown in FIG. 11 , previously mentioned padded shells 210 and 212 have gaps at approximately the three o'clock and nine o′clock positions. In other embodiments such as shown in FIG. 12 three shells 46 , 48 , and 50 may be arranged with gaps at approximately the two o'clock, six o'clock and 10 o'clock positions (i.e., shell 46 on the extension side and shells 48 and 50 primarily on the volar side).
[0070] While the devices of FIGS. 10-12 are mentioned for treating a forearm, they can equally be applied to different body parts such as the upper arm, calf, or thigh.
[0071] To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly described in connection with the embodiment of FIGS. 1-7 .
[0072] Heat deformable panel 14 is trimmed to size based on the size and proportions of hand H. To customize padded shell 12 , hand H may be placed atop panel 14 , palm up, and the outline of the hand may be traced with a pencil or other writing instrument. Panel 14 will then be trimmed to extend longitudinally from the end of the wrist to the base of the fingers. Panel 14 will also be trimmed to extend from the right to the left edge of the hand H with a little excess to allow the panel to curl slightly around the edge of the hand. Panel 14 will be allowed to extend outwardly slightly outwardly along extension 12 A to cover a portion of the thumb knuckle. This extension will be useful in applying pressure in this region without restricting the mobility of thumb T.
[0073] To customize padded shell 10 , hand H may be placed atop panel 14 , palm down, and the outline of the hand may be traced with a pencil or other writing instrument. Panel 14 will be trimmed as before except that previously mentioned thumb extension 12 A will be replaced with a thumb notch 10 A. This notch will be useful in allowing articulation of thumb T. In fact, the wrist, thumb T and all the fingers of hand H can be moved so the user will retain most of the function of hand H. This ability to move the wrist and fingers and thereby exercise the hand will enhance the natural ability of the body to reduce edema by means of the natural pumping action produced when exercising the fingers and wrist.
[0074] Panels 14 of shells 10 and 12 can be further shaped by immersion in hot water to soften the panels. The panels may be curved in a general way to accommodate the shape of hand H. Special attention may be given to the right and left edges of panel 14 to roll these edges slightly around the hand H. For thumb extension 12 A, panel 14 may be bowed about the thumb axis to provide a proper fit.
[0075] The foregoing trimming and shaping may be performed after a session with a therapist who examines and measures hand H. The therapist may either personally perform the trimming and shaping, but in some cases the information gathered by the therapist will be sent to a specialized lab along with a general description of the characteristics of hand H, so that the lab can customize the panel 14 . In any event, this trimming and shaping will be based upon a therapist's experience and judgment.
[0076] Pads 20 and 22 ( FIG. 4 ) may be provided as a kit having a variety of padding materials. The materials will offer a selection of different thicknesses, softness, etc. As noted above, the padding materials can include commercially available, closed cell foams that are designed for the treatment of lymphedema. The padding materials can also include softer, open cell foams of various types. In some cases the padding will be some other type of non-foam, synthetic material.
[0077] As noted previously, the padding may be cut into discrete segments as shown in FIG. 9 . Again, the selection and arrangement of padding materials will be based on the therapist's experience and judgment.
[0078] Pad 20 may be secured in place by taking advantage of a natural propensity to adhere to hook and loop material 18 . Where such a propensity does not exist, a mating sheet of a hook and loop material may be glued to pad 20 . Likewise, hook and loop material may be used to connect pads 20 and 22 together. The advantage of using hook and loop material is that the therapist can experiment with a variety of combinations of pads and pad shapes. This ability to modify will be important when initially establishing the most desirable combination and also afterward when the arrangement needs to be modified as the patient's condition changes.
[0079] Also, while hook and loop fastening material will work satisfactorily, in some embodiments other fastening means may be employed, including releasable adhesives that allow repositioning and replacement of pads.
[0080] Next, a therapist will make judgments about the zones where pressure ought to be applied. In the embodiment of FIGS. 1-7 , two compression zones are achieved by using two tensioners 28 and 30 and two independent circuits 24 and 26 . A therapist can determine the course of circuits 24 and 26 by positioning guides 34 and 32 A- 32 E. In the disclosed embodiment, circuit 24 is arranged with four crossovers between shells 10 and 12 , which determine the compression forces between the shells.
[0081] For circuit 24 , the compression affects primarily the knuckles at the base of the fingers. Specifically, the crossover between courses 24 A and 24 B applies pressure on the proximal and outer side of the knuckle for forefinger I. The crossover between courses 24 B and 24 C applies pressure on the distal side of the knuckles for fingers I and M, at the gap between those fingers. The crossover between courses 24 C and 24 D applies pressure on the distal side of the knuckles for fingers A and S, at the gap between those fingers. The crossover between courses 24 D and 24 E applies pressure on the distal and outer side of the knuckles for finger S.
[0082] For circuit 26 , compression affects the portion of the hand H spaced proximally from the knuckles. Specifically, the crossover between courses 26 A and 26 B applies pressure on the pinky side of the hand about midway between the fingers and wrist. The crossover between courses 26 B and 26 C applies pressure on the pinky side of the hand at a position that is fairly close to the wrist. The crossover between courses 26 C and 26 D applies pressure on the thumb side of the hand between the thumb T and wrist. The crossover between courses 26 D and 26 E applies pressure on the thumb side of the hand about midway between thumb, T and forefinger I.
[0083] It will be appreciated that therapist can adjust the routing of courses 24 and 26 to change the manner in which pressure is applied to hand H. Also, since panels 14 of shells 10 and 12 are relatively stiff, the forces applied by the shells are substantially perpendicular to the palmar and dorsal surfaces of hand H, so that the hand is not squeezed laterally.
[0084] Winders 28 and 30 can be independently adjusted to establish the compression forces and their respective regions. By tightening (loosening) circuit 24 compression forces can be increased (reduced) around the knuckles at the base of the fingers. By tightening (loosening) circuit 26 compression forces can be increased (reduced) around the portion of hand H between the wrist and the knuckles at the base of the fingers. Normal forces will be transmitted primarily by pad 20 . Pad 22 will usually be a softer material to increase comfort and to provide feathering of compression forces near the edges of shells 10 and 12 .
[0085] Initially, the compression forces will be the established at the time the therapist first places the device on hand H. However, the patient will be taught how to independently place the device on hand H without professional assistance. Thereafter, the patient can wear the device during the time periods recommended by the therapist. In some cases, a patient may be asked to wear a compression glove under the device in order to assist in reducing edema, but this choice will depend upon the specific condition of this patient.
[0086] To don the device, one will start with winders 28 and 30 arranged to fully slacken circuits 24 and 26 . A patient can then slip the fingers between shells 10 and 12 on the proximal edge of the shells. When hand H is positioned as shown in FIGS. 1-3 , winders 28 and 23 can be adjusted to produce the tension in circuits 24 and 26 recommended by a therapist.
[0087] During the course of a day, a patient may find it necessary to increase or decrease the compression forces. Since winders 28 and 30 are easily adjusted, these compression forces can be easily changed. Also, the patient can be given a supply of replacement pads in order to replace pad 22 when it becomes soiled.
[0088] Also, the device is easily removed by using winders 28 and 30 to remove all tension on circuits 24 and 26 . Thereafter, hand H is withdrawn in a direction opposite to the direction used to don the device. Accordingly, the patient can temporarily remove the device for routine activities such as bathing.
[0089] When the device is worn, the compression forces will tend to reduce the edema. The compression forces will tend to urge edematous fluids in a proximal direction. Also, the patient's fingers and thumb will remain highly mobile. Thus, the patient can perform most daily activities. Accordingly, the fingers and thumb will be routinely exercising, which will produce a natural pumping effect that tends to reduce edema. In addition, the device is relatively open so that air can reach the hand H, which will enhance comfort and avoid elevated temperatures.
[0090] The patient will still need to periodically visit a therapist to check the progress and to perform different types of CDT. At these visits the therapist can inspect the condition of the body part. If necessary, therapist can change pads 20 and 22 to a different type of pad.
[0091] The advantages of this device are: time savings and ease of application, comfort, safety, and therapeutic efficacy. Using appropriate materials and an effective tensioning system, this device offers a high working, low resting pressure environment similar to that which his offered to lymphedema patients during CDT using short stretch (non-elastic) bandaging materials. Furthermore compression is achieved while avoiding trauma to the lymphatic, hemodynamic and neurological system, by using customizable thermoplastics and padding to areas like the hand, forearm, upper arm, calf, thigh and other body parts.
[0092] It will be appreciated that various modifications may be implemented with respect to the above described embodiments. In some cases a variety of shells may be manufactured in sizes and shapes designed to accommodate the affected body part of most patients. In some embodiments shells may be provided with a large number of molded eyes or lacing hooks, so that the therapist can effectively route a tensioning cord through almost any desired route by selecting different eyes or hooks. In still other embodiments, the winders may be mounted in fixed positions, in which case the ligature network is adjusted by changing the routing of the cords connected to the tensioner. In some cases the ligature network will be formed of a single cord but will be segregated into different independent sections by tying some intermediate point on the cord to an anchor, so that tension is not transferred from one section to the other. While a double layer pad is disclosed, in some embodiments the pad may be a single layer or may employ more than two layers.
[0093] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | A compression device can treat edema with a number of curved shells, each having an internal pad. A ligature network employing tensioners is routed across the shells for compressing them. Tensioners on at least some of the shells can separately adjust tension in different portions of the ligature network. The ligature network is (a) releasably mounted on the shells, and (b) repositionable to allow spatial adjustment of compression forces produced by the compression device. By adjusting the routing of the ligature network across the shells, tailored compression forces are provided. With a body part embraced by the padded shells, tension is separately adjusted in different portions of the ligature network to provide different compression forces at spaced positions along the plurality of padded shells. | 39,876 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to French Patent Application No. 1202672 filed Oct. 5, 2012. This application is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to a method of transmission between a transmitter and a receiver using a mode of adaptive modulation and coding, wherein the modulation and coding are selected based on the comparison of a characteristic variable of the signal to noise ratio measured by the receiver with a threshold value plus a margin, which margin is variable depending on the prior change in the signal to noise ratio.
BACKGROUND OF THE INVENTION
The transmissions, in particular by satellite in the Ka (K-above) and EHF (Extremely High Frequency) bands are sensitive to various different phenomena that can degrade the budget of the link between a transmitter and a receiver. These phenomena can lead to very rapid variations, such as masking or interference. The connection of the link can then be reduced by several decibels per second.
Other phenomena, such as weather related variations, in particular rain fade or antenna pointing errors have rapid effects that lead to a reduction of the gain by a few tenths of decibels per second.
Finally, other phenomena, such as the geographic location or situation of the receiver when it is mobile may result in slower variations of the gain of the link of the order of a hundredth of a decibel per second.
In order to be better adapted to these variations, mechanisms for adapting the modes of modulation and coding have been implemented. The goal is to dynamically adapt the parameters of the waveform so as to be well adapted to the link budget. This mechanism is known by the acronym AMC in English, for “Adaptive Modulation and Coding”.
As it is known per se, the AMC mechanism makes it possible, by comparing the signal to noise ratio to the baseline reference values to define the mode of modulation and coding adapted to the conditions of the link.
The propagation of information between the entities of the chain of transmission for transmitting the information pertaining to the state of communication and orders of change in modulation and coding requires a substantial amount of time, so that when the signal to noise ratio decreases, it takes a certain amount of time for the transmitter to be able to react to this decrease.
In order to ensure that the signal to noise ratio of the link is never less than a baseline reference signal to noise ratio necessary for the receiver, it is a well known practice to provide for a margin, added to the baseline reference signal to noise ratio in order to anticipate the losses of the link budget and to be able to change the modulation and coding early enough before the conditions become far too degraded.
This margin is called AMC margin.
The AMC margin depends on the worst case scenario variation of link budget to which the transmission system must be resistant as well as the reaction time of the system.
In general, the AMC margin is static and is of the order of 2 to 3 decibels for transmissions in the Ka band and the AMC margin may be higher in the EHF band.
When the conditions for signal propagation are stable, typically with a clear sky, the margin is unnecessary since the signal to noise ratio does not vary. The transmission power is thus 2 to 3 decibels higher than necessary thereby causing a decrease of the speed or the bandwidth of the order of 50% to 100%.
It is a known technique to make the AMC margin vary based on the historical information related to the change in the signal to noise ratio.
These solutions have the drawback of sometimes impose unnecessarily high AMC margins. The variation in signal to noise ratio may be of the order of 20 decibels, leading to the possibility of retaining an AMC margin of around several decibels, without this improving the communication, the phenomena deemed to have caused the variation in signal to noise ratio having been very brief and thus not having needed to be compensated for by a change in modulation or coding.
The aim of the invention is to provide a method of transmission with adaptive modulation and coding in which the changing of the AMC margin:
makes possible the optimisation of the transmission power when conditions for signal propagation are stable does not lead to changes in the mode of coding or modulation considered unnecessary, in particular in the event of masking or interference.
SUMMARY OF THE INVENTION
To this end, the object of the invention relates to a method of transmission of the aforementioned type, characterized in that the margin changes based on a statistical function with an order greater than 1 of the characteristic variable of the signal to noise ratio measured by the receiver over at least one time horizon.
According to particular embodiments of implementation, the method comprises of one or more of the following characteristic features:
the margin changes based on a linear combination of statistical functions with an order greater than 1 of the characteristic variable of the signal to noise ratio measured by the receiver over several time horizons of different lengths; the number of time horizons considered is between 2 and 4; the or each time horizon has a duration between 2 and 90 seconds; the statistical function depends on the standard deviation of the characteristic variable of the signal to noise ratio measured by the receiver; the statistical function depends on the standard deviation of the characteristic variable of the signal to noise ratio measured by the receiver or on a predetermined maximum value of the standard deviation if the standard deviation of the characteristic variable of the signal to noise ratio measured by the receiver is greater than the maximum value; the said method includes the calculation of a predicted signal to noise ratio that corresponds to the difference between the measured signal to noise ratio minus at least one variable margin, and the modulation and coding are selected based on the comparison of the predicted signal to noise ratio with a threshold value plus a fixed margin.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood upon reading the description which follows, provided solely by way of example and with reference made to the drawings in which:
FIG. 1 is a schematic view of a transmission installation for the implementation of the method according to the invention; and
FIG. 2 is a flowchart of the algorithm for determination of the modes of modulation and coding in the transmission method according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1 a transmission installation 10 is represented that demonstrates the implementation of a transmitting station 11 a satellite 12 and a ground receiving station 14 . The transmission takes place for example by band or in EHF band from the transmitting station 11 to the ground station 14 via satellite 12 , by any known means considered suitable. In a similar fashion, the transmission also takes place in the reverse direction.
The transmission method implements a mechanism for adapting the modes of modulation and coding known by the acronym AMC in English for “Adaptive Modulation and Coding” that makes it possible to dynamically adapt the parameters of the waveform so as to be well adapted to the link budget.
The ground station 14 includes the means for transmitting to the station 11 via the satellite 12 the information concerning the measured characteristics of the transmission, and the requests made by the receiving station in order to satisfy its needs.
The station 11 comprises, as is known per se the means for determination of the mode of modulation and coding to be used for the transmission based on the information received from the station 14 , in particular depending on the signal to noise ratio required by the station 14 , this latter being denoted by C/N 0 — predicted .
By design, the station 11 is capable of determining the mode of modulation and coding selected by comparison of the signal to noise ratio required by the ground station 14 C/N 0 — predicted with a baseline reference signal to noise ratio C/N 0 — ref plus a fixed AMC margin, denoted by Margin fixe . The fixed AMC margin Margin fixe is for example equal to 0.5 decibels (dB).
This figure also provides an illustration of the clouds 16 , which can degrade the conditions of transmission, and thereby reduce the signal to noise measured by the ground station 14 , possibly requiring the modification of the mode of modulation and coding.
As is known per se, the transmission is carried out by frame, also called packet according to the mode of modulation and coding.
The algorithm described with reference to FIG. 2 is set to run continuously during the transmission partially in the ground station 14 and in the station 11 by the means for computing that deploy the appropriate computer programmes.
As illustrated in FIG. 2 , during the transmission and for each group of n of k frames a channel error denoted by ErrCanal(n) is calculated during the step 100 by the receiver, that is, the ground station 14 in the example considered. A group of k frames is called super frame SF (k is chosen in order for the duration of a super frame to be of the order of 100 ms so as to be statistically significant). This channel error is the difference between the signal to noise ratio measured by the ground station 14 over the super frame n denoted by ΔC/N 0 — meas — ST — n and the transmission power of the station 11 denoted by PIRE Consigne — ST — n .
Thus, ErrCanal(n)=ΔC/N 0 — meas — ST — n −PIRE Consigne — ST — n .
During the step 102 , and for several different time horizons numbered i, the standard deviation of the channel denoted by DACMMA_σ i is determined by the receiver over the N i last seconds constituting the time horizon i considered.
For example, the time horizons constitute periods of 3, 10, 30 and 60 seconds such that N 1 =3; N 2 =10; N 3 =30; N 4 =60.
Thus, the standard deviation of the channel error for a determined time horizon i is given by
DACMMA_σ i = [ 1 nST i ∑ n = 1 nST i ChannelErr ( n ) 2 - ( 1 nST i ∑ n = 1 nST i ChannelErr ( n ) ) 2 ] 1 / 2
wherein
nST i is the number of super frames in the time horizon i. During the step 104 a narrow (bounded) standard deviation is determined for each time horizon i by the receiver. This narrow standard deviation is denoted by Clip(i) and is given by Clip (i)=Min(DACMMA_σ i ; DACMMA MaxVariation) wherein DACMMA MaxVariation is a constant. Thus, the narrow standard deviation is equal to the standard deviation of the channel error if the latter is less than a predetermined maximum value of the standard deviation denoted by DACMMA MaxVariation or equal to the predetermined maximum value of the standard deviation if not, this being so in order to not take into account extremely large variations in the standard deviation.
During step 106 , the receiver determines a time variable margin constituted by a linear combination of narrow standard deviations Clip(i) calculated over the four time horizons. Thus, the time variable margin is written as follows Margin time variable =α 1 Clip (1)+α 2 Clip (2)+α 3 Clip (3)+α 4 Clip (4) where α 1 , α 2 , α 3 and α 4 are non zero positive real numbers. By default, the coefficients á 1 , á 2 , á 3 and á 4 are all taken to be equal to 1.
During the step 112 , the receiver calculates a predicted signal to noise ratio denoted by C/N 0 — predicted which corresponds to the difference between the measured signal to noise ratio minus the variable margin calculated in step.
Thus C/N 0 — predicted =C/N 0 — meas −Margin time variable .
It is conceivable that with such a method, the AMC margin can be maintained at a highly reduced level during periods of low variation in the signal to noise ratio, in particular the periods with clear skies and that the AMC margin is shown to be increased in a rapid manner during significant but not abrupt changes in the signal to noise ratio, thereby making it possible to adequately anticipate the modifications in mode of modulation and coding in order for the signal to noise ratio to be maintained in all circumstances at a level higher than the signal to noise ratio required by the receiver, without the signal to noise ratio however being constantly much higher than the signal to noise ratio required at the receiver, in particular during periods of clear weather conditions. | The method of transmission between a transmitter and a receiver using a mode of adaptive modulation and coding, wherein the modulation and coding are selected based on the comparison of a characteristic variable of the signal to noise ratio measured by the receiver with a threshold value plus a margin, which margin is variable depending on the prior change in the signal to noise ratio.
The margin changes based on a statistical function of a higher order than 1 of the characteristic variable of the signal to noise ratio measured by the receiver over at least one time horizon. | 13,351 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 11/615,835 filed on Dec. 22, 2006, and is also related to U.S. application Ser. No. 11/615,854 filed on Dec. 22, 2006, which applications claim priority to U.S. provisional application No. 60/758,494 filed on Jan. 12, 2006. These applications are hereby incorporated by reference as if fully disclosed herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an apparatus for sewing fabrics and attaching rings to fabrics wherein the fabrics are, for example, usable in coverings for architectural openings and more particularly to an apparatus that takes a single or multi-ply sheet of material and either forms hems, tunnels, hobbles, and/or attaches rings to the material so it is suitable for connection to a control system for a covering for an architectural opening.
2. Description of the Relevant Art
While early forms of coverings for architectural openings consisted principally of draped fabrics or fabrics which were gathered along a top edge so as to form drapery, in recent years designer window coverings have taken on many numerous forms. Included in those forms are coverings that utilize fabric that can be raised or lowered and gathered in the process wherein rings or other guide systems are incorporated into the fabric to slidably confine lift cords or the like. Further, in Roman shade type products, horizontal droops in the fabric, otherwise referred to as hobbles, might be formed in the fabric for aesthetics.
While sewing machines have been used to form hobbles or attach rings to fabric, it was all hand operated with an operator literally moving and shifting the fabric as it was passed through an appropriate sewing machine for either stitching the fabric to provide hems or tunnels across the width of the fabric or to attach suitable guide rings.
There has, accordingly, been a need in the industry for automating the fabrication of fabric for use in coverings for architectural openings or in the use of fabrics that might have other uses wherein stitching, hobbles, the attachment of rings, or the like, is a requisite.
SUMMARY OF THE INVENTION
The apparatus of the present invention includes a vertically oriented and adjustable lift rack to which a top edge of a fabric material can be secured with the remainder of the material hanging by gravity through a lower housing where clamps are utilized to control the fabric during operations thereon.
A sewing carriage including a pair of tandem sewing machines having different capabilities are mounted together for movement in unison in a reciprocal path back and forth across the width of the fabric. One sewing machine is adapted to stitch the fabric from one side edge to the other while the other sewing machine is adapted to attach horizontally spaced rings to the fabric in a return movement of the sewing machines across the width of the fabric. When stitching the fabric, which might be a dual layer or dual panel fabric, the layers can be handled separately so that one layer might have hobbles formed therein while the other layer remains flat. Tunnels are also defined by the stitching in which rigidifying bars might be inserted. When forming tunnels and/or attaching guide rings to the fabric, a tucker blade is utilized to advance a horizontal section of the fabric into a position for engagement by the sewing machines with the tucker blade being retractable before stitching or the attachment of rings to the fabric. A vacuum chamber is also utilized in one embodiment to gather a horizontal segment of one layer of the fabric to form a hobble while the other layer is unaffected by the vacuum so that both layers can be stitched together with a hobble being formed in one layer. In a second embodiment, the hobble is formed by manipulating the layers with the lift rack.
A lower releasable clamp in the first embodiment is positioned beneath the sewing machines and has three distinct positions with an open position permitting the free passage of at least a layer of material therethrough, a soft clamp position providing some resistance to movement of the fabric with brushes for removing lint wrinkles or the like from the fabric and a hard clamp position where the fabric can be positively gripped during a sewing operation.
When the sewing machines have completed one operation of stitching, forming hobbles and/or sewing rings to the fabric, they are repositioned at a home position so the fabric can be elevated or dropped a predetermined amount, depending on the embodiment, for a repeat of the afore-described operation whereby vertically adjacent rows of hobbles, tunnels, rings, or the like, are formed in the fabric until the entire fabric has been treated. It can then be removed from the lift rack and is suitable for attachment to a control system for a covering for an architectural opening in which the fabric forms an integral part.
Other aspects, features, and details of the present invention can be more completely understood by reference to the following detailed description of the preferred embodiment, taken in conjunction with the drawings and from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic fragmentary isometric of the apparatus of the present invention.
FIG. 2 is a front isometric of a fabric formed from the apparatus of FIG. 1 .
FIG. 3 is a rear isometric of the fabric shown in FIG. 2 .
FIG. 4 is an isometric similar to FIG. 1 showing the sewing machines separated as they might be for maintenance purposes.
FIG. 5 is a diagrammatic isometric of the apparatus illustrating a first step in treating a fabric.
FIG. 6 is a diagrammatic isometric similar to FIG. 5 showing a second step in the treatment of a fabric.
FIG. 7 is a diagrammatic isometric similar to FIG. 6 showing a third step in the treatment of a fabric.
FIG. 8 is a diagrammatic isometric similar to FIG. 7 showing a fourth step in the treatment of a fabric.
FIG. 9 is a diagrammatic isometric similar to FIG. 8 showing a fifth step in the treatment of a fabric.
FIG. 10 is a diagrammatic isometric similar to FIG. 9 showing a sixth step in the treatment of a fabric.
FIG. 11 is a diagrammatic isometric similar to FIG. 10 showing a seventh step in the treatment of a fabric.
FIG. 12 is a diagrammatic isometric similar to FIG. 11 showing an eighth step in the treatment of a fabric.
FIG. 13 is an enlarged diagrammatic fragmentary section taken along line 13 - 13 of FIG. 5 .
FIG. 14 is an enlarged diagrammatic fragmentary section taken along line 14 - 14 of FIG. 7 .
FIG. 15 is a section similar to FIG. 14 showing the vacuum chamber advanced into a clamping position with the fabric.
FIG. 16 is a section similar to FIG. 15 with the vacuum chamber having drawn the fabric thereinto.
FIG. 17 is a section similar to FIG. 16 with one layer of fabric having been gripped by a lower clamp and removed from the vacuum chamber.
FIG. 18 is an enlarged diagrammatic section taken along line 18 - 18 of FIG. 8 .
FIG. 19 is a section similar to FIG. 18 with the tucker blade having been tilted.
FIG. 20 is an enlarged diagrammatic fragmentary section taken along line 20 - 20 of FIG. 9 .
FIG. 21 is an enlarged diagrammatic fragmentary section taken along line 21 - 21 of FIG. 10 .
FIG. 22 is a diagrammatic section similar to FIG. 21 showing hobbles and rings having been formed in the fabric in a plurality of horizontal rows.
FIG. 23 is an enlarged fragmentary section taken along line 23 - 23 of FIG. 20 .
FIG. 24 is a section taken along line 24 - 24 of FIG. 23 .
FIG. 25 is an enlarged fragmentary section taken along line 25 - 25 of FIG. 21 .
FIG. 26 is a fragmentary section taken along line 26 - 26 of FIG. 25 .
FIG. 27 is a section similar to FIG. 25 showing the ring and fabric having been shifted for receipt of the sewing needle within the ring.
FIG. 28 is a section taken along line 28 - 28 of FIG. 27 .
FIG. 29 is a fragmentary section taken along line 29 - 29 of FIG. 14 showing the lower clamp in a soft clamping position.
FIG. 30 is a section similar to FIG. 29 showing the lower clamp in a full clamping position.
FIG. 31 is a section similar to FIG. 29 showing the lower clamp in an open position.
FIG. 32 is a fragmentary section taken along line 32 - 32 of FIG. 14 .
FIG. 33 is a top plan view of the portion of the apparatus shown in FIG. 32 .
FIG. 34 is an enlarged fragmentary section taken along line 34 - 34 of FIG. 32 .
FIG. 35 is a fragmentary section taken along line 35 - 35 of FIG. 26 .
FIG. 36 is a section taken along line 36 - 36 of FIG. 35 .
FIG. 37 is a section similar to FIG. 36 showing the ring clamp in an open position.
FIG. 38 is a section taken along line 38 - 38 of FIG. 14 .
FIG. 39 is an enlarged fragmentary section similar to FIG. 38 showing the drive mechanism for linearly translating the sewing machines with the view taken at the left end of the apparatus when the sewing machines are positioned at the left end.
FIG. 40 is a fragmentary section similar to FIG. 39 with the sewing machines positioned at their home position at the right end of the apparatus.
FIG. 41 is an isometric of a second embodiment of the apparatus of the present invention.
FIG. 42 is a front isometric of a fabric formed from the apparatus of FIG. 41 having hobbles formed on the front face thereof.
FIG. 43 is a rear isometric of the panel shown in FIG. 42 showing tucks and rings sewed to the panel.
FIG. 44 is an isometric similar to FIG. 41 showing the sewing machines separated as for maintenance purposes.
FIG. 45 is a front isometric of the apparatus of FIG. 41 with the upper edge of two sheets of fabric material anchored to lift towers of the apparatus in preparation for processing a fabric as viewed in FIGS. 42 and 43 .
FIG. 46 is an isometric similar to FIG. 45 with the panels of fabric having been elevated by the lift towers prior to processing the fabric panels.
FIG. 47 is an isometric similar to FIG. 46 with the panels of fabric material having been dropped into a position for initial operation of the apparatus.
FIG. 48 is an isometric similar to FIG. 47 with the tucker blade having been advanced into the sheets of fabric material for forming a tuck in the material.
FIG. 49 is an isometric similar to FIG. 48 with the tucker blade having been removed from the fabric sheets and the ring sewing machine positioned for initiating an attachment stitch into the fold of the sheets of material.
FIG. 50 is an isometric similar to FIG. 49 with the ring sewing machine positioned to initiate a stitch into a ring for attachment to a fold in the sheets of material.
FIG. 51 is an isometric similar to FIG. 49 with a complete fabric having been formed showing the lift tower at its lowermost position.
FIG. 52 is an isometric similar to FIG. 51 with the lift tower having elevated the completed fabric.
FIG. 53 is an enlarged section taken along line 53 - 53 of FIG. 45 .
FIG. 54 is an enlarged section taken along line 54 - 54 of FIG. 46 .
FIG. 55 is an enlarged section taken along line 55 - 55 of FIG. 47 .
FIG. 56 is an enlarged section taken along line 56 - 56 of FIG. 48 .
FIG. 57 is a section similar to FIG. 56 with the stabilizing clamp having been energized.
FIG. 58 is a section similar to FIG. 57 with the stitching machine sewing a tuck into the sheets of material.
FIG. 59 is a section similar to FIG. 58 with the ring sewing machine positioned to initiate a stitch along a folded edge of the sheets of material.
FIG. 60 is an enlarged section taken along line 60 - 60 of FIG. 49 .
FIG. 61 is an enlarged section taken along line 61 - 61 of FIG. 60 .
FIG. 62 is an enlarged section taken along line 62 - 62 of FIG. 58 .
FIG. 63 is a section taken along line 63 - 63 of FIG. 62 .
FIG. 64 is a section similar to FIG. 61 where the ring sewing machine is positioned for sewing a ring to sheets of material that do not have a hobble but are merely formed with tucks to which rings are attached.
FIG. 65 is a rear isometric showing a panel of fabric material having tucks and rings sewn thereto but with no hobbles.
FIG. 66 is a section similar to FIG. 64 wherein the ring sewing machine is positioned to sew a ring to the panels of fabric material where no tuck is formed in the material.
FIG. 67 is a rear isometric showing a panel where rings are sewn to the panel but no tucks or hobbles are formed on the panel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Looking first at a first embodiment of the invention shown in FIGS. 1-40 , the apparatus 41 ( FIG. 1 ) can be seen to include a housing 42 on which a lift rack 44 is mounted. As will be described hereafter, the housing includes various components of the apparatus for handling fabric that is being treated while the lift rack supports an upper edge of the fabric and is vertically movable to raise or lower the fabric into or out of the housing. As seen in FIGS. 2 and 3 , a completed fabric 46 which could be formed with the apparatus of the present invention is illustrated. It is shown to include a backing or rear layer 48 and a front layer 50 with the front layer secured to the backing layer along horizontal vertically spaced tucks 52 in the fabric in a manner whereby a plurality of vertically aligned horizontally disposed hobbles or droops 54 in the fabric are formed so the fabric resembles a Roman shade. A tunnel 56 can be formed along the top and bottom edges of the fabric for receipt of a stiffening bar (not seen) with the tunnel possibly being formed from two horizontal lines of stitching that are vertically spaced or by folding the edge and with one stitch forming a hemmed edge. The top tunnel would typically be formed in the fabric before the fabric is treated with the apparatus of the present invention. The top edge of the fabric is then supported in the lift rack 44 so the fabric is properly disposed for processing within the apparatus.
The lift rack 44 consists of a pair of horizontally spaced vertically extending support towers 58 that are interconnected at their top ends to support a horizontal drive shaft 60 and a motor 62 for reversibly rotating the drive shaft. The lift towers have lift cords (not seen) disposed therein with the lift cords being operably connected to opposite ends of a vertically adjustable horizontally extending transverse lift bar 66 which is referred to hereafter as an upper clamp. Reversible rotation of the drive shaft raises or lowers the upper clamp for purposes to be described hereafter.
The housing 42 includes a number of operative components which will be described hereafter and which are adapted to grip and manipulate a virgin fabric 68 ( FIGS. 5-9 ) to properly position the fabric so that one or both of a pair of sewing machines 70 and 72 mounted on the housing for reciprocal horizontal translating movement can direct sewing operations to the fabric in a preselected manner.
One of the sewing machines 70 is provided to stitch horizontal lines in the fabric while the other 72 is provided to attach guide rings 74 ( FIGS. 3 , 21 , 22 and 25 - 28 ) commonly found in certain coverings for architectural openings such as Roman Shades. Both sewing machines are conventional for their intended purpose and will therefore only be described broadly hereafter with specific regard to their operation and relationship to the fabric being treated.
The apparatus is designed to treat virgin fabric 68 in several different ways so the fabric can be formed with a plurality of hobbles 54 , a plurality of guide rings 74 attached thereto, a plurality of horizontal tunnels 56 on the front or rear of the fabric, and various combinations of the above. The treatments are accomplished in one continuous operation of the apparatus.
The apparatus is controlled through a conventional computer control module 76 that energizes various pumps, motors, and pneumatic pistons for achieving the various operations performed by the apparatus on the fabric. A detailed description of the software for driving the control module will not be described herein but suffice it to say the various operating mechanisms in the apparatus are controlled from the module and with an appropriate computer-controlled system.
The sewing machines 70 and 72 are mounted on two interconnected halves 78 and 80 , respectively, of a sewing machine carriage 82 with the halves typically being interconnected so the sewing machines move in unison but can be separated as shown in FIG. 4 for individual maintenance of the machines. One sewing machine 70 in the preferred embodiment is a walking foot/needle feed lock stitch machine used to stitch the fabric in a manner to become clear hereafter and might be for example a Seiko SSH-88LDC-DTFL machine manufactured by Seiko of Japan. The other machine 72 in the preferred embodiment is a conventional button sewing machine which might be for example a Pfaff 3307 button or ring-stitching machine manufactured by Pfaff of Belgium. The ring-stitching machine, while normally being used for sewing buttons, can sew rings of the type used as guide rings 74 on fabrics for coverings for architectural openings wherein the rings are retained in a hopper (not seen) on the machine and fed to the sewing head where they are connected to the fabric. It is not important which of the two sewing machines is on the right or on the left as they both move in unison across the entire width of the fabric being treated.
The interconnected halves 78 and 80 of the carriage 82 for the sewing machines 70 and 72 are mounted on a horizontally disposed linear bearing or guide track 84 for reciprocal horizontal movement as the carriage, with the sewing machines thereon, is reversibly translated across the width of the housing 42 . The sewing machines on the carriage are typically stationed at a home position at the right end of the apparatus as viewed in FIG. 1 and during one operation on a virgin fabric 68 , the carriage translates to the left for a stitching operation and then back to the right for a ring attaching operation where it remains in its home position until another row of operations is performed on the fabric. Movement of the carriage is accomplished with a tensioned timing belt 86 as best appreciated by reference to FIGS. 1 and 38 - 40 , which is anchored to the housing 42 at opposite ends with fixed brackets 88 . One of the carriage halves 78 has a motor (not seen) that reversibly drives a gear wheel 90 in operative engagement with the timing belt with the timing belt passing across idler pulleys 92 on opposite sides of the driven gear wheel. It can therefore be appreciated that rotation of the gear wheel in one direction causes the carriage 82 to translate linearly in one direction across the apparatus and rotation of the gear wheel in the opposite direction causes the carriage to translate linearly in the opposite direction so it can be moved from one side of the apparatus 41 to the other at predetermined and/or intermittent speeds.
FIGS. 5-12 illustrate diagrammatically the various steps that can be applied to a virgin fabric 68 with the apparatus 41 of the present invention in forming a completed fabric 46 of the type illustrated in FIGS. 2 and 3 . The completed fabric in the example shown includes a plurality of horizontal hobbles or loops 54 formed in vertically adjacent rows on the front layer of the fabric ( FIG. 2 ) and a plurality of horizontally extending vertically spaced tucks 52 having horizontally spaced guide rings 74 secured thereto formed on the rear layer 48 of the fabric as seen in FIG. 3 . Looking first at FIG. 5 , a virgin fabric consisting of two layers of sheet material that have been pretreated to form a tunnel 56 along a top edge thereof with a rigidifying slat (not seen) possibly inserted therein is clamped to the upper clamp 66 . The upper clamp includes a pair of horizontal bars 94 and 96 that can be clamped together or released. In the released position, the top edge of the virgin fabric 68 can be inserted between the bars and in the clamped position releasably secured between the bars. While the fabric could be positioned at any place across the width of the upper clamp, if in fact the fabric were narrower than the width of the lift rack 44 as illustrated, it is preferably positioned along one side edge (illustrated as the right side edge) for a purpose to be more clear hereafter.
After the virgin fabric 68 is secured to the upper clamp 66 , the upper clamp is elevated with the motor 62 and drive shaft 60 to the position of FIG. 6 so the fabric is substantially vertically suspended with its lower edge at the top of the housing 42 . The upper clamp is then lowered and depending upon the operations to be applied to the virgin fabric, the two layers of the fabric can be maintained together or separated so as to straddle various components within the housing. Once the layers of the fabric are positioned for the operations to be applied thereto within the housing, the upper clamp is lowered to an initial operative position shown in FIG. 7 . Thereafter, a hobble 54 is formed in the front layer 50 and a reciprocating horizontally disposed tucker blade 98 , which will be described in more detail later, which is normally in a retracted position adjacent to the front layer of the fabric, is advanced as shown in FIG. 18 to form a tuck 52 off the rear of the fabric on which the sewing machines 70 and 72 can operate. The tuck in the fabric is then gripped with a tuck clamp 100 (to be described later) and the tucker blade retracted so a first operation of the sewing machines as shown in FIG. 9 can be initiated with the sewing machines translating from their home position at the right end of the apparatus 41 to the left end of the apparatus. As shown in FIG. 10 , a subsequent pass of the sewing machines from the left end of the apparatus back to their home position allows one of the sewing machines to perform a separate operation. For example, in the fabric 46 illustrated in FIGS. 2 and 3 where both hobbles 54 and guide rings 74 are applied to the fabric, the movement from the home position to the left as shown in FIG. 9 would be used to form a horizontal stitch with one of the sewing machines 70 along the tuck to hold the two layers of material in the tuck together and the reverse movement of the sewing carriage 82 , as shown in FIG. 10 , would be used for attaching the guide rings with the other sewing machine 72 along the edge of the tuck. After one such operation, one row of a tunnel 56 , defined by a tuck, with its associated guide rings is completed along with a hobble and at that time, the upper clamp 66 is elevated a predetermined distance, i.e. the height of a hobble, and the operation is repeated. By repeating the operation a new row is formed and the upper clamp is again elevated a predetermined amount as shown in FIG. 11 until the entire fabric 46 has been completed as illustrated in FIG. 12 .
Referring to FIG. 13 , which is a vertical section through the apparatus 41 with the layers 48 and 50 of virgin fabric having been connected to the apparatus as shown in FIG. 5 with the upper clamp 66 , the internal working components of the apparatus are shown diagrammatically. It will there be seen beneath the upper clamp is the tuck clamp 100 that includes an elongated horizontally disposed generally U-shaped rail 101 extending the width of the apparatus and connected to a pair of pneumatic cylinders 102 mounted at opposite ends of the rail with mounting brackets 104 on the rear face of the rail. A lower edge of the rail carries a beveled strip 106 supporting a spring steel upper clamp jaw 108 with a gripping edge of material 110 secured on its lower face along a distal edge thereof. The pneumatic cylinders 102 are operative to raise or lower the rail and the upper clamp jaw in a manner such that in a lowered position of the tuck clamp, as seen for example in FIG. 19 , the upper clamp jaw engages a tuck 52 of material and presses the material against a platen 112 with a gripping upper surface mounted vertically therebeneath on the housing 42 . In the normal elevated position of the tuck clamp, a space is defined between the upper clamp jaw and the platen through which a tuck in the fabric can be advanced for proper positioning relative to the sewing machine carriage 82 as will be discussed later.
In horizontal opposing relationship to the tuck clamp rail 101 and positioned horizontally between the pneumatic cylinders 102 and beneath a support plate 114 in the housing is a vacuum clamp 116 . The vacuum clamp includes an elongated horizontally disposed plenum 118 where a low pressure is maintained and a horizontally aligned elongated vacuum chamber 120 communicating with the plenum and having a horizontal slot-like opening 122 in a front wall 124 thereof facing the tuck clamp rail. While the opening 122 extends the full length of the vacuum chamber, an extendable closure tape 126 ( FIGS. 32-34 ) is mounted at one end of the chamber to be selectively extended across a portion of the chamber to close a portion of the opening if the fabric is not wide enough to cover the entire length of the opening. The plenum and vacuum chamber are reciprocally mounted on the plungers 128 of a second pair of pneumatic cylinders 130 secured to the support plate 114 so that when the plungers for the cylinders are extended, the front wall 124 of the vacuum chamber is advanced into engagement with the tuck clamp rail 101 . Of course, retraction of the vacuum chamber with a retraction of the plungers 128 of the second pair of pneumatic cylinders 102 withdraws the chamber and moves it to the left as viewed in FIG. 13 so as to define a space between the rail of the tuck clamp and the vacuum chamber. The plenum for the vacuum chamber is connected with a conventional conduit to a selectively operable vacuum pump 132 positioned within the housing.
The tucker blade 98 is a horizontal elongated blade of thin profile extending the full width of the apparatus 41 and mounted on a horizontal support plate 133 secured to the rack 134 of a rack and pinion reciprocal drive system 136 ( FIG. 13 ). The pinion 138 of the drive system is reversibly driven by a motor (not seen). Obviously, rotation of the pinion in one direction drives the rack and the tucker blade horizontally to the right as viewed in FIG. 13 into an extended position as seen in FIG. 18 while rotation of the pinion in the opposite direction retracts the tucker blade to its retracted position of FIG. 13 . In the extended position shown in FIG. 18 , it is extended between the upper clamp jaw 108 and platen 112 of the tuck clamp 100 with the front elongated edge 140 of the tucker blade being positioned beyond the tuck clamp immediately adjacent to the sewing carriage 82 . The horizontal support plate 132 on which the tucker blade is mounted is supported on a lever arm 142 pivotal about a pivot shaft 144 by a pair of low-pressure pneumatic cylinders 145 which could in fact be a gas spring even though in the disclosed embodiment it is a pneumatic cylinder carrying low pressure. The pneumatic cylinders are therefore adapted to pivot the lever arm and thus the tucker blade about the pivot shaft for a purpose to become clear hereafter.
A lower clamp 146 is positioned beneath the tucker blade 98 at an elevation also beneath the platen 112 . The lower clamp has a horizontally movable vertically disposed bar 148 that supports pairs of large 150 and small 152 pneumatic cylinders which are probably best appreciated by reference to FIGS. 29-31 . The movable vertically disposed bar confronts a second vertically disposed bar 154 that is fixedly mounted on a vertically movable support plate 156 . The fixedly mounted bar has an upper horizontal rearwardly directed brush 158 with a plurality of flexible bristles that overlaps a similar elongated horizontally disposed brush 160 mounted on the movable bar 148 . The lower clamp is a three-position clamp and movable between an open position as shown in FIG. 31 wherein the brushes 158 and 160 are not vertically overlapping but rather define a vertical passage therebetween, a soft closed position as shown in FIG. 29 where the brushes partially overlap as seen for example in FIG. 13 as well as FIG. 29 and a fully closed clamping position as shown in FIG. 30 where the lower brush 160 carried by the movable bar is engaged against the fixed bar 154 .
The plungers 162 of the large cylinders 150 are secured at their distal end to the fixed bar 154 such that extension of the plungers causes the movable bar 148 to retract or move to the left relative to the fixed bar and retraction of the cylinders causes the movable bar to move to the right toward the fixed bar. The plungers 164 on the small cylinders 152 merely extend into the space between the fixed and movable bars regardless of whether or not they are extended or retracted.
To move the lower clamp 146 between its three positions, and again with reference to FIGS. 29-30 , in the open position of FIG. 31 , the large pneumatic cylinder plungers 162 are fully extended so as to fully separate the two bars 148 and 154 and the brushes 158 and 160 mounted thereon to define a vertical gap between the brushes. The plungers 164 of the smaller cylinders 152 are also fully extended but non-engaging with the fixed bar 154 due to their relatively short length. To move the clamp to the soft clamping position of FIG. 29 , the large cylinder plungers are retracted to pull the movable bar toward the fixed bar until the plungers of the small cylinders engage the fixed bar to fix the spacing between the movable and fixed bars of the lower clamp. To move the lower clamp to its fully closed and full clamping position of FIG. 30 , the plungers on the small cylinders are fully retracted as are the plungers on the large cylinders so the lower brush 160 on the movable bar closely approaches the fixed bar in which position the fabric can be positively gripped for purposes to be described hereafter. A positive grip is best established with a horizontal channel member 166 ( FIG. 19 ) opening off the face of the movable bar 148 and a fixed leg 168 with gripping pads 170 on the fixed bar with the leg being inserted into the channel when the clamp is fully closed.
The fixed bar 154 , as mentioned previously, is mounted on the support plate 156 that is of L-shaped configuration and itself vertically reciprocably mounted on another pair of pneumatic cylinders 172 , which can elevate the fixed bar and movable bar 148 of the lower clamp 146 to the position of FIG. 13 , for example, or lower the fixed and lower bars of the lower clamp to the position of FIG. 17 .
Also provided within the housing 42 near the bottom thereof are a pair of support rods 174 that support a flexible cradle 176 of any suitable material in which the virgin fabric 68 can gather when the upper clamp 66 is lowered to the position of FIG. 5 , for example. In fact, with reference to FIG. 14 , a virgin fabric 68 is shown in the position of FIG. 5 and is gathered in the cradle from which it can be removed as the upper clamp is raised during processing of the fabric.
Referring to FIG. 14 , the apparatus 41 is postured for forming a fabric 46 of the type shown in FIGS. 2 and 3 with hobbles 54 and guide loops 74 and for such a fabric, when the upper clamp 66 is lowered to the position of FIG. 5 , the rear layer 48 of the fabric is threaded through the lower clamp 146 , as shown in FIG. 14 , and the front layer 50 of the fabric is passed on the rear side of the movable bar 148 of the lower clamp so as to bypass the lower clamp. As will be appreciated from the description herein, the reference to the layers of the fabric as front 50 and rear 48 layers, for illustrative purposes, is the reverse of the reference to the parts of the apparatus since the fabric is mounted in the apparatus with its front layer facing the rear of the apparatus. It will also be appreciated in the positioning of the fabric in FIG. 14 , both layers of the fabric pass freely past the tuck clamp 100 and the vacuum clamp 116 and will also slide through the lower clamp even though the lower clamp is in its soft-clamping position with the rear layer of the fabric engaging the upper and lower brushes 158 and 160 of the lower clamp.
Referring to FIG. 15 , when forming the fabric 46 of FIGS. 2 and 3 , having both hobbles 54 and guide loops 74 , the first step in the operation is to grip the virgin fabric 68 with the vacuum clamp 116 so the fabric is pinched between the vacuum chamber 120 and the tucker rail 101 . The closure tape 126 can be pulled across the opening in the front wall of the vacuum chamber from the left edge of the opening to the left edge of the fabric to maintain adequate vacuum in the chamber. A vacuum is then drawn by energizing the vacuum pump 132 which pulls both layers of fabric into the vacuum chamber as seen in FIG. 16 as the upper clamp 66 is lowered to provide more fabric to the vacuum clamp. Typically, in a fabric of this type, the front layer 50 is less porous than the rear layer 48 so the vacuum is more effective on the front layer but there is enough vacuum to draw both layers into the vacuum chamber.
With both layers 48 and 50 of the fabric drawn a predetermined amount into the vacuum chamber 120 , which is permitted by the top clamp 66 being lowered a predetermined amount, the lower clamp 146 is moved into its full clamping position as shown in FIG. 17 so the rear layer of the fabric is fully gripped by the lower clamp but the front layer is free to move up or down. Thereafter, as also seen in FIG. 17 , the vacuum clamp 116 is withdrawn and simultaneously the lower clamp is lowered which pulls the rear layer of the fabric out of the vacuum chamber so it is relatively straight while the front layer still forms a loop within the vacuum chamber which will ultimately form a hobble 54 in the fabric.
Subsequently, as shown in FIG. 18 , the tucker blade 98 is advanced with the rack and pinion system 136 while the tucker blade is in a horizontal orientation which forces both layers 48 and 50 of the fabric between the upper clamp jaw 108 and the platen 112 of the tuck clamp 100 thereby forming a tuck 52 in both layers of the fabric. Before the tucker blade is advanced, however, the lower clamp 146 is moved to its soft clamp position of FIG. 18 so the rear layer of the fabric is drawn through and across the lower clamp and across the brushes 158 and 160 to remove lint and any wrinkles while the front layer of the fabric, which is freely hanging can be moved therewith. When advancing the tucker blade in this manner, it will be appreciated that since both layers of the fabric are gripped by the vacuum clamp 116 , even though only the front layer 50 is drawn into the vacuum chamber 120 , all of the material is fed upwardly from below the tucker blade and therefore the material slides slightly across the leading edge 140 of the tucker blade 98 . If a hobble 54 was not being formed in the fabric during this step, the vacuum clamp would remain in a retracted position and there would be no loop or hobble of the front layer of fabric in the vacuum chamber. Rather, both layers would be in adjacent side-by-side relationship and by lowering the upper clamp as the tucker blade is advancing, equal amounts of material can be pulled downwardly from above the tucker blade as pulled upwardly from below the tucker blade to avoid having to draw the material across the leading edge of the tucker blade which minimizes any opportunity for damage to the fabric.
Referring to FIG. 19 , with the tucker blade 98 in the position of FIG. 18 , the tuck clamp 100 is lowered so the tuck 52 of fabric with the tucker blade therein is clamped between the upper clamp jaw 108 and the platen 112 of the tuck clamp and due to the bevel or inclination of the upper clamp jaw of the tuck clamp, the tucker blade is tilted which is permitted by pivoting of its support plate 132 about the pivot shaft 144 which is further permitted by the low pressure in the pneumatic cylinders 144 or if the pneumatic cylinders were replaced with a gas spring it would be permitted by the gas spring through minimal resistance to such pivotal movement.
The tucker blade 98 is coated with Teflon® or another low-friction material so that once the tuck 52 in the material has been gripped by the tuck clamp 100 , the tucker blade can be easily withdrawn, as shown in FIG. 20 , leaving the tuck of fabric positioned between the upper clamp jaw 108 and platen 112 of the tuck clamp. The low-friction coating of the tucker blade allows easy sliding removal of the tucker blade even though the tuck of fabric is positively gripped and held in position.
In the position of FIG. 20 , the sewing machine carriage 82 is energized so as to translate from the rest position at the right of the apparatus 41 to the left side of the apparatus and as it is making this pass, the stitching sewing machine 70 is activated while the ring-attaching sewing machine 72 is deactivated. The tuck 52 in material, as can be seen in FIGS. 20 and 23 , is aligned with the stitching needle 178 so that as the sewing machine carriage is advanced or translated across the apparatus, a stitch 180 ( FIG. 23 ) is formed in the fabric at a spaced parallel location from the fold 182 at the edge of the tuck. This establishes a tunnel 56 in the tuck between the stitching and the folded edge of the tuck in which a reinforcing bar (not shown) can be placed if desired.
After the stitch 180 has been formed and the carriage 82 is at the left side of the apparatus, the carriage is then driven to the right. The stitching machine 70 is deactivated and the ring-attaching sewing machine 72 is activated to attach rings 74 at predetermined spaced locations along the width of the fabric and along the folded edge 182 of the tuck 52 . The spacing of the rings is predetermined depending upon the number of rings desired per width of the fabric and this can all be calculated and computed within the control module.
As mentioned previously, the ring-attaching machine 72 is a conventional button sewing machine which includes a hopper (not seen) for a plurality of buttons or rings 74 and a ramp 184 ( FIG. 21 ) that might vibrate for example that confines a string of rings on a downward sliding path from the hopper to a linearly reciprocating ring gripper 186 as shown in FIGS. 21 , 25 - 28 , and 35 - 37 . In the Pfaff ring-stitching machine used in the preferred embodiment of the invention, the sewing needle 178 on the head of the sewing machine 72 reciprocates up and down at a predetermined position but it is desired to stitch across one edge of a ring 74 so that some of the stitches are outside the ring and others are inside the ring so the ring is positively attached to the folded edge 182 of the tuck 52 . In order to establish the stitching across the ring, the ring gripper reciprocates forwardly and rearwardly shoving the ring and the edge of the fabric into one position for allowing the sewing needle to establish a stitch 188 ( FIG. 27 ) within the ring and then retracting the ring which allows the folded edge to also return therewith so the folded edge of the material is aligned with the needle. Accordingly, the next stitch 188 can go through the folded edge of the fabric. By repeating this operation, a predetermined number of threads secure an edge of the ring to the folded edge of the tuck. Thereafter, the ring-attaching machine is moved linearly toward its rest position until it is stopped by the control module at a location where the next ring is to be attached and the ring is attached at that location in the same manner.
With reference to FIGS. 25-28 and 35 - 37 , the ring clamp or gripper 186 has two spaced arms 190 with the distance between the spaced arms being adjustable in the Pfaff sewing machine so that in a gripping position shown in FIGS. 25-28 , 35 and 36 , the ring 74 is positively held so it can be advanced or retracted for desired alignment with the sewing needle 178 . After the ring has been attached to the tuck 52 , the arms of the ring clamp are retracted as shown in FIG. 37 and the ring clamp itself retracted so the sewing machine can be linearly advanced toward home base and once reaching its next position of attachment for a ring, the arms 190 receive the next ring in line which is dropped therebetween so it too can be gripped and handled as described previously.
As will be appreciated from the above, with one complete reciprocal pass of the sewing carriage 82 across the width of the fabric and back, a tunnel 56 can be formed along the edge of the fabric securing the tuck 52 and rings 74 can be attached at predetermined spaced locations to the tuck. On the opposite face or front layer 50 of the fabric, a hobble 54 is formed during the same operation as a loop of the front layer was confined during the operations within the vacuum chamber 120 . Accordingly, a hobble, tunnel and associated rings forming one row of the fabric are established each time the sewing carriage passes through a reciprocating path back and forth across the width of the fabric. After a row has been formed, the upper clamp 66 can be elevated a predetermined distance corresponding to the desired height of a hobble for another identical subsequent operation until a complete fabric 46 has been formed as shown in FIGS. 2 and 3 . Once formed, the fabric is simply removed from the upper clamp where it is ready for incorporation into a control system for the architectural covering in which it is to be incorporated.
It will be appreciated from the above that by selecting various operations, a fabric 46 with hobbles 54 and guide rings 74 can be formed as described above or a one or more layer fabric can be formed with simply the guide rings by leaving the vacuum clamp 116 in an inoperative or retracted position so the hobbles are not formed. If tucks were desired with rings, both the stitching and ring attaching sewing machines would be used but if no tucks were desired in the finished fabric, a stitch would not be placed in the tuck established by the tucker blade but only rings would be attached at the folded edge established by the tucker blade. Similarly, if the rings were not desired for a fabric but the hobbles were, then the operation would be as described above except in the return path of the sewing carriage 82 , the ring-attaching sewing machine 72 would not be activated so a fabric would be formed with only hobbles.
If only tunnels 56 were desired for the fabric, the vacuum clamp 116 would again be deactivated or retained in its withdrawn position and the two layers 48 and 50 of the fabric would be handled together with both layers passing through the lower clamp 146 but other than this distinction, the formation of horizontal tunnels at vertically spaced locations would follow the above procedure. Again, however, only the stitching machine 70 would be operative and the ring-attaching machine 72 would be deactivated so that tucks 52 and tunnels were formed off the rear of the fabric along parallel vertically spaced lines. Of course, if the tunnels were desired on the front of the fabric, the virgin fabric 68 could be reversed in the upper clamp 66 so the tunnels were formed on the front of the fabric rather than the rear.
Clearly from the various options available with the apparatus, fabric for different types of coverings for architectural openings can be made automatically. Further, varying widths of fabrics can be handled up to the spacing of the lift towers on the lift rack.
The second embodiment 200 of the apparatus of the invention is shown in FIGS. 41-67 . This embodiment of the invention is somewhat similar to the previously described embodiment and accordingly, where appropriate, like parts have been given like reference numerals.
In the second embodiment, the vacuum clamp 116 of the first embodiment has been removed and replaced with a stabilizing clamp 202 so there is no longer a vacuum chamber 120 into which fabric is drawn when forming a hobble. Further, there is no lower clamp 146 . In addition, there are two lift racks 44 f and 44 r that are identical except the rear rack 44 r is higher than the front rack 44 f . The remainder of the apparatus is identical to the first-described embodiment including the sewing machines 70 and 72 and their mounting on a sewing machine carriage 82 . The tucker blade 98 is identical to that of the first-described embodiment and operates in the same manner so as to cooperate with the tuck clamp 100 and the sewing machines in forming tucks 52 and/or attaching rings 74 to the fabric. In the second embodiment to be described hereafter, the hobbles 54 are formed in a different manner since the vacuum system used for forming hobbles in the first embodiment has been removed.
The two lift racks 44 f and 44 r , as mentioned, are identical to each other and to the lift rack 44 of the first embodiment except the lift rack 44 r is slightly taller than the lift rack 44 f as can be seen in FIG. 41 .
With reference to FIG. 53 , the stabilizing clamp 202 can be seen to have replaced the vacuum clamp 116 of the first-described embodiment and includes a gripping head 204 for compressing engagement with the fabric to hold the fabric against the U-shaped rail 101 . The stabilizing clamp head is reciprocated with the pneumatic cylinder 130 in the same manner of operation as in the first-described embodiment. Similarly, the tuck clamp 100 is opened and closed through the use of the same pneumatic cylinder 102 which raises and lowers the upper clamp jaw 108 into and out of engagement with the lower clamp jaw or platen 112 . Also, the tucker blade 98 is again reciprocated in a horizontal plane with the rack and pinion reciprocal drive system 136 .
In initially describing the operation of the second embodiment of the apparatus, it will be described in connection with the fabrication of a fabric 46 as illustrated in FIG. 42 wherein a back or backing sheet of material 206 and a front sheet 208 are interconnected and horizontal hobbles 54 are formed in vertically spaced relationship with each other on the front sheet by forming loops of the front sheet material and securing the looped sheet material of the front sheet to the rear sheet. In accordance with the second embodiment of the invention, the front and rear sheets of material that are sewn together with the apparatus of the invention are pre-treated as in the first described embodiment by sewing a lower edge of the sheets of material together preferably defining a hem 210 in which a weighted bottom rail or ballast bar 212 can be inserted. The back sheet 206 , which lies toward the front of the machine, is shorter than the front sheet 208 as can be seen, for example, in FIG. 46 , and is clamped along its upper edge to an upper clamp 66 on the front lift rack 44 f . The upper edge of the front sheet is attached to the upper clamp 66 associated with the rear lift rack 44 r . This can be done with both lift racks being lowered as shown in FIG. 45 where the clamps are readily accessible to an operator.
After the top edges of the front 208 and back 206 sheets are attached to the associated upper clamps 66 of the lift racks, the lift racks are elevated as shown in FIG. 46 so the sheets are vertically suspended in abutting face-to-face relationship with each other with the longer front sheet extending above the shorter back sheet. The lower edges of the sheets, of course, are coincident with the weighted bottom rail 212 retaining the sheets in a fully-extended condition and with the bottom edges slightly above the housing 42 of the apparatus.
To begin forming the fabric of FIG. 42 , the bottom rail at the bottom edges of the front and back sheets of material is dropped below the tucker blade 98 a predetermined amount as shown, for example, in FIG. 55 . It will also be appreciated the front sheet 208 , which appears on the left in FIG. 5 , has been dropped slightly further than the back sheet 206 with the difference in dropped distance being equivalent to the height desired for a hobble 54 that will be formed in the finished fabric. For example, if a hobble is to be four inches in depth from top to bottom, the front sheet will be dropped four inches further than the back sheet so as to form a loop 214 for the first hobble to be formed in the fabric. With the sheets of material positioned as shown in FIG. 55 , the tucker blade is advanced as shown in FIG. 56 a predetermined distance so as to form a tuck 52 in the fabric of a predetermined depth. As the tucker blade is being advanced, the upper clamps 66 for both the front and back sheets of material are lowered a corresponding amount to the depth of the tucks while the bottom rail is lifted that same amount so the fabric does not slide around the leading edge 140 of the tucker blade but rather both sheets of fabric are pulled down and up equivalent amounts as the tucker blade forms the horizontal tuck. After the tuck has been formed, the upper jaw 108 of the tucker clamp is lowered by the pneumatic cylinder 102 until the upper jaw clamps the tucked sheets of material and the tucker blade between the upper jaw and the platen 112 . After the tuck is secured with the tuck clamp 100 , the stabilizing clamp 202 is advanced into engagement with the fabric having the rail 101 as the backing plate by activating the pneumatic cylinder 130 . The stabilizing clamp thereby grips the fabric and stabilizes the fabric so there is no movement in the fabric above the tucker blade when the tucker blade is withdrawn as shown in FIG. 58 .
With the tucker blade 98 withdrawn, as shown in FIG. 58 , the stitching sewing machine 70 ( FIGS. 62 and 63 ) commences it traverse along the width of the sheets of material so as to sew a seam in the fabric defining a tuck or tunnel 52 to the right of the seam between the stitching and the folded edge of the sheets of material. After the seam has been sewn across the entire width of the sheets of material, the ring attaching sewing machine 72 is positioned as shown in FIG. 59 above the tuck in the sheets of material so it can initially place a stitch through the folded edge of the sheets of material as shown in FIG. 60 and then after withdrawing the needle 178 , the first ring 74 , which has been positioned for attachment to the sheets of material, is advanced beneath the needle, as described with the first embodiment, so the needle's next stitch goes through the open center of the ring and by reciprocating the ring back and forth along with the folded edge of the sheets of material in synchronization with reciprocation of the needle, the ring is attached to the folded edge. It should also be appreciated that a hobble or loop 54 has been formed in the front sheet 208 of material during this process, which was initially set up by lowering the front sheet a greater distance than the back sheet 206 prior to the stitching operations.
The above process is repeated as many times as is necessary to complete a fabric 46 of the size desired.
If it were not desired to form hobbles 54 in the fabric, but rather to simply sew rings 74 to a tuck 52 to form a fabric panel 216 as shown in FIG. 65 , when the front 208 and rear 206 sheets of material were first dropped into position, as shown in FIG. 55 , the front and rear sheets would be dropped equivalent distances rather than dropping the front sheet a greater distance than the rear sheet. Accordingly, no loops or hobbles would be formed in the front sheet. This is illustrated in FIG. 64 and it will be appreciated the tucks are formed and sewn identically to that previously described as are the rings.
If it were desired to attach rings to a fabric panel 218 , as shown in FIG. 67 with no tucks, the tuck would be formed with the tucker blade 98 , as previously described, but the stitching previously described as being applied with the first sewing machine 70 would not be applied. Rather, only rings would be attached with the ring attaching machine 72 to the formed but not sewn tuck, as shown in FIG. 66 . Accordingly, when the formed but not sewn tuck is released from the tuck clamp 100 , it will be appreciated a ring has been attached to the sheets of material, but there is no tuck in the material.
These different forms of fabric which can be made with the second embodiment of the machine of the present invention are similar to those made with the first embodiment with the primary distinction being in the manner in which the hobbles are formed.
Although the present invention has been described with a certain degree of particularity, it is understood the disclosure has been made by way of example and changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims. | An apparatus for forming fabrics for use, by way of example, in coverings for architectural openings includes a system for handling single or multi-layered fabrics by suspending the fabric from a lift tower, threading the fabric through various clamp systems within a housing for the apparatus, and subsequently forming horizontal rows of hobbles, tunnels, and/or attached rings by gripping and releasing the fabric with a vacuum clamp, upper and lower clamps, and a tucker blade clamp while a reciprocating tucker blade forms horizontal tucks in the fabric. Hobbles can also be formed in one layer of the fabric through use of the vacuum clamp which gathers a portion of one layer of the fabric while the other layer is handled differently. In doing so, hobbles are formed between tucks in the fabric with the hobbles establishing a fabric resembling a Roman shade. | 54,943 |
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured, used, and licensed by or for the United States Government without the payment of royalties.
REFERENCE TO A COMPUTER PROGRAM LISTING
Reference is made to the computer program listing accompanying this application that is herein incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to polarimetric synthetic aperture radar. The synthetic aperture radar image is a two-dimensional image, with the two dimensions corresponding to cross-range (azimuth or travel direction) and slant-range (or lateral); each being perpendicular to each other. Synthetic aperture radar frequently uses a platform and the synthetic aperture correlates to the distance the SAR platform covers during the period in which a target can be observed from the forward extent of the azimuth view angle on the platform's approach to the aft extent of the azimuth view angle upon its departure. In addition, the electromagnetic radiation produced by synthetic aperture radar has a polarization. Such polarization is useful for identification of materials. Symmetric, man-made objects produce very different synthetic aperture radar (SAR) signatures when examined using different polarizations. This is especially noticeable when these objects are metal. By using radar pulses with a mixture of polarizations and receiving antennas with a specific polarization, different images can be collected from the same series of radar pulses.
The present invention also relates to detection of manmade objects. Since manmade objects often exhibit “left-right” symmetry not found in nature, sensors capable of detecting “left-right” symmetry have the capability of distinguishing manmade (symmetric) objects from naturally occurring (asymmetric) objects.
Detection of objects with specific sizes and shapes is disclosed in U.S. Pat. No. 8,125,370 ('370 patent) to Rodgers, et al, hereby incorporated by reference. The '370 patent discloses a method for processing a polarimetric synthetic aperture radar (SAR) image of a region in order to screen large areas to identify candidate pixels that correspond to a position in the image that contains a candidate object. To obtain polarimetric SAR images, the system disclosed in the '370 patent transmits and receives pulses with both horizontal and vertical polarization. Polarimetric SAR imagery consists of two, three or four independent channels of complex data (amplitude plus phase) consisting of HH (Horizontal transmit, Horizontal receive), HV (Horizontal transmit, Vertical receive), VV (Vertical transmit, Vertical receive), and VH (Vertical transmit, Horizontal receive). For a fully polarimetric or quad-polarization SAR system (four channels), all four combinations HH, HV, VV and VH are employed.
The processing of different polarizations is particularly useful when metal objects are encountered. For example, a co-pol (HH or VV) response will be very high in the pixels containing a metal object's points of “left-right” symmetry. This could include multiple downrange pixels, depending on the target size and image pixel size. Such pixels could represent, for example, the centers of unexploded ordinances, Explosively Formed Penetrators (EFPs), or even the centers of trihedrals. The cross-pol response, on the other hand, will be very small in the same image pixels. It is an object of the present invention to exploit this physical phenomenon to enhance the target response from symmetric, man-made objects.
SUMMARY OF THE INVENTION
The present invention is directed to a system for detecting symmetric objects using fully polarimetric, synthetic aperture radar (SAR) imagery. While other inventions exploit calculated parameters of various representations of the polarization state, the present invention operates directly on the measured co- and cross-polarization data, utilizing spatial averaging to reduce pixel variability, and exploits anomaly detection concepts commonly used within single SAR images.
The present invention is directed to a preferred embodiment system for determining the location of a man-made object based upon symmetry of the object comprising:
at least one of a transmitter and receiver combination or transceiver for emitting and receiving mixtures of polarizations and using receiving antennas with a specific polarization to thereby collect images from radar pulses, the receiver-transmitter mixtures of polarizations comprising horizontal-horizontal polarimetric images, vertical-vertical polarimetric images, vertical-horizontal polarimetric images and horizontal-vertical polarimetric images,
at least one processor, the at least one processor configured to combine the horizontal-horizontal polarimetric images and vertical-vertical polarimetric images to form co-polarimetric images and operate on one or both of the vertical-horizontal polarimetric images and horizontal-vertical polarimetric images to form cross-polarimetric images;
the at least one processor configured to process the co-polarimetric and cross-polarimetric images individually; each of the co-polarimetric and cross-polarimetric images comprising a plurality of incrementally selected pixels under test, the at least one processor configured to select a pixel under test and analyze the surrounding pixels to determine whether a manmade object is present; the at least one processor configured to perform spatial averaging using the cross polarimetric image by replacing the pixel under test and the pixels adjacent to the pixel under test with an average pixel value calculated from the pixel under test and pixels adjacent thereto;
using the co-polarimetric image, the at least one processor configured to determine the intensity of the background of the pixel under test and the surrounding pixels in order to diminish the effect of background to produce clearer co-polarimetric and cross-polarimetric images;
the at least one processor is configured to locate the left-right point of symmetry indicative of a man-made object by comparing each pixel under test in the cross-polarimetric image to pixels in the vicinity and if the intensity of the pixel under test differs by at least 3 dB, the pixel under test is a determined to be a candidate pixel for locating a cross-range coordinate determinative of a point of symmetry indicating a man-made object.
Optionally, the at least one processor is configured such that if the pixel under test differs by at least 15 dB, the pixel under test is determined to be a candidate pixel for locating a cross-range coordinate determinative of a point of symmetry indicating a man-made object. Optionally, the at least one processor is configured to perform spatial averaging using the cross polarimetric image by replacing the pixel under test and the pixels above and below the pixel under test with an average pixel value calculated from the pixel under test and pixels located above and below the pixel under test.
Optionally, the at least one processor is configured to reduce the value of the pixel under test that is a candidate pixel for the left right point of symmetry using a normalization process using a predetermined number pixel of values in the cross-polarimetric image on both sides of the pixel under test at the left right point of symmetry to thereby reduce effects of background.
In the alternative, the at least one processor determines the intensity of the background using the pixels surrounding the pixel under test and calculating an average pixel value of the surrounding pixels in order to capture a background average for pixels on either side of the point of left-right symmetry. Optionally, the complex magnitude of each component image pixel may be utilized, thereby enabling the exploitation of spatial averaging for speckle reduction. Optionally, the polarimetric images are polarimetric SAR images, and the horizontal-horizontal polarimetric images, the vertical-vertical polarimetric images, and one or both of the vertical-horizontal polarimetric images and horizontal-vertical polarimetric images are co-registered SAR images, and a location in each of the images has a corresponding location in the other co-registered SAR images.
Alternatively, the at least one processor utilizes spatial averaging to compute a spatial average and the at least one processor is configured to divide the spatial average by the intensity of the background. The spatial average may be computed using the equation:
I filter ( x , y ) = ∑ l = 0 N p I ( x , y - ⌊ N p / 2 ⌋ + i )
where I filter (x,y) denotes the image from either co-polarimetric or cross polarimetric radar data pixel at (x,y), where x and y are coordinates, N p is the number of pixels used for spatial averaging, and └Np/2┘ denotes the largest integer less than or equal to N p /2, where N p could be equal to zero for the co-polarimetric image.
Optionally, the at least one processor is configured to refine the corresponding pixel under test in the filtered co-polarimetric image by dividing by the ratio of the spatial average to the intensity of the background. Optionally, the at least one processor, for each pixel in the filtered cross-pol image, determines the effect of background pixels in the cross polarimetric image using the equation:
I
cross
denominator
(
x
,
y
)
=
∑
i
=
m
+
1
M
I
filter
,
cross
(
x
-
i
,
y
)
+
∑
i
=
m
+
1
M
I
filter
,
cross
(
x
+
i
,
y
)
where, I filter, cross is the filtered cross-pol image and I cross denominator is used to determine the I cross contrast in the following equation where x and y are coordinates, M is the number of cross-range cells on either side of a pixel under test in the cross-polarimetric image, m is the number of guard cells on either side of the pixel under test to be skipped before calculating a background average, where m may be equal to zero, and using the image cross denominator.
Optionally, for each pixel in the cross-pol image the at least one processor calculates the contrast between the pixel under test and any high intensity values the surrounding pixels by calculating the cross image contrast using the equation:
I cross contrast ( x , y ) = I filter cross ( x , y ) I cross denominator ( x , y )
where I filter cross (x,y) is the filtered image at coordinates (x,y), and I cross denominator (x,y) correlates to the background intensity in the cross polarimetric image at coordinates (x,y) used as a denominator and, using the cross contrast of the surrounding pixels, the at least one processor calculates a polarimetric manmade object detector output statistic T PMOD using the equation:
T PMOD ( x , y ) = I filter , co ( x , y ) I cross contrast ( x , y ) ,
where I filter, co (x,y) denotes the filtered co-pol image at coordinates (x,y).
As a further option, the at least one processor is configured to incrementally select pixels under test, determine the spatial average, determine the background intensity, use the corresponding pixel under test in the filtered co-polarimetric image and divide by the ratio of the spatial average to the intensity of the background to compile a list of statistical values indicating the likelihood of a manmade object, and compare the statistical value to the correlated value of corresponding pixel under test in the co-polarimetric image and wherein if the pixel under test value of the copolarimatric image has a larger value, it is more likely to be indicative of a manmade object. Alternatively, the at least one processor is configured to determine whether the ratio of the statistical value to the correlated value of corresponding pixel under test in the co-polarimetric image is greater than 4 dB to indicate the presence of a man-made object.
The present invention is also directed to a preferred method for determining the location of a man-made object comprising the following steps, not necessarily in order;
inputting image data comprising four co-registered polarimetric SAR images of a common scene; the four co-registered polarimetric images comprising horizontal-horizontal, horizontal-vertical, vertical-vertical and vertical-horizontal polarimetric images, the inputted image data comprising pixel values representing the polarimetric SAR images, a location in each of the four co-registered SAR images having a corresponding location in the other three co-registered SAR images;
each of the four co-registered SAR images being inputted into at least one processor, the at least one processor being configured to calculate a statistic indicating the likelihood that a manmade object is present by selecting a pixel under test and:
(i) using at least one processor, spatial averaging at a plurality of pixel locations in the vicinity of the pixel under test using the equation:
I filter ( x , y ) = ∑ l = 0 N p I ( x , y - ⌊ N p / 2 ⌋ + i )
where I(x,y) denotes the image from either co-polarimetric or cross polarimetric radar data at pixel (x,y), where x and y are coordinates, N p is the number of pixels used for spatial averaging, and └Np/2┘ denotes the largest integer less than or equal to N p /2, where N p could be equal to zero for the co-polarimetric image;
(ii) capturing a background average by determining the number of cross-range cells (M) on either side of a pixel under test in the cross-pol image to calculate a background average for pixels on either side of the point of left-right symmetry and then specifying m, the number of “guard” cells on either side of the pixel under test to be “skipped” before calculating this background average, where m could be equal to zero;
(iii) for each pixel in the filtered cross-pol image, calculating the quantity:
I
cross
denominator
(
x
,
y
)
=
∑
i
=
m
+
1
M
I
filter
,
cross
(
x
-
i
,
y
)
+
∑
i
=
m
+
1
M
I
filter
,
cross
(
x
+
i
,
y
)
where, I filter, cross is the filtered cross-pol image and I cross denominator is used to determine the I cross contrast in the following equation;
(iv) for each pixel in the cross-pol image calculating the quantity:
I
cross
contrast
(
x
,
y
)
=
I
filter
,
cross
(
x
,
y
)
I
cross
denominator
(
x
,
y
)
(v) calculating a polarimetric manmade object detector output statistic T PMOD using the equation:
T PMOD ( x , y ) = I filter , co ( x , y ) I cross contrast ( x , y ) ,
where I filter, co (x,y) denotes the filtered co-pol image;
(vi) processing the image (two-dimensional array) of polarimetric manmade object output detector values to determine if the object under investigation is man-made.
An alternative preferred embodiment system for determining the location of a man-made object comprises:
at least one input configured to input image data comprising four co-registered SAR images of a common scene, each scene comprising a plurality of pixel values, the pixel values representing a radar cross section of the same region in each of the four basis polarizations;
at least one processor, each of the four co-registered SAR images being inputted into the at least one processor, the at least one processor being configured to calculate a statistical likelihood that a manmade object is present; the at least one processor configured to perform spatial averaging at a plurality of pixel locations according to the equation:
I filter ( x , y ) = ∑ l = 0 N p I ( x , y - ⌊ N p / 2 ⌋ + i )
where I(x,y) denotes the image from either co-polarimetric or cross polarimetric radar data at pixel (x,y), N p is the number of pixels used for spatial averaging, and └Np/2┘ denotes the largest integer less than or equal to Np/2, and Np possibly equal to zero for the co-polarimetric image;
the at least one processor configured to determine M, the number of cross-range cells on either side of a pixel under test in the cross-pol image in order to capture a background average for pixels on either side of the point of left-right symmetry;
the at least one processor configured to determine the number (m) of“guard” cells on either side of the pixel under test to be “skipped” before calculating this background average, where m may be equal to zero;
the at least one processor configured to calculate for each pixel in the filtered cross-polarimetric image the quantity:
I cross denominator ( x , y ) = ∑ i = m + 1 M I filter , cross ( x - i , y ) + ∑ i = m + 1 M I filter , cross ( x + i , y )
where, I filter, cross is the filtered cross-polarimetric image;
the at least one processor configured to, for each pixel in the cross-pol image, calculate the quantity:
I
cross
contrast
(
x
,
y
)
=
I
filter
,
cross
(
x
,
y
)
I
cross
denominator
(
x
,
y
)
;
the at least one processor configured to calculate a polarimetric manmade object detector output statistic using the equation:
T PMOD ( x , y ) = I filter , co ( x , y ) I cross contrast ( x , y ) ,
where I filter, co (x,y) denotes the filtered co-polarimetric image; and
the at least one processor configured to create a two-dimensional array of values to determine if the object under investigation is man-made.
BRIEF DESCRIPTION OF THE DRAWINGS
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
The foregoing and other objects, features, and advantages of the invention will be apparent from the following more detailed description of the preferred embodiments of the invention, as illustrated in the accompanying drawings, wherein:
FIG. 1 is a schematic illustration of a preferred embodiment of the present invention.
FIG. 2 is an illustration representative of the physical target having a tetrahedral shape which was detected by the polarimetric manmade object detector to detect the left-right symmetry indicative of manmade objects,
FIG. 3A is an illustration showing the cross-polarimetric image of the SAR image produced from a target represented by FIG. 2 .
FIG. 3B is the co-polarimetric image produced by the SAR image formation software of the manmade object detector component 30 . The color scales are set relative to the maximum pixel value in the image. Note the region of lower radar cross section in the cross-polarimetric image.
FIG. 4 is an illustration depicting the processing of the SAR image formation including the processing steps performed in block 30 (see FIG. 1 ) of the polarimetric manmade object detector system.
FIG. 5 is an illustration showing examples of target signature enhancement achieved by the preferred embodiments of the present invention for different target emplacement geometries. Enhancements of 10.5 dB for target 1 and 6.8 dB for target 2 are shown.
A more complete appreciation of the invention will be readily obtained by reference to the following Description of the Preferred Embodiments and the accompanying drawings in which like numerals in different figures represent the same structures or elements. The representations in each of the figures are diagrammatic and no attempt is made to indicate actual scales or precise ratios. Proportional relationships are shown as approximates.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of the invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments of the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples should not be construed as limiting the scope of the embodiments of the invention. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the dimensions of objects and regions may be exaggerated for clarity. Like numbers refer to like elements throughout. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the full scope of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
It will be understood that the terminology left-right or left right is based upon the orientation of the image and that if the image is rotated 90 degree, left right symmetry will appear as up and down symmetry. As used herein, pixels to the side of the pixel under test are those pixels appearing adjacent to the pixel in the left right direction (or if rotated 90 degrees, then in the up and down direction).
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. For example, when referring first and second components, these terms are only used to distinguish one component from another component.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
FIG. 1 is a schematic block diagram of a preferred embodiment polarimetric manmade object detection system. The preferred embodiment synthetic aperture radar sensor produces imagery having sufficient down-range and cross-range resolution to ensure that one image pixel encompasses the target's point of left/right symmetry without including contributions from non-target objects. The synthetic aperture radar images—collected simultaneously at different polarizations—contain information regarding the polarization state of the target. A preferred embodiment enhances target signatures by combining of co-polarimetric (VV and HH) and cross-polarimetric (HV and VH) radar data using co-polarimetric and cross-polarimetric radar images.
The polarimetric SAR receiver 10 comprises four input/output receiver/transmitters or “basis” channels 11 A to 11 D for inputting data into SAR receiver sections 12 A through 12 D through to the SAR processor 20 . The data is fully polarimetric and includes (A) horizontal antenna transmitted data which was received by a horizontal receiver antenna data (shown s horizontal Tx horizontal Rx in FIG. 1 ) transmitted and received at 11 A, (B) horizontal antenna transmitted data which was received by a vertical receiver antenna data (shown s horizontal Tx vertical Rx in FIG. 1 ) transmitted and received at 11 B, (C) vertical antenna transmitted data which was received by a horizontal receiver antenna data (shown as vertical Tx, horizontal Rx in FIG. 1 ) transmitted and received at 11 C and (D) vertical antenna transmitted data which was received by a vertical receiver antenna data (shown as vertical Tx, vertical Rx in FIG. 1 ) transmitted and received at 11 D. The synthetic aperture radar sensor produces imagery of high enough down-range and cross-range resolution to ensure that one image pixel encompasses the target's point of left/right symmetry without including contributions from non-target objects. The synthetic aperture radar images—collected simultaneously at different polarizations (A-D) contain information regarding the polarization state.
The inputted data is then focused to produce four co-registered SAR images 12 A- 12 D of a common scene, wherein a specified pixel value represents the radar cross section (RCS) of the same patch of ground in each of the four basis polarizations. The four images are then inputted through channels 14 A- 14 D to the polarimetric manmade object detector 30 , which calculates a statistic indicating the likelihood that a manmade object is present. The polarimetric manmade object detector 30 calculates a statistic indicating the likelihood that a manmade object is present.
FIG. 2 illustrates the physical target 31 having a tetrahedral shape which was detected by the polarimetric manmade object detector to detect the left-right symmetry indicative of manmade objects,
The SAR images focused using measured data are shown in FIGS. 3A and 3B . A cursory examination of the imagery reveals that the radar cross section in the cross-polarimetric image drops suddenly at the pixel with cross-range coordinate encompassing the left-right point of symmetry (shown generally as 31 ). This well-documented effect is precisely the phenomenon exploited by the polarimetric manmade object detector 30 to detect symmetric objects. While HH (horizontal Tx and horizontal Rx) and HV (horizontal Tx and vertical Rx) are used to illustrate the co-pol and cross-pol channel behaviors, similar co- and cross-pol behavior will be observed in the VV (vertical Tx and vertical Rx) and VH (vertical Tx and horizontal Rx) channels.
FIG. 3A is an image of the tetrahedral target under consideration (represented in FIG. 2 ) processed by the SAR image formation software. The color scales are set relative to the maximum pixel value in the image. FIG. 3B is the co-polarimetric image produced by the SAR image formation software of the manmade object detector component 30 . The color scales are set relative to the maximum pixel value in the image. Note the region of lower radar cross section in the cross-pol image.
FIG. 4 depicts the processing steps of the polarimetric manmade object detector (PMOD) algorithm. From the diagrams, the polarimetric manmade object detector (PMOD) algorithm first performs spatial averaging to reduce speckle. It then reduces the value of the cross-pol pixel at the point of symmetry through normalization by stronger cross-pol values on either side of the point of symmetry. Finally, the polarimetric manmade object detector (PMOD) algorithm divides the co-pol pixel value (which is typically high for metallic, symmetric, man-made objects) by this reduced co-pol pixel value. In regions where left-right symmetry exists, the co- to cross ratio should tend to be higher. These steps can be summarized as:
(i) Select one co-pol channel (either HH or VV) and one cross-pol channel (either HV or VH) (see FIG. 1 ) for use by the polarimetric manmade object detector (PMOD) processor 30 . (ii) Determine the number of down-range cells, N p , for use in spatial averaging for polarization p=0 (co-polarimetric) and p=1 (cross-polarimetric), and perform spatial averaging at each pixel location according to:
I
filter
(
x
,
y
)
=
∑
l
=
0
N
p
I
(
x
,
y
-
⌊
N
p
/
2
⌋
+
i
)
,
(
1
)
where I(x,y) denotes the image (either HH, VV, HV, or VH) pixel at (x,y), and └Np/2┘ denotes the largest integer less than or equal to Np/2, where Np could be equal to zero for the co-polarimetric image.
(iii) specify, M, the number of cross-range cells on either side of a pixel under test (PUT) in the cross-pol image used to capture radar cross section levels (i.e., a background average) for pixels without left-right symmetry. Specify m, the number of “guard” cells on either side of the pixel under test to be “skipped” before calculating this background average, which could be equal to zero. For each pixel in the filtered cross-pol image, calculate the quantity
I
cross
denominator
(
x
,
y
)
=
∑
i
=
m
+
1
M
I
filter
,
cross
(
x
-
i
,
y
)
+
∑
i
=
m
+
1
M
I
filter
,
cross
(
x
+
i
,
y
)
,
(
2
)
where, I filter, cross is the filtered cross-pol image.
(iv) For each pixel in the cross-pol image calculate the quantity (Box 38 ):
I cross contrast ( x , y ) = I filter , cross ( x , y ) I cross denominator ( x , y ) ( 3 )
[Note that a large cross denominator is indicative of high intensity pixels in the area, which are in turn indicative of manmade object.]
(v) Calculate the polarimetric manmade object detector (PMOD) output statistic (Box 39 ) as:
T
PMOD
(
x
,
y
)
=
I
co
,
filtered
(
x
,
y
)
I
cross
contrast
(
x
,
y
)
,
(
4
)
where I filter, co (x, y) denotes the filtered co-pol image.
(vi) Process the image (two-dimensional array) of PMOD values to determine if the object under investigation is man-made.
FIG. 5 illustrates the enhanced target response produced by the preferred embodiment system for different target ranges. The labels within the imagery (e.g. 65.0 dB) indicate the peak pixel value on target, and the polarimetric manmade object detection system enhances the target response by 10.5 dB (target 1 ) and 6.8 dB (target 2 ) respectively, as shown in the lower four images of FIG. 5 . When a similar comparison is performed of clutter pixels, on average the polarimetric manmade object detection system-processed pixel values are within a fraction of a dB of the input co-pol pixel values. Hence, on average, an enhancement in clutter-to-target ratio is expected to be on the order of the target enhancement realized by the PMOD system. The two images on the top show results from a different data collection (wherein a difference of nearly 4 dB was observed) for the same target used to the bottom two images.
Advantages of the Invention
Various systems have already been proposed for the detection of the symmetries in fully polarimetric SAR. These systems, however, rely on the calculation of specific statistics produced by transformation of the underlying polarization states. For example, the asymmetry angle produced by polarimetric decompositions has been proposed for detection of symmetric objects in a SAR image. The value of this statistic is compared to expected values for man-made objects, and a decision is made as to whether or not a target is present in the scene. Such a method, however, is not inherently amenable to spatial averaging (i.e. speckle reduction). Hence, it is subject to the high variability commonly encountered in SAR image pixel values.
Some approaches increase the number of available SAR images by breaking the synthetic aperture into several sub-apertures, each sub-aperture producing a corresponding image of the scene. While increasing the number of images available for averaging, this approach has the side-effect of reducing the resolution in each of the new images. In addition it could also corrupt the inherent symmetry of a target object if too much squint is introduced within some of the sub-apertures. Still other methods proposed in the past combine the SAR images from each polarization channel (i.e. co-polarimetric and cross-polarimetric) to create a single image for use by downstream target detection algorithms. Such approaches have been leveraged to detect larger, tactical targets in high resolution imagery. While achieving optimum performance in terms of a specific measurement criterion, they fail to exploit the very explicit co-pol to cross-pol relationship present in symmetric, man-made objects.
The method of the preferred embodiment differs from the current state of the art in several respects. First, it operates on, inter alia, a full-aperture SAR image, thereby maintaining the highest possible underlying image resolution. Second, it utilizes the complex magnitude of each component image pixel, thereby enabling the exploitation of spatial averaging for speckle reduction. Finally, it leverages the fundamental concepts of anomaly detection to “amplify” the signal from symmetric, man-made targets while leaving signals from asymmetric, natural clutter objects essentially unchanged. This results in a greater contrast between target and non-target objects within the scene.
The present invention is designed to reduce the variability of statistics calculated to detect symmetric, man-made objects in SAR imagery. This is achieved via the incorporation of averaging and the utilization of non-coherent, magnitude data. Based on data examined to date, the algorithm increases the target-to-clutter ratio when targets are symmetric while leaving them nearly unchanged when targets are asymmetric.
The invention could also be used in imagery produced by other sensors if multiple channels are available, and the measured signals from targets of interest are larger in certain channels while remaining smaller in others. This method has, however, not yet been extended to other sensor data (such as hyperspectral or multispectral imagery).
The invention represents a novel extension of anomaly detection techniques to target detection in fully polarimetric SAR data. While SAR anomaly detection algorithms (e.g. constant false alarm rate (CFAR) prescreeners) typically operate on a single image, the present invention combines information from multiple channels to enhance the contrast between target and background.
Since manmade objects often exhibit left-right symmetry not found in nature, a sensor capable of distinguishing such symmetries effectively distinguishes manmade (symmetric) objects from naturally occurring (asymmetric) ones. The present invention comprises such a system for detecting symmetric objects in fully polarimetric, synthetic aperture radar (SAR) imagery. Other state-of-the-art systems rely on the calculation of specific statistics produced by transformation of the underlying polarization states. Since a single value is determined, typically without exploiting any sort of averaging, the result may be subject to a large amount of variance. Some approaches have addressed this problem through sub-aperture processing, thus increasing the number of available images. This approach, however, reduces the resolution of the imagery available for subsequent processing. Other methods combine the SAR images from each polarization channel (i.e. co-polarimetric and cross-polarimetric) to create a single image for use by downstream target detection algorithms. While achieving optimum performance in terms of a specific measurement criterion, they fail to exploit the highly specific co-polarimetric to cross-polarimetric relationship present in symmetric, man-made objects.
The present invention operates on a full-aperture SAR image, thereby maintaining the highest possible underlying image resolution. The present invention may incorporate the complex magnitude of each component image pixel, thereby enabling the exploitation of spatial averaging for reduction of pixel variability. Finally, it leverages well-established concepts of anomaly detection to “amplify” the signal from symmetric, man-made targets while leaving signals from asymmetric, natural clutter objects essentially unchanged.
POTENTIAL USES
Potential military uses include the detection of unexploded ordinances (UXOs) such as 155 shells and landmines, explosively formed penetrator (EFP), also known as an explosively formed projectile (a self-forging warhead, or a self-forging fragment), as well as general remote monitoring of the environment.
The present invention is not restricted to the illustrative examples described above. Examples are not intended as limitations on the scope of the invention. Methods, apparatus, compositions, and the like described herein are exemplary and not intended as limitations on the scope of the invention. Changes therein and other uses will occur to those skilled in the art. The scope of the invention is defined by the scope of the claims.
As used herein, the terminology “symmetry” means the quality of being made up of substantially similar parts facing each other or around an axis. Alternatively, symmetry means substantially invariant to a transformation, such as for example, reflection but including other transforms too.
As used herein the terminology “point of left-right point of symmetry” means the point where substantial symmetry occurs or exists to the left and right of the “point of left-right symmetry.” If the object is rotated, the axis of symmetry will rotate correspondingly.
As used herein, the terminology “polarimetric” means relating to the rotation of the plane of polarization of polarized electromagnetic waves.
As used herein, the terminology “pixel under test” means the pixel being tested or the pixel chosen to undergo review.
As used herein, the terminology “polarimetry” means the process of measuring the polarization of electromagnetic waves, such as radar waves, generally in the context of waves that have traveled through or have been reflected, diffracted or refracted by a material or object.
In polarimetric systems, pulses are transmitted and received with both horizontal and vertical polarizations. As used herein, the terminology (a) “horizontal-horizontal” or HH means horizontal transmit, horizontal receive, (b) HV, horizontally transmit, Vertical receive, (c) VV, Vertical transmit, Vertical receive, and (d) VH, Vertical transmit, Horizontal receive).
As used herein, the terminology “co-polarimetric” radar data means horizontal-horizontal,” or horizontal transmit, horizontal receive, radar data, and VV, Vertical transmit, Vertical receive radar data.
As used herein the terminology cross polarimetric radar data means one or both of HV, horizontally transmit, Vertical receive and/or VH, Vertical transmit, Horizontal receive radar data.
As used herein, the terminology “patch” is a portion of the radar image.
As used herein, the term “complex magnitude” is determined by calculating the square root of the sum of the squares of the in-phase and quadrature components of the synthetic aperture radar (SAR) image pixel.
Patents, patent applications, or publications mentioned in this specification are incorporated herein by object to the same extent as if each individual document was specifically and individually indicated to be incorporated by object.
The foregoing description of the specific embodiments are intended to reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims. | A system and method for locating a man-made object comprising a transmitter and receiver combination or transceiver configured to emit mixtures of polarizations comprising HH, VV, VH and or HV polarization images, at least one processor configured to form co-polarimetric and cross-polarimetric images, to select a pixel under test and analyze the surrounding pixels by performing spatial averaging using the cross polarimetric image, and to replace the pixel under test and the pixels adjacent thereto with an average pixel value calculated from the pixel under test and pixels adjacent thereto; the at least one processor configured to diminish background effects to produce clearer co-polarimetric and cross-polarimetric images and to locate the left-right point of symmetry indicative of a man-made object by comparing each pixel under test in the cross-polarimetric image to pixels in the vicinity to locate an intensity differential in excess of 3 dB. | 57,802 |
BACKGROUND OF THE INVENTION
This invention pertains to "pots" or traps for capturing crabs and, more particularly, to entrance gate apparatus for allowing entry of crabs into, while preventing escape of crabs from, a crab trap.
One type of crab trap that is in common use today is shown in U.S. Pat. No. 4,184,283 issued to Robert E. Wyman, a coinventor of the entrance gate apparatus disclosed here. Such traps are formed by steel rods welded together to form a generally rectangular box frame structure, the walls of which are formed by nylon netting. As shown in the '283 Patent, entry tunnels, formed by netting, extend inwardly from opposite ends of the trap and terminate in a rectangular frame that is secured to the netting, providing an opening through which the crabs fall into, and to the bottom of, the trap. Bait of pieces of meat such as herring or horse meat is secured by a hook or canister in a central region of such traps.
In recent years, the crab fishing industry has faced declining harvests of crabs and has been subjected to substantially shortened fishing seasons imposed by fishery authorities to preserve the future supply of crabs. To make matters worse, fishery authorities have also been concerned about, and have made allowances for, the effects of the so-called "bycatch" problem that exists when fishing for one crab species results in capture of crabs of other species that are out of season. For example, when fishing for a smaller species, such as the Opilio tanner crab, larger species such as king crab or Bairdi tanner crab are often captured. Handling of such out of season crabs results in a certain mortality percentage for those tossed back into the sea after being removed from the pots. This mortality factor is particularly significant when larger out of season crabs are in the molting state, at which time they are unusually vulnerable to injury. This bycatch mortality problem has prompted fishery closure dates that leave millions of pounds of the established quota for smaller crabs, such as Opilio tanner crabs, unharvested.
Accordingly, it is a specific object of this invention to provide apparatus for selectively preventing the capture of various sized out of season larger crab species while accommodating the capture of the smaller species for which the season is open.
In the past, a great many devices have been proposed for capturing crabs, fish and other animals in a trap. Such devices are described in patents found in U.S. Pat. Office Class 43 and subclasses 100, 101, 102, 103, 104 and 105. For example, U.S. Pat. No. 4,184,283, referred to above, describes resiliently bendable tines to prevent the escape of crabs once they have entered a trap. However, neither this reference nor any other prior art reference of which the inventors are aware, describes an apparatus for selectively preventing the capture of larger crabs or other shellfish while accommodating the capture of smaller species.
SUMMARY OF THE INVENTION
The entrance gate apparatus of this invention is, in a preferred embodiment, self contained and adapted to be rapidly attached to a wall opening of a conventional crab trap. The apparatus preferably is constructed of light weight and durable molded plastic components and comprises a rectangular frame assembly suitable for quick nesting insertion with, and attachment to, a similar frame attached to a wall of the crab trap. Flexible finger assemblies are attached inside of the cross-section of a tubular first longitudinal member of the rectangular frame assembly and are easily deflected upward by crabs to allow their entry into the trap. Trapped crabs attempting to escape will bend the flexible finger assemblies downward to block their escape through the entrance gate. An adjustable divider mechanism provides means for selectively reducing the size of the rectangular opening of the entrance gate thereby preventing crabs of a larger than desired size from entering the trap. The divider mechanism is constructed as a beam that will be stiff, or difficult to deflect, in the direction of the plane of the rectangular frame assembly. It also provides means for establishing the angular positioning of the flexible finger assemblies with respect to the rectangular frame. Additionally, the divider mechanism also preferably includes a clip or strut member for reacting the beam of the divider mechanism near its midspan and thereby stiffening it substantially more to prevent deflection that would allow inadvertent entry of larger crabs. The divider mechanism is designed to be readily removable from the entrance gate apparatus to allow fishing for the larger species of crabs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a crab pot or trap with the entrance gate apparatus of this invention installed in opposite facing framed openings of the trap
FIG. 2 is a partial sectional side view taken through the entrance gate apparatus of FIG. 1.
FIG. 3 is a plan view of the entrance gate apparatus of this invention taken at 3--3 of FIG. 2.
FIG. 4 is a side view of the entrance gate apparatus taken at 4--4 in FIG. 3.
FIG. 5 is a cross-section view of the entrance gate apparatus taken at 5--5 in FIG. 3.
FIG. 6 is a cross-section view of the divider mechanism taken at 6--6 in FIG. 3.
FIG. 7 is a plan view of the entrance gate apparatus similar to that of FIG. 3 showing a narrowed opening for smaller crabs.
FIG. 8 is a cross-section view similar to that of FIG. 5 showing an increased angular displacement of the fingers with respect to the frame.
FIG. 9 is a cross-section view similar to that of FIG. 6 showing an increased length of the stiffening strut member.
FIG. 10 is a perspective view of the entrance gate apparatus of this invention.
DETAILED DESCRIPTION
With reference to FIG. 1, a generally conventional crab pot or trap 10 is constructed of steel bars 12 that are welded together to form a rectangular box frame structure. Nylon netting 14 forms the walls including end walls 16. Such crab traps are often about seven feet by seven feet by three feet high and weigh up to 600 lbs. each. The opposed end walls 16 are sloped to form converging tunnels that terminate with rectangular entrance frames 18. A bait container 20 is located in a central region of the trap. The entrance gate apparatus 22 of this invention is shown installed in nesting relationship with the rectangular frame 18. The entrance gate apparatus 22, which will be shown in more detail in other figures of the drawings, is secured to the frames 18 by convenient means such as electrical tie bands (not shown) that may be drawn tight around the frames of the apparatus 22 and the frames 18 of the trap 10. As shown here, the gate apparatus 22 may quickly and easily be installed in and removed from the trap 10.
FIG. 2 is a partial side cross-sectional view taken through the trap 10 and entrance gate apparatus 22. The rectangular frames 18 are attached to the netting 14 at the end walls 16. Tension tie cords 23 are attached to the frames 18 at each end and are drawn tight to urge the end walls 16 together to form a unitary structure for the trap 10. As can be seen in FIG. 2, the rectangular frame 24 of the entrance gate apparatus 22 is smaller than, and fits inside of, the rectangular frame 18 of the trap 10.
FIG. 3 shows, in plan view, the entrance gate apparatus 22 of this invention. Flexible finger assemblies 26 are shown attached to a first longitudinal member 30 of the rectangular frame 24. The frame 24 includes side members 38 joined to first and second longitudinal members 30 by corner elbow members 40 with securing means comprising stainless steel screws 41. Tee section members 42 are slidably attached around the side members 38 and are secured in place by screws 41 at a desired position to provide support for, and to locate, a divider mechanism 43. The divider mechanism 43 includes a stiffening beam comprising a divider bar member 44, a plate member 46, a finger adjustment member 48, and a beam reaction strut member 50.
FIG. 4 is an end view taken at 4--4 in FIG. 3. Frame 18 of trap 10 is shown in phantom lines to illustrate its nesting relationship with the entrance gate apparatus 22 of this invention. Finger assemblies 26 are positioned against the finger adjustment member 48 to provide an acute angle relationship, preferably less than 45 degrees, with the plane of the rectangular frame 24. This relationship has been established by the selected adjusted location of the finger adjustment member 48 of the divider mechanism 43 and an appropriate rotation of the upper longitudinal member 30 prior to its being attached by set screws, or other means, to the elbow members 40.
FIG. 5, which is a cross-section taken at 5--5 in FIG. 3, shows in more detail the configuration of the divider mechanism 43. The divider bar member 44 is preferably a plastic slit, or C-section, pipe or tube into which the plate 46 is inserted and joined by a solvent weld adhesive. Similarly, the plate 46 is inserted into and joined to the finger adjustment member 48 which also is a slit or C-section plastic pipe. These two members and plate form a stiffening beam means that is quite stiff in the plane of the plate 46. In this configuration, the divider mechanism is rigid in the direction necessary to prevent deflections that might allow larger crabs into the trap 10. It will be noted that the divider bar member 44 and the longitudinal member 30 may be rotated, prior to securing them with screws 41, in order to position the finger adjustment member 48 higher or lower than shown in FIG. 5 and to adjust the position of the finger assemblies 26 and hence the size of the opening "A" and the size of the acute angle formed between the finger assemblies 26 and the side members 38. FIG. 5 also shows the first longitudinal member 30, to which the finger assemblies 26 are attached, to have an open or C-shaped cross-section within which a pair of perpendicular lugs 52 provide for a snug fit.
FIG. 6 is a cross-section taken at 6--6 in FIG. 3 and shows details of the clip or strut member 50. The function of this member 50 is to provide still more stiffness for the divider mechanism 43 to prevent deflections of the divider bar member 44 that would allow larger crab to enter and be trapped. The strut member 50 is attached to the first longitudinal member 30 which is in turn attached to the frame 18 of trap 10. The strut member 50 is also attached to the divider mechanism 43 and the stiffening beam formed by its members 44, 46 and 48. The strut member 50 performs the function of reacting this stiffening beam near its center span, thereby substantially reducing the deflection of the beam when it is loaded by a large crab attempting to gain entry to the trap. As indicated by the dimension "B" of FIG. 6, the strut member 50 is of a length that is required by the location selected for the divider mechanism 43.
As is best shown in FIG. 7, the distance between longitudinal members 30, here labeled "C", may be, for example, about 8 inches for trapping larger crab when the divider mechanism 43 of this invention is not installed. However, when the divider mechanism 43 is used, the reduced dimension "D" establishes the size of the rectangular opening and is effective in restricting the entry of larger crabs. For example, in fishing for Opilio tanner crabs, a dimension "D" of 5 inches may be appropriate for preventing a bycatch of king or Bairdi tanner crabs. As previously indicated, this entrance gate apparatus allows selective adjustment of the dimension "D" defining the opening to the trap.
FIG. 8 illustrates the selective positioning of the finger adjustment member 48 to provide for a smaller opening dimension "E" than is shown by the dimension "A" of FIG. 5. This adjustment is achieved by appropriate rotation of divider member 44 and the first longitudinal member 30 prior to installation of screws 41 or other securing means in those members.
FIG. 9 illustrates an increased length "F" for the strut member 50 thereby establishing a smaller rectangular opening for the entrance gate apparatus of this invention.
FIG. 10 is a perspective plan view showing two crabs at the entrance gate apparatus. One crab is shown deflecting the flexible finger assemblies 26 upward to gain entrance to the trap. The other crab is shown starting to put its weight on the flexible finger assemblies 26 from above. This will deflect them downward to close the trap entrance and prevent the escape of the crab from the trap.
Even though this entrance gate apparatus has been described in the context of harvesting crabs, it will be apparent that it may have utility in capturing other species of shellfish such as lobsters and other animals.
In this entrance gate apparatus, the divider mechanism, which can easily be calibrated, will allow the opening dimension to be changed by fishermen to accommodate various sized crab species. For instance, Alaska may allow an opening of up to 40 sq. inches for Dungeness crabs whereas Washington may allow only 32 sq. inches for Dungeness crabs. Further, the fabrication technique used, wherein individual plastic parts are joined together, allows use of a variety of plastic and perhaps other materials best suited to the needs of the parts; for example, flexibility under extreme cold temperatures without brittleness is important for the flexible finger assemblies and may not be so important in the case of other parts.
While a particular embodiment of the invention has been disclosed herein, it will be readily apparent to persons skilled in the art to which this invention pertains that numerous changes, modifications, and substitution of equivalent components may be made without departing from the spirit of the invention that has been disclosed herein.
For example, a mechanical joint with small plastic parts like "male-female" gear teeth could be used for quickly and accurately adjusting the rotation of the upper longitudinal member 30 and/or the divider bar member 44 when adjusting the position of the flexible finger assemblies 26.
Similarly, the Tee-section members 44 could be provided with an adjustment spring pin or other mechanical device to allow a quick change in the size of the opening of the entrance gate between the lower longitudinal member 30 and the divider bar member 44.
Accordingly, the scope of this invention should be considered limited only by the spirit and scope of the elements of the appended claims or their reasonable equivalents. | In an entrance gate apparatus for a crab, shellfish, or other animal trap; said apparatus is adapted to be attached to a wall of said trap, and means are provided for selectively adjusting the size of the opening of said entrance gate to prevent animals of a larger than desired size from entering said trap. An adjustable divider mechanism provides means for selectively reducing the size of the opening of the entrance gate. A flexible finger assembly is provided to allow entrance to, while preventing exit from, the trap. The apparatus is preferably constructed of light weight and durable tubular and other molded plastic components. | 14,888 |
This application is a divisional, of copending application Ser. No. 877,883, filed on Feb. 15, 1978, now U.S. Pat. No. 4,211,892.
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a synthetic-speech calculator.
A synthetic-speech calculator is well known in the art of calculators. The prior art synthetic-speech calculator was adapted such that respective ones of digit keys and function keys were assigned their own unique audible sounds. The operation results or entered information was not easily distinguished from other information not assigned a unique audible sound, for example, index information and tabulation information.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide an improvement in a synthetic-speech calculator which provides audible sounds indicative of not only numerical information but also conditional information having a particular meaning with respect to that numerical information.
In one preferred form of the present invention, a synthetic-speech calculator includes a keyboard consisting of digit keys and function keys, a desired number of registers for storing information entered by the depression of selected ones of the digit keys, a read-only-memory for storing a large number of digital codes as sound quantizing information, counter means for specifying the address of the memory so as to take a specific digital code out of the memory, a digital-to-analog converter for converting the specific digital code taken out of the memory into an audible sound signal, and a loud speaker driven by the audible sound signal and producing an audible sound. There are provided means for producing audible sounds indicative of not only numerical information but also conditional information having a particular meaning with respect to that numerical information, such as index information, position information and tabulation information. Sound quantizing digital codes indicative of such conditional information are previously loaded into the read-only memory.
In the case of a law-of-exponent calculator, distinction codes are interposed between the mantissa portion and index portion. When a decision circuit senses the development of the distinction codes, digital codes indicating exponent information are derived from the read-only-memory. Alternatively, in the case of a conventional calculator, a counter is provided to sense the most significant digit of numerical information contained within a piece of a random-access-memory and provide the output thereof for an address counter associated with the read-only-memory, enabling the loud speaker to produce audible sounds indicative of the most significant digit type position information. This makes it easy for the operator to register operation results in a correct position while these are being delivered in an audible form.
Further, pursuant to the teachings of the present invention, it is possible to produce audible sounds indicative of, for example; previously selected tabulation information as soon as a power switch is thrown or a specific key is manually depressed.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and novel features of the present invention are set forth in the appended claims and mode of operation will best be understood from a consideration of the following detailed description of the embodiments taken in conjunction with the accompanying drawings, wherein;
FIG. 1 is a perspective view of a synthetic-speech calculator embodying the present invention;
FIG. 2 is a block diagram of the synthetic-speech calculator shown in FIG. 1;
FIG. 3 (comprised of A and B) shows an example of the contents of a register in case of a law-of-exponent calculator;
FIG. 4 is a circuit diagram which is effective in producing audible sounds indicative of exponent information;
FIG. 5 is a block diagram showing another preferred form of the present invention;
FIG. 6 is a flow chart provided for the purpose of explanation of operation of the embodiment shown in FIG. 5;
FIG. 7 shows an example of the contents of a register in the embodiment of FIG. 5;
FIG. 8 is an example of audible output forms in the example of FIG. 7;
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1 of the drawings, there is illustrated a perspective view of a synthetic-speech calculator embodying the present invention in the first embodiment which includes a body 1, a display 2, a power switch 3, a loud speaker 4, a sound key 5 available for indicating that keyed information or operation results are to be produced in an audible form, and digit keys and function keys 6. The speech synthesis technique is fully disclosed in many of U.S. Patents, for example, U.S. Pat. No. 3,102,165, SPEECH SYNTHESIS SYSTEM to Genung L. Clapper and U.S. Pat. No. 3,398,241, DIGITAL STORAGE VOICE MESSAGE GENERATOR to Lyle H. Lee.
FIG. 2 illustrates a block diagram of the synthetic-speech calculator. A keyboard KB contains a family of digit keys 10K, a family of function keys FK, etc. In response to the depression of a specific key, the corresponding signals are introduced into an encoder EC for code conversion. The outputs of the encoder EC are sent to a calculation circuit or central processor unit CPU and an output register OR. Keyed information and operation results are transferred from the output register OR to an address counter AC via the central processor unit CPU. The address counter AC is coupled with a read-only-memory ROM storing a large number of voice quantizing digital codes in advance. The address counter AC provides access to specific areas of the ROM containing selected ones of the voice quantizing digital codes. By the addressing of the ROM, the digital codes indicative of keyed information and operation results are picked up and converted into an audible form via a digital-to-analog converter D/A, a low-pass filter LPF, a speaker driver D and the loud speaker SP. As noted earlier, the ROM stores the digital codes that sample analog voice information containing vocal sounds, syllables, words etc., and quantize them at preselected amplitude levels. Fidelity of the reproduction from the ROM depends largely upon the number of samples and the number of quantizing levels. Amplitude quantum is a binary code and four-level quantizing requires two bits of binary codes, thereby enhancing fidelity. Sixteen-level quantizing with four bits of binary codes is substantially free of distortion.
According to a law-of-exponent calculator, numerical information consists generally of a mantissa and an index as shown in FIG. 3. In a first example (a), the mantissa portion is 1.2345 and the index portion is 10 12 (the tenth power). Numerical information is stored in the output register OR and distinction codes such as blank codes and negative sign codes are interleft to establish a distinction between the mantissa portion and index portion. For example, five bits of "01111" are selected for the blank codes and ones of "11111" are selected for the negative sign codes apart from the code representation of numerical information.
These distinction code signals are supplied to the address counter AC. The blank codes "01111" specify the digital codes indicative of distinction sounds between the mantissa portion and index portion, followed by addressing the sound quantizing digital codes corresponding to a word "power" in the tenth power. The thus addressed digital codes are sequentially taken out of the ROM, producing audible sounds via the loud speaker beginning with the mantissa portion. Numerical information indicative of the index portion is then derived in the order of "twelfth", "power", and "of ten". For the example of (b), audible sounds "five", "point", "three", "six", "seven", "multiply", "power", "minus", "power", "of", and "ten" are produced in a sequence.
FIG. 4 shows another preferred form of the present invention wherein a way to produce the mantissa portion in an audible form is different from that for the index portion. The components in the embodiment of FIG. 4 are given the same numbers as in FIG. 2 wherever possible in order to point up the close relationship. While the mantissa portion may be produced digit-by-digit in an audible form despite its digit significance, when producing audible sounds of the index portion. As mentioned previously, the register OR stores the blank codes "01111" and the negative sign codes "11111." Either of these codes are sensed via AND gates g1, g2, an OR gate O 1 and an AND gate g3, placing a flip flop F 1 into the set condition. When the flip flop F 1 is in the set state, the set output a is developed to indicate that the next succeeding information relates to the index portion. The set output a of the flip flop F 1 is supplied to the ROM to select information while taking digit significance into consideration. In this instance, the sound "power" is necessarily produced after the delivery of audible sounds of the mantissa portion. It is obvious that the present invention is applicable to power calculations.
FIG. 5 shows still another embodiment of the present invention the position of the most significant digit of numerical information is indicated in an audible form in advance to the delivery of that numerical information in the case of a conventional calculator. For example, if the most significant digit of numerical information is in the eighth digit position, then audible sounds "line", and "eight" are sequentially produced in accordance with the present invention. In FIG. 5, a register X stores numerical information and an address counter R 1 specifies the address of the register X beginning with the most significant digit thereof and ending with the least significant digit. A buffer register DC 1 stores the specific digit position of the register X which is addressed by the address counter R 1 .
An address counter VAC sequentially addresses the ROM, producing audible sounds indicative of not only numerical information contained within the register X but also position information indicative of the position of the most significant digit position of that numerical information. For the purpose of the invention three decision circuits or latches F B , F C and K are provided.
Mode of operation of the synthetic-speech calculator shown in FIG. 5 will be described referring to a flow chart of FIG. 6. Assume now that numerical information contained within the register X is "123456" as in FIG. 7.
In the first place, the latches F C , F B and K are reset for operation in the steps n 1 , n 2 and n 3 . The address counter R 1 is loaded with "8" in the step n 4 (that is, the most significant digit is at the eighth position). The step n 5 permits the contents of the register X specified by the address counter R 1 to be transferred into the buffer register X 0 . Information at the eighth digit position of the register X is φ entered into the buffer register X 0 . Because the latch K is initially in the reset state, the step n 7 is advanced where decision is effected as to whether X 0 =0 to inhibit spurious display of upper "0 S ". If X 0 is 0", the address counter R 1 is one reduced in the step n 8 . Therefore, R 1 =7. The step n 5 (X→X 0 ) is returned where information at the seventh digit position of the register S is shifted into the buffer register X 0 . These steps are repeatedly carried through. The seventh-digit information is entered into the buffer register X 0 , proceeding toward the step n 8 because of X 0 =). R 1 -1 is effected with R 1 =6. In the next step n 5 (X→X 0 ) X 0 ≠0 is established for the first time (X 0 receivers "1" at this time). The latch K is placed into the set state in the step n 8 , followed by the step n 9 . Under the circumstances the address counter VAC specifies the initial address. The procedure L→VAC in the step n 9 allows the initial address of an area of the ROM containing the sounds "line" to be specified. Thereafter, the flip flop F A is set in the step n 10 , starting to produce audible sounds "line." The step n 11 deals with decision as to whether the output of the ROM is an END code, which is usually loaded at the end of each word. The address counter VAC keeps on incrementing in the step n 12 to complete the production of audiable sounds "line" until the END code is reached. Upon the END code sensed the flip flop F A is reset in the next step n 13 and the address counter VAC is also reset in the step n 14 . The address counter VAC in the reset state does not specify any of the respective areas of the ROM. The latch F C is reset in the step n 15 , followed by the step n 16 because of F C =0. The procedure R 1 = 0 means decision as to whether the overall contents of the register X including the least significant digit position or the first digit position have been taken out, and a terminating requirement for the procedure 8→R 1 in the step n 4 . The n 5 step is reverted to effect operation X→X 0 when R 1 ≠0. The address of the register X remains unchanged R 1 =6 with the buffer X 0 loaded with "1". The latch K is set in the step n 8 to make up a sequence of the events n 16 →n 18 →n 19 →n 20 . After setting the flip flops F B and F C , R 1 →VAC is achieved in the step n 21 . R 1 =6 specifies an area of the ROM containing voice "SIX". The chained steps n 10 →n 14 allows sounds "six" to be produced via the loud speaker. The latch F C in the step n 15 reveals that F C =1 in the preceding step n 20 , proceeding toward the steps n 15 →n 16 . The procedure ·→VAC in the step n 16 is effected for the reason that a simple sound for example "peep" is to be interposed between "line six" and "numerical data." Thus, the initial address of an area containing a sound "peep" is specified. After ·→VAC, the latch F C is reset in the step n 17 to return back to the step n 15 . A sequence of the steps n 15 →n 16 →n 5 is carried through because F C in the reset state in the step n 17 . X→X 0 is a data input to the sixth digit position of the X register as ever. The steps n 6 →n 18 →n 22 are effected so that the address counter R 1 for the X register is decremented with R 1 =5. The procedure X 0 →VAC in the step n 23 is to specify the initial address of an area of the ROM containing audible sounds "one" which corresponding to "1" at the sixth digit position. Audible sounds indicative of numerical data are produced in the next succeeding steps n 10 →n 14 .
This follows the steps n 15 →n 16 →n 5 . Because R 1 =5 in the procedure X→X 0 the fifth digit position data "2" is introduced into the buffer X 0 . The steps n 18 n 22 results in R 1 -1=4. The step n 23 specifies the initial address of an area of the ROM containing sounds "two". The sounds "two" are produced in the steps are n 10 -n 14 . The above mentioned procedures are repeated such that the fifth digit data of the X register is introduced into the buffer X 0 in the step n 5 . The development in the steps n 6 →n 18 →n 22 results in R 1 -1=0. The address counter VAC in the step n 23 specifies the initial address of an arc containing sounds "six" (the fifth digit position data). Audible sounds of the fifth digit position data are produced with advance to n 15 →n 16 . R 1 =0 halts all the procedures. FIG. 8 shows the order of the audible sounds produced from the loud speaker SP.
Occasionally, a calculator contains one or more mode selectors on the operation panel, for example, a tabulation selector, a normal/constant operation selector and a counting fraction selector. Through the use of the present invention it is possible to produce audible sounds indicative of the operation states of these selector. Furthermore, audible sounds indicative of the operation states of the mode selector may be produced once a power switch is thrown or a specific function key (e.g., a clear key C C is depressed.
While only certain embodiments of the present invention have been described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as claimed. | A synthetic-speech calculator includes a keyboard consisting of digit keys and function keys and, if desired, or more mode selectors, a desired number of registers for storing numerical information entered by the depression of selected ones of the digit keys, a read-only-memory for storing a large number of digital codes as sound quantizing information, counter means for specifying the address of the memory so as to take a specific digital code out of the memory, a digital-to-analogue converter for convering the specific digital code taken out of the memory into an audible sound signal, and a loud speaker driven by the audible sound signal and producing an audible sound. There are further provided means for producing audible sounds indicative of not only numerical information but also its associated conditional information having a particular meaning with respect to that numerical information, for example, position information, index information, tabulation information, etc. Those numerical information and conditional information is derived in different audible forms. Specifically, a first sound indicates the most significant digit of the data, a second sound (monotone peep) separates the first sound from a third sound representing the data. | 16,780 |
This application is a continuation-in-part of U.S. application Ser. No. 08/181,918, filed Jan. 18, 1994, now abandoned, which is a continuation-in-part of U.S. application Ser. No. 07/984,480, filed Dec. 2, 1992, now abandoned.
FIELD OF THE INVENTION
The present invention relates to methods for diagnosing and treating myocardial infarction and hypertension using an antibody which specifically recognizes marinobufagin-like immunoreactivity, methods for assaying marinobufagin and other bufodienolides for research purposes using antibodies, hybridomas producing these antibodies, a process for preparing the antibodies, and
BACKGROUND OF THE INVENTION
Hypertension is the primary risk factor for coronary, cerebral and renal vascular diseases which cause over half of all deaths in the United States. It has been estimated that the number of hypertensive patients in the United States alone is substantially 57 million and on the rise. The widespread awareness of the danger of elevated blood pressure has become the most frequent reason for visits to physicians. No single or specific cause is known for the hypertension referred to as primary (essential) hypertension. Primary hypertension has been attributed to such causes as hemodynamic pattern, genetic predisposition, vascular hypertrophy, hyperinsulinemia, defects in cell transport or binding, defects in the reninangiotensin system (low-renin or high renin hypertension) and along with insulin, angiotensin and natriuretic hormone, catecholamines arising in response to stress are known to be pressor-growth promoters. Increased sympathetic nervous activity may raise the blood pressure in a number of ways, for example, either alone or in concert with stimulation of renin release by catecholamines, causing arteriolar and venous constriction, by increasing cardiac output, or by altering the normal renal pressure-volume relationship. Primary hypertension is also associated with, for example, obesity, sleep apnea, physical inactivity, alcohol intake, smoking, diabetes mellitus, polycythemia and gout. Secondary forms of hypertension may arise from oral contraceptive use and parenchymal renal disease: renovascular hypertension caused by, for example, atherosclerotic disease, tumors (renin-secretory tumors); Cushing's Syndrome; heart surgery; and pregnancy. Chronic hypertension and renal disease during pregnancy may progress into eclampsia, a primary cause of fetal death.
It has been theorized that blood serum and various mammalian tissues contain a substance, biologically and immunoreactively, similar to digitalis glycosides and digoxin (ouabain)-like which have been labeled endogenous digoxin-like factors (EDLF). This theory has been supported in recent years by considerable evidence of a causal role for sodium in the genesis of hypertension. The evidence includes the finding of increased intracellular sodium in hypertensive mammals. Increases have also been noted in normotensive children of hypertensive parents. It has been discovered that an increased fluid volume stimulates the secretion of EDLF that inhibits the Na+,K+-ATPase pump. The inhibition is brought about by the reaction of the EDLF with the alpha-subunit of the ouabain-sensitive-magnesium-dependent, Na+,K+-ATPase in a manner similar to the digitalis glycosides. In the case of renovascular types of hypertension, inhibition of the sodium pump increases renal sodium excretion and restores vascular volume while at the same time leading to hypertension by increasing intracellular sodium content by potentiating preexisting vasoconstriction and finally initiating a new circle in the pathogenesis of hypertension. Increased plasma concentrations of EDLF have been discovered in hypertension caused by other physical and pathological conditions. Consequently, it was discovered that the administration of an antidigoxin antiserum to hypertensive animals causes a pronounced decrease in the blood pressure.
The exact chemical nature, as well as the site of origin, of EDLF is not known. It has been proposed that endogenous digoxin is a peptide originating in the hypothalamus. It has also been reported that EDLF originates in the adrenals and the heart. It has been shown that the EDLF substance exists in several different molecular forms, at least one of the forms being steroidal in nature. Confirming this, it was discovered that several steroids with digitalis-like imnunoreactivity and ability to inhibit Na+,K+-ATPase were identified in various amphibian tissues.
It was discovered that EDLF has direct effects on the heart and that the mammalian heart contains a substance with digoxin-like immunoreactivity and other properties of digitalis. The existence of the different subpopulation of the high-affinity receptors for digitalis in myocardium and neural endings in the heart indicated the existence of an endogenous ligand(s) at these receptor sites. It is known that an overdose of digitalis glycosides provokes cardiac arrhythmias, including ventricular tachycardia and ventricular fibrillation, rather than increasing cardiac contractility. Acute myocardial ischemia (AMI) sensitizes the myocardium to the arrhythmogenic effect of digitalis and is associated with both the inhibition of myocardial sodium pump activity and with the loss of digitalis specific receptors. Based upon this prior knowledge, it was hypothesized that the increased plasma concentrations of EDLF contributed to the origin of the hypersensitivity of the ischemic myocardium to digitalis and that EDLF participates in the genesis of myocardial ischemia-induced arrhythmias. Based upon this hypothesis, it was discovered that the plasma concentration of digoxin-like immunoreactivity, (for example) EDLF, was significantly increased after a first transmural myocardial infarction. It was further discovered that acute myocardial ischemia is associated with a marked increase in the concentration of EDLF, which increase occurs in parallel with the onset of ventricular arrhythmias.
BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to (1) an antibody reacting specifically to marinobufagin, a bufodienolide, (2) antibodies to other bufodienolides, (3) hybridomas for producing such antibodies, (4) a process for preparing such antibodies, (5) a method for measuring marinobufagin-like immunoreactivity which comprises using such an antibody, (6) a method for diagnosing hypertension using such an antibody, (7) a method for diagnosing myocardial infarction and the risk of cardiac arrhythmias using such an antibody, and (8) a method of treating myocardial infarction using such an antibody.
DETAILED DESCRIPTION OF THE INVENTION
When this work began, crude venom from the parotid glands of the Bufo marinus toad was used. Liquid venom was obtained by gently pressing on the skin around the glands. About twenty four hours after the liquid venom was obtained it crystallized at room temperature. The Bufo marinus venom was compared with the effects of bufalin obtained from Sigma (0.1-50 mm). The testing was carried out on isolated abdominal aortic strips obtained from adult male Wistar rats. The animals were sacrificed by exsanguination. Rings of the abdominal aorta (1-1.5 mm diameter) were excised proximal to the origin of the renal arteries and suspended in a 10.0 ml bath perfused by 32° C. Tyrode solution bubbled by a mixture of 95% O 2 and 5% CO 2 under resting tension of 1 gram. Contractions of the aortic strip were recorded isometrically using a force transducer and displayed on a pen oscillograph. After a 60 minute equilibration period, dose-response curves to the vasoconstrictor effect (aortic strips) of the venom were plotted in the absence, and in the presence, of various pharmacological agents.
At concentrations of 0.3-10 ug/ml (n=9 for each described experiment) crude Bufo marinus venom possessed a dose-dependent vasoconstrictor response. Vasoconstrictor response to the venom was unaffected by alpha- and beta- adrenergic antagonists, 5-HT antagonists and calcium channel blockers. Addition of antidigoxin antibody to the incubation medium significantly reduced the vasoconstrictor response, while in vitro preinoculation of the venom with the antidigoxin antibody for twenty minutes completely prevented the vasopressor effect.
DIGIBIND, Fab fragments of bovine antidigoxin antibody (Burroughs Wellcome Co.), at concentrations up to 40.0 mg/ml had no effect on the vasoconstrictor effects of the venom. Bufalin at concentrations of 0.1-10 μM/l displayed weak and delayed vasoconstriction.
It was concluded that (1) The digitalis-like compound(s) contained in the venom from the parotid glands of the Bufo marinus toad, unlike previous candidates for the role of endogenous digitalis (EDLF), possess significant in vitro vasoconstrictor activity. These vasoconstrictor effects were blocked by antidigoxin antibody. (2) DIGIBIND, Fab fragments of bovine antidigoxin antibody, is absolutely ineffective in blocking the action of EDLF from the toad venom. (3) Since antidigoxin immunoglobulin G recognized and antagonized EDLF, but DIGIBIND, Fab fragments of bovine antidigoxin antibody, failed to bind EDLF: EDLF has immunoreactions different from digoxin. We hypothesized from the foregoing that antibody raised against EDLF should recognize EDLF better than antidigoxin antibody. As mentioned, Bufo marinus venom possessed significant vasopressor activity. As shown in the art the venom contains a mixture of several steroids.
To carry the experimentation further, Bufo marinus toad poison was collected from the parotid glands of five adult spades of both sexes of the toad. Following crystallization at 37° F. for twenty four hours, 800 mg of the poison was extracted in 5.0% ethanol for about two weeks with periodic shaking. The ethanol extract was filtered and the sediment was further washed with 3 ml of 50% ethanol. For further extraction of the steroids, equal volumes of the ethanol solution was diluted 1:1 with distilled chloroform. The mixture was then centrifuged in order to obtain chloroform and ethanol phases. The chloroform phase was isolated and another portion of distilled chloroform was added. The procedure was repeated two times after which the chloroform phases were mixed and vacuum distilled. A dark brown oily residue was obtained and dissolved in 1 ml of concentrated ethyl ether in acetic acid. The non-dissolvable portion of the residue was separated by filtration. A mixture of steroids was separated by thin-layer chromatography. Ethyl acetate was used as the eluent.
Rat aortic rings were treated by the mixture of steroids (0.1-5 ug/kg) in six experiments. The blood vessels were constricted in a dose dependent manner. The vasoconstriction effect of the mixture of steroids was unaffected by the adrenergic blockade of 2 μM phentolamine. Accordingly, it was concluded that the vasoconstrictor effect of the venom was due to the presence of the steroidal substance(s).
The steroids in the venom were then identified using UV. A spot corresponding to marinobufagin was scraped, divided into three portions and extracted with ethyl acetate. In a parallel manner all of the spots corresponding to the steroids present were extracted with ethyl acetate. The spots yielded, in addition to marinobufagin, resibufagenin, substance L, bufalin, telocinobufagin, argentinoginin, jamaicogenin, gellerbrigenol, gamabufotalin and substance D.
The compounds were each studied for their ability to contract isolated rat aorta (n=4) in each series. Only the fraction of marinobufagin showed rapid and strong vasoconstrictor effects insensitive to adrenergic blockers.
The major constituent of the Bufo marinus toad venom (7.9% of the total venom weight) is marinobufagin. The second major constituent of the venom is bufalin (0.48%) which compound did not show any intrinsic vasoconstrictor activity. The third and fourth major steroids present were telocinobufagin (0.06%) and resibufagenin (0.04%) which were in such low concentrations that neither was able to produce any results. It is therefore concluded that the vasoconstrictor action was attributable solely to the marinobufagin.
From the examples set out hereinafter taken with the foregoing it was concluded that marinobufagin is an EDLF in mammals as well as rats. It is also shown that anti-marinobufagin antibody utilized in acute myocardial ischemia in rats suppressed arrythmias better than anti-digoxin antibody. Moreover, in patients with acute myocardial infarctions, an ELISHA immunoassay based on anti-marinobufagin antibody allowed one to detect plasma levels of marinobufagin to orders of the highest magnitude as compared with digoxin immunoassay. It was further determined that the ELISA marinobufagin assay allowed one to detect plasma levels of marinobufagin exactly corresponding to the ability of marinobufagin to inhibit Na,K-ATPase.
It was unexpectedly discovered that the antibody prepared from marinobufagin prevented the effects of increased plasma concentrations of EDLF, for example arrhythmias, and prevented hypertension. The invention enabled a method of diagnosis and of predicting the onset of cardiac arrhythmias caused by various pathological conditions. It was previously discovered that antibodies prepared from the steroid compounds derived from marinobufagin effectively blocked endogenous digoxin-like factors found in the plasma of man.
Treatment to prevent or alleviate cardiac arrhythmias utilizing the antibody of the invention may be by any of the conventional routes of administration, for example, oral, intramuscular, intravenous or rectally. In the preferred embodiment, the antibody is administered in combination with a pharmaceutically-acceptable carrier which may be solid or liquid, dependent upon choice and route of administration. Examples of acceptable carriers include, but are not limited to, for example, physiological saline solution.
In the preferred embodiment, the inventive compounds are administered intravenously. The actual dosage unit will be determined by such generally recognized factors as body weight of patient and the severity and type of pathological condition the patient might be suffering from. With these considerations in mind, the dosage of a particular patient can be readily determined by the medical practitioner in accordance with the techniques known in the medical arts.
EXAMPLE 1
Purification and Characterization of Marinobufagin.
The Bufo marinus toad poison used in the examples was obtained from venom obtained from the parotid glands of Bufo marinus male and female adult toads obtained from the St. Petersburg, Russia and Riga, Latvia Zoological Gardens. The venom was extracted by gently pressing on the skin around the glands. The venom crystallizes at room temperature within 24 hours. We extracted 800 mg of the crystallized poison using 50% ethanol at a temperature of 30° C. over a two-week period.
Following the alcoholic extraction, the mixture was filtered through Shott Nr 4 filters. The filtrand was divided into two portions. Each portion was washed with 3 ml 30% ethanol. After removal of the filtrate the residue was further extracted with a 1:1 solution of 50% ethanol and chloroform followed by centrifugation in order to obtain chloroform and ethanol phases. The chloroform phases were isolated and extracted by centrifugation repeated two times after which the chloroform phases were mixed and distilled under vacuum. A dark brown oily residue resulted which was dissolved in 1 ml of ethyl acetate. The non-soluble residue was separated by filtration.
A mixture of steroid compounds was obtained and separated by thin-layer chromatography (Silufol VV 254, Sigma Chemicals), plates were pre-exposed to 1 hour preincubation at 100° C. Ethyl acetate was used as the eluent . Identification of the individual steroids was performed by UV. A spot corresponding to marinobufagin (Mbg) was scraped, divided into three (3) portions and extracted with ethyl acetate. In parallel series all eleven (11) spots corresponded to the steroids resibufagenin, substance L, bufalin, marinobufagin, telocinobufagin, argentinogenin, gellerbrigenin, jamaicogenin, gellerbrigenol, gamabufotalin, and substance D.
Detection of marinobufagin and other bufosteroids was accomplished by (a) visualization under ultraviolet (UV) light and comparison of chromatographic mobility, (b) spraying a saturated chloroform solution of SbCl 3 for color reactions, and (c) UV absorbance characteristics that are typical for marinobufagin (=300 nM, E=18600).
The other steroid compounds and substances were scraped from the Silufol plates and treated by the same procedure as the marinobufagin. The steroids developed and used in the experiments herein are as follows:
1. Resibufagenin, 3 beta hydroxy 14,15 epoxybufodienolide
2. Marinobufagin, 3 beta, 5 beta dihydroxy 14,15 epoxybufodienolide
3. Cinobufagin, 3 beta 16 beta acetoxy 14,15 epoxybufodienolide
4. Bufalin, 3 beta 14 beta dihyroxybufodienolide
5. Telocinobufagin, 3 beta 5 beta 14 beta trihydroxybufodienolide
6. Gamabufotalin, 3 beta 11 beta 14 beta trihydroxybufodienolide
7. Gellerbrigenin, 3 beta 5 beta 14 beta trihydroxy 19 nor-19 aldehyde bufodienolide
EXAMPLE 2
Synthesis of Antibodies to Marinobufagin
In order to become immunogenic, marinobufagin must first be conjugated with a sugar residue in order to further conjugate it with BSA.
We dissolved 50 mg of marinobufagin (purified by thin layer chromatography) in 10 ml of absolute dry benzene. Then 80 mg of Ag 2 CO 3 was added to the solution. The solution was then heated to boiling, and, while stirring, a solution of 180 mg of acetobromo-D-glucose in 15 ml of dry benzene was added by drops to the marinobufagin solution. The reaction was controlled by thin-layer chromatography on silicagel; disappearance of the spot corresponding to marinobufagin showing that conjugation of marinobufagin with glucose was successful. After the reaction was finished the silver salt was filtered and the filtrand was evaporated. The compound was dissolved in ether; the nondissolvable residue was filtered; and the glycoside was crystallized from the filtrand.
Conjugation of marinobufagin-glycoside with bovine serum albumin (BSA) was performed as described by Curd et al for digoxin.
Prior to the immunization, the conjugate Mbg-glycoside-BSA was further compared with Mbg for its ability to react with polyclonal antidigoxin rabbit antibody from the DELFIA immunoassay. In the DELFIA assay equimolar concentrations of Mbg and its conjugate demonstrated exactly similar displacement of digoxin standards. Therefore, the conjugation procedure did not alter the immunoreactive properties of the antigen.
Immunization and Development of Antibodies
The polyclonal antimarinobufagin antibody of the invention was obtained by immunizing chinchilla rabbits with a marinobufagin-3-glycoside-bovine serum albumin conjugate. Each animal was injected with 0.5 mg of the conjugate dissolved in 0.5 ml water and mixed in a ratio of 1:1 with Freund's adjuvant. The mixture was administered by subcutaneous injection in five different locations on the backs of the rabbits over a four-week period.
Serum was obtained from the rabbits and the inventive immunoglobulins were separated from the whole serum in the following steps:
Step 1. The serum was diluted (1:4) with an acetate buffer (60 mM CH 3 COONa--CH 3 COOH, pH 4). The pH of the solution was adjusted to pH 4.5 using O0.1 N NaOH.
Step 2. We slowly added 25 NL Caprylic (octanoic) acid with stirring to 1 ml of the serum solution. The final solution was stirred for thirty (30) minutes followed by centrifuging to separate proteins of non-immunoglobulin nature.
Step 3. The supernatant from Step 2 was filtered and the filtrate was dissolved, 9:1, in a phosphate buffer solution (150 mM NaCl, 3 mM KCl, 8 mM Na 2 HPO 4 , 1.5 mM KH 2 PO 4 , pH 7.2). The pH was adjusted to 7.4 with 1N NaOH. The resulting solution was cooled to 40° C. followed by the addition of NH 4 OH. The resulting mixture was centrifuged and a precipitate of proteins separated.
Step 4. The precipitate from Step 3 was dissolved in the minimal amount of distilled water and dialyzed in separate dialysis bags (threshold, protein with m.w. 17,000 D) against two changes of 1 liter of distilled water. Dialysis was controlled by concentrated BaCl 2 (in the presence of the SO 4 ions we saw undissolvable BaCl 2 ). The dialyzed anti-Mbg immunoglobulin of the invention obtained hereby was used in the tests.
EXAMPLE 3
Characterization of the Antibody
Immunoassay-ELISA
The test of cross-immunoreactivity was defined as the ratio: Amount of Mbg required to displace 50% of maximally bound Mbg from antiMbg antibody:Amount of the cross-reactant to give the same 50% displacement ##EQU1##
Mbg content in blood serum and tissue was assayed using half area enzyme immunoassay plates coated with BSA (bovine serum albumin) marinobufagin by adding to each well 50-100 μl of 1 ng/ml BSA-Mbg in a buffer (50 mM sodium carbonate, pH 8.6). The plates were stored at 4° C. for 1-2 days. Unbound BSA-Mbg conjugate was washed out by washing each well repetitively with rinse solution (0.09% NaCl) containing 0.05% TWEEN 20 (polyoxyethylenesorbitan monolaurate).
The titer of anti-Mbg antibody from immunized rabbits or produced by the hybridoma technique was determined on plates as described above. Doubling dilutions of antibody were added to the wells starting from 1:1000. The plates were incubated with shaking for 60 minutes at a temperature of 30° C.; this allows the anti-Mbg antibody to bind to the BSA-Mbg conjugate attached to a plate. After incubation, the antibody was washed out with four rinses. Antibody which bonded to Mbg remained attached to the wells. Then 1:1,000 dilutions of goat anti-rabbit IgG horseradish peroxidase conjugate were added to each well for 60 minutes with continuous shaking. The unbound goat anti-rabbit IgG-peroxidase conjugate was then washed away. Then TMB reagent was added (50 μl to each well). After 15 minutes the reaction was stopped by addition of 50 μl of 1M H 3 PO 4 .
The absorbance of each well was measured at 450 nm. A standard Mbg (marinobufagin) curve was plotted (0.1 to 10000 nM/1). Addition of Mbg prevents binding of anti-Mbg antibody to BSA-Mbg conjugate in the well. Consequently, less goat anti-rabbit IgG binds to the well and we see less absorbance at 450 nm.
In our experiments cross-reactivity of the anti-Mbg antibody with ouabain, ouabagenin and bufalin was less than 1%. Cross-reactivity with digoxin, digitoxin, digoxigenin, and digitoxigenin was less than 10%.
It will be understood by those skilled in the art that other methods of immunoassay are readily available in the art, for example, radioimmunoassay.
Immunoassay-2, Fluoroimmunoassay
Marinobufagin-like immunoreactivity was measured using a solid-phase fluoroimmunoassay. The method is based on competition between the immobilized conjugate (marinobufagin-3-glycoside-RNAase, 19:1) and a rabbit polyclonal antimarinobufagin antibody. Marinobufagin-3-glycoside-RNAase conjugate was prepared, and rabbits were immunized with marinobufagin-3-glycoside-BSA, as previously reported by Curd et al for digoxin. Marinobufagin-3-glycoside-RNAase conjugate (1.0 μg of conjugate in 100 μl of phosphate buffered saline per well) was immobilized on the bottom of NANC microtitration strip wells as reported in detail previously by Helsingius et al. We added 40 μl of marinobufagin standards and unknown samples to the coated wells, followed by 100 μl of marinobufagin antibody. After one hour incubation, the strips were washed twice (DELFIA wash solution, Wallac Oy, Turku, Finland), following which 100 μl of secondary antibody (europium-labeled goat anti-rabbit antibody, Wallac Oy, Turku, Finland) was added. After one hour incubation, the wells were washed six times with the wash solution. Then, 200 μl of enhancement solution, which releases the europium conjugated with the secondary antibody, (Wallac Oy, Turku, Finland) was added to each well, the strips were shaken for 5 minutes, and after 10 minutes more the fluorescence of free europium was measured (DELFIA 1234 Arcus Fluorometer, Wallac Oy, Turku, Finland). The sensitivity of the immunoassay was 0.001 nmol. Cross immunoreactivity of the assay was expressed as the ratio of the amount of cross-reactant required to displace 50% of antimarinobufagin, antiouabain or antidigoxin antibody from immobilized conjugate to the amount of the cross-reactant to give the same 50% displacement. Cross-reactivity of antimarinobufagin antibody with digoxin, ouabain, digitoxin bufalin, cinobufagin, mixture of bufosteroids from Bufo marinus toad excluding marinobufagin, prednisone, spironolactone, proscillaridine, progesterone and 5-beta cholanic acid was 0.1%, <0.01%, 3%, 1%, 0.1%, 5%, <0.1%, <0.1%, 1%, <0.5% and 1%, respectively.
EXAMPLE 4
Preparation of Hybridoma
The monoclonal antibody of the invention is prepared by emulsifying about 1-5 mg/ml of Mbg-BSA conjugate in saline solution with Freund's complete adjuvant 1:1. Emulsification can be readily carried out by repeatedly squirting the suspension through the nozzle of a syringe. A total dosage of about 0.3 ml is injected into multiple sites in mice, for example, in the legs and at the base of the tail. Injections are repeated at intervals of three to five weeks. Approximately ten days after each treatment, a drop of blood is taken from the tail of each mouse. The extracted blood is tested for the presence of specific antibodies. The animals yielding the best antiserum are selected for fusion.
After a rest period of at least one month, 0.2-0.4 ml of the Mbg-BSA conjugate solution, without Freund's adjuvant, is injected intravenously into each mouse. The injected mice are sacrificed 3-4 days later and the spleens removed under sterile conditions. The spleens are placed into a petri dish containing about 5 ml of 2.5% FCS-DMM kept on ice and washed gently. The spleens are then transferred to a round-bottomed tube, cutting them into three or four pieces per spleen, with about 5 ml of fresh 2.5% FCS-DMM. Using a Teflon pestle, the pieces are squashed gently to make cell suspensions. The clumps and pieces of connective tissues are allowed to sediment, then the cell suspensions are transferred to round-bottomed tubes. The tubes are filled with 2.5% FCS-DMM and spun at room temperature for 7-10 minutes at 400 g. The pellets are resuspended in about 10 ml of fresh medium and centrifuged as above. The pellets are then resuspended in 10 ml of medium, and the cells counted. Viability at this point should be higher than 80%.
Enough myeloma cells from a culture in logarithmic growth are pelleted by centrifugation at room temperature for 10 minutes at 400 g. The pellets are resuspended in 10 ml of 2.5% FCS-DMM and counted. Although the fusion and the initial selection of hybrids by growth in HAT medium are quite distinct stages, for convenience they are described together. For convenience, the fusion of cells in suspension is being described as by the spleens. The Mbg/spleen cells and the myeloma cells are prepared as above. About 10 8 spleen cells and 10 7 myeloma cells are mixed. DMM is added to a volume of 50 ml. The cells are spun down at room temperature for 8 minutes at about 400 g. The supernatant is removed with a Pasteur pipette connected to a vacuum line. Complete removal of the supernatant is essential to avoid dilution of the PEG (polyethylene glycol solution). The pellet is broken by gently tapping the bottom of the tube. The tube is placed in a 200-ml beaker containing water at 40° C. and maintained there during the fusion.
We add 0.8 ml of 50% PEG prewarmed to 40° C. to the pellet using a 1-ml pipette, over a period of 1 minute, continuously stirring the cells with the pipette tip. Stirring of the cells in 50% PEG is continued for a further 1.5 minutes. Agglutination of the cells is evident. With the same pipette, 1 ml of DMM is added, taken from a tube containing 10 ml of DMM kept at 37° C., to the fusion mixture, continuously stirring as before, over a period of 1 minute. The preceding step is repeated and then repeated twice adding the medium in 30 seconds. Using the same pipette with continuous stirring, the rest of the 10 ml of DMM is added over a period of about 2 minutes. With a 10 ml pipette, 12-13 ml of prewarmed DMM is added and the mixture spun down for about 8 minutes at 400 g. The supernatant is discarded and the pellet gently broken up by tapping the bottom of the tube and suspended in approximately 49 ml of 20% FCS-DMM.
This fusion suspension is distributed in the 48 wells of two Linbro plates. With a further 1 ml of 20% FCS-DMM 10 8 spleen cells/ml are added to the wells. The wells are incubated overnight at 37° C. in a CO 2 incubator. Using a Pasteur pipette connected to a vacuum line, 1 ml of the culture medium is removed from each well without disturbing the cells. The plate is fed with a 1 ml HAT medium for 2-3 days afterwards until a vigorous growth of hybrids is evident under the microscope. The culture becomes more yellow and may be tested for antibody activity. Duplicates of the growing hybrid cultures, either all or selected ones, are prepared and fed for a week with HAT medium.
EXAMPLE 5
Effects of Antibodies During Acute Myocardial Ischemia in Rats
Acute myocardial ischemia was set up in seventy-three adult male Wistar rats anesthetized with sodium pentobarbital (75 mg/kg intramuscularly) and artificially ventilated via tracheostomy. After thoracotomy, the left coronary arteries were ligated 1-2 mm distal to their origins. The hearts were monitored by three standard ECG leads. Test drugs were administered into the femoral veins via polyethylene catheters. After fifteen minutes of acute myocardial ischemia, the animals were sacrificed by exsanguination. It will be understood by those skilled in the art that the fifteen minute period corresponds to an approximate three to four hour period of myocardial infarction in humans. Blood samples were collected from the abdominal aortas into cooled polyethylene tubes containing 0.1 M EDTA and 10 μM phenylmethylsulfonylfluoride (50 μl per 4 ml blood). The resulting solution was frozen at -20° C. for determination of digoxin-like immunoreactivity (DLIR) in the plasma. The digoxin-like immunoreactivity was measured using dissociation enhanced lanthanide fluoroimmunoassay (DELFIA) kits by LKB, Finland. This assay of digoxin is a solid phase immunoassay based on competition between immobilized digoxin and sample digoxin (in the present case, EDLF) for europium-labeled polyclonal antidigoxin antibodies derived from rabbits. Standard and sample (or EDLF) reduce the binding of the europium labeled antibodies to the immobilized digoxin molecules. Finally fluorescence in the strip wells is measured in a resolved time result LKB-Wallac fluorometer. Plasma levels of marinobufagin-like immunoreactivity (MLIR) were measured as mentioned above in Example 3.
Arrhythmia incidence was defined as the total duration of ventricular tachycardia (VT) and ventricular fibrillation (VF) during the fifteen minute postligation period. The animals were divided into five groups as follows:
Group 1. Twelve (12) control, rats subjected only to thoracotomy;
Group 2. Twenty-eight (28) rats pretreated with an intravenous injection of 0.2 ml isotonic saline prior to the period of acute myocardial ischemia;
Group 3. Fifteen (15) rats pretreated by intravenous injection of 260 ug/kg antidigoxin immunoglobulin;
Group 4. Five (5) rats pretreated by intravenous injection with 5 mg/kg DIGIBIND (Fab fragments of bovine antidigoxin antibody, a drug produced for the treatment of digoxin overdose by Burroughs Wellcome Co.); and
Group 5. Seven (7) rats pretreated with 40 mg/kg DIGIBIND, Fab fragments of bovine antidigoxin antibody,
Group 6. Ten rats pretreated with antimarinobufagin antibody (250 ug/kg).
All pretreatment of the animals was carried out thirty minutes prior to coronary ligation. The control animals were pretreated thirty minutes prior to thoracotomy.
No heart rhythm disturbances were observed in the control animals. The plasma concentration of DLIR in the control animals was 0.48±0.09 ng/ml. Acute coronary ligation in Group 2 (ischemia without treatment) animals resulted in typical ischemic changes of the ECG, i.e., increase in the R wave, elevation of the ST-T segment and in the onset of ventricular arrhythmias. Average duration of VT and VF in Group 2 was 201±31 sec. Plasma concentration of DLIR 15 minutes post coronary artery ligation was 1.13±0.32 ng/ml, p<0.05. In the (Group 2) rats with acute myocardial ischemia the plasma concentration of MLIR was 3±0.5 μM/l 15 minutes after the coronary ligation as compared with 0.3±0.05 μM/l in the control group (which was the same as in intact rats without thoracotomy).
The Group 3 animals (pretreated with antidigoxin IgG) exhibited a reduced average duration of VT and VF to 46±18 sec. (p<0.01) The Group 4 animals (pretreated with DIGIBIND, Fab fragments of bovine antidigoxin antibody,) did not exhibit any change in the incidence of post-ligation arrhythmias.
The average duration of VT and VF was reduced to 74±34 sec in the Group 5 (pretreated with high-dose DIGIBIND, Fab fragments of bovine antidigoxin antibody, animals. This difference was not statistically significant when compared with the Group 1 (untreated) animals with myocardial ischemia.
The average duration of VT and VF in 10 rats pretreated with antimarinobufagin antibody (Group 6) was the lowest, 18.7±6.5 sec.
From this experiment, it was concluded:
1. Acute myocardial ischemia in rats is associated with an increase of the concentration of digoxin-like immunoreactivity and a more marked increase in Mbg-like immunoreactivity. This indicates that MLIR is a marker for acute myocardial infarction.
2. The increase in digoxin-like and Mbg-like immunoreactivity occurs in parallel with the onset of ventricular arrhythmias. This suggests that increasing levels of EDLF (or specifically, Mbg) cause cardiac arrhythmias.
3. Pretreatment of the animals with polyclonal antidigoxin rabbit IgG significantly reduces the incidence of arrhythmias and pretreatment with anti-Mbg antibody markedly reduces arrhythmias. We believe this means that antidigoxin IgG and anti-Mbg bind the circulating EDLF and prevent the development of its physiological effects.
4. DIGIBIND, Fab fragments of bovine antidigoxin antibody, even at extremely high concentrations was almost inactive in suppressing the ischemia-induced arrhythmias. Digoxin, therefore, is not the EDLF responsible for causing arrhythmias.
EXAMPLE 6
Human Myocardial Infarction
EDLF in Human AMI
Fifty-four (54) patients who had never taken digitalis drugs and had no known history associated with increased concentrations of EDLF, e.g., severe hypertension, renal or hepatic disease, and endocrine dysfunction, who were admitted to the coronary care unit of the Djanelidze Emergency Medicine Institute with a first time transmural acute myocardial infarction (AMI) were studied. Also not included in the study were patients who received systemic thrombolytic therapy. The diagnosis of AMI was based upon: typical chest pain of at least thirty minutes duration, ST segment elevation on the ECG with subsequent development of Q waves in the involved leads (Minnesota Codes 1-1-1, 1-2-5, 1-2-6, and 1-2-7), and increase of plasma total creatine phosphokinase and lactate dehydrogenase.
Patients known to have unstable angina pectoris, suspected (but not later confirmed) AMI, and healthy donors served as controls.
Venous blood samples were obtained from the patients each day for ten days and on the fourteenth day following the diagnosis of AMI. Blood was collected in cooled polyethylene tubes containing 10 μM phenylmethylsulfonylfluoride in 0.1 mol/liter EDTA. The mixture was frozen at -18° C. prior to assay. Plasma concentrations of EDLF were measured using the dissociation-enhanced lanthanide fluoroimmunoassay method digoxin kit and expressed as ng/ml of digoxin equivalents. The results were analyzed statistically using student's t-test.
Fifty-four Caucasian patients (47 male, 7 females) ages 39 to 72 years, (mean age 45 years) with AMI, 16 Caucasian male patients with unstable angina pectoris and suspected AMI ranging in age from 40 to 67 years, and eight healthy donors (3 males, 5 females), mean age 39.3 years, were enrolled in the study.
Plasma concentrations of digoxin-like immunoreactivity in patients during the first 24 hours following onset of AMI were significantly increased (1.25±0.26 ng/ml) as compared with the healthy controls (0.34±0.08 ng/ml) and patients with unstable angina pectoris (0.0414 0.06 ng/ml) . The condition of seven of the patients within the first 24 hours after onset of AMI was complicated by primary ventricular fibrillation. In these patients the concentration of EDLF was significantly higher (2.54±0.67 ng/ml) than in the 47 patients with AMI who did not experience ventricular fibrillation (1.05 0.27 ng/ml), p<0.05). During the first 24-hour period of time, 14 of the patients exhibited manifestations of severe congestive heart failure. In these patients, the concentration of EDLF immunoreactivity was significantly lower (0.32±0.09 ng/ml) than in the other 40 patients with AMI and without congestive heart failure (1.51±0.32 ng/ml).
Between the period of 24-48 hours after onset of AMI the plasma levels of EDLF of the AMI group decreased to levels of the control group (0.26±0.04), and did not differ significantly from the control values during the subsequent two-week period of assay and observation. Commencing after the second day of AMI no significant differences were observed in the plasma concentrations of digoxin-like immunoreactivity between patients with uncomplicated AMI and those with AMI complicated by ventricular fibrillation or congestive heart failure.
The results with the human patients discussed in this example were in agreement with the results obtained in Example 5 demonstrating that plasma concentration of the substances having the property to inhibit Na,K-ATPase is increased in animals exposed to acute coronary ligation. The results of the experimental tests clearly prove the proarrhythmic action of EDLF in AMI and the correlation between plasma levels of EDLF and incidence of ventricular arrhythmias.
Mbg in Human AMI
Eight male patients the first day after the onset of a first MI were studied as above. The peak plasma levels of marinobufagin-like immunoreactivity were 4.30±0.7 μMoles/l as compared with 1.2±0.2 μMoles/l in the 6 healthy controls.
Samples of heparinized blood were obtained from 3 male patients during the first 12 hours after the onset of first transmural myocardial infarction. The activity of the ouabain-sensitive Na,K-pump was measured using the known Rubidium (ouabain-inhibitable rubidium uptake) technique. Blood samples of the patients were analyzed in duplicate, in the presence and in the absence of monoclonal antiMbg antibody (100 ug/ml). In the untreated samples, activity of Na,K-pump (ouabain-sensitive Rb uptake by 1 ml of the suspension of erythrocytes) was inhibited by 70%. At the same time, preincubation of the whole blood with antibody for 30 minutes completely restored the activity of the Na,K-pump. Activity of the Na,K-pump in the erythrocytes from 8 healthy controls was unaffected by the pretreatment with antiMbg antibody.
This example demonstrates that the activity of the Na,K-pump in red blood cells in the acute period of myocardial infarction is depressed and that MLIR acts as a marker for acute MI in humans. This observation is in agreement with the previous data showing that activity of Na,K-ATPase in humans with myocardial infarction and in rats with acute myocardial ischemia is inhibited. It is known and has been repeatedly demonstrated that the changes in the membrane of erythrocytes reflect the membrane changes occurring in cardiovascular tissues in various diseases and due to the treatment with different drugs.
EXAMPLE 8
Diagnosis of Hypertension
Adult male Wistar rats (n=6) were subjected to acute plasma volume expansion as described by Gonick et al. Measurements as described above showed a 30% inhibition of the Na,K-pump and a four-fold increase in the level of MLIR. Thus, in this model of hypertension, MLIR was a marker for hypertension.
CONCLUSION
While the invention has been described in detail and with reference to specific embodiments thereof, it is apparent to one skilled in the art that various changes and modifications may be made therein without departing from the spirit of the present invention and therefore, that these descriptions should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.
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46. Helsingius P, Hemmila I, Lovgren T, Solid phase immunoassay of digoxin by measuring time resolved fluorescence. Clin Chem 1986; 32: 1767-1769. | The present invention relates to methods for diagnosing acute myocardial infarction through the measurement of the level of marinobufagin-like immunoreactivity in the blood of patients suspected of this diagnosis; a method for treating patients with acute myocardial infarction with antibody to marinobufagin, a bufodienolide, to prevent the occurrence of cardiac arrhythmias; antibodies which specifically recognize marinobufagin or other bufodienolides; hybridomas producing these antibodies; a process for preparing such antibodies; and an immunoassay method for marinobufagin for research purposes using its specific antibody.
The antibodies of the present invention make it possible to conveniently measure bufodienolides with specificity and high sensitivity. This is useful in determining the existence and degree of hypertension and myocardial infarction, and in treating myocardial infarction. | 49,744 |
BACKGROUND OF THE INVENTION
The invention relates to a lightweight constructional element or structural member of a sandwich structure having two cover plates which are held at a distance apart by a honeycomb structure. Said lightweight constructional element is intended in particular as a structural part of a solar collector.
Solar collectors require a very large area because the incident energy radiation of the sun per square meter is relatively small. Such solar collectors are set up as large paraboloids on steel frames and must follow the path of the sun. To achieve adequate energy yield a large area is necessary which in turn means a relatively high weight. As support for such paraboloids usually lightweight structural members or constructional elements are employed which however have to be specially made and are very expensive. Such lightweight constructional elements as described for example in DE-OS 2,836,418 can however also be used as support for solar cells.
THE SUMMARY OF THE INVENTION
Accordingly, it is an object of my invention is to provide a lightweight constructional element in particular for solar collectors which is relatively economical, can be easily made and has high strength.
In keeping with these objects and with other which will become apparent hereinafter, the honeycomb structure between the cover plates is formed by essentially cylindrical cans whose axes are perpendicular to the cover plates. This provides a lightweight structural member having basic elements which do not need to be specially made but which are obtained from waste products. In can recycling as hitherto employed only the material value of the drink cans was of interest. However, due to their precise shape these cans, which accrue in very large quantities, have a very much higher value than that of their raw material alone.
In particular, the substantially cylindrical sheet metal cans made by extrusion of aluminium, aluminium alloys or steel have in spite of their very small wall thickness of for example 0.07 to 0.1 mm a very high dimensional stability in the axial direction. This dimensional stability is increased still further in used beverage cans by the lid which is connected at its periphery to the cylindrical wall of the can by folding. Opening the can by pulling out an opening tab does not appreciably change this very high dimensional stability. These drink cans, connected together in as close an arrangement as possible along their lines of contact, in particular adhered together, form the cells of the honeycomb structure which in known manner is also connected by adhesion to the cover plates.
In the production of these drink cans of standardised size and form from aluminium or steel a certain percentage of rejects always occurs and hitherto these were melted down again. These reject cans, due to their shape, can be used just like already used cans as honeycomb cells for this lightweight constructional element. Since these reject cans are not provided with a lid it is possible to connect them together also by spot welding or riveting.
To obtain a homogeneous lightweight constructional element which can be loaded equally on both sides it is advantageous to arrange these cans which are open on one side so that they bear with the bottom side in uniform distribution alternately on the one cover plate and on the other cover plate.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of the invention will be described in detail in the following description with reference to the drawings, wherein:
FIG. 1 is a view of a lightweight constructional element along the section line I--I of FIG. 2,
FIG. 2 is a cross sectional view of the lightweight constructional element along the section line II--II of FIG. 1,
FIG. 3 is a perspective view of a solar collector or parabolic mirror of which the support plate is a lightweight constructional element according to the invention,
FIG. 4 is a plan view, partially in section, of two different embodiments of the lightweight constructional element according to my invention,
FIG. 5 is a side view of a lightweight constructional element according to the invention, partially in section, and
FIG. 6 is a sectional view of a lightweight constructional element having two honeycomb structures made from cans.
DETAILED DESCRIPTION OF THE INVENTION
The lightweight constructional element 10 according to FIGS. 1 and 2 consists of empty cans 11 which are connected together at their contact points 12 and are arranged between two cover plates 13, 14. The cans 11 connected together in tight packing form a honeycomb structure which is connected by adhesion, for example by means of epoxy resin, to the cover plates 13 and 14. The connecting of the cans 11 can be effected by adhesion, soldering or welding. The adhesion of the cans 11 can also be effected by initial dissolving of the stove enamel with which the beverage cans 11 have already been painted in their production to show their contents and as protection against corrosion. To improve the connection of the cans 11 with each other the cans of a lightweight constructional element 10 may be clasped or tied with a wire 18 or a band. Since in the vicinity of the bottom 16 and the lid 17 beverage cans also take up laterally acting forces said clasping wire 18 is preferably to be arranged in the vicinity of the cover plates 13, 14.
The lightweight constructional elements 10 according to the invention are suitable in particular as support element for large-area solar collectors, parabolic mirrors 20 and plane mirrors for heliostats. FIG. 3 shows a parabolic mirror 20 having a large-area support 23 which is formed by a lightweight constructional element according to the invention which is installed on a framework 16 so that the mirror can follow the sun.
The lightweight constructional elements according to FIGS. 2 and 3 are hexagonal. As FIG. 4 shows, they may also be rectangular or square. As apparent from the left part of FIG. 4 the cans 11 can be arranged in vertical and horizontal parallel rows or, as shown by the right part of FIG. 4, in extremely tightly packed array in which each horizontal row R is offset with respect to the adjacent row R' by the radius of the cans 11. In this arrangement the intermediate spaces 25 are smaller than the intermediate spaces 25' in the arrangement first described. The extremely tightly packed array shown on the right is often called a close packed or hexagonal close packed array (in two dimensions). This close packed array provides the closest type of packing, i.e. the packing in which the cans occupy the greatest fraction of the space in the constructional element or in other words leave a minimum fraction of intermediate space. Furthermore the cans shown in FIG. 4 are open on top.
The edges of the lower cover plate 14 are bent upwardly so that said cover plate 14 with the side walls 26 forms an open box having a size adapted to the size of the cans 11 in such a manner that the cans 11 can be inserted into the box with slight play. The remaining gaps between the cans 11 are filled with adhesive. The adhering of the cans 11 to each other and to the cover plates 13 and 14 can also be effected by foamed plastic which fills the intermediate spaces 25 or 25' at least in the more highly stressed regions. It is also possible to fill the cans 11 with foam to increase the loadability of the constructional element. To take up relatively large forces and enable them to be dissipated the constructional element is surrounded by a frame 28 of Uprofile rails 29 having flanges 30, 31 which engage over the edges of the cover plates 13, 14.
As FIG. 5 shows the cans 11 are arranged in uniform distribution with their bottoms 16 bearing alternately on the one cover plate 13 or the other cover plate 14 to obtain good homoqeneity of the constructional element.
In the embodiment of FIG. 6 two honeycomb structures of cans 11 are arranged one above the other with interposition of an intermediate plate 33. The intermediate plate 33 is also connected by adhesion to the honeycomb structures of cans 11. The cover plate 14 forms with its side walls 26 an open box which can receive the two layers of cans. The upper cover plate 13 is provided with downwardly directed edges 32 in such a manner that an open box is formed which can be fitted over the lower box. In this manner reinforced edges are formed round the constructional element and the stress to be taken up can be dissipated through said reinforcing edges.
By using beverage cans which are exactly made in standard sizes and which occur in large amounts as refuse and due to the relatively simple assembly of these beverage cans 11 to form a honeycomb structure, the lightweight constructional elements can be used as large-area supports for reflectors and concentrators of a solar heater in countries in which these solar heaters can be used to advantage. Such countries are usually relatively poor undeveloped countries.
Said constructional elements may be several square meters large. The thickness of the plates corresponds to the height of the drink cans used plus the thickness of the cover sheets, i.e. a total of about 118 or 171 mm or a multiple thereof.
At the outer edges the cover plates may be edged and adhered or welded so that a hermetically sealed hollow body is formed.
Due to the sandwich structure described the constructional elements have a high strength and rigidity for their material expenditure and weight. They are resistant to weather and buoyant and can therefore be used for a great variety of purposes.
The material and the thickness of the cover plates is to be adapted to the particular forces to be taken up. Constructional elements or structural members of aluminium beverage cans with aluminium cover plates are extremely large whilst having high loadability. A lightweight constructional element according to the invention may comprise two or more honeycomb structures and an intermediate plate, in particular of aluminium sheet, is arranged between the respective honeycomb structures.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of structures differing from the types described above.
While the invention has been illustrated and described as embodied in a lightweight constructional element of a sandwich structure, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims. | The lightweight constructional element of a sandwich structure having two cover plates comprises a honeycomb structure arranged between the cover plates which holds the cover plates spaced from each other. The honeycomb structure is formed by empty cans, especially used beverage cans, placed side by side whose axes are at right angles to the cover plates and which are arranged in a close packed or a rectangular array. The cans may be attached by adhesive to form a low cost lightweight and strong array. | 11,287 |
STATEMENT OF RELATED CASES
This case claims priority of U.S. Provisional Patent Applications 60/359,199 and 60/359,200, both of which were filed on Feb. 21, 2000 and both of which are incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates to wireless telecommunications in general, and, more particularly, to a hand-held processor having wireless communications capabilities.
BACKGROUND OF THE INVENTION
Hand-held processors, which are commonly called Personal Digital Assistants (“PDAs”), are becoming increasingly popular. PDAs possess relatively limited information processing, storage and retrieval capabilities. With these limited capabilities, a PDA performs specific tasks, such as functioning as an electronic diary, phone book, personal database, memo taker, calculator, alarm clock, etc. A user inputs data directly into a PDA using a stylus or a reduced-size keyboard. Additionally, PDAs are generally capable of exchanging information with a desktop computer, either by a physical connection or an infrared transceiver. PDAs typically include a relatively large display (i.e., large relative to the overall size of the PDA) and several buttons or keys for accessing specific applications and for scrolling to view information. Some PDAs also include a reduced-size keyboard.
Lately, wireless telecommunications capabilities have been incorporated into PDAs. Doing so provides advanced functions such as transmitting, receiving and displaying text messages. It also relieves a user of having to transport both a PDA and a wireless terminal (e.g., cellular telephone, pager, etc.).
Currently, most of the combined PDA/wireless terminals have one or more shortcomings that relate, among other areas of deficit, to compromised ergonomics or “user-friendliness” relative to a dedicated PDA or a dedicated wireless terminal. For example, some combined PDA/wireless terminals have hinged keyboards that rotate from a closed position to an open position for use. In some of these devices, the telecommunications capabilities can be accessed whether the keyboard is in the open or the closed position. While this arrangement provides a convenience for the user, it causes problems related to the usability of the display and the keys.
SUMMARY OF THE INVENTION
The present invention is a combined PDA/wireless terminal (hereinafter a “portable terminal”) that avoids some of the shortcomings of combined PDA/wireless terminals in the prior art.
A portable terminal in accordance with the illustrative embodiment of the present invention includes a base, a housing, and a display having a display screen. The housing is rotatably-coupled to the base and/or display. The portable terminal can be closed, wherein the housing overlies the base, or open, wherein the housing and the base flank the display. The portable terminal is opened by rotating the housing out-of-plane of the base. The display is fully visible to a user whether the portable terminal is open or closed.
The telecommunications capabilities of the portable terminal can be accessed when the portable terminal is closed and when it is open. Most of the PDA capabilities of the portable terminal are accessed when the portable terminal is open, wherein a keyboard having keys that are apportioned between the housing and the base is accessible.
When the portable terminal is open, it is typically held by a user in a different orientation than when it is closed. In particular, when closed, the portable terminal is held like a phone (i.e., in a “vertical” orientation) and, when open, it is typically held like an open book (i.e., in a “horizontal” orientation). The display screen is rotated relative to the user as between these two positions. Consequently, if text appears “right-side-up” when the portable terminal is closed, it will appear to a user to be on its side when the portable terminal is open.
In accordance with the illustrative embodiment of the present invention, the image in the display screen is rotated 90 degrees when the portable terminal is opened. This rotation re-orients the image so that it is “right-side-up” to a user (when he or she changes the orientation of the portable terminal). The image in the display screen can be electronically rotated, either automatically as the portable terminal is opened or by user command (a keystroke, etc.). In a variation of the illustrative embodiment, the display itself can be physically rotated.
In some variations of portable terminal, when the image in display screen is electronically rotated, the functionality of certain soft “convenience” keys that border the screen is also “shifted” or “rotated.” The functionality is shifted so that a key appearing in a certain position relative to the display, from the user's perspective, always performs the same function.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a block diagram of the salient components of a portable terminal in accordance with the illustrative embodiment of the present invention.
FIG. 2 depicts a plan view of a portable terminal in accordance with the illustrative embodiment of the present invention.
FIG. 3 depicts a perspective view of the portable terminal shown in FIG. 2 .
FIG. 4 depicts the portable terminal of FIGS. 2 and 3 in an open position wherein its keyboard is accessible.
FIGS. 5A-5D depicts the housing of a portable terminal in accordance with the illustrative embodiment being rotated from a fully closed position to a fully open position.
FIG. 6A depicts a portable terminal when closed, with particular attention to a user's perspective relative to an image in the display screen.
FIG. 6B depicts a portable terminal when open, with particular attention to a user's perspective relative to an image in the display screen.
FIG. 7A depicts a portable terminal in accordance with the illustrative embodiment, wherein the portable terminal is open and the image in the display screen has not been electronically rotated.
FIG. 7B depicts the portable terminal of FIG. 7A but after electronic rotation of the image in the display screen.
FIG. 8A depicts a portable terminal in accordance with the illustrative embodiment, wherein the portable terminal is open and wherein the display has not been physically rotated.
FIG. 8B depicts the portable terminal of FIG. 8A but after physical rotation of the display.
FIG. 9A depicts a portable terminal having four convenience keys that border the corners of the display screen in accordance with the illustrative embodiment.
FIG. 9B depicts the portable terminal of FIG. 9A after an image in the display has been electronically rotated and a user has changed his or her viewing perspective.
FIG. 10 depicts a block diagram showing electronic rotation of an image in the display screen and rotation of the functionality of convenience keys of a portable terminal in accordance with the illustrative embodiment of the present invention.
DETAILED DESCRIPTION
This Detailed Description begins with a relatively high-level description of the functionality of various circuitry/components (hereinafter collectively “components”) that compose a portable terminal in accordance with the illustrative embodiment of the present invention. Following this, various physical implementations of some these components, and their mechanical and functional interrelationships with other parts of the portable terminal, are described.
FIG. 1 is a high-level block diagram of portable terminal 100 in accordance with the illustrative embodiment of the present invention. Portable terminal 100 provides both wireless telecommunications capabilities and personal computing (i.e., PDA-type) capabilities.
With regard to its telecommunications capabilities, portable terminal 100 is capable of transmitting and receiving both voice and data with wireless base stations (not shown) or other wireless terminals, or both. Additionally, portable terminal 100 is capable of supporting telecommunications with wireline terminals through a wireless base station and wireline infrastructure. As to its personal computing capabilities, portable terminal 100 provides typical PDA computing and storage capabilities, including, without limitation, scheduling, address book storage and retrieval, note-taking, and an ability to run a variety of application software packages (e.g., calculators, games, etc.).
Portable terminal 100 advantageously includes: control circuitry 102 , transmitter 104 , receiver 106 , antenna 108 , speaker 110 , microphone 112 , display screen 114 , keyboard 116 , additional tactile input devices 118 , infrared transceiver 120 , keyboard-open sensor 122 , environmental sensor(s) 124 and power supply 126 .
Control circuitry 102 is advantageously capable of coordinating and controlling the other components of portable terminal 100 to provide, as appropriate, wireless telecommunications capability and personal computing capability, in known fashion. Control circuitry 102 typically includes a processor, memory, and electrical interconnections, among other hardware. In some variations of the illustrative embodiment, a single processor is used for carrying out and controlling PDA operations and wireless telecommunications operations. In some other variations, separate processors are used for PDA operations and wireless telecommunications operations.
It will be understood that as used herein, the term “processor” equivalently means a single integrated circuit (“IC”), or a plurality of ICs or other components that are connected, arranged or otherwise grouped together, such as microprocessors, digital signal processors, application-specific integrated circuits, associated memory (e.g., RAM, ROM, etc.) and other ICs and components. Control circuitry 102 can include programmed general-purpose hardware or special-purpose hardware, or both.
Transmitter 104 and receiver 106 provide wireless telecommunications capability to portable terminal 100 at radio frequencies. Embodiments of present invention can use any access technology (e.g., frequency-division multiple access, time-division multiple access, time-division duplex, code-division multiple access, etc.) and any modulation scheme (e.g., frequency shift keying, quadrature phase-shift keying, etc.) in accordance with any interface (e.g., IS-41, IS-54, IS-95, GSM, etc.). Furthermore, portable terminal 100 can transmit and receive at any frequency (e.g., 800 MHz, 1800 MHz, etc.). It will be clear to those skilled in the art how to make and use transmitter 104 , receiver 106 and antenna 108 .
Speaker 110 is capable of outputting an acoustic signal (e.g., the speech of another person, an alerting or ringing signal, etc.) to a user of portable terminal 100 in well-known fashion. Furthermore, control circuitry 102 is capable of adjusting the volume of the acoustic signal output from speaker 110 .
Microphone 112 is capable of receiving an acoustic signal (e.g., the speech of the user of portable terminal 100 , etc.), converting it to an electrical signal containing information that is indicative of the acoustic signal, and of conveying that information to control circuitry 102 for transmission via transmitter 104 in known fashion.
Display 114 is a visual display for outputting information (e.g., text, images, video, etc.) to a user of portable terminal 100 . Display 114 includes a display screen, such as a liquid crystal display (“LCD”), and various electronics that, in conjunction with control circuitry 102 , drives the display screen. Display 114 also typically includes a light source (not depicted) for illuminating the display screen. It will be clear to those skilled in the art how to make and use display screen 114 .
Keyboard 116 is a tactile input device that includes a set of keys that enables portable terminal 100 to receive information from a user. The keys in keyboard 116 can be used to input a variety of different types of information to portable terminal 100 . For example, the keys of keyboard 116 can be representative of, without limitation, alphabetic characters of an alphabet, numerals, mathematical operators, mathematical functions, specific commands that are useful in conjunction with certain types of application software (e.g., games, etc.), retail items (e.g., food and drink that is offered by a restaurant, specific types of inventory in a warehouse, etc.).
Keyboard 116 can include one or more keypads (i.e., regional groupings or grids of numerical and/or function keys arranged for efficient use). Advantageously, keyboard 116 is illuminated by a light source, under the control of control circuitry 102 , to aid the user of portable terminal 100 to enter information into keypad 116 . It will be clear to those skilled in the art how to make and use keyboard 116 .
Additional tactile input devices 118 include keys or key-like elements (e.g., a joystick, etc.) that are not physically co-located with the group of keys that define keyboard 116 . These additional keys enable user to deliver information to portable terminal 100 . In some embodiments, the information provided by additional tactile input devices 118 is different than the information that can be provided via the keys in keyboard 116 . For example, one additional tactile input device 118 is a pointing device that moves a cursor in display screen 114 . A second additional tactile input device 118 is a scroll button that allows a user to scroll through menu selections that are presented in display screen 114 . It will be clear to those skilled in the art how to make and use additional tactile input devices 118 .
Infrared transceiver 120 is a device (e.g., an IrDA compliant device, etc.) that enables portable terminal 100 to communicate with other devices by modulating infrared light. It will be clear to those skilled in the art how to make and use infrared transceiver 120 .
Keyboard-open sensor 122 is a device that senses when keyboard 116 , which in some variations of the illustrative embodiment is rotatable between an open position and a closed position, is in the open position (and/or is being opened). A signal from the keyboard-open sensor is delivered to control circuitry 102 , which, as appropriate, can take certain actions, as described later in this specification. Keyboard-open sensor 122 can be implemented in any of variety ways known to those skilled in the art (e.g., as a mechanical sensor, as an optical sensor, etc.).
Environmental sensor(s) 124 are one or more devices that sense ambient environmental factors (e.g., temperature, vibration, noise, light, motion, etc.). Environmental sensor(s) 124 generate a signal that is responsive to the environmental factor, and the generated signal is received by control circuitry 102 . The control circuitry then alters certain aspects of various components (e.g., the level of illumination that is provided to display screen 114 and/or keyboard 116 , the volume of speaker 110 , etc.).
It will be appreciated that the specific implementation of environmental sensor(s) 124 is a function of the environmental factor that is being sensed. For example, when environmental sensor 124 is required to sense ambient noise, environmental sensor 124 can be, for example, a microphone, such as microphone 112 . When environmental sensor 124 is required to sense ambient light intensity, it can be, for example, a cadmium-sulfide photoresistor, a charge-coupled device, or other known light-sensitive device. It will be clear to those skilled in the art how to make and use environmental sensors 124 .
Power supply 126 supplies electrical power to the components of portable terminal 100 that require power (e.g., processor(s), display screen 114 , sensors 122 and/or 124 , etc.). Power supply 126 is advantageously implemented with rechargeable or replaceable batteries. In some embodiments, at least two separate power supplies 126 are provided. One of the supplies, which is the primary power supply, has greater energy output and storage capacity and is used for powering portable terminal 100 during normal operations. The second supply is a back-up that is used, for example, to maintain data (e.g., address book information, scheduling information, etc.) in memory when the primary power supply is removed (e.g. for replacement, etc.).
Various physical implementations of the components that are described (functionally) above, and their mechanical and functional interrelationships with other parts of the portable terminal, are described in applicant's co-pending patent application Ser. No. 10/161,831 “Portable Terminal With Foldable Keyboard”), which is incorporated herein by reference. Many of the components that are described therein, and which are properly included in at least some versions of the illustrative embodiment of the present invention, are not described herein. The purpose for these omissions is to maintain a focus on elements that are germane to an understanding of the present invention. Also, for the sake of clarity, the components that have been described in terms of their functionality (see FIG. 1 ), are provided with a “call-out” (i.e., numerical identifier) that is in the range 102 through 198 . The illustrative physical implementations these components, some of which appear in FIGS. 2 through 6D , have been provided with a different call-out. The purpose for this is that, in some cases, a component, as functionally described, incorporates more elements (additionally circuitry, etc.) than is depicted in the illustrative physical implementations.
With reference to FIGS. 2 through 5D , portable terminal 100 includes display 228 and keyboard-housing 230 . Display 228 has a display screen 232 and one or more convenience keys 236 that are advantageously “soft” (i.e., re-definable) keys. Keyboard-housing 230 consists of base 338 and housing 340 (see, FIGS. 3 through 5 D). Housing 340 is rotatably connected to base 338 and/or display 228 at pivot 442 . By virtue of pivot 442 , housing 340 is capable of rotating “out-of-plane” (of base 338 ) about pivot axis 1 — 1 . Pivot axis 1 — 1 bisects display 228 . In the illustrative embodiment, pivot 442 is implemented as rod 444 , and cooperating receiver 446 that depends from housing 340 .
In accordance with the illustrative embodiment of the present invention, portable terminal 100 can be used in either of two basic configurations: “closed,” as depicted in FIGS. 2 , 3 , and 5 A or “open,” as depicted in FIGS. 4 and 5D .
When portable terminal 100 is closed, housing 340 is superposed over base 338 so that the two housings coincide and serve as a handle for gripping the portable terminal 100 in the manner of a conventional wireless phone. Additionally, in this state, base 338 and housing 340 serve as a cover for a keyboard. As described further below, the keyboard is partitioned into two portions, one disposed on the inner surface of the base and the other on the inner surface of the housing. When closed, portable terminal 100 can be used to make and receive telephone calls.
To use various PDA-type applications (e.g., address book, schedule, etc.) of portable terminal 100 or to enter alphanumeric data (e.g., to send a data message, etc.), the keyboard of portable terminal 100 is accessed. To do so, portable terminal 100 is opened by rotating housing 340 out-of-plane away from base 338 , as illustrated in FIGS. 5B and 5C .
In the illustrative embodiment, the keyboard is implemented in two portions, keyboard portion 548 and keyboard portion 550 . Keyboard portion 548 is disposed within base 338 and keyboard portion 550 is disposed within housing 340 . When portable terminal 100 is open, display 228 is disposed between keyboard portion 548 and keyboard portion 550 .
In the illustrative embodiment, housing 340 is rotated 180 degrees out-of-plane to a “fully-open” position. It will be understood, however, that housing 340 need not be rotated a full 180 degrees to access and use the keyboard. In fact, a user might prefer to rotate housing 340 somewhat less than 180 degrees (e.g., 160 degrees rotation, etc.). In particular, some users might find that when base 338 and housing 340 are less than 180 degrees apart, less stress is placed on their wrists, especially during periods of extended use (e.g., game playing, etc.). Alternatively, in some variations of portable terminal 100 , housing 340 is rotatable beyond 180 degrees, again for the comfort of the user.
As suggested above, when portable terminal 100 is closed, it is most likely to be used in the manner of a conventional wireless terminal to send and receive calls. FIG. 6A depicts portable terminal 100 (keyboard housing 230 shown in phantom) closed. From the perspective of a user that is holding “closed” portable terminal 100 in front of himself or herself, N(orth) is “up,” S(outh) is “down,” E(ast) is “right,” and W(est) is “left,” (this is the same view that is presented to the reader, as he or she gazes at FIG. 6 A). So, to the user, the word “CLOSED,” which appears in display screen 232 , is properly oriented for reading.
As previously indicated, when it is open, portable terminal 100 is most likely being used as a PDA. FIG. 6B depicts portable terminal 100 (base 338 and housing 340 shown in phantom). From the perspective of a user that is holding “open” portable terminal 100 in front of himself or herself, N(orth) is “right,” S(outh) is “left,” E(ast) is “down,” and W(est) is “up.” This is the view that is presented to the reader when he or she rotates FIG. 6B clockwise by 90 degrees. So, to the user, the word “OPEN,” which appears in display screen 232 , is not properly oriented for reading. (A user could use portable terminal 100 in the manner of a “flip-phone” [i.e., in a vertical orientation] when it is open, so that the word “OPEN” would be properly oriented for reading. But this would make it very difficult to use the keyboard, in particular the alpha-character keys.)
Consequently, in accordance with the illustrative embodiment of the present invention, the image in display screen 232 is rotated counterclockwise 90 degrees. For a user that is holding portable terminal 100 in a “horizontal” orientation (i.e., housing 340 to the right of display 228 and base 338 to the left of display 228 ), this re-orients the image so that it is in a “normal” reading orientation. This horizontal orientation is assumed to be the user's orientation for the description of FIGS. 7A , 7 B and 8 A and 8 B, below. Consequently, these Figures should be viewed as indicated by the arrows that appear in those Figures.
Rotation can be accomplished in at least two ways. One way is to electronically rotate the image. Electronic rotation is described with reference to FIGS. 7A , 7 B and 10 . FIG. 7A depicts open portable terminal 100 before the image in display screen 232 is electronically rotated. In FIG. 7A , screen image N(orth) is “right,” and screen image W(est) is “up,” etc. To a user, the word “OPEN,” which appears in display screen 232 , is not properly oriented.
FIG. 7B depicts open portable terminal 100 after the image in display screen 232 is electronically rotated. In FIG. 7B , screen image N(orth) is “up,” screen image W(est) is “left,” etc. To a user, the word “OPEN,” which appears in display screen 232 , is now properly oriented.
Portable terminal 100 is advantageously capable of automatically (i.e., in the absence of an explicit command from the user) electronically rotating the image in display screen 232 and also capable of electronically rotating the image on command from the user. In accordance with the illustrative embodiment of the invention, automatic rotation is triggered as a user rotates housing 340 away from base 338 to open portable terminal 100 . More particularly, when keyboard open sensor 122 senses that the portable terminal 100 is being opened, it sends a signal to control circuitry 102 . When the signal is received by control circuitry 102 , image-rotating processing rotates the image in display screen 232 . It is within the capabilities of those skilled in the art to electronically rotate an image, so implementation details are not described here.
Alternatively, a user can cause an image in display screen 232 to electronically rotate by explicit command. That is, the user can rotate the image by depressing a key. This key can be, without limitation, a key in keyboard portion 548 or keyboard portion 550 or one of convenience keys 236 .
FIG. 10 depicts a high-level block diagram that illustrates, among other functions, electronic image rotation, as described above and performed by control circuitry 102 . As depicted in FIG. 10 , an image is generated in operation 962 . In operation 964 , the image is rotated (e.g., counterclockwise by 90 degrees, etc.) if user-generated rotate command 966 is issued (e.g., a user depressing a key, etc.) or if automatic rotate command 968 is issued (e.g., from keyboard open sensor 122 , etc.). To rotate the image 90 degrees counterclockwise, the image is transformed as follows:
( x,y )→(− y,x ) [1] where: x and y are the coordinates in a two-dimensional Cartesian coordinate system.
Operations 962 , 964 , 966 , and 968 can be performed by hardware, software, or a combination of both. When portable terminal 100 is closed (after having been open) such that keyboard-open sensor 122 no longer senses an “open” condition, image rotation ceases. Alternatively, a keystroke by a user can cause the image rotation to stop.
A second way to rotate the image is to physically rotate display 228 (or display screen 232 ). Physical rotation is illustrated with reference to FIGS. 8A and 8B . FIG. 8A depicts open portable terminal 100 before display 228 is rotated (e.g., by hand, etc.). In FIG. 8A , screen image N(orth) is “right,” and screen image W(est) is “up,” etc. To a user, the word “OPEN,” which appears in display screen 232 , is not properly oriented.
It will be appreciated that portable terminal 100 must be specifically configured or adapted to enable display 228 to rotate independently of housing 340 and base 338 . Representative of such an adaptation is an arrangement consisting of ball 858 and two hemispherical detents 860 A and 860 B. When ball 858 engages detent 860 A, display 228 locks in place with the orientation depicted in FIG. 8 A. With turning force, ball 858 disengages from detent 860 A and display 228 is free to rotate. With continued rotation, ball 858 engages detent 860 B, such that display 228 is locked in place with the orientation depicted in FIG. 8 B. In FIG. 8B , screen image N(orth) is “up,” screen image W(est) is “left,” etc. To a user holding portable terminal 100 in a horizontal position (as described above), the word “OPEN,” which appears in display screen 232 , is now properly oriented. A variety of other arrangements, as are well known to those skilled in the art, that enable display 228 to rotate independently of housing 340 and base 338 can suitably be used in other variations of the illustrative embodiment.
In some variations of portable terminal 100 , display 228 includes four convenience keys 236 . For example, in FIGS. 9A and 9B , which show display 228 without housing 340 and base 338 , display 228 includes convenience keys 236 - 1 , 236 - 2 , 236 - 3 , and 236 - 4 bordering the corners of display screen 232 . In variations of the portable terminal 100 in which the image in display screen 232 (but not display 228 ) is rotated (i.e., electronic image rotation), the spatial orientation of convenience keys 236 - 1 , 236 - 2 , 236 - 3 , and 236 - 4 changes, relative to the image, upon such rotation. This scenario is illustrated by FIGS. 9A and 9B .
In FIG. 9A , portable terminal 100 is closed, and a user views display screen 232 as indicated by the arrows. Consequently, the user sees convenience key 236 - 1 bordering the upper left of display screen 232 and convenience key 236 - 2 bordering the lower left of display screen 232 , etc. Assume that the user opens portable terminal 100 . And, in conjunction with this, assume that the image in display 232 is electronically rotated as described above and the user repositions portable terminal 100 such that it is being held in a horizontal position and viewed as shown by the arrows in FIG. 9 B.
From the user's perspective, convenience key 236 - 1 no longer borders the upper left of display screen 232 and convenience key 236 - 2 no longer borders the lower left of display screen 232 . As can be seen from FIG. 9B , the user sees convenience key 236 - 1 bordering the upper right of display 232 and convenience key 236 - 2 bordering the upper left of display screen 232 .
If the various convenience keys perform different functions, this change in spatial orientation might be problematic for a user. In particular, with continued use, a user will tend to associate the function of a first convenience key with its position relative to the screen (e.g., the key to the lower-left of the screen accesses a telephone directory, etc.). But when the image is electronically rotated, and the user changes his or her perspective relative to portable terminal 100 , a second convenience key is, from the user's perspective, now in the position that was occupied by the first convenience key. Consequently, to the extent that a user associates the function of a key with its position relative to display screen 232 , he or she must recognize that the function will change depending upon whether portable terminal 100 is open or closed. This is undesirable.
In accordance with some variations of portable terminal 100 , when the image in display screen 232 is electronically rotated, the functionality of convenience keys 236 is “shifted” or “rotated” accordingly so that a key appearing in a certain position relative to the display, from the user's perspective, always performs the same function. So, for example, the convenience key that appears, from a user's perspective, at the lower left of the display always accesses the telephone directory, etc. For the scenario illustrated in FIGS. 9A and 9B , the functionality of each convenience key should be “shifted” to the convenience key that next appears with counterclockwise rotation. That is, the functionality of convenience key 236 - 1 is shifted to convenience key 236 - 2 , the functionality of convenience key 236 - 2 is shifted to convenience key 236 - 3 , etc. To this end, convenience keys 236 are advantageously software re-definable (i.e., soft) keys.
It will be understood that the terms “shifted” or “rotated,” as used to describe the change in function of convenience keys 236 , is intended to be descriptive of the end result rather than the process itself. That is; the functionality of one key is not actually shifted to another; rather, the operation of the keys are simply redefined or reprogrammed by the circuitry/software of portable terminal 100 in known fashion. This is the sense in which the terms “shifted” or “rotated” are used in this description and the appended claims with regard to convenience keys 236 .
FIG. 10 depicts a high-level block diagram of method 900 for operating portable terminal 100 . The method pertains to rotation of an image and shifting of convenience-key functionality, as described above and performed by control circuitry 102 .
As depicted in FIG. 10 , in operation 970 , the functionality of convenience keys 962 is rotated (e.g., counterclockwise by 90 degrees, etc.) if user-generated rotate command 966 is issued (e.g., a user depressing a key, etc.) or if automatic rotate command 968 is issued (e.g., from keyboard open sensor 122 , etc.). Operations 966 , 968 , and 970 can be performed by hardware, software, or a combination of both. When portable terminal 100 is closed (after having been open) such that keyboard-open sensor 122 no longer senses an “open” condition, rotation of image or shifting of convenience-key functionality ceases. Alternatively, a keystroke by a user can cause the rotation and shifting to stop.
It is to be understood that the above-described embodiments are merely illustrative of the present invention and that many variations of the above-described embodiments can be devised by those skilled in the art without departing from the scope of the invention. It is therefore intended that such variations be included within the scope of the following claims and their equivalents. | A portable terminal having personal computing capability and wireless telecommunications capability. The portable terminal includes a display that is integral with, or otherwise attached to, a display. A housing is rotatably-coupled to the base and/or display. The portable terminal can be closed, wherein the housing overlies the base, or open, wherein base and housing flank the display. The display is fully visible to a user whether the portable terminal is open or closed. When open, a keyboard having keys that are apportioned between the housing and the base is accessible. To accommodate a change in the way in which a user is likely to hold and view the portable terminal when it's closed versus when it's open, the image in the display screen is rotated on command, or automatically, when the portable terminal is opened. | 33,574 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to body sensation providing devices and more particularly relates to skin contacting units adapted to be powered by one channel of audio output of a stereo amplifier enabling a couple, each wearing one of the units, to feel as well as hear the sound output of the amplifier when the couple is in skin contact with each other.
2. Description of the Prior Art
The sense of sight has often been used to complement the sense of hearing and thereby enhance the enjoyment of music. Thus, electrical impulses related to sound generation for speakers has been used to modulate various colored lights to respond to rhythms, amplitudes and melodies providing so called psychedelic lighting effects for simultaneous visual stimulation while listening and dancing to the music. This invention enables the listeners to feel as well as hear the music and may have uses in dance instruction for the profoundly hearing impaired.
SUMMARY OF THE INVENTION
Among the objects of the invention is to provide a device enabling a wearer to feel music and enjoy such feeling with another wearer by skin contact between both wearers, which device shall include two separate units, each adapted to encircle the torso of one of the two wearers and be connected by a lead wire to one of the output terminals of one of the channels of a stereo amplifier while the wearers hear the sound emitted by the other channel. A hand held wand replacing one of the torso encircling units shall permit an individual wearer to experience the feeling. The pair of units and wand shall comprise few and simple parts which are economical to manufacture and assemble at low cost in quantity production, which shall be durable, dependable and safe to operate.
The pair of units embodying the invention each comprises an elongated band formed as a torso encircling belt having adjustable buckle means for providing a snug fit around the wearer's torso. Each belt features a sheet of an electrical conductor material, such as, an aluminum foil or a thin flexible aluminum sheet, provided on one exposed surface thereof adapted to contact the wearer's skin. One end of a conductor lead wire is riveted to each belt making electrical contact with the sheet, the opposite end of the wire being adapted for connecting to one of the output terminals of a channel of a stereo amplifier which has been disconnected from its speaker. When the units are worn by two individuals, the sensation is primarily felt in the area of skin contact between the wearers.
A hand held wand of metal tubing connected to one end of a conductor lead wire may also be provided whereby the opposite end of the wand lead wire replaces or parallels one of the belt wires in the latter's connection to the output terminal of the amplifier. This enables a wearer of one of the belts to grasp the wand and feel the sensation while executing a dance routine where skin contact with a partner is lacking. Both belts may also be worn by one individual, or in a modified form, a pair of spaced conductor sheets, insulated from each other, may be mounted on a single belt. Where both conductor sheets are worn by one individual, the sensation is felt in the area of skin contact with the sheets.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of the device embodying the invention showing the belts mounted around the waists of two listeners and connected by lead wires to the output of a stereo amplifier.
FIG. 2 is an enlarged fragmentary view of one of the belts shown in FIG. 1 removed from the wearer and spread flat with the body contacting side thereof exposed.
FIG. 3 is an enlarged fragmentary top edge view of the belt shown in FIG. 2 but depicted as worn in FIG. 1 with the opposite ends secured together in overlapping relation.
FIG. 4 is a fragmentary view similar to FIG. 2 but of a belt modified to mount a pair of conductor sheets for providing the sensation to an individual wearer.
FIG. 5 is a fragmentary view similar to FIG. 2 showing a modified belt construction embodying the invention.
FIG. 6 is an enlarged sectional view taken on line 6--6 in FIG. 5 showing details of construction, and
FIG. 7 is an elevational view of a wand embodying the invention, with parts broken away to show interior structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring in detail to the drawings, 10 generally denotes a device for feeling music, embodying the invention, seen in FIG. 1 to comprise a pair of body encircling belts 11 and a pair of lead wires 20, each wire 20 being connected at one end thereof to one of the belts 11 and having a separable holder 21 interposed along the length thereof housing a replaceable fuse 22. Belts 11 are identical in construction, one being shown in FIGS. 2 and 3 as formed with a supporting sheet or layer 12 of a flexible but shape retaining material having electrical non-conducting or insulating properties, such as, a vinyl or other suitable plastic resin, and a lining or layer 13 of an electrical conductor, such as aluminum foil, adhesively or otherwise bonded to layer 12. Belt 11 is provided with a suitable buckle means for adjustably connecting opposite ends 11a and 11b thereof in a snug, waist encircling position to accommodate wearers having waists in a range of different sizes. Such buckle means is seen as located along the midline of belt 11 and to comprise a series of spaced openings or holes 14 extending through both layers 12 and 13 adjacent end 11a and a hook 15 which may be made of wire bent to provide a pair of spaced loops 15a at an attachment end thereof through which a staple 16 extends and fastens hook 15 to layer 12 in position to project beyond the edge of belt end 11b.
For positive and durable attachment of lead wire 20 to belt 11 as well as an electrical connection between wire 20 and conductor layer 13, the end 20a of lead wire 20 mounts a wire connector 23 which may be of the eyelet type attached to lead wire 20 either by crimping or soldering in the conventional manner. Wire connector 23 is permanently attached to the outfacing side of plastic layer 12 of belt 11 by suitable means, shown in FIG. 3 as a grommet-type metal rivet 24 which extends through the eyelet of connector 23 and through both layers 12 and 13 making electrical contact with the latter. The opposite end 20b of lead wire 20 is suitably fashioned for connecting to an audio output terminal of one of the channels of a stereo amplifier and may be provided with a connector of the prong-type (not shown) or simply may terminate in a short length of bare wire from which the insulation has been stripped to be connected as hereinafter described.
The practical utility and operation of device 10 will now be apparent. Lead wires 20 extending from belts 11 are supplied in desired lengths, such as, 9, 12 or more feet, in order to provide for adequate distance between the wearers and the amplifier A as well as for freedom of movement to permit dancing. FIG. 1 illustrates a representation of the rear side of any conventional stereo amplifier A to which device 10 and particularly ends 20b of lead wires 20 are to be attached preparatory to use. Amplifier A is shown as having right and left channel output terminals RT1, RT2 and LT1, LT2 which are connected to terminals in the rear of right speaker RS and left speaker LS by wiring RW1, RW2 and LW1, LW2, respectively. The terminals (not shown in detail) of speakers RS and LS usually permit easy attachment and separation of the short length of bare wire provided to terminate wiring RW1, RW2 and LW1, LW2 for this purpose. The lengths of bare wire at ends 20b of lead wires 20 or any connector mounted thereon may be attached directly to the terminals RT1, RT2 of the right channel or to terminals LT1, LT2 of the left channel after disconnecting therefrom wiring RW1, RW2 or LW1, LW2, respectively. Also, as an alternative, wiring RW1, RW2 or LW1, LW2 may be disconnected at the respective speaker terminals and spliced onto ends 20b by twisting the two bare wires together and applying a twisted wire retention cap 25 to each splice in the well known manner. In the illustration in FIG. 1, wiring LW1, LW2 are shown disconnected from left speaker LS and spliced onto lead wires 20 with the aid of retention caps 25 while right speaker RS remains connected to the right channel terminals RT1, RT2 for providing sound therethrough.
Each person of the participating couple then places one of the belts 11 around his/her waist with layer 13 facing inwardly in contact with the bare skin and, bringing end 11b to overlie end 11a, selectively engages hook 15 in the appropriate opening 14 to provide a snug fit for belt 11. Adjustment for proper output of amplifier A is then accomplished by initially setting the volume control to a minimum and the balance control to a maximum for the channel to which the belts 11 are attached, this being the left channel in the hook-up shown in FIG. 1. Music is then played through amplifier A and, with the participants in skin contact with each other, as for example, holding hands as shown in FIG. 1, the volume control is advanced until the desired tingling sensation is felt in the area of skin contact between the participants. The balance control is then rotated toward the right channel until the sound emitted by right speaker RS is at a comfortable volume for listening. This will reduce the sensation and may require a volume increase and another balance adjustment. By slight alternate adjustments of the volume and balance controls the desirable sound and sensation levels can be achieved. In disco and rock music, adjustment of the base and treble controls to accentuate the base imparts a rhythm beat or bounce to the sensation while accentuation of the treble and attenuation of the base imparts more of a tingling sensation.
Device 10 may be utilized by one person rather than by a couple by such person wearing both belts 11, preferably around the torso, in spaced relation so that conductor layers 13 do not make direct contact and thereby short circuit each other. To facilitate this, a modified form of the invention is shown in FIG. 4 as device 30 which comprises a single, body encircling belt 31 considerably wider than belt 11, formed with a supporting sheet or layer 32 for a pair of longitudinally extending electrical conductor layer sections 33 spaced from each other along a midline section 32a, layer 32 and layer sections 33 being similar in material and properties to layers 12 and 13, respectively, of belt 11. Similarly, each layer section 33 has a lead wire 40 connected thereto by a wire connector 43 and rivet 44, while hook 35 and openings 34, located in midline section 32a, provide the buckle means for belt 31. Lead wires 40 are also protected by replaceable fuses (not shown) and the opposite ends thereof are adapted to connect to the pair of terminals of one of the channels of amplifier A in the same manner as wires 20.
Device 50 is a structural modification of device 10 embodying the invention and comprising a pair of belts 51 each having a lead wire 60 for connection to amplifier A. One of such belts 51 is shown in FIGS. 5 and 6 to comprise metal sheet 53 of a thickness to provide both the support characteristics and flexibility of layer 12 and the electrical conductivity of layer 13 of belt 11. Sheet 53 may be made of 0.015 to 0.020 inch thick aluminum or 0.010 to 0.015 inch thick stainless steel. The edges 53a of sheet 53 are all beaded or rolled in a conventional manner to prevent cutting the skin by a sharp unfinished edge when belt 51 is handled or worn. Hook 55 is stapled directly to sheet 53 which is also formed with spaced openings 54 serving as adjustable buckling means. To facilitate manufacture, openings 54 may extend along the entire length of sheet 53. Lead wire 60 is similar to lead wires 20 and 40, having a connector 63 attached to wire end 60a and secured to sheet 53 by a rivet 64, here shown as being of the solid type. To reduce the possibility of undesirable electrical contact with sheet 53 when in use, a layer 52 of vinyl resin, serving as an insulator, may be sprayed onto the outfacing surface of sheet 53, or the latter may be made from sheeting material preformed with a coating of enamel or the like paint which serves the same purpose as well as adding to the aesthetic appeal of belt 51.
To provide greater versatility to devices 10 and 50, a hand held wand 70 may be included for use with one or both belts 11 and 51 in the manner hereinafter described. Wand 70 is seen in FIG. 7 to comprise a length of aluminum tubing 71 sized for easy grasping in one hand and having a lead wire 80 secured thereto for electrically connecting wand 70 to one of the output terminals of stereo amplifier A. The opposite ends of tubing 71 are preferably closed and finished by suitable slip-on, fitted caps 72 and 72a, as shown, made of rubber or plastic, or a plug type closure may also be used. Whereas any suitable means may be used for securing lead wire 80 to tubing 71, the wand connecting end 80a of wire 80 is shown in FIG. 7 as extending through an opening in cap 72a into the bore of tubing 71 and terminating in a wire connector 83 secured to the interior surface of tubing 71 by a suitable rivet 84 which may be of the outside pull or "pop" type. Lead wires 60 and 80 may each also be fitted with a separable fuse holder and replaceable fuse similar to holder 21 and fuse 22 of lead wire 20, the rating of the fuses used in lead wires 20, 40, 60 and 80 being selected in the fraction of an ampere range to afford maximum protection. Likewise, lead wire 80 is of a length comparable to lead wire 20 or 60 and has the opposite end 80b thereof prepared for attachment to the appropriate output terminal of amplifier A.
When device 10 or 50 is provided as a three-unit device by including a wand 70 in addition to the pair of belts 11 or 51, respectively, the pair of lead wires 20 or 60 are connected as hereinbefore described in the operation of device 10 and the opposite end 80b of lead wire 80 is connected to the appropriate output terminal of amplifier A so that the wand 70 is in parallel with one of the belts 11 or 51. When the participants wish to hold hands to feel the sensation, wand 70 is held in the other hand by the participant wearing the belt 11 or 51 which is connected in parallel with wand 70. When the participants desire to separate, wand 70 is passed to the other participant who will feel the sensation, which is similar to that experienced between the grasped hands, in the hand grasping wand 70. Also, wand 70 may be passed to a third participant for grasping in one hand while holding hands and feeling the sensation with the participant wearing the belt 11 or 51 which is not connected in parallel with wand 70.
The scope of the invention also contemplates a device comprising two wands 70 connected to the terminals of amplifier A in the manner described for belts 11 of device 10. Each wand 70 is then grasped in one hand by each of the two participants while they hold each other's other hand.
The three-unit device 10 or 50 may be useful in teaching dancing to the profoundly hearing impaired where the instructor wears the belt 11 or 51 which is wired in parallel with wand 70. The instructor holds the wand 70 while dancing in hand contact with the student, but passes the wand 70 to the student when the dance instruction requires the student to separate from and move independently of the instructor.
Metal sheets 13, 33 and 53 render satisfactory results when each sheet is made in a length sufficient to substantially encircle the torso of the wearer in skin contact therewith and is 3 and 4 inches in width providing an overall skin contacting area of about 90 to 130 sq. inches. Wand 70 when having tubing 71 of 3/4 inch O. D. and about 10 inches in length is easy to handle and renders satisfactory results in use.
One output terminal of each of the channels of amplifier A may be a common ground so that, instead of the output configuration shown in FIG. 1, amplifier A has only three output terminals, namely, a right and left channel output and a common ground terminal to which one lead to both right and left speakers RS and LS connect. Thus, it will be understood that a recitation in the claims of two output terminals to which units of devices 10, 30 and 50 connect is to include one terminal of a channel and the common ground of such three terminal arrangement.
The two- and three-unit devices for feeling music herein disclosed are seen to achieve the several objects of the invention and to be well adapted to meet conditions of practical use. As various possible embodiments might be made of this invention, and as various changes might be made in the disclosed units, it is to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not in a limiting sense. | An electrically chargeable plate of predetermined surface area is retained in contact with the skin of each of two participants. An electrical conductor connects each plate to one of the two terminals of the audio output of one of the channels of a stereo amplifier while the other channel plays through its speaker. Physical contact between the participants completes the circuit enabling both participants to feel the modulated impulses of the sound as well as hear the output of the speaker on the other channel. Both plates may be worn by one person to experience a comparable feeling or one plate and an electrically chargeable wand used in place of or in addition to the other plate enables either one or two persons to participate. | 17,271 |
This application is a divisional of U.S. patent application Ser. No. 12/502,577, filed on Jul. 14, 2009 (presently pending) which claims benefit of U.S. Provisional Patent Application Ser. No. 61/080,406, filed on Jul. 14, 2008. The teachings of U.S. Provisional Patent Application Ser. No. 61/080,406 and U.S. patent application Ser. No. 12/502,577 are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
A wide variety of consumer products are frequently packaged in aerosol cans. These products include paints, hair spray, insecticides, herbicides, air fresheners, perfumes, fragrances, antimicrobial agents, cleaners, anti-sticking agents, and the like. Even though packaging these types of products in aerosol cans has been well accepted by consumers for decades, the continued use of aerosol cans for packaging consumer products is coming under greater and greater scrutiny. Most of the criticism relating to the use of aerosol cans originates from the thesis that aerosols are harmful to the environment. Additionally, the aerosol cans themselves are typically discarded after being used and generally end up in landfills as solid waste. In actual practice the steel of which aerosol cans are made is seldom recycled.
Aerosol cans also have the drawback of potentially exploding and causing personal injury and/or property damage if they are exposed to high temperatures during storage or transportation. This danger of explosion limits the manner in which products that are packaged in aerosol cans are transported, stored, and utilized.
Power sprayers that can be used to apply liquid compositions, such as paints, insecticides, lubricants, and the like to substrates are a viable alternative to aerosols. In fact, power sprayers circumvent many of the problems associated with the use of aerosols. For instance, the use of power sprayers does not present the explosion hazard or the environmental concerns associated with aerosol products. However, power sprayers are frequently awkward to handle and difficult to clean after being used.
SUMMARY OF THE INVENTION
The subject invention relates to a power sprayer that can be conveniently used by both professionals and amateurs. This power sprayer offers flexibility of movement because it can be battery operated. It also is designed to eliminate the need for cleaning its spray nozzle after being used. The media being sprayed can also be easily changed quickly and easily. For instance, paint colors can be changed quickly and repeatedly by simply changing the media cartridges that are adapted for simple attachment to the sprayer. The media cartridges used in conjunction with the sprayers of this invention also eliminate the inconvenience associated with refilling conventional power sprayers with a desired media. Even more importantly, it eliminates the need for extensive clean-up and cleaning materials, such as solvents, rags, paper towels, etc., which is time-consuming and has a negative impact on the environment. One of the most important benefits of the present invention is the ability to deliver virtually any media, including waterborne systems, without compromising the spray quality and flexibility of a spray can. In fact, the power sprayer of this invention offer even better flexibility than conventional sprayers or spray cans by virtue of being capable of being used while in any orientation.
The present invention more specifically discloses a media cartridge system for a sprayer comprising: (a) a media container, (b) a self-cleaning nozzle, (c) a media shut-off means, (d) a primary media atomizing aperture in a configuration relative to the self-cleaning nozzle, (e) a movable media containment member within the media container, (f) a gas transfer interface, and (g) a power unit engagement means.
The subject invention further discloses a sprayer which is comprised of ( 1 ) an electrical power source, ( 2 ) an electric motor, ( 3 ) a pump which is driven by the motor, ( 4 ) an output, ( 5 ) an electrical control switch, ( 6 ) a media cartridge air transfer interface, ( 7 ) a media cartridge engagement means, and ( 8 ) a media cartridge which is comprised of (a) a media container, (b) a self-cleaning nozzle, (c) a media shut-off means, (d) a primary media atomizing aperture in a configuration relative to the self-cleaning nozzle, (e) a movable media containment member within the media container, (f) a gas transfer interface, and (g) a power unit engagement means.
The present invention also reveals a sprayer which is comprised of ( 1 ) a power unit which includes (a) an electrical power source, (b) an electric motor, (c) a pump which is driven by the motor, (d) an output control, and (e) an electrical control switch, ( 2 ) a nozzle unit which includes (a) a media cartridge air transfer interface, (b) a power unit engagement means, (c) a gas transfer interface, and ( 3 ) a media container wherein the media container includes (a) a media cartridge engagement means, (b) a movable media containment member within the media container, (c) a media container air transfer interface and (d) a media supply line interface.
The subject invention further discloses a sprayer having a configuration which comprises a media outlet, a storage device/energy source (such as a capacitor, a fuel cell or a battery), at least one primary atomization outlet, and at least one spray pattern shaping/secondary outlet that minimizes power usage, wherein the primary outlet utilizes higher pressure than the secondary outlet, wherein the higher pressure utilized by the primary outlet is at least 2 times the pressure of the pressure utilized by the secondary outlet and wherein the primary atomization aperture is configured in a convex shape relative to the media aperture to provide enhanced self-cleaning as well as increased gas flow by entrainment of ambient gases through a coanda effect. The objective of this sprayer system is to deliver and shape a higher level of media at the same level of power consumption as compared to conventional spraying technology. This is accomplished by separating the need for high energy atomization air flow from the lower pressure needed to attain a desired spray pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a power sprayer of this invention.
FIG. 2 is a partial exploded view of the power sprayer depicted in FIG. 1 showing the media cartridge detached from the power unit.
FIG. 3 is a cross-sectional view of the power sprayer depicted in FIG. 1 as cut along section line 3 - 3 .
FIG. 4 is a partial section view showing one embodiment of this invention depicting an electro-magnetic vibrator for media agitation.
FIG. 5 is a partial section view showing one embodiment of this invention depicting an acoustical/electro-magnetic vibrator for media agitation.
FIG. 6 is a cross-sectional view of another embodiment of the power sprayer of this invention.
FIG. 7 is a cross-sectional view of the power-sprayer of FIG. 6 highlighting the internal components of the nozzle portion of the media cartridge in a “closed/not spraying” mode.
FIG. 8 is an orthographic view of the media cartridge.
FIG. 9 is a cross-sectional view of the power-sprayer of FIG. 6 highlighting the internal components of the nozzle portion of the media cartridge in an open spraying mode depicting the flow pattern of both the spray media and primary and secondary air.
FIG. 10 is a cross-sectional view of the power-sprayer of FIG. 6 highlighting the internal components of the nozzle portion of the media cartridge in an open spraying mode depicting an oval spray pattern that can be attained due to positioning of the tip guard.
FIG. 10 illustrates both a vertical flat pattern 61 and a horizontal flat pattern 62 either of which can be attained via appropriate orientation of the secondary air pattern shaping outlet port 40 .
FIG. 11 is a cross-sectional view of the power-sprayer of FIG. 6 highlighting the internal components of the nozzle portion of the media cartridge in an open spraying mode depicting a round spray pattern that can be attained due to positioning of the tip guard. FIG. 11 depicts a shut media nozzle 63 before and after spraying occurs and further depicts an open media nozzle 64 utilized to attain a round spray pattern 65 .
FIG. 12 is a schematic view of another embodiment of the power sprayer of this invention.
FIG. 13 is a schematic view of another embodiment of the power sprayer of this invention showing a wand hand extension.
FIG. 14 is a schematic view of the power sprayer of FIG. 13 showing an optional pivot arm with a wheel attachment.
FIG. 15 is a schematic view of a media cartridge adaptor depicting a nozzle and a power unit interface 66 and an external media supply connector 67 .
FIG. 16 is a schematic view of a media cartridge equipped with a piston 59 as the movable media containment member.
FIG. 17 is a schematic view of a media cartridge equipped with a bellows 60 as the movable media containment member depicts the media as partially expended.
FIG. 18 is a schematic view depicting a media cartridge wherein an air bladder 68 indirectly activates the media containment bladder 36 .
FIG. 19 is a schematic view depicting a media cartridge having two movable media containment members which in this embodiment of the invention are bellows 60 . In this embodiment of the invention, there are two media shutoff means 29 . In this figure the movable media containment member depicts the media as partially expended.
REFERENCE NUMERALS USED IN FIGURES
The reference numerals used in the drawings to identify various parts or elements of the power sprayer and media cartridge used in the practice of this invention are as follows:
1 . media cartridge 2 . power unit 3 . power unit handle 4 . nozzle 5 . flexible bladder (moveable media containment member) 6 . media container 7 . agitation sphere (media preparation device) 8 . trigger 9 . batteries (electrical power source) 10 . electric motor 11 . gear train 12 . pump 13 . constant output control 14 . power unit gas transfer line 15 . media cartridge (air) gas transfer interface 16 . electromechanical vibrator 17 . acoustical plate 18 . electromagnetic drive 19 . power unit engagement means 20 . power unit mounting bracket 21 . power unit gas transfer interface (gas transfer interface) 22 . control switch (electrical) 23 . media flow control means 24 . tip guard 25 . air inlet 26 . secondary air blower 27 . primary air aperture (primary media atomizing aperture) 28 . media aperture 29 . media needle (media shut-off means) 30 . mechanical interference 31 . mechanical interference seat 32 . shut-off spring 33 . media supply valving needle 34 . diaphragm 35 . secondary air supply 36 . bladder (movable media containment member) 37 . media 38 . access port 39 . seals 40 . secondary air pattern shaping outlet port 41 . secondary air outlet 42 . convex nozzle tip 43 . media nozzle tip 44 . trigger/nozzle engagement member 45 . spray pattern 46 . atomized media 47 . secondary air 48 . primary atomization air 49 . pattern shaping air 50 . wand 51 . handle 52 . wand trigger 53 . pivot arm 54 . wheel 55 . power sprayer 56 . wand sprayer 57 . media cartridge engagement means 58 . power unit identification means 59 . piston 60 . bellows 61 . vertical flat pattern 62 . horizontal flat pattern 63 . shut media nozzle 64 . open media nozzle 65 . round spray pattern 66 . nozzle and power unit interface 67 . external media supply connector 68 . air bladder 69 . external media container
DETAILED DESCRIPTION OF THE INVENTION
The power sprayers of this invention can be made utilizing a wide variety of designs wherein the power unit and media cartridge can be of a variety of different shapes and orientations to each other. FIG. 1 depicts one typical design for such a power sprayer 55 . As can be seen, the power sprayer depicted in FIG. 1 includes a media cartridge 1 which attaches to the top of a power unit 2 . This sprayer includes a power unit handle 3 which connects the power unit 2 to the media cartridge 1 . The media cartridge includes a nozzle 4 which extends forwardly from the media cartridge 1 .
FIG. 2 depicts the power sprayer of FIG. 1 wherein the media cartridge 1 is disengaged from the power unit 2 . The media cartridge can be affixed to the power unit via the power unit mounting bracket 20 to which the power unit engagement means 19 attaches. In the design shown, this attachment is effectuated by the interlocking edges which taper in one direction to engage the media cartridge to the power unit at the desired orientation. In this orientation, the power unit gas transfer interface 21 which is a port that aligns with a media cartridge gas transfer interface 15 (as shown in FIG. 3 ).
FIG. 3 is a cross-sectional view of the power sprayer of FIG. 1 showing the media cartridge affixed to the power unit. As can be seen, the media cartridge includes a media container 6 which is filled with media 37 . In cases where the media is a liquid it is highly preferred from the movable media containment member to be essentially free of gases. In any case, the media is contained in the media container 6 with a movable media containment member 5 . The media container also includes an agitation sphere 7 for preparing the media for application to a substrate by agitating the media to attain a homogeneous mixture. As can be seen, the media cartridge includes a nozzle 4 through which the media passes while being sprayed. The media cartridge also includes a media cartridge gas transfer interface 15 which mates with the power unit gas transfer interface 21 to provide a pressurized gas such as air which provides force to compress the movable media containment member 5 to force the media 37 there from and ultimately out through nozzle 4 into a desired spray pattern.
The gas from the power unit is compressed by pump 12 which is typically powered by an electric motor 10 having an appropriate gear train 11 , if necessary. The electric motor is typically powered with DC batteries 9 which provide DC current to the electric motor. This supply of electricity optimally is through an output control 13 which is capable of providing the electric motor with constant voltage to attain consistent motor speed (constant revolutions per minute). In other embodiments of this invention, the output control 13 can be designed to provide variable output motor speed to attain desired spray patterns or can be designed to provide controllable output. For instance, the output of the motor can be automatically set by the device to attain a desirable spray pattern predicated upon the distance of the spray nozzle from a substrate surface as could be automatically determined utilizing an infrared, radar, or ultrasonic distance measurement system.
The operation of the unit can be controlled via switch 22 which toggles between an open and closed position via trigger 8 to provide power to the unit as desired. In one embodiment of this invention the switch can be a variable control which will allow the motor to increase or decrease in speed depending upon the degree to which the trigger is pulled. The variable control can be a rheostat, a pot, or any other device capable or providing a variable signal to the output control 13 .
FIG. 4 depicts a media cartridge having a nozzle of convex shape. This device shows an electro-mechanical vibrator 16 for agitating the media to attain a homogeneous mixture. FIG. 5 also depicts such a media cartridge wherein an acoustical plate 17 or an electromagnetic device 18 is utilized to agitate the media wherein such agitation can optionally be carried out with the aid of an agitation sphere 7 . It should be noted that a convex nozzle shape provides enhanced resistance to air nozzle clogging.
FIG. 6 depicts another embodiment for a spray gun 55 in accordance with this invention. This design includes a tip guard 24 which protects the tip of the nozzle from damage which could occur during mishaps such as dropping the spray gun which would adversely affect the quality of the spray. In this design, inlet air 25 is drawn in by the power unit 2 by a secondary air blower 26 . The inlet air acts to cool the electric motor 10 and the pump 12 . The compressed air exiting the secondary air blower moves through the power unit assembly and enters into the media cartridge as depicted in FIG. 7 . FIG. 6 shows a trigger 8 which is integrated with a media flow control means 23 . The media flow control means can be a valve that limits the gas (air) pressure in the media container 6 to moderate the amount of pressure applied to the bladder 36 in the embodiment of the invention. In an alternative embodiment of this invention the media flow control means 23 can also limit the travel of the trigger to a desired stop point which also limits the travel of the needle 29 to limit the amount of atomized media 46 spray (as shown in FIG. 10 and FIG. 11 ). In still another embodiment of this invention the trigger is used to control the ratio of media flow to gas (air) flow. The trigger 8 can further be used to operate the control stitch 22 to activate the output control 13 and to attain the desired electric motor 10 operating speed (rpm output) desired. As can be seen in FIG. 6 and FIG. 7 , the trigger 8 has a flexible element that engages the trigger/nozzle engagement member 44 . In one embodiment of this invention, the trigger/nozzle engagement member 44 is phased to allow the control switch to activate gas flow before media flow. On trigger 8 the media 37 flow can be terminated before gas flow (primary atomization air 48 flow and secondary air 47 flow) is terminated to enhance the self-cleaning feature of the nozzle 4 .
The secondary air flows through the nozzle of the media cartridge and is the source of the secondary air supply 35 can change the desired spray pattern and the secondary air supply 35 can result in augmented secondary air 47 through the coanda effect (as illustrated in FIG. 10 and FIG. 11 ). The pump provides pressurized air which flows through a power unit gas transfer line 14 through the power unit gas transfer interface 21 (as shown in FIG. 7 ) and into the media cartridge gas transfer interface 15 and through the nozzle as primary atomizing air 48 and ultimately through the primary air aperture 27 of the nozzle. The primary atomizing air 48 and the secondary air 47 converge to provide an atomized media 46 as shown in FIG. 10 and FIG. 11 .
FIG. 7 is a cross-sectional view of the power-sprayer of FIG. 6 highlighting the internal components of the nozzle portion of the media cartridge in a “closed position” depicting the typical resting position of the mechanical interference 30 when the nozzle 4 is not spraying atomized media. In this position the mechanical interference 30 closes the nozzle 4 by moving forward to form a seal by contact with the mechanical interference seat 31 . In this position the media supply valve needle 53 is not penetrating through the diaphragm 34 to allow media 37 to flow from the moveable media containment member 5 to the nozzle 4 . The power unit identification means 58 can be a mechanical or electrical device that identifies the cartridge and optionally its contents. It typically also adjusts output parameters to attain a desired result. These parameters can include but are not limited to a fine, medium or heavy spray output and coverage or quality. This is accomplished through control by varying the output of the primary and secondary air supplies, motor, pump and/or media output.
FIG. 9 is a cross-sectional view of the power-sprayer of FIG. 6 highlighting the internal components of the nozzle portion of the media cartridge in an “open position” depicting the position of the mechanical interference 30 when the nozzle 4 is spraying atomized media. In this position the mechanical interference 30 is pulled back to open the nozzle 4 by to allow media to flow through the media aperture 28 . In this open position the media shut off needle is pulled away from the mechanical interference seat 31 to allow media 37 to flow around it and out of the primary aperture 27 . In this position the media supply valve needle 53 penetrates through the diaphragm 34 to allow media 37 to flow from the media bladder 36 to the nozzle 4 . FIG. 9 also shows the flow pattern of the atomized spray media 46 , the primary atomizing air 48 , and secondary air 47 .
FIG. 10 is a cross-sectional view of the power-sprayer of FIG. 6 highlighting the internal components of the nozzle portion of the media cartridge in an open spraying mode depicting an oval spray pattern that can be attained by appropriate positioning of the tip guard 24 . FIG. 11 is a cross-sectional view of the power-sprayer highlighting the internal components of the nozzle portion of the media cartridge in an open spraying mode depicting a round spray pattern that can be attained by positioning the tip guard 24 in a different orientation. As can be seen in FIG. 10 and FIG. 11 , the atomized media 46 can be sprayed into a variable and desired spray pattern 45 . It should be noted that the gas flow acts to both cause media atomization and media flow. Media flow is caused by a force differential which can be mechanical, vacuum, and/or positive pressure. For instance, a pressure can be applied upon the moveable media containment member 5 to attain an adequate pressure differential to cause the desired level of media flow. FIG. 10 also depicts that secondary air pattern shaping outlet ports 40 cause a convergence of the secondary air supply 35 onto the primary atomization air 48 . The pattern shaping air 49 acts in concert with the secondary air 47 to provide the desired spray pattern 45 .
FIG. 12 is a schematic view of another embodiment of the power sprayer of this invention. In this embodiment of the invention the power sprayer 55 is affixed to a folding power unit handle 3 . As illustrated in FIG. 13 the power sprayer 55 can be affixed to a wand 50 (an extension handle) having a handle 51 and a wand trigger 52 to facilitate spraying objects that would ordinarily be difficult to reach. For instance, the wand could be affixed to the power sprayer 50 to spray substrates that ordinarily could not be reached without using a ladder. FIG. 14 is a schematic view that depicts another embodiment of the invention in the form of a ward sprayer 56 wherein an optional pivot arm 53 with a wheel 54 is attached to the power sprayer 55 . This embodiment of the invention can be conveniently be used to spray lines on a highway, parking lot, or field.
While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. | The subject invention relates to a power sprayer that offers flexibility of movement because it can be battery operated and is designed to eliminate the need for cleaning its spray nozzle after being used. Paint colors can be changed quickly by simply changing the media cartridges that are adapted for simple attachment to the sprayer. The media cartridges used in conjunction with the sprayers of this invention can also eliminate the inconvenience associated with refilling conventional power sprayers with a desired media. The present invention more specifically discloses a sprayer media cartridge system comprising: (a) a media container, (b) a self-cleaning nozzle, (c) a media shut-off means, (d) a primary media atomizing aperture in a configuration relative to the self-cleaning nozzle, (e) a movable media containment member within the media container, (f) a gas transfer interface, and (g) a power unit engagement means. | 23,988 |
TECHNICAL FIELD
The present invention is in the field of automatic dishwashing. In particular it relates to an automatic dishwashing product comprising a multi-dosing detergent delivery device capable of scenting during an automatic dishwashing operation and between automatic dishwashing operations. The product of the invention adds convenience and improves the automatic dishwashing experience.
BACKGROUND OF THE INVENTION
Items to be cleaned in an automatic dishwashing machine are soiled with food residues. The nature of the residues is quite diverse depending on the food that has been deposited on or cooked in the dishware/tableware. Usually the food residues have a plurality of malodours associated to them. Malodours can also come from food residues accumulated in dishwasher's parts such as the filter. The filter is usually a wet environment with food residues prone to bacteria degradation that usually have malodours associated to it.
The malodours can become evident during the automatic dishwashing operation either because there is superposition or combination of malodours that in terms give rise to other malodours and/or because the high temperature and humidity conditions found during an automatic dishwashing operation contribute to an easier perception of the malodours. Malodours can also be evident upon loading the dishwasher, especially if food residues degrade or rot.
Automatic dishwashing machines are usually placed in kitchens where users cook and frequently eat and they do not like to have unpleasant odours coming from the automatic dishwashing machine.
Auto-dosing devices are permanently placed into the automatic dishwashing machine and they are prone to collect food and residues during the automatic dishwashing operation. The food and residues can generate additional malodours.
There is a need to reduce or eliminate the malodours that are generated during an automatic dishwashing operation and substitute the malodours by pleasant fragrance in the area surrounding the dishwasher during use.
Machine fresheners are known in the art. They are devices that hang in the dishwasher and release a perfume over time. The perfume release profile tend to be non-homogeneous over time, usually a high level of perfume is delivered at the beginning of the life of the freshener—that sometime can be overpowering—and the release profile can drop dramatically with time. In addition, the fluctuating temperature and humidity conditions found in an automatic dishwashing environment lead to some difficulties with some of the known machine fresheners.
The aim of the present invention is to overcome the above mentioned drawbacks.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided an automatic dishwashing product. The product comprises a multi-dosing detergent delivery device for use in an automatic dishwashing machine. The device comprises: i) a housing for receiving therein a detergent holder; and ii) a detergent holder. The detergent holder accommodates a plurality of detergent doses. Preferably the detergent holder is replaceable or refillable. Once all the detergent doses have been used the holder can be replaced by a new holder or it can be filled with new doses. Especially preferred from an easiness of use viewpoint are replaceable detergent holders.
By “multi-dosing detergent delivery device” is meant a device capable of delivering one or more detergent doses over a plurality of automatic dishwashing operations without human intervention, i.e. the user places the device in the automatic dishwashing machine and the device delivers the doses over a number of operations. Once the detergent doses are finished the detergent holder is refilled or replaced.
The detergent holder accommodates a scenting composition, by “scenting composition” is herein meant a product capable of delivering a pleasant smell such as a fragrance or perfume.
The scenting product of the invention comprises a perfume and a polyolefin. The polyolefin preferably has a crystallinity of from about 5% to about 60%, more preferably from about 6% to about 50%, even more preferably from about 10% to about 40% and especially from about 10% to about 30%.
The scenting composition preferably has a crystallinity of from about 0.5% to about 60%, more preferably from about 1% to about 50%, even more preferably from about 5% to about 40% and especially from about 10% to about 30%.
The scenting composition provides a very uniform perfume delivery profile even under stressed conditions such as the high temperature and humidity condition found in an automatic dishwashing machine in operation. The composition would deliver perfume in a nearly constant manner during dishwashing operations and in between them. The composition also presents very good physical properties, it is quite malleable and pleasant to touch.
Preferably the composition has a melting point above 70° C., more preferably above 75° C. and especially above 80° C. (measured as described herein below). This implies that the composition is solid and allows the formation of shaped solid bodies that provide sustained release of perfume. The solid bodies are extremely suitable to be placed into the detergent holder. The scenting composition can be placed in a central cavity of the detergent holder to continuously release a perfume or bad odour suppressor into the dishwashing machine over a number of dishwashing operation and in between dishwashing operations. The scenting composition can be activated at first use by removing a sealing label or the like covering the cavity.
The preferred polyolefin for use herein is polybutene-1. The term “polybutene-1” includes a homopolymer of butene-1 or a copolymer of butene-1 with another α-olefin having 2 to 20 carbon atoms. In case of the copolymer, the ratio of another α-olefin to be copolymerized is 20 mole % or less, preferably 10 mole % or less and particularly preferably 5 mole % or less. Examples of another α-olefin to be copolymerized include ethylene, propylene, hexene, 4-methylpentene-1, octene-1, decene-1, octadecene-1, etc. Especially preferred for use herein are copolymers of butane-1 and ethylene.
In preferred embodiments the composition comprises a wax, preferably a microcrystalline wax. Without being bound by theory, it is believed that wax, in particular microcrystalline wax, contribute to improve the physical properties of the composition, in particular the wax can contribute to reduce brittleness.
The composition of the invention can optionally comprise a nucleating agent. A nucleating agent is a processing aid that accelerates crystal formation reducing the processing times.
In preferred embodiments, the perfume comprises at least about 10%, more preferably at least about 20% and especially at least 30% by weight of the perfume of blooming perfume ingredients having a boiling point of less than 260° C. and a ClogP of at least 3. The perfume would also typically comprise non-blooming perfume ingredients having a boiling point of more than 260° C. and a ClogP of at least 3, preferably less than about 30%, more preferably less than about 25% and preferably between 5 and 20% by weight of the perfume of non-blooming perfume ingredients.
The perfume of the composition of the present invention are typically very effusive and consumer noticeable, leaving minimal residual perfume on the washed items, including dishes, glasses and cutlery, especially those made of plastic, rubber and silicone. The compositions can leave a residual perfume in the automatic dishwashing machine that can be enjoyed by the user in between dishwashing operations.
A blooming perfume ingredient is characterized by its boiling point (B.P.) and its octanol/water partition coefficient (P). The octanol/water partition coefficient of a perfume ingredient is the ratio between its equilibrium concentrations in octanol and in water. Since the partition coefficients of the preferred perfume ingredients herein have high values, they are more conveniently given in the form of their logarithm to the base 10, log P. The B.P. herein is determined at the normal, standard pressure of 760 mm Hg.
In preferred embodiments the composition comprises from about 20% to about 90%, more preferably from about 30% to about 70% and especially from about 35% to about 65% by weight thereof of polyolefin, preferably the polyolefin is polybutene-1. The composition preferably comprises from about 10% to about 60%, more preferably from about 20% to about 55% and especially from about 30% to about 50% by weight thereof of perfume. The composition preferably comprises from about 20% to about 60%, more preferably from about 25% to about 55% and especially from about 30% to about 50% by weight thereof of wax, preferably a microcrystalline wax.
The scenting composition can be placed into the detergent holder described in WO 2007/052004 and WO 2007/0833141. The dosing elements can have an elongated shape and set into an array forming a delivery cartridge which is the refill for an auto-dosing dispensing device as described in case WO 2007/051989. The detergent holder can be placed in an auto-dosing delivery device, such as that described in WO 2008/053191.
Preferably the device comprises a mono-dimensional actuating means for providing movement of the holder relative to the housing. By “mono-dimensional” is herein meant that the movement happens in only one plane as opposite to more than one as the case is with the device disclosed in WO 2008/053178. In '178 device the indexing means needs to move firstly in one plane and secondly in a second plane perpendicular to the first one to deliver a dose in each dishwashing operation. The mono-dimensional actuating means of the device of the present invention allows for devices of simpler construction than the devices of the prior art and allows for more space efficient geometries, such as planar geometry. The device of the invention is suitable for the delivery of different doses at different points of the dishwashing operation. '178 device seems only be suitable for the delivery one dose per dishwashing operation. The next dose is only ready for delivery in the next dishwashing operation.
Preferably, the actuating means comprises a guided means and a driving means. Preferably the driving means comprises a thermally reactive element. Whilst the thermally reactive element may be any of a memory metal/memory alloy, thermal bimetal, bimetal snap element or shape memory polymer, it is most preferably a wax motor. A wax motor is a small cylinder filled with a heat sensitive wax which expands upon melting and contracts upon solidifying. This expansion of the wax can be used by the driving means to drive the guided means forward.
The thermally reactive element is preferably designed to react at temperatures between 25° C. and 55° C., more preferably 35° C. to 45° C. The thermally reactive element preferably has a hysteresis effect. This delays the operation of the thermal element to ensure that the device is not reset by the fluctuating temperatures that can be found in the different cycles of an automatic dishwashing operation but is only reset once the machine has carried out a full dishwashing operation.
Preferably the thermally reactive element has an activation temperature of from about 35° C. to about 45° C. and a de-activation temperature of from about 25° C. to about 33° C. For the wax motor the melting and solidification profile of the wax can be used to achieve the desired hysteresis, because certain waxes show a slow solidification compared to melting.
The guided means are driven by the driving means. The guided means preferably comprise a following means and a track to accommodate the following means, i.e. the path taken by the following means is dictated by the track. The track preferably has a zig-zag configuration in which each up and down path corresponds with a full dishwashing operation. To deliver x detergent doses over x dishwashing operations the zig-zag track needs to have x paths forwards and x paths downwards.
The zig-zag track preferably can be used in a circular pattern which leads to a circular movement of the detergent holder or it can be used in a linear pattern which leads to a linear movement of the detergent holder. A wave pattern or combinations of arc segments and linear patterns can be used to accommodate specific designs and movements of the detergent holder.
It should be noted that the track can be integrated in one of the permanent component of the housing and the motion of this component can then be transferred to the detergent holder via mechanical means or the track can be integrated directly into the detergent holder so that after insertion of the holder the following means engage with the track. The track can be manufactured via injection molding, thermoforming, vacuum casting, etching, galvanizing sintering, laser cutting or other techniques known in the art.
The following means travels alternatively forwards and backwards within the track, powered by the driving means. Preferably, the actuating means further comprises returning means that helps the driving means to return to its initial position once the appropriated conditions are achieved in the automatic dishwashing machine (for example, when the temperature is below about 30° C. in the case of the driving means comprising a wax motor, the wax would contract and the returning means would take the driving means to its initial position). The returning means could for example be a biasing spring or flexible element with sufficient spring force to push the piston in the wax motor back to its initial position when the wax solidifies and therefore contracts.
The advancement of the detergent holder is accomplished by the combination of the driving means, the guided means and if present the returning means. This combination allows for the delivery of two different doses at two different times of the dishwashing operation.
For instance the first dose in the detergent holder can be readily exposed at the start of the wash cycle or get exposed to the wash water or it can be ejected from the detergent holder early in the wash cycle when the temperature slowly rises in the dishwasher and the wax motor starts to expand. The second dose can be exposed or ejected when the wax motor is further expanded when the dishwasher heats up further or during the cold rinse cycles when the first contraction starts. At the end of the wash cycle the complete contraction moves the detergent holder to the next dose ready for the next wash cycle.
It should be noted that the configuration of the track and the angles of its zig-zag pattern determine the movement of the detergent holder and therefore the movement and desired release points of detergent doses can be pre-dictated by this track. This enables large design flexibility in the delivery of the detergent doses at various times during a dishwashing operation. Even a sequential release of three or more doses can be achieved by the use of this kind of tracks.
Preferably, the track comprises slots and ramps. The role of the ramps is to guide the movement of the detergent holder in one direction only. When the temperature increases the following means are driven through the track powered by the driving means and move over the ramp into the first slot. These slots prevent that the following means return through the same path in the track upon contraction of the driving means. As such the followings means are forced to follow the desired return path in the track and translate this movement into a further movement of the detergent holder. At the end of the contraction the following means are driven over a second ramp into the next slot and move the detergent holder further.
To enable the following means to move up over the ramps and down into the slots the following means can be designed to pivot either by a spring loaded pin or by a pivot point to keep the following means at all times in the track.
Preferably, the track comprises harbours. The role of the harbours is to allow further expansion or contraction of the driving means without causing further movement of the detergent holder and to prevent the build-up of high forces in the system when the driving means reaches its maximum expansion or contraction. For instance with a wax motor with a total expansion stroke of 15 mm, the harbours enable to use only the expansion from 5 mm to 10 mm to generate movement of the detergent holder while in the first 5 mm or last 5 mm of the stroke the following means are kept in the harbours and therefore the detergent holder is kept in the same position. This feature helps to overcome the large variation in dishwashing machine cycles and temperature profiles and enable a very specific and pre-defined movement of the detergent holder.
The device is preferably a stand-alone device. By “stand-alone” is herein meant that the device is not connected to an external energy source.
The device of the present invention is preferably of a planar geometry (ie., a disc, a square, a rectangle, etc). Planar geometry is more space efficient than any tri-dimensional geometry, thereby leaving more free space in the dishwasher for the items to be washed.
According to a second aspect of the invention, there is provided a method of scenting an automatic dishwashing machine during a dishwashing operation and between operations, the method comprising the step of using the automatic dishwashing product of the invention to continuously deliver a perfume. The product provides a very consistent perfume delivery profile over time. The perfume delivery during a dishwashing operation is very similar to that in between operations. The consumer gets a very pleasant scent when interacting with the automatic dishwasher, i.e. during loading and unloading.
The method is suitable for scenting environments in which the temperature rises significantly above room temperature. The method is especially suitable for scenting an automatic dishwashing machine, during a dishwashing operation and in between dishwashing operations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows in perspective an assembly view of the actuating means 1 comprising a baseplate with the driving means 2 and a rotating cover with the guided means 5 .
FIG. 2 shows a perspective assembly detail of the driving means 2 with the rotating cover 5 removed.
FIG. 3 : shows a perspective view of the circular guided means inside the rotating cover 5 with a circular zig-zag track 10 .
FIGS. 4( a ) and 4 ( b ) are perspective exploded views of the actuating means mechanism with following means 8 with follower pin 9 and returning means 7 and 71 .
FIG. 5 shows in perspective cross-sectional view the assembled actuating mechanism with waxmotor 18 and follower pin 9 in the expanded position.
FIGS. 6( a ) and 6 ( b ) shows respectively a schematic perspective of the actuating mechanism in a cylindrical housing and in a planar disc shaped housing.
FIG. 7 shows an exploded view of the multi-dosing detergent holder 102 in a disc shaped housing 101 and 110 with the actuating mechanism and the perfume composition 202 in a cavity 201 with a perfume release window 203 .
FIG. 8 shows a perspective assembly view of the actuating mechanism 51 for a rectangular shaped guided means.
FIG. 9 shows a perspective view of the rectangular guided means 55 with a linear zig-zag track 100 .
FIGS. 10( a ) and 10 ( b ) show perspective assembly views of the actuating mechanism 51 and the rectangular guided means 55 .
FIG. 11 shows a schematic view of the rectangular shaped multi-dosing detergent holder 55 comprising the guided means with linear track 100 comprising multiple doses of the first detergent composition 104 and the second detergent composition 106 .
FIG. 12 shows a perspective detailed schematic view of the driving means 18 driving the following means 8 with follower pin 9 through the linear track 100 of FIG. 11 .
FIG. 13 ( a ) and FIG. 13 ( b ) respectively show a schematic view of the driving means in contracted (cold) position (i.e.; temperature less than 30-34° C. wax contracts return stroke via bias spring) and in the expanded (hot) position (i.e.; temperature greater than 36-38° C. wax expands stroke up to 15 mm).
FIG. 14 shows a graph illustrating the hysteresis profile of the actuation temperature of the wax motor during an expansion (heating) and contraction (cooling) cycle.
DETAILED DESCRIPTION OF THE INVENTION
The present invention envisages a product comprising an auto-dosing device which comprises a scenting composition and a method for scenting an automatic dishwashing machine using such product. The product is extremely suitable for use in an automatic dishwashing machine which involves high temperature and humidity conditions. The product of the invention provides a multitude of benefits. The scenting occurs during the operation of the appliance and in between operations. The scenting composition is part of the auto-dosing device thus the user does not need to use two separate products. As indicated herein before, the product provides a uniform perfume delivery profile over time, even under the high temperature and humidity conditions found in an automatic dishwashing machine.
An automatic dishwashing operation typically comprises three or more cycles: a pre-wash cycle, a main-wash cycle and one or more rinse cycles. The pre-wash is usually a cold water cycle, the main-wash is usually a hot water cycle, the water comes in cold and is heated up to about 55 or 65° C. Rinsing usually comprises two or more separate cycles following the main wash, the first being cold and, the final one starting cold with heat-up to about 65° C. or 70° C.
Polyolefin
Any semi-crystalline polyolefin having a crystallinity of from about 5% to about 60% is suitable for use herein. Preferred polyolefin for use herein is polybutene-1. The term “polybutene-1” includes any semi-crystalline homopolymers obtained by the polymerization of high-purity butene-1, preferably in the presence of a Ziegler-type catalyst. The term “polybutene-1” also includes copolymers of butene-1 with other polyolefin like ethylene, propylene, hexene, 4-methylpentene-1, octene-1, decene-1, octadecene-1, etc. Especially preferred polybutene-1 is a copolymer of polybutene-1 and ethylene.
The polybutene-1 for use herein is semi crystalline, and typically has high-molecular-weight, with a high degree of isotacticity that offers useful combinations of high heat resistance and freeze tolerance as well as flexibility, toughness, stress crack resistance and creep resistance. Polybutene-1 present slower setup times than those of other polyolefins, this seems to be because of its unique delayed crystallization, and by its polymorphism. High crystallinity olefins usually are not highly mixable with perfumes. Because of its unique crystallinity behavior polybutene-1 is mixable with perfumes at higher concentration than other polyolefins. When mixing the polybutene-1 with perfume in the certain amount as here disclosed the crystals formation is further delayed as well as the rate of formation is decreased but not totally. The final mixture can retain some of the mechanical properties of the polybutene-1.
Preferred polybutene-1 for use herein includes DP8510M and DP8911 supplied by Basell-Lyondel. Especially preferred for use herein is DP8911.
Crystallinity
The degree of crystallinity has a great influence on hardness, density, transparency, softening point and diffusion of solid materials. Many polymers have both a crystalline and amorphous regions. In these cases, crystallinity is specified as a percentage of the mass of the material that is crystalline with respect to the total mass.
Crystallinity can be measured using x-ray diffraction techniques and differential scanning calorimetry (DSC).
For example, methods ASTM E 793-06 (Enthalpies of Fusion and Crystallization by Differential Scanning calorimetry) or ASTM F 2625-07 (Measurement of Enthalpy of Fusion, Percent Crystallinity, and Melting Point of Ultra-High-Molecular Weight Polyethylene by Means of Differential Scanning calorimetry) can be used to determine the Enthalpy of Fusion and then the crystallinity of the polyolefin and the composition of the invention. For the purpose of this invention, crystallinity is measured following ASTM E 793-06. The crystallinity of a polyolefin is calculated against published values of the 100% crystalline corresponding material. For example, in the case of polybutene-1 the enthalpy of fusion of 100% crystalline material (stable form I) is 135 J/g (ref. “The heat of fusion of polybutene-1” table 3, Howard W. Starkweather Jr., Glover A. Jones E.I. du Pont de Nemours and Company, Central Research and Development Department, Experimental Station, Wilmington, Del. 19898).
To measure the crystallinity of the composition, a sample of it must be first conditioned for 15 days at 23° C. in a sealed aluminum bag to avoid perfumes loosing over time. Then a DSC analysis is run according the method ASTM E 793-06 (temperature rate 10° C./min) to measure the enthalpy of fusion of the composition. In order to have an indication of where the reference peak of the DSC of the composition should be found a DSC of the current polyolefin of the mixture is run to determine the melting point of the polyolefin.
The enthalpy of fusion of the composition sample is then normalized by dividing the obtained value by the weight of the sample to get the specific enthalpy of fusion by gram of sample (i.e. J/g) and then by dividing again this latter value by the standard 100% polybutene-1 crystalline material enthalpy of fusion value (i.e. 135 J/g) to finally get the crystallinity of the composition.
It has to be noted that many DSC instruments are able to calculate directly both the normalized enthalpy of fusion of the sample and the crystallinity.
The crystallinity of the polybutene-1 is measured in an analogous manner.
Melting Point
The melting point of the composition of the invention is determined using the standard method ASTM D-4440 (Dynamic Mechanical Properties Melt Rheology). The method consists in measuring the rheological properties of a composition disc specimen in a temperature range (from 25° C. to 100° C.). The disc specimen has the same diameter of the parallel plate geometry used in the measurement. A 25 mm disc is used. The discs are prepared previously using plastic frames with 25 mm discs hole and 2 mm thickness. The composition is melt and poured in the disc frames. Exceeding material is removed with a spatula. The sample is then cooled down and stored for 24 hr at 23° C. in a climatic room and in sealed aluminum bags. The rheometer used is a SR5 Stress controlled (Rheometrics®). The “melting point” (also referred as melting at crossover point) of a viscous-elastic material like the composition of the invention is defined as the temperature value at which the “liquid/viscous characteristic part” (known as loss modulus G″) and the “rigid/solid characteristic part” (known as elastic modulus G′) are equal.
Perfume
Any perfume is suitable for use in the product of the invention, any of the current compositions used in perfumery. These can be discreet chemicals; more often, however, they are more or less complex mixtures of volatile liquid ingredients of natural or synthetic origin. The nature of these ingredients can be found in specialised books of perfumery, e.g. in S. Arctander (Perfume and Flavor Chemicals, Montclair N.J., USA 1969).
The perfumes herein can be relatively simple in their composition or can comprise highly sophisticated, complex mixtures or natural and synthetic chemical components.
In preferred embodiments, the perfume comprises at least about 10%, more preferably at least about 20% and especially at least 30% by weight of the perfume of blooming perfume ingredients having a boiling point of less than 260° C. and a ClogP of at least 3. The perfume would also typically comprise non-blooming perfume ingredients having a boiling point of more than 260° C. and a ClogP of at least 3, preferably less than about 30%, more preferably less than about 25% and preferably between 5 and 20% by weight of the perfume of non-blooming perfume ingredients.
The perfume of the composition of the present invention are typically very effusive and consumer noticeable, leaving minimal residual perfume on the washed items, including dishes, glasses and cutlery, especially those made of plastic, rubber and silicone. The compositions can leave a residual perfume in the automatic dishwashing machine that can be enjoyed by the user in between dishwashing operations.
A blooming perfume ingredient is characterized by its boiling point (B.P.) and its octanol/water partition coefficient (P). The octanol/water partition coefficient of a perfume ingredient is the ratio between its equilibrium concentrations in octanol and in water. Since the partition coefficients of the preferred perfume ingredients herein have high values, they are more conveniently given in the form of their logarithm to the base 10, log P. The B.P. herein is determined at the normal, standard pressure of 760 mm Hg.
Wax
Suitable wax for use herein includes paraffin wax, long-chain alkanes, esters, polyesters and hydroxy esters of long-chain primary alcohols and fatty acids, naphthenic and iso-paraffinic long chain hydrocarbons, petrolatum. They can be natural or synthetic. The waxes are excellent oil binding allowing perfume incorporation in the composition at high levels.
Commercial waxes include beeswax, carnauba wax, petroleum waxes, microcrystalline wax, petroleum jelly and polyethylene waxes. Especially preferred for use herein is a microcrystalline wax. Preferred commercial material includes Permulgin 4201 supplied by Koster Keunen (Holland)
Nucleating Agent
Nucleating agents accelerate the formation of crystals in polymers containing polybutene and copolymers thereof. Nucleating agents promote the growth of the crystal by lowering the activation energy required for crystal organization. By using nucleating agents, the nucleation starts occurring at a higher temperature than in the polyolefin containing composition without nucleating agents. Further during the cooling phase, the number of polymer crystals increases as well as the final distribution result more uniform than in the case in which no nucleating agent is used. Suitable nucleating agents include talc, benzoates, phosphate ester salts, sorbitol derivatives, or commercial products like Hyperform® HPN-20E, Hyperform® HPN-68L by Milliken Co.
Optional components to be added to the scenting composition of the product of the invention include tackifying resins, as those described in US 2008/0132625 A1, paragraph [0020], plasticizers, as those described in US 2008/0132625 A1, paragraph [0023]. If present the tackifying resin would be in a level of from about 1% to about 50% wt. If present the plasticizer would be in a level of from about 1% to about 50% wt. Further additives can be incorporated into the product of the invention in quantities of up to 15 wt % in order to vary certain properties. These can be, for example, dyes, pigments, or fillers such as titanium dioxide, talcum, clay, chalk, and the like. They can also, for example, be stabilizers or adhesion promoters.
Examples of devices in accordance with the present invention will now be described with reference to the accompanying drawings, in which:
FIGS. 1 , 2 , 3 , 4 and 5 show respective assembled, perspective exploded and internal perspective views of the rotating actuating means 1 comprising the driving means 2 and the guided means 5 . The driving means 2 comprises an axes 3 around which the cover with the guided means 5 can rotate at specific intervals defined by the profile of the guided track 10 inside the cover 5 .
The driving means further comprise a thermal reactive element 18 which is in this configuration a wax motor. As shown in FIG. 13( a ) a wax motor 18 is basically a cylinder filled with a thermal sensitive wax 60 under a piston 6 . When temperature in the automatic dishwashing machine brings the wax to or above its melting temperature it will start to expand as shown in FIG. 13( b ) This expansion pushes the piston outwards developing a considerable force, up to 50N and more and a considerable movement, or stroke of the piston. For instance for a cylinder with a total length of 30 mm and +/−6 mm diameter half filled with a solid wax under the piston a stroke of the piston of 15 mm can be achieved, meaning an expansion of the wax by a factor 2 upon melting.
This outward movement of the piston puts the returning means, which in FIG. 2 are two coil springs 7 and 71 , and in FIGS. 13( a ) and 13 ( b ) a single coils spring, under tension.
When the temperature in the dishwasher cools down below the solidification temperature again, at the end of the wash, the wax contracts, allowing the piston 6 to move back. The returning means pushes the piston back into the starting position.
This forwards and backwards movement of the piston or “the stroke” of the wax motor 18 is used to drive the following means 8 with the following pin 9 forward and backwards assisted by the returning means 7 and 71 . The returning means, in this case two tension springs 7 and 71 are connected on one side to the following means 8 and on the other side to the static baseplate 2 . To achieve a linear and smooth motion forward and backwards the following means run in supporting rails 20 and 22 .
It should be noted that the returning means in the form of a compression spring can also be inserted inside of the wax motor 18 , above the piston 6 so that upon expansion of the wax the spring compresses and upon cooling it can expand to its starting position.
In one preferred embodiment of the invention this forward and backwards movement of the driving means 18 and following means 8 and following pin 9 can now be used to rotate the cover 5 via the guided means 10 on the inside of this cover.
FIG. 3 shows a detail of the guided means, in this configuration the guided means 10 are a circular zig-zag repetitive track with harbours 13 and 16 , ramps 11 and 14 and slots 12 and 15 . The following describes one complete cycle:
At the start of an automatic dishwashing operation the automatic dishwashing machine is cold and the wax motor is contracted with the follower pin 9 positioned in the “cold” harbour 16 . When the machine heats up the wax starts to expand when it reaches its melting temperature. This drives the follower pin 9 forward through the first path of the track over the ramp 11 and as such rotates the cover over a certain angle. At further expansion the following pin drops over the ramp into the slot 12 and from there the further expansion drives it into the “warm” harbour 13 . The harbour allows the following pin to continue moving till full expansion without causing any further movement to the cover 5 .
When the automatic dishwashing machine starts to cool down below the solidification temperature of the wax, the wax motor slowly starts to contract and moves the following pin out of the “warm” harbour 13 . The slot 12 prevent that pin can return through the path with ramp 11 and therefore forces the pin to follow the new path over ramp 14 into slot 15 causing a further rotation to the cover 5 . The further contraction moves the pin 9 back into the next “cold” harbour 116 where it can fully contract without causing further motion to the cover 5 .
At this point the actuating device is ready for the next dishwashing operation.
It should be noted that one forward and backward movement through the zig-zag track corresponds with one complete wash program of the dishwashing machine.
In this circular configuration as per FIG. 3 the multiple peaks and valleys on the zig-zag track define the number of detergent dosages that can be provided. The shown configuration can automatically provide detergent over 12 complete dishwashing operations.
It will now be described how the rotational movement of the cover 5 drives the detergent holder 102 in the housing 110 and 101 shown in exploded perspective view FIG. 7 . In this configuration the driving means 2 with the wax motor 18 , the returning means 7 and 71 and following means 9 and follower pin 9 are in this case integrated in one half of the housing 110 . The rotating cover 5 with guiding means is clipped over it with the follower pin positioned in the first “cold” harbour.
The detergent holder 102 with the multiple detergent doses is inserted in this housing with the bottom engaging with the rotating cover 5 . The housing is closed with the second half of the housing 101 . The cover 5 can have guiding ribs 4 and other features to easily mate with detergent holder 102 so that the circular movement of the rotating cover can be transferred to the detergent holder throughout the various dishwashing operations.
It should be noted that the configuration of the track 10 and the angles of its zig-zag pattern determine the movement of cover 5 and thus the detergent holder 102 . Therefore the movement and desired release points can be dictated by this track. This enables large design flexibility in the delivery of the products at various points during the wash and rinse cycle(s). Even a sequential release of two or more doses can be achieved by the use of this kind of tracks.
In another preferred embodiment the guided means 10 can be directly integrated into the detergent holder 102 . In this case there is no need for a rotating cap 5 and the back and forward motion of the driving means can be directly transferred into the rotation of the detergent holder.
It should be noted that in this case the pattern of the track can be flexible and be different for different detergent holders, enabling specific release points in the dishwashing operation tailored to deliver different detergent doses at optimum times in a dishwashing operation.
The zig-zag track 10 in the rotating cap or into the detergent holder can be formed via various techniques known in the art like injection molding, thermoforming, compression molding, laser cutting, etching, galvanising or the like or can be separately produced and fixed to cap or the detergent holder via well known glueing, welding or sealing or mechanical clipping techniques.
The release of the detergent doses can be established in various ways using this multi-dosing detergent delivery device. In one preferred embodiment shown on FIG. 7 a first detergent dose 104 and a second detergent dose 106 are placed in separate cavities 103 and 105 of the detergent holder 102 . The detergent holder in this case can contain a non limiting number of 12 doses of the first and 12 doses of the second detergent.
At the start of the dishwashing operation the first detergent 104 can be exposed to the wash liquor in the automatic dishwasher via the open gate 107 in the housing while the other detergent doses are protected from the liquor by the housing. As explained before as the temperature rises the wax in the wax motor 18 expands and the piston 6 drives the follower pin 9 through the track 10 which rotates the detergent holder 102 to the next position where the second detergent 106 gets exposed to wash liquor via the open gate 107 . When the machine cools down again the wax motor contracts and rotates the detergent holder to the next position ready for the next wash.
It should be noted that during the rotation more than one detergent dose can be exposed or released sequentially, either direct at the start, in the first prewash, during the main-wash or during the first or second rinse cycle and even during the final heating, drying cycle and cooling cycle by accurately making use of the specific expanding or contracting stroke length of the wax motor in function of temperature. The shape and angles of the zig-zag track then define the rotational speed and rotational angle of the detergent holder.
The first 104 and or second detergent doses 106 can either be exposed to the wash liquor or can be dropped into the dishwashing machine through the open gate 107 using gravity or by actively pushing it out of the cavities 103 and/or 105 by running the detergent holder over a small ramp featured on the inside of the housing 110 . This ramp feature applies a gradual increasing force on the underside of the cavity to pop the detergent dose out of the cavities 103 and/or 105 during the rotational movement. In this case a deformable base in the detergent holder like a flexible deep drawn film, a blister pack or thin wall thermoformed cavities will help the release of the first and/or second detergent doses.
In another embodiment the ramp feature can run through one or more open slots in the base of the detergent cavities 103 and/or 105 to actively push the content out through the open gate 107 into the dishwashing machine. In a further variation the housing can have more than one open gate 107 .
The first and second detergent doses can be protected against the high humidity and high temperature conditions in the dishwashing machine via additional sealing and barrier features and materials in the housing or by covering the cavities of the detergent holder with a water-soluble PVA film or a non soluble moisture barrier film which can be pierced or torn open during the release operation.
The perspective view in FIGS. 6( a ) and 6 ( b ) illustrate that the actuating means 1 can be used in a cylindrical housing 30 or in a disc shaped housing 40 or any further shape that can accommodate the rotational movement. The detergent holders can also have different shapes to match with these specific housings.
Further means for easy insertion and removal of the detergent holder can be integrated in the housing and the detergent holder, like locking features, clipping features, (spring loaded) opening features, (spring loaded) ejecting features, etc.
Another embodiment of this invention is shown in the perspective assembly, detailed and exploded views shown in FIGS. 8 , 9 , 10 , 11 and 12 . The driving means with the wax motor 18 and the forward and backward moving following means 8 and follower pin 9 on the piston 6 are in this configuration transferred into a linear unidirectional motion of the guided plate 55 via the linear zig-zag track 100 with ramps, slots and harbours as described before.
As shown in FIG. 11 this linear zig-zag track 100 can be integrated into a rectangular shaped detergent holder 55 with a number of individual cavities containing the first 104 and second detergent doses 106 . As described before each up and down path through the track 100 corresponds with a heating and cooling phase during the dishwashing operation. Two or more detergent doses can be delivered one after the other in the dishwashing machine at specific points in the wash. On FIG. 11 detergent doses for twelve different dishwashing operations are shown however it should be understood that this can easily be varied from 2 to 36 or more dishwashing operations, depending on the size of the detergent holder.
In a preferred embodiment of the invention this rectangular shaped detergent holder is a blister pack.
The automatic dishwashing detergent delivery system of the invention can have further features to indicate the number of doses used or still left to help the consumer decide when to refill the detergent holder. FIG. 7 shows a transparent window 108 on the housing 101 to display one number of a range, printed or marked in a circular pattern on the centre 109 of the detergent holder 102 . When the detergent holder rotates, from one dishwashing operation to the next, the number changes behind the window 108 . It should be noted that other characters, specific icons or colour coding can be used to communicate how many doses are left.
In more advanced executions of the invention sound or light signals can be generated by for instance storing energy in a coil-spring that slowly winds up with the rotational movement of the detergent holder and releases it energy via a mechanical switch when the detergent holder is almost empty.
Examples
A scenting composition is prepared as follows: 50 grams of Polybutene-1 grade DP8911M, supplied by LyondellBasell Industries are added to 50 grams of perfume, the resulting product is mixed at 85° C. for 4 h and then cooled down. 10 grams of this composition are placed in an auto-dosing device according the invention. The auto-dosing device has doses for 12 dishwashing operations. A pleasant smell can be noticed each time that the automatic dishwashing machine is open.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”. All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to the term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. | An automatic dishwashing product comprising a multi-dosing detergent delivery device comprising a housing ( 101, 110 ) for receiving therein a detergent holder ( 102 ) and a detergent holder ( 102 ) accommodating a plurality of detergent doses ( 104, 106 ) and a scenting composition wherein the scenting composition comprises a perfume and a polyolefin. | 47,268 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an insertion device, such as a catamenial tampon applicator. More particularly, the present invention relates to a multiple-component tampon applicator formed from at least three distinct and separate components.
[0003] 2. Description of the Prior Art
[0004] The majority of commercial tampon applicators are of approximately uniform cross-section and are formed from only two components, namely a barrel and a plunger. The fingergrip, if any, is formed as an integral part of the barrel component. Some applicators have a fingergrip and a plunger of a cross-sectional area reduced from that of the applicator barrel. This feature has been found not only to render the tampon applicator more grippable, but it is also more aesthetically preferred.
[0005] For current reduced cross-sectional area fingergrip tampon applicators, the tampon pledget must be loaded into the insertion end of the applicator due to the smaller opening at the fingergrip end. Thus, these tampons are restricted to top or insertion end loading. This requires the petals of the applicator, if any, to be post-formed to their final shape after the pledget has been loaded. Post-forming of petals requires the material to be plasticized. Typically, plastic petals are plasticized by heat and are easily shaped by the use of an external forming die.
[0006] On the other hand, cardboard petals are more difficult to plasticize and require the additional use of an internal mandrel. Usual methods involve heating the tip to volatize the water (either existing or supplemental moisture), and then forcing the petal into shape using an internal mandrel in conjunction with the external die. The internal mandrel has a cross-sectional area that is approximately the same as the barrel's interior, and consequently would not be able to enter through a reduced cross-sectional fingergrip area. Therefore, the necessity of the internal mandrel to shape the petal tip has thus far precluded the manufacture of a reduced cross-sectional fingergrip area on a cardboard applicator.
[0007] Therefore, there is a need for a tampon applicator, and more specifically a cardboard applicator, that can be manufactured such that petal tips can be pre-formed or integrated on the insertion end of the applicator barrel, prior to loading an absorbent pledget, using existing manufacturing processes and equipment.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a tampon applicator that is assembled from at least three distinct and separate components.
[0009] It is another object of the present invention to provide such a tampon applicator that has a barrel formed from cardboard.
[0010] It is still another object of the present invention to provide such a tampon applicator having a fingergrip with a reduced cross-sectional area compared to that of the applicator barrel.
[0011] It is a further object of the present invention to provide such a tampon applicator having petals at the insertion end of the cardboard barrel prior to loading the barrel with an absorbent pledget.
[0012] It is still a further object of the present invention to provide such a tampon applicator in which the petals are pre-formed using existing processes and equipment.
[0013] It is yet a further object of the present invention to provide such a tampon applicator in which the petals are formed on a separate and distinct insertion tip component that may be connected to a separate barrel component either before or after a pledget is loaded into the barrel component.
[0014] It is still yet a further object of the present invention to provide such a tampon applicator that prior to assembly of the applicator, and prior to loading the barrel component with an absorbent pledget, petals may be formed on the insertion end of the barrel using existing processes and equipment.
[0015] These and other objects of the present invention will be appreciated from a multiple-component tampon applicator formed from at least three separate and distinct components. A separate insertion tip component having petals may be formed. This separate component may then be connected to the barrel component either before or after an absorbent pledget is loaded into the barrel component. Also, a fingergrip may be formed as a separate component or it may be integrally formed with the barrel.
[0016] The multiple components may be formed from materials including, for example, plastic, cardboard, paper slurry, pulp slurry, pulp molded paper, heat shrink plastic, plastic tubing, biopolymers including carbohydrates and proteins, or any combinations thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is an exploded view of a multiple-component applicator having three components that form the tampon applicator of the present invention;
[0018] FIG. 2 is an exploded view of a multiple-component applicator having four components that form the tampon applicator of the present invention;
[0019] FIG. 3 is an exploded view of a three-component applicator of the present invention where the barrel component includes the fingergrip;
[0020] FIG. 4 is a perspective view of an assembled three-piece tampon applicator of FIG. 1 ;
[0021] FIG. 5 is a perspective view of a fingergrip component of the tampon applicator of FIG. 1 ;
[0022] FIG. 6 is a perspective view of a fingergrip component according to another embodiment of the present invention;
[0023] FIG. 7 is a perspective view of a three-piece applicator according to yet another embodiment of the present invention;
[0024] FIG. 8 is a perspective view of several embodiments of fingergrip components having various gripping structures according to the present invention;
[0025] FIG. 9 is a perspective view of a fingergrip component according to another embodiment of the present invention.;
[0026] FIG. 10 is a perspective view of a fingergrip component according to another embodiment of the present invention;
[0027] FIG. 11 is a perspective view of a fingergrip component according to another embodiment of the present invention;
[0028] FIG. 12 is a perspective view of a multiple-component applicator having three components that form one embodiment of a tampon applicator of the present invention;
[0029] FIG. 13 is a perspective view of the fingergrip and barrel components of FIG. 12 in a heated former; and
[0030] FIG. 14 is a perspective view of a multiple-component applicator with the barrel and fingergrip formed in the heated former of FIG. 13 .
DETAILED DESCRIPTION OF THE INVENTION
[0031] Referring to the drawings and in particular FIG. 1 , a first embodiment of a multiple-component tampon applicator of the present invention is represented generally by reference numeral 10 . One distinguishing feature of this applicator 10 is that instead of being formed from two components, namely, a barrel and a plunger, it is formed from three distinct components. In a preferred aspect of this first embodiment, the three distinct components are barrel 12 , plunger 14 , and fingergrip or fingergrip component 16 .
[0032] The barrel 12 retains its approximately uniform cross-section, thus allowing petals 18 to be formed prior to pledget insertion. The petals 18 can be formed with the assistance of an internal mandrel, if desired.
[0033] Referring to FIG. 2 , a second embodiment of the multiple-component tampon applicator according to the present invention is depicted. This applicator 10 is formed from four distinct components. Again, as a preferred aspect of this second embodiment, the preferred components are barrel 12 , plunger 14 , fingergrip 16 , and insertion tip 19 . Petals 18 are formed on insertion tip 19 . As such, an absorbent pledget may be loaded into barrel 12 either before or after insertion tip 19 is connected to barrel 12 .
[0034] Referring to FIG. 3 , a third embodiment of the multiple-component applicator of the present invention is shown. This applicator 10 is formed from at least three distinct components, namely, barrel 12 , plunger 14 , and insertion tip 19 . Barrel 12 has a forward end 21 . In this embodiment, fingergrip 16 is integrally formed as part of barrel 12 . An absorbent pledget may be loaded into barrel 12 through forward end 21 , prior to connecting insertion tip 19 to the barrel.
[0035] Barrel 12 of the multiple-component applicator 10 of the present invention may be formed from any suitable material. Suitable materials for forming barrel 12 include, for example, biopolymer, cardboard, heat shrink plastic, paper slurry, plastic, plastic tubing, pulp slurry, pulp-molded paper, or any combinations thereof. Preferably, barrel 12 is formed from cardboard. Barrel 12 may be formed from spiral wound or convolutely wound cardboard.
[0036] Any individual component that forms the multiple-component applicator, and especially barrel 12 , may be internally and/or externally coated with any suitable material to enhance its strength and/or reduce surface friction. Suitable coatings include, for example, cellophane, cellulose, epoxy, lacquer, nitrocellulose, nylon, plastic, polyester, polylactide, polyolefin, polyvinyl alcohol, polyvinyl chloride, silicone, wax, or any combinations thereof. It should also be understood that barrel 12 , while depicted as a single component, may be formed from one or more components, such that when assembled, the one or more components form barrel 12 .
[0037] Plunger 14 may be formed from any suitable material. Suitable materials for forming plunger 14 include, for example, biopolymer, cardboard, heat shrink plastic, paper slurry, plastic, plastic tubing, pulp slurry, pulp-molded paper, or any combinations thereof. Preferably, plunger 14 is formed from cardboard.
[0038] Referring to FIGS. 1 and 2 , fingergrip 16 , as a separate component, provides a way to create an applicator having a cardboard barrel with pre-formed petals and, perhaps, a reduced cross-sectional fingergrip area with an accompanying reduced cross-section plunger 14 . Fingergrip 16 has two distinct ends, barrel or forward end 20 having a diameter approximately equal to that of barrel 12 , and plunger or rearward end 22 having a diameter slightly larger than that of plunger 14 . Fingergrip 16 also has channel 26 , which extends axially through the entire length of the fingergrip. Channel 26 has a cross-sectional area slightly larger than that of plunger 14 so as to accommodate the plunger during assembly of applicator 10 . The pledget (not shown) is loaded into barrel 12 through fingergrip or rearward end 24 of the barrel. Petals 18 , if any, on barrel 12 have been pre-formed into their final shape, as in FIG. 1 .
[0039] As shown in FIG. 2 , when insertion tip 19 and fingergrip 16 are formed as separate components, an absorbent pledget (not shown) may be loaded either through forward end 21 or barrel rearward end 24 of barrel 12 .
[0040] Referring to FIG. 3 , when insertion tip 19 is formed as a distinct component, it also allows barrel 12 and fingergrip 16 to be formed as one component. With this configuration, an absorbent pledget may be loaded into barrel 12 through forward end 21 , prior to assembling the multiple-component applicator.
[0041] By way of example, FIG. 4 shows the three-component applicator of FIG. 1 assembled. Once an absorbent pledget (not shown) is loaded into barrel 12 , barrel forward end 20 of fingergrip 16 is connected to barrel 12 at barrel rearward end 24 . Plunger 14 is then inserted into fingergrip plunger end 22 through channel 26 . Alternately, plunger 14 may be loaded into channel 26 of fingergrip 16 prior to the fingergrip being connected to barrel 12 . Fingergrip 16 may be secured permanently to barrel 12 by any conventional method. Preferably, fingergrip 16 is connected to barrel 12 with an adhesive. Outer edge 25 of fingergrip 16 may be of such a size that it creates a continuous surface flush with the outer edge of barrel 12 .
[0042] It should be understood that the multiple-component tampon applicators depicted in FIGS. 2 and 3 may also be assembled according to the same basic tenets set forth for assembling the three-component applicator of FIG. 1 . One distinguishing feature of the applicator of FIG. 2 with respect to assembly, is that the absorbent pledget may be loaded into barrel 12 either through forward end 21 or barrel rearward end 24 . Therefore, the order in which the components are assembled may depend on which end of barrel 12 the pledget is loaded. A distinguishing feature of the applicator of FIG. 3 , with respect to assembly, is that barrel 12 and fingergrip 16 are formed as one component, therefore, the absorbent pledget must be loaded into barrel 12 through forward end 21 , prior to assembling insertion tip 19 with barrel 12 .
[0043] It should also be understood that each component of the tampon applicator set forth above may be formed from one or more individual parts or sections (i.e. barrel 12 , plunger 14 , fingergrip 16 and/or insertion tip 19 may be formed from one or more individual parts or sections that are connected to form the component). In addition, it should be understood that while each applicator component is shown above as being discrete and separate from each other, any two or more of the components may be integrally formed and then assembled with the one or more separate components. By way of example, the insertion tip 19 , the barrel 12 , the fingergrip 16 , and/or the plunger 14 may be integrally formed, in any combination. In addition, any component that is made up from two or more parts or sections, as set forth above, may be connected to form that component, prior to connecting with any other individual component to form an assembled applicator 10 . However, the overall applicator will, nonetheless, have at least three components.
[0044] Fingergrip 16 can be formed from any suitable moldable material. Suitable moldable materials include, for example, biopolymer, cardboard, heat shrink plastic, paper slurry, plastic, plastic tubing, pulp slurry, pulp-molded paper, or any combinations thereof. In a preferred embodiment of the present invention, fingergrip 16 is formed from pulp molded paper.
[0045] FIG. 5 is another embodiment of the present invention. Fingergrip 16 is formed with a connector ring 32 on barrel forward end 20 . Connector ring 32 has a diameter slightly larger than the internal diameter of barrel 12 so that fingergrip 16 can be connected and secured to barrel 12 by interference fit.
[0046] FIG. 6 is another embodiment of the present invention. Connector ring 32 may be formed with one or more tabs, ridges and/or slots 34 . One or more tabs, ridges and/or slots 34 can interlock with corresponding tabs, ridges and/or slots (not shown) formed on the inner surface of barrel 12 , thus securing fingergrip 16 to barrel 12 . The one or more tabs, ridges and or slots may be formed on external and/or internal surfaces.
[0047] FIG. 7 is another embodiment of the present invention. In this embodiment, fingergrip 16 is formed from a heat-shrinkable material 36 that has an initial diameter larger than the outer diameter of barrel 12 , and shrinks to a diameter at least as small as plunger 14 . Heat-shrinkable material 36 at barrel end 20 is shrunk to fit the outside of barrel 12 snugly. The union between heat-shrinkable material 36 and barrel 12 can be reinforced with an adhesive. Plunger or rearward end 22 of fingergrip 16 is shrunk so that it is just larger than the outside diameter of plunger 14 .
[0048] The fingergrip 16 may be formed with any number and/or configuration of gripping structures, to further enhance the applicator's grippability. Fingergrip 16 may be smooth or, more preferably, may include one or more patterned or textured structures extending above and/or below the surface of the fingergrip.
[0049] The gripping structures may include, for example, one or more abrasive materials, embossments, grooves, high wet coefficient of friction materials, lances, pressure sensitive adhesives, protuberances, slits, treads, or any combinations thereof. In addition, the gripping structures may be formed in any shape, including, for example, arc, circle, concave, cone, convex, diamond, line, oval, polygon, rectangle, rib, square, triangle, or any combinations thereof.
[0050] Referring to FIG. 8 , by way of example, several different fingergrip embodiments having various gripping structures are depicted. FIG. 8A depicts fingergrip 16 with one or more bands 38 circumferentially disposed around fingergrip rearward end 22 . FIG. 8B depicts fingergrip 16 with one or more dot-like structures 40 disposed circumferentially around fingergrip rearward end 22 . FIG. 8C depicts fingergrip 16 with one or more circular structures 42 disposed circumferentially around fingergrip rearward end 22 . FIG. 8D depicts fingergrip 16 with two or more wavy bands 44 disposed circumferentially around fingergrip rearward end 22 .
[0051] It should be understood that the gripping structures may be arranged circumferentially around fingergrip 16 in any pattern suitable for forming a gripping area. For example, the gripping structures can form a distinct pattern, such as, rows, columns or may be formed intermittently with breaks in structure or in any random order or pattern.
[0052] FIG. 9 is another embodiment of the present invention. In this embodiment, fingergrip rearward end 22 may be formed with a circumferentially flared or ridge-like structure end 46 , to further enhance the gripping characteristics of the applicator.
[0053] FIG. 10 is another embodiment of the present invention. In this embodiment, fingergrip rearward end 22 is formed with a stepped taper to further enhance the gripping characteristics of the applicator.
[0054] FIG. 11 is another embodiment of the present invention. In this embodiment, fingergrip rearward end 22 may be formed with a knob-like structure 48 to further enhance the gripping characteristics of the applicator.
[0055] Any combinations of the features depicted in FIGS. 8 through 11 , and described above, are possible as well. In addition, the gripping structures could be raised, depressed, or any combination thereof, with respect to the surface of the fingergrip area. The gripping structures can be formed in any shape, in any number, and in any pattern or configuration suitable for forming an enhanced gripping area on fingergrip 16 . As such, it should be clear that the present invention is in no way limited by those features depicted or described above.
[0056] It is also understood that the cross-section of barrel 12 , plunger 14 , fingergrip 16 and insertion tip 19 can be circular, oval, polygonal or elliptical. Also, insertion tip 19 can be tapered, elliptical, dome-shaped or flat. Barrel 12 can be straight, tapered, or curvilinear along its length.
[0057] Referring to FIGS. 12 through 14 , a method of assembling a multiple component tampon according to another embodiment of the present invention is depicted. Applicator 10 has independent or discrete barrel 12 , plunger 14 and fingergrip 16 . To assemble the components, adhesive 50 is applied to the fingergrip barrel end 20 . As depicted in FIG. 13 , fingergrip 16 is inserted into cavity 62 of heated shaper 64 . Mandrel 60 is inserted into fingergrip 16 housed in cavity 62 . Barrel 12 is inserted over mandrel 60 . The barrel 12 and fingergrip 16 are allowed to remain in position in heated shaper 64 for about 1 to 20 seconds and more preferably 5 to 10 seconds.
[0058] Referring to FIG. 14 , when removed from the mandrel 60 and heated shaper 64 , the fingergrip 16 is connected to barrel 12 at tapered rearward end 66 . Plunger 14 may then be inserted into fingergrip 16 .
[0059] The foregoing specification and drawings are merely illustrative of the present invention and are not intended to limit the invention to the disclosed embodiments. Variations and changes, which are obvious to one skilled in the art are intended to be within the scope and nature of the present invention, which is defined in the appended claims. | There is provided a multiple-component tampon applicator formed from at least three separate components. A fingergrip having a reduced cross-section as compared to that of the barrel may be formed such that it is a separate component or is integrally formed with a barrel component. The reduced cross-section fingergrip provides exceptional grippability to the user. The multiple components may be formed from materials including, for example, biopolymer including starches and proteins, cardboard, heat shrink plastic, paper slurry, plastic, plastic tubing, pulp slurry, pulp-molded paper, or any combinations thereof. Prior to assembly of the applicator and prior to loading the barrel component with an absorbent pledget, petals may be formed on the insertion end of the barrel using existing processes and equipment. Alternatively, a separate insertion tip component having petals may be formed. This separate component may then be connected to the barrel component either before or after an absorbent pledget is loaded into the barrel component. | 21,448 |
Subsets and Splits