description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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This is a division, of Application Ser. No. 505,183, filed Sept. 11, 1974.
BACKGROUND OF THE INVENTION
This invention relates to an improved apparatus for production of synthetic multifilamentary yarns having uniform quality from high molecular weight linear polymers, in particular polyamides and polyesters, according to an improved melt spinning process.
An important area of use of such synthetic multifilamentary yarns is the production of tire cord. A number of high polymers are well suited for this utility, especially polyesters and polyamides; however, in the following description reference will be made particularly to filaments of polyethylene terephthalate.
Since tire cord and the structures formed from it are among the essential construction elements for the safety and useful life of a tire, high quality requirements are naturally placed on such endless filaments. In view of the alternating stretching and compression stresses which tires experience in operation, a necessary precondition for the use of synthetic multifilamentary yarns for tire cord is an adequate fatigue resistance of the filaments. For optimum results, it is critical that the individual filaments be substantially uniform. Accordingly, it is common practice to determine the coefficient of variation of the evenness of the yarn (U %) using an Uster evenness tester as manufactured by the Zellweger Company of Uster, Switzerland, and described in "Handbook of Textile Testing and Quality Control" by E. Groover and D. S. Hamby.
The production of polyester yarns useful for tire, textile and industrial purposes is well known. In many of the prior art methods, the spinning and drawing and twisting of the filaments are separately carried out. However, several processes have been developed which involve conditions of continuously spinning and drawing filaments.
U.S. Pat. No. 3,433,008 to T. B. Gage discloses production of a bulked yarn by a process comprising applying a finish of an ester of polyethylene glycol of molecular weight between 150 and 600 and an aliphatic carboxylic acid to continuous melt spun filaments before the filaments are drawn. The filaments are then drawn and bulked in a turbulent fluid jet to give the bulked yarn.
U.S. Pat. No. 3,511,677 to A. J. Strohmaier et al. discloses preparation of a sized zero-twist synthetic fiber yarn by a process comprising applying a coating of a volatile medium containing a thermoplastic filmforming polymeric material to an undrawn yarn, drawing the yarn while wet with the volatile medium and then heating the drawn yarn to dry the coating before winding the yarn on a package.
U.S. Pat. No. 3,793,425 to R. J. Arrowsmith discloses a process for pretreating polyester filamentary material for subsequent rubber adhesion, the process comprising extruding a polyester filamentary material capable of being drawn and before the extrudate is fully drawn, coating with a composition containing an epoxy resin.
More recently, it has been suggested that a high strength polyester fiber can be produced by melt-spinning a polyester polymer under conditions of substantially simultaneous spinning and drawing wherein prior to said drawing the filaments of the fiber are lubricated by surface contact with a lube roll surface of not less than about 90 RMS. However, in commercial operation of said process at high throughput rates of 50 pounds per hour or greater through the spinneret, serious problems have been encountered due to "flicking" of filaments from the main yarn bundle above the lube roll, which flicking results in production of yarn of relatively poor quality. "Flicking" has been particularly troublesome in so-called double-end melt spinning of synthetic fibers, i.e., using one spin pot to feed both sides of a "split" spinneret. Accordingly, research has been continued in an effort to solve these deficiencies.
The term "RMS," which is short for root-mean-square, is an arbitrary measurement of surface texture and is described in detail in the publication, Surface Texture (ASA B 46.1 - 1962), The American Society of Mechanical Engineers, United Engineering Center, 345 East 47th Street, N.Y. 17, New York, page 16 (1962). Such measurement is utilized throughout this invention disclosure unless otherwise stated.
The term "flicking" is conventionally applied and is used herein to mean a momentary slackness of a filament in the undrawn yarn above the lube zone. The slack filament bows out of phase from the main bundle, thus "flicking". It is known that excessive "flicking" normally causes production of yarn of relatively low quality having an excessive number of defects such as missing filaments, filament breaks and loops.
SUMMARY OF THE INVENTION
The present invention relates to an improved melt-spinning apparatus for preparing synthetic multifilamentary yarns having uniform quality. The invention particularly relates to an improved melt-spinning process which involves applying a protective spin finish to the synthetic multifilamentary yarns by use of a novel lubricating and yarn-converging device, whereby "flicking" of the filaments from the main yarn bundle above the lubricating zone is substantially reduced or eliminated and the product yarns have improved quality.
These advantages are provided, in apparatus for melt spinning a large number of filaments at high speed from a spinneret, wherein said filaments are cooled, converged into a bundle and a protective spin-finish is applied before the filaments are drawn, by the improvement of a convergence guide having an essentially rectilinear primary yarn-contacting surface of smoothly-rounded contour for converging the filaments into a flat bundle and contiguous yarn-contacting surfaces of smoothly-rounded contour for controlling the width of the yarn bundle, and, in combination therewith, means for distributing a uniform film of lubricant over said primary yarn-contacting surface, which surface is defined as having a surface of at least 10 RMS, preferably 20 to 200 RMS.
The process of the present invention may be summarized as follows. In a process for the production of a synthetic multifilamentary yarn from a high-molecular weight thermoplastic polymer, selected from the group consisting of linear polyester and polyamide polymers, by melt-spinning, including the steps of applying a melt of said polymer at a temperature below the spinning temperature, and heating the melt to spinning temperature prior to filament formation, the improvement which comprises:
a. extruding the molten synthetic polymer at a rate of at least 50 pounds per hour downwardly through a spinneret having a plurality of extrusion orifices;
b. advancing the extruded filaments downwardly through a substantially stationary column of air having a temperature of 100° to 330° C. immediately below the spinneret, the average distance between adjacent filaments immediately below the spinneret being at least 0.24 inch, preferably 0.28 to 0.4 inch;
c. subsequently advancing the filaments downwardly through a quenching zone wherein they are in contact with cooling air introduced into the path of the filaments, said air contacting the filaments at a volumetric rate of 100 to 800 cubic feet of air per pound of filaments entering the quenching zone; and
d. simultaneously lubricating the cooled filaments and converging said filaments into a yarn bundle of uniform essentially rectilinear cross-section by drawing said filaments into contact with a grooved convergence guide having an essentially rectilinear primary yarn-contacting surface of smoothly-rounded contour for converging the filaments into a flat bundle and contiguous yarn-contacting surfaces of smoothly-rounded contour for controlling the width of the yarn bundle, and in combination therewith, means for distributing a uniform film of lubricant over said primary yarn-contacting surface, which surface is defined as having a surface of at least 10 RMS.
The lubricated filaments may be drawn in accordance with prior art processes which involve the following steps:
a. heating said filaments substantially immediately above their second order transition temperature;
b. drawing said filaments substantially instantly at a temperature in the range of from about above their second order transition temperature to within about 5° -methylene-bis-(C. of their melting point;
c. compacting said filaments sufficiently for subsequent processing of said filaments; and
d. winding up said filaments.
It will be understood that the drawing steps are conventional and can be modified if desired. For example, the yarn may be drawn on a seven roll panel or on a four roll panel. However, regardless of panel set up, the draw panel process steps preferably involve pretensioning to provide yarn stability on the rolls, feed rolls to provide constant yarn supply to the draw zone, a draw point localizer to provide draw-down point in the draw zone, draw rolls to maintain constant draw ratio and relax rolls to provide for control of yarn physical properties. Optionally, a yarn compaction jet may be used before or after the relax rolls to provide yarn entanglement.
Surprisingly, in operation of the process of the present invention, "flicking" of filaments from the main yarn bundle above the lube zone is significantly reduced with a corresponding marked decrease in product defects.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an over-all schematic diagram of the spinning apparatus showing location of the convergence guide of this invention.
FIG. 2 is a plan view of a preferred embodiment of the convergence guide of this invention.
FIG. 3 is a sectional elevation taken on line 3--3 of FIG. 2.
FIG. 4 is a schematic of a two end embodiment of the draw panel labeled 9 in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
It has now been found that synthetic multifilament yarn, e.g., polyethylene terephthalate multifilament yarn, including such yarn of high denier per filament, e.g., 20 to 50 denier per filament (undrawn) can be melt spun continuously from a single spinneret at high production rates such as 50 to 90 pounds per hour, and this yarn can be continuously drawn without an intermediate step of winding up, at draw ratios of at least 4:1. These results are achieved in accordance with this invention, by employing controlled conditions whereby the "flicking" of filaments from the yarn bundle above the lube zone is not above 10 per minute. More specifically, in accordance with the present process, a relatively large number of heavy filaments are extruded downwardly into a substantially stationary column of air having a temperature of 100° to 330° C. and a height of from 0.5 to 2 feet, preferably 1 to 1.5 feet, immediately below the spinneret, the distance between adjacent filaments immediately below the spinneret being preferably 0.28 to 0.4 inch, and subsequently advancing the filaments through a quenching zone wherein they are contacted with cooling air entering the zone at a volumetric flow rate of 100 to 800, preferably 200 to 700 cubic feet of air (measured at standard temperature and pressure) per pound of entering filaments, the air being at inlet temperature not above 35° C.
Preferably, the cooled filaments are converged into a yarn bundle of uniform essentially rectilinear cross-section and simultaneously lubricated by a protective spinning finish composition, preferably at a temperature of 20° to 60° C., by drawing said filaments into contact with a grooved convergence guide having an essentially rectilinear primary yarn-contacting surface of smooth-rounded contour for converging the filaments into a flat bundle and contiguous yarn-contacting surfaces of smoothly-rounded contour for controlling the width of the yarn bundle, and in combination therewith, means for distributing a uniform film of lubricant over said primary yarn-contacting surface, which surface is defined as having a surface of at least 10 RMS, preferably 20 to 200 RMS.
A conventional spinning finish composition is used to lubricate the filaments. A typical finish comprises a lubricant and may contain a diluent, an antistatic compound, an emulsifier and a wetting agent. For example, excellent results have been obtained when the filaments are coated with from about 0.3 to about 0.6 weight percent based on the weight of the yarn of a liquid composition consisting essentially of about 10 to about 20 weight percent of said composition of each hexadecyl stearate and refined coconut oil, about 3.0 to about 6.0 weight percent of said composition of ethoxylated tallow amine, about 10 to about 20 weight percent of said composition of ethoxylated lauryl alcohol, about 8.0 to about 12.0 weight percent of said composition of sodium salt of alkylarylsulfonate, about 1.0 to about 3.0 weight percent of said composition of dinonylsodium-sulfosuccinate, about 1.0 to about 3.0 weight percent of said composition of an antioxidant selected from the group consisting of 4,4'-butylidene-bis-(28 6-tert-butyl-m-cresol), thio-bis-(di-sec-amylphenol), trinonyl phenol phosphite, and 2,2-methylenebis-(4-methyl-6-tert-nonylphenol), about 35 to 50 weight percent of said composition of white mineral oil having a boiling point of between 510° F. and 620° F.
Preferably, the viscosity of the finish composition is maintained at about 10 to 100 centipoises, measured at the temperature of application.
One preferred embodiment of this invention is directed to an improved melt spinning process and apparatus involving double-end spin-draw and take-up for multifilament synthetic polymer fibers.
In order to demonstrate the invention, the following examples are given. They are provided for illustrative purposes only and are not to be construed as limiting the scope of the invention, which is defined by the appended claims. In these examples, parts and percentages are by weight unless otherwise indicated. The intrinsic viscosity of the polyester is given as a measure for the mean molecular weight, which is determined by standard procedures wherein the concentration of the measuring solution amounts to 0.5 g/100 ml., the solvent is a 60 percent phenol-40 percent tetrachloroethane mixture, and the measuring temperature is 25° C. In the examples, the diameter fluctuations along an unstretched bundle of filaments serve as a measure of uniformity. For high quality yarn, it is important that the filaments be substantially uniform. Accordingly, the coefficient of variation of the evenness (U %) is determined using an Uster evenness tester manufactured by the Zellweger Company of Uster, Switzerland and described in "Handbook of Textile Testing and Quality Control" by E. Groover and D. S. Hamby.
EXAMPLE 1
A melt of polyethylene terephthalate having an intrinsic viscosity of about 0.92 was supplied at a rate of 60 pounds per hour, at a temperature of about 291° C., to the apparatus shown in FIGS. 1 to 4. The molten polymer was fed by extruder 1 to spinning pump 2 which fed spinning block 3 containing a conventional spinning pot comprising a spinning filter and a spinneret, the spinning filter being disposed between the spinning pump and the spinneret. The spinning filter consisted of a conventional sieve filter combination of 24 metal screen layers. The pressure drop through said spinning filter averaged 200 to 400 atmospheres. The spinning pot was enclosed in a controlled high temperature atmosphere so that loss of heat from the polymer was minimized. The melt enthalpy increase through the pump and sieve filter was sufficient to heat the melt at a point immediately above the spinneret to about 305°-310° C., and the pressure at this point was about 50 atmospheres. The flow of polymer through the spinneret was maintained at a constant rate of 60 pounds per hour by spinning pump 2.
The spinning pot spinneret was divided into two parts by means of an undrilled "stripe" wide enough to form a visible split between the multiple ends below the spinneret. The spinneret plate had 384 holes (192 holes on each side of the undrilled stripe), each of 0.018 inch diameter, spaced so that the distance between the filaments formed was 0.28 to 0.40 inch immediately below the spinneret.
From said spinneret there was extruded two ends 4-5 of multifilament, continuous filament yarn, and the two ends were passed downwardly into a substantially stationary column of air contained in a heated sleeve 11, about 15 inches in height, disposed immediately beneath the spinneret. The air temperature in the heated sleeve was maintained at about 300° C. at the top of the sleeve, decreasing to about 115° C. at the bottom. The temperature of the metal in the heated sleeve was about 330° C. at the top and 220° C. at the bottom of the sleeve. The minimum distance between filaments at the bottom of the heated sleeve was about 0.24 inches. A heated sleeve baffle 12 was provided at the bottom of the heated sleeve forming an inwardly extending flange to minimize flow of cooling air into the heated sleeve.
Yarn leaving the heated sleeve was passed directly into the top of a quenching chamber in quenching chimney 6. The quenching chimney was an elongated chimney 70 inches in height, substantially rectangular in cross-section and provided with imperforate top, rear and side walls. The front of the chimney was partially covered by an imperforate door which terminated about 17.5 inches short of the top wall and presented an open passage for air discharging from the chimney. The interior of the quenching chimney was partitioned by a perforated distribution plate which formed the boundary between a plenum chamber and the quenching chamber. Quenching air at about 25° C. and 65% relative humidity was supplied to the plenum chamber at about 200 cubic feet of air per pound of filaments entering the quenching chamber.
The two ends 4-5 of multifilament, continuous filament yarn were advanced downwardly through said quenching chamber wherein they were in contact with the cooling air introduced into the path of the filaments. The temperature of the cooled yarn at the bottom of the quenching chamber was about 40°-50° C.
Following quenching, the filaments were lubricated and converged by drawing said filaments into contact with convergence guides 7 shown in detail in FIGS. 2 and 3. The primary yarn-contacting surface 31 of the ceramic convergence guides used had a surface of 20-40 microinches RMS. A constant finish temperature of about 50° C. was maintained. The viscosity of the finish was about 13 centipoises at the temperature of application. About 0.3 to 0.4 weight percent of the finish composition was applied to the yarn based on the weight of the yarn. Convergence guides 7 have means for connection to finish composition source, not shown, and means for distributing a uniform film of lubricant over primary yarn-contacting surface 31.
______________________________________Finish Components Parts Function______________________________________Refined coconut glyceride 14.7 LubricantHexadecyl stearate 14.7 LubricantEthoxylated laurylalcohol (4 EO) 12.7 EmulsifierSodium petroleum sulfonate60-62% active in mineral Antistatoil 9.8 emulsifierEthoxylated tallow amine Antistat(20 EO) 4.9 emulsifierSodium salt of sulfonatedsuccinic ester 2.0 Wetting agent"Naugawhite" (2,2-methylene-bis-(4-methyl-6-tert-nonylphenol) 2.0 AntioxidantMineral oil viscosity Continuous40 SSU 39.2 phase______________________________________
Each convergence guide 7, mounted in fixed support 8, is set forward of the threadline such that the filaments slide across the primary yarn-contacting surface 31 as indicated by the layer of filaments 4 in FIG. 2. Convergence of the filaments within the substantially vertical plane which includes the yarn-contacting surface of the convergence guide continues beyond the guide as shown in FIG. 1. The coefficient of variation of the evenness of the undrawn yarn (U %) was not above 10 over an extended period of operation.
In this example, "flicking" of filaments from the main yarn bundle above the lube zone was observed at intervals over an extended period of operation. For testing purposes, flicking was arbitrarily defined as any movement of a filament greater than 0.25 inch from the main bundle. The point of measurement was arbitrarily selected at 3 inches above the main bundle. Any movement of filaments greater than 0.25 inch were counted for a period of 5 minutes. The average number of "flicks" was less than 0.5 per minute. Thus, the prior art problem of "flicking" was substantially eliminated.
Following lubrication, the ends 4-5 were passed to draw panel 9, shown in detail in FIG. 4. As shown in FIG. 4, the yarn was passed to pretension roll 21 with its accompanying separator roll 21a. The yarn was then passed over cold feed roll pair Godet rolls 22 and 23, then through a draw point localizer 29 which was a conventional steam jet, then to a draw roll pair of Godet rolls 24 and 25 operated to about 145° C. and traveling at a speed 5.0 to 6.6 times faster than the feed roll, then to a relaxation pair of Godet rolls 26 and 27, and optionally through an entangling apparatus such as a conventional air operated interlacing jet, and on to winder 10 as shown in FIG. 1. Typical yarn prepared at a draw ratio of 6 had the following properties:
______________________________________Denier 1,000Tenacity, g/d 9.25Elongation, % 13.5Shrinkage, % 9.5B. Q. I. <90______________________________________
The term "beaming quality index" (B.Q.I.) is defined as defects (broken filaments, strip backs, nubs, etc.) per million yards in beaming of yarn.
It will be understood that the above-described draw panel can be modified if desired. For example, the yarn may be drawn on a seven roll panel or on a four roll panel. However, regardless of panel set up, the draw panel process steps involve pretensioning to provide yarn stability on the rolls and on entry of the yarn into the draw point localizer steam jet, feed rolls to provide constant yarn supply to the draw zone, a draw point localizer to provide drawdown point in the draw zone, draw rolls to maintain constant draw ratio and relax rolls to provide for control of yarn physical properties. Optionally, a yarn compaction jet may be used before or after the relax rolls to provide yarn entanglement.
FIGS. 2 and 3 are, respectively, plan and cross-sectional elevation views of the preferred convergence guide of the present invention, which guide was used in this example. As shown in FIG. 1, two convergence guides were used for the two fiber ends; however, in the following description reference will be made particularly to the guide used for the filaments of end 4 of FIG. 1, the other guide being substantially identical.
FIG. 2 shows a schematic representation of the approximate distribution of filaments of end 4 in the bundle cross-section during yarn production. This embodiment has one essentially rectilinear primary yarn-contacting surface 31 of smoothly-rounded contour for converging the filaments of end 4 into a flat bundle, and two contiguous yarn-contacting surfaces 32 of smoothly-rounded contour for controlling the width of said yarn bundle. The spinning finish is fed into the convergence guide 7 by means of spinning finish inlet 33 and led upwardly through conduit 34 to a slot 35 which feeds the finish onto a downwardly-sloping weir 36. The spinning finish flows by gravity from slot 35 downwardly over the downwardly-sloping weir 36 to the primary yarn-contacting surface 31 where it is uniformly distributed onto the filaments of end 4. The sectional elevation 3--3 of FIG. 2 of this embodiment is shown in FIG. 3. Like numbers in FIG. 3 correspond to like elements in FIG. 2.
EXAMPLE 2
The procedure of Example 1 was followed except that the heated sleeve baffle at the bottom of the heated sleeve was opened so that there was no longer a substantially stationary column of air in the heated sleeve. The extent of "flicking" increased to greater than 60 "flicks" per minute, and high quality yarn could not be produced. In other tests, it was demonstrated that optimum results are obtained when the heated sleeve baffle is used and the air temperature in the heated sleeve is maintained at about 300° C. at the top of the sleeve, decreasing to about 115° C. at the bottom of the sleeve.
EXAMPLE 3
The procedure of Example 1 was followed except that the filaments advancing through the quenching zone were contacted with cooling air entering the zone at 100 cubic feet of air (measured at standard temperature and pressure) per pound of entering filaments. (In Example 1, cooling air entered the zone at 200 cubic feet of air per pound of filaments). In this test no significant decrease in flicking was observed; however, quenching was considered inadequate because predrawing began to occur. When the filaments were contacted with cooling air at rates higher than 700 cubic feet of air per pound of filaments, the number of "flicks" per minute were increased to greater than 5. Accordingly, it is generally desirable for the cooling air to enter the zone at 200-700 cubic feet of air per pound of entering filaments.
Discussion
It is important that the above-described process of the present invention permits a significant increase in production capacity of a polymer spinning operation. In some cases, it is practical to convert a single-end fiber plant to double-end plant with only simple changes in the original equipment, the yarn production being increased for example by a factor of 2. Also, the present invention substantially overcomes problems of poor yarn quality such as the formation of fused filaments, loose filament loops and broken filaments.
The present invention is particularly useful for economical production of polyamide and polyester tire and industrial yarn. By "polyamide" is meant the polymers made by condensation of diamines with dibasic acids or by polymerization of lactams or amino acids, resulting in a synthetic resin characterized by the recurring group -CONH-. The preferred polyesters are the linear terephthalate polyesters, i.e., polyesters of a glycol containing from 2 to 20 carbon atoms and a dicarboxylic acid component containing at least about 75% terephthalic acid. The remainder, if any, of the dicarboxylic acid component may be any suitable dicarboxylic acid such as sebacic acid, adipic acid, isophthalic acid, sulfonyl-4,4'-dibenzoic acid, or 2,8-dibenzofuran-dicarboxylic acid. The glycols may contain more than two carbon atoms in the chain, e.g., diethylene glycol, butylene glycol, decamethylene glycol, and bis-1,4-(hydroxymethyl) cyclohexane. Examples of linear terephthalate polyesters which may be employed include poly(ethylene terephthalate), poly(butylene terephthalate), poly(ethylene terephthalate/5-chloroisophthalate) (85/15), poly(ethylene terephthalate/5-[sodium sulfo]isophthalate) (97/3), poly(cyclohexane-1,4-dimethylene terephthalate), and poly(cyclohexane-1,4-dimethylene terephthalate/hexahydroterephthalate) (75/25).
The materials of construction for the convergence guide of the present invention are not critical and may be selected from any materials that are known to be satisfactory for the preparation of conventional convergence guides, for example, steel or ceramic. | It has been suggested that synthetic multifilamentary yarns can be produced by melt-spinning a polyamide or polyester polymer under conditions of substantially simultaneous spinning and drawing wherein prior to said drawing the filaments of the fiber are lubricated with a spin finish by surface contact with a lube roll surface of not less than about 90 RMS. However, in commercial operation of the process at high throughput rates of 50 pounds per hour or greater through the spinneret, serious problems have been encountered due to "flicking" or momentary slackness of one or more filaments from the main yarn bundle above the lube roll, which flicking results in production of yarn of relatively poor quality. It has now been found that the occurrence of said flicking of the filaments can be greatly reduced by applying the spin finish from a convergence guide having a yarn-lubricating surface of not less than about 10 RMS and means for distributing a film of lubricant over said surface. The resulting high-strength multifilament yarn having relatively uniform quality is particularly applicable for tire and industrial uses. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional patent application Ser. No. 61/173,507 filed Apr. 28, 2009 and to U.S. provisional patent application Ser. No. 61/321,009 filed Apr. 5, 2010, and hereby incorporates the same provisional applications by reference herein in their entirety.
TECHNICAL FIELD
[0002] The present disclosure is related to the field of apparatuses, in particular, hand held pipe wipers and seals for wiping fluids and solids off pipe sections of a string used in the drilling of a well, or in the servicing of a well, as the pipe sections are removed from the well, and methods of using same.
BACKGROUND
[0003] As sections of pipe in a string used either on a drilling rig in the drilling of wells or on a service rig in the servicing of wells are removed from or “tripped out” of the well, they are often covered with solids and/or fluids. Before the pipe sections are put back into a storage rack or facility, it is desirable that the solids or fluids be removed or stripped off of the pipe. Known methods for removing solids or fluids from pipe sections being tripped out of a well are cumbersome and can be difficult, if not dangerous, for drilling personnel to use.
[0004] Known methods for removing solids or fluids from pipe sections being tripped out of a well include the manual use of rags and gunny sacks which require the hands of drilling personnel to be in close proximity to the drilling fluid. The drilling fluid is often at high temperatures and can burn the hands of drilling personnel. The known methods can result in the wiping device being dropped down into the drill hole.
[0005] It is, therefore, desirable to provide a pipe wiper and seal that can wipe or strip off solids from pipe sections being tripped out of a well that is easy to handle by personnel on the well.
SUMMARY
[0006] An apparatus and method for stripping solids and fluids from sections of pipe on a string used in the drilling of wells or used in the servicing of wells is disclosed. For purposes of this specification and the claims contained herein, the term “string” is defined to include a drill string comprised of multiple sections of drill pipe joined together and used on a drilling rig for the drilling of wells, a string of pipe comprised of multiple sections of pipe joined together and used on a service rig for the servicing of wells, and coil tubing that is used in the directional drilling of wells in addition to the servicing of wells. For purposes of this specification and the claims contained herein, the term “rig” is defined to include both well drilling rigs and well servicing rigs as well as snubbing units, push/pull rigs, coil tubing units, and other mechanical devices used to insert or remove string from a well.
[0007] In one embodiment, an apparatus is provided comprising a hand held pipe wiper. The pipe wiper can be used primarily to strip off solids and fluids from a string when it is being removed from a well. The pipe wiper can be provided with handles so it can be used manually by drilling personnel.
[0008] In one embodiment, the pipe wiper can comprise two or more portions that are hinged together so that the pipe wiper can be opened and placed around a string and then closed around the string to form a generally cylindrical body that encloses the string in a clamshell fashion. The pipe wiper can further comprise a releasable latch mechanism that can hold the pipe wiper body portions together. In this manner, the pipe wiper can easily and quickly be connected when installed on a string, and then easily and quickly disconnected and removed from the string when the string has been stripped of solids and fluids.
[0009] In another embodiment, the pipe wiper can further comprise a flexible toroidal seal disposed in the pipe wiper body. The seal can have multiple parts, one part for each portion of the hinged body. When the pipe wiper is enclosed around a string, the seal can form a toroidal sealing member having a central opening that can fit tightly around the string. In another embodiment, the seal can be configured to flex and stretch such that the central opening can expand in diameter so that the seal can pass over a connection between sections of pipe as the string is being raised out of a well, and then contract in diameter to the pipe's diameter after the pipe connection has passed through the pipe wiper. In operation, the pipe wiper can be placed and enclosed around a string and can be held in position by drilling personnel on the rig floor by gripping the handles to ensure stabilization of the pipe wiper as the string is being raised out of the well. As the string is raised, it passes through the pipe wiper and the sealing member in the pipe wiper strips off solids and fluids from the exterior surface of the string, the solids and fluids falling onto the rig floor.
[0010] In a further embodiment, the seal can be removably installed in the pipe wiper so as to provide a variety of seals having differently sized openings to accommodate strings of different diameters, or to be able to easily replace a damaged seal in the pipe wiper.
[0011] “Handle” as used herein can include anything know in the art or yet to be developed which will allow a worker to grip the apparatus. The handle can be integrally formed into the body of the apparatus or can be attached separately. The handle can allow for increasing the distance between the hands of drilling personnel and the drilling fluid.
[0012] Broadly stated, a hand held pipe wiper is provided for stripping off solids and fluids from a string in the drilling or servicing of a well, comprising: two or more arcuate body portions pivotally connected together and configured to form a cylindrical body when enclosed around the string; a latch mechanism disposed on one or more body portions, the latch mechanism configured to releasably connect the arcuate body portions together to form the cylindrical body; one or more handles disposed on the arcuate body portions; and a sealing member disposed in the cylindrical body, the sealing member configured to form a toroidal seal around the string when the cylindrical body is enclosed around the string whereby the sealing member strips solids and fluids off of the string when the string passes through the pipe wiper.
[0013] Broadly stated, a sealing member is provided which can be removably received by an apparatus having two or more arcuate body portions pivotally connected together and configured to form a cylindrical body when closed together for stripping off solids and fluids from a string used in the drilling or servicing of a well, the sealing member comprising: a plurality of seal portions having a top face and a bottom face, one seal portion for each arcuate body portion; and the seal portions configured to form an opening that forms a toroidal seal around the string when the cylindrical body is enclosed around the string whereby the sealing member strips solids and fluids off of the string when the string passes through the apparatus.
[0014] Broadly stated, a method is provided for stripping off solids and fluids from a string being removed from a well, the method comprising the steps of: providing a hand held pipe wiper, comprising: two or more arcuate body portions pivotally connected together and configured to form a cylindrical body when enclosed around the string, a latch mechanism disposed on one or more body portions, the latch mechanism configured to releasably connect the arcuate body portions together to form the cylindrical body, one or more handles disposed on the arcuate body portions, and a sealing member disposed in the cylindrical body, the sealing member configured to form a toroidal seal around the string when the cylindrical body is enclosed around the string whereby the sealing member strips solids and fluids off of the string when the string passes through the pipe wiper; enclosing the pipe wiper around the string whereby the sealing member has formed the toroidal seal around the string; and holding the pipe wiper in position while the string is being raised out of the well whereby the sealing element strips off solids and fluids from the string.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a top plan view depicting a pipe wiper;
[0016] FIG. 2 is a side elevation view depicting the pipe wiper of FIG. 1 ;
[0017] FIG. 3 is a side cross-section view depicting the pipe wiper of FIG. 2 along section lines A-A;
[0018] FIG. 4 is a perspective view depicting the pipe wiper of FIG. 1 installed on a string being raised;
[0019] FIG. 5 is a perspective view depicting a sealing member for a pipe wiper;
[0020] FIG. 6 is a side elevation view depicting the sealing member of FIG. 5 ;
[0021] FIG. 7 is a cross-section view depicting the sealing member of FIG. 5 along section lines B-B;
[0022] FIG. 8 is a perspective view depicting a female seal half of the sealing member of FIG. 5 ;
[0023] FIG. 9 is a side elevation view depicting the female seal half of FIG. 8 ;
[0024] FIG. 10 is a side cross-section view depicting the female seal half of FIG. 8 along section lines C-C;
[0025] FIG. 11 is a perspective view depicting a male seal half of the sealing member of FIG. 5 ;
[0026] FIG. 12 is a side elevation view depicting the male seal half of FIG. 11 ; and
[0027] FIG. 13 is a side cross-section view depicting the male seal half of FIG. 11 along section lines D-D.
DETAILED DESCRIPTION OF EMBODIMENTS
[0028] Referring to FIGS. 1 and 2 , an embodiment of pipe wiper 10 is shown. In this embodiment, pipe wiper 10 can comprise body 12 consisting of arcuate or semi-circular body halves 14 and 16 that are pivotally connected together with hinge 18 . When body halves 14 and 16 are closed together to meet at seam 19 , body 12 defines interior 11 through which a string can be placed and pass through. While this embodiment comprises two semi-circular body halves 14 and 16 to form cylindrical or tubular body 12 , it should be understood that three or more arcuate body portions pivotally connected together can be used to form body 12 . In other embodiments of pipe wiper 10 , body 12 can have a cross-sectional shape that is not circular, such shapes including: triangular, square, rectangular, oval and polygonal cross-sectional shapes. For the purposes of this specification and the claims contained herein, the terms “arcuate”, “semi-circular”, “cylindrical”, “tubular” and any other like terms are hereby defined to include both circular and non-circular cross-sectional shapes of body 12 and parts therefor, including a sealing member that is disposed in body 12 and discussed in further detail below.
[0029] Body 12 can further comprise handle 20 disposed on body half 14 and handle 22 disclosed on body half 16 so as to enable a person to grasp and hold onto pipe wiper 10 when a string is raised through it. Pipe wiper 10 can further comprise latch mechanism 24 to hold body halves 14 and 16 together when pipe wiper 10 is being used. In the illustrated embodiment, latch mechanism 24 can comprise fixed hinge member 28 disposed on body half 14 that can be pivotally connected to movable latch member 30 , which, in turn, can be pivotally connected to handle 26 . Handle 26 can be further configured to engage a keeper or stay member disposed on body half 16 (not shown) to hold body halves 14 and 16 together when handle 26 is rotated towards body 12 whereby latch mechanism 24 can operate as an “over center latch.” To open pipe wiper 10 , handle 26 can be pulled and rotated away from body half 16 to disengage the keeper disposed thereon whereby handle 26 and latch member 30 can be rotated further away from body half 16 so as to enable the removal of pipe wiper 10 from a pipe section. It should be apparent that any suitable latching mechanism can be used in substitution of the illustrated latch mechanism 24 to couple body halves 14 and 16 together.
[0030] Referring to FIG. 3 , a cross-sectional view of pipe wiper 10 is shown, namely, the interior view of body half 16 . As shown in this embodiment, the interior surface of body half 16 can comprise groove 32 disposed thereon where a sealing element can be removably placed. A corresponding groove 32 can also be disposed on the interior surface of body half 14 (not shown). Groove 32 enables the easy installation and removal of sealing elements in body halves 14 and 16 so that the sealing element can be replaced when it becomes damaged or when a sealing element for a different diameter pipe is required.
[0031] Referring to FIG. 4 , pipe wiper 10 is shown installed on pipe 36 as it is being raised through pipe wiper 10 . In this embodiment, pipe wiper 10 is shown comprised of semi-circular body halves 14 and 16 each having arcuate seal members 34 and 35 disposed therein, respectively. When pipe wiper 10 is installed around pipe 36 , as shown, seal members 34 and 35 meet at seam 40 to form opening 39 that, in turn, forms a toroidal seal around pipe 36 . Seal members 34 and 35 can be configured to be removably placed or installed in grooves 32 disposed in body halves 14 and 16 . Seal members 34 and 35 can be made of any suitable elastomeric material that enables seal members 34 and 35 to flex and stretch so as to maintain contact with the external surface of pipe 36 due to any irregularities to the cross-sectional shape of pipe 36 or to the contour of the pipe's external surface and, in addition, to allow opening 39 to expand in diameter so as to enable any joint connection between two sections of pipe to pass through seal members 34 and 35 as a joint connection can have a larger diameter than the diameter of the pipe itself. Suitable examples of the elastomeric material for seal members 34 and 35 can include natural rubber, neoprene rubber, foam rubber, silicone-based rubber, nitrile rubber and any other material that is suitable for use as a seal that can be used to strip petroleum-based substances from a string. The elastomeric material for seal members 34 and 35 can also be a low weight material which would allow seal members 34 and 35 to float on the drilling fluid if seal members 34 and 35 were dropped into well.
[0032] In another embodiment, seal members 34 and 35 can further comprise means for allowing opening 39 to expand and contract in diameter. In one embodiment, the means can comprise a plurality of relief cuts 38 disposed thereon to allow opening 39 to expand in diameter when a joint connection between two pipe sections are passed through pipe wiper 10 , and to contract in diameter when the joint connection has passed through pipe wiper 10 . In the illustrated embodiment, relief cuts 38 are shown as straight cuts in a radial configuration extending outwardly from opening 39 . The relief cuts 38 can be of any other suitable configuration on seal members 34 and 35 so as to allow opening 39 to expand and contract in diameter as a pipe joint connection passes through seal members 34 and 35 .
[0033] In a representative embodiment, body 12 , handles 20 and 22 , and latch mechanism 24 can be made of a polymer plastic material so as to minimize the weight of pipe wiper 10 and still maintain the necessary structural strength required for a tool of this nature. However, it should be understood that other materials can be used in the construction in pipe wiper 10 , such as metal, metal alloys or any other suitable construction material.
[0034] Referring now to FIGS. 5-13 , a further embodiment of a sealing member for use with pipe wiper 10 is shown as seal insert 42 . Seal insert 42 can include a female seal half 44 and a male seal half 46 . Outer edge 48 of seal insert 42 can be configured such that seal insert 42 can be removably placed or installed in body halves 14 and 16 . Seal insert 42 can include a top face 50 and bottom face 52 . Seal grooves 56 can be used to removably place seal insert 43 into groove 32 on the interior surface of body half 16 and the interior surface of body half 14 . Groove 32 can enable the easy installation and removal of seal halves 44 and 46 in body halves 14 and 16 so that the seal insert 42 can be replaced when it becomes damaged or when a seal insert 42 for a different diameter pipe 36 (as shown in FIG. 3 ) is required.
[0035] Female seal half 44 and a male seal half 46 can be made of any suitable elastomeric material that enables female seal half 44 and a male seal half 46 to flex and stretch so as to maintain contact with the external surface of pipe 36 due to any irregularities to the cross-sectional shape of pipe 36 or to the contour of the pipe's external surface and, in addition, to allow seal insert opening 54 to expand in diameter so as to enable any joint connection between two sections of pipe to pass through seal insert opening 54 as a joint connection can have a larger diameter than the diameter of the pipe 36 itself. Suitable examples of the elastomeric material for female seal half 44 and a male seal half 46 can include natural rubber, neoprene rubber, foam rubber, silicone-based rubber, nitrile rubber and combinations thereof or any other material suitable for use as a seal that can be used to strip petroleum-based produced substances from a string. The elastomeric material for female seal half 44 and a male seal half 46 can also be a low weight material which would allow female seal half 44 and a male seal half 46 to float on the drilling fluid if female seal half 44 and a male seal half 46 were dropped into well.
[0036] Referring to FIGS. 8 , 9 , and 10 , female seal half 44 can have notch 58 for receiving a tongue disposed on seal half 46 . Referring to FIGS. 11 , 12 , and 13 , male seal half 46 can have tongue 60 that can be inserted into notch 58 so that female seal half 44 and male seal half 46 can be brought together to form seal insert 42 which, in turn, can form a toroidal seal around pipe 36 (as shown in FIG. 3 ).
[0037] In another embodiment, seal insert 42 can also include channel 62 disposed between the top face 50 and bottom face 52 of seal insert 42 . Channel 62 can allow for a pipe joint or irregularity on pipe 36 to pass through seal insert opening 54 while allowing seal insert 42 to still strip pipe 36 of solids and fluids collected on the outside surface of pipe 36 .
[0038] Although a few embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention. The terms and expressions used in the preceding specification have been used herein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims that follow. | An apparatus and method is provided for stripping solids and fluids from a string used in the drilling or servicing of a well when the string is removed from the well. The apparatus can comprise two or more pivotally connected arcuate body portions that can be enclosed around the string in a clamshell fashion. The apparatus can further comprise a seal disposed therein to provide a toroidal sealing member around the string when the apparatus encloses the string. A quick release latch mechanism is provided on the apparatus for easy and quick installation on, and removal from, the string. Handles on the apparatus allow personnel to hold the apparatus in a stationary position as the string passes through the apparatus when being raised from the well. In so doing, the sealing member strips solids and fluids from the string. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related generally to electronic current sensor type circuits and more particularly to such type circuits for use in electronic metering devices wherein phase inversion or amplitude-mark-space modulation (time division) techniques are employed to make precision measurements of alternating current and/or voltage.
2. Description of the Prior Art
While the present invention has application in most any environment where the magnitude of a large AC signal has to be sensed and/or measured, it finds particular application in such devices as watthour meters, watt-transducers and the like.
In recent years, electronic watt-hour or energy consumption meters have come into existence, with the expectation that they will one day replace the older prior art induction type meters. This electronic metering technology is still in the refinement stages of development. Three such type electronic energy consumption meters are disclosed in my U.S. Pat. Nos. 3,955,138; 3,875,509, and 3,875,508. The entire disclosure of these earlier patents is hereby incorporated by reference. The entire right, title and interest in and to the inventions described in the aforementioned patents and the entire right, title and interest in and to the invention herein disclosed, as well as in and to the patent application of which this application is a part, are assigned to the same assignee.
One major problem in electronic watt-meter design is to sense or measure the magnitude of the current of an AC signal with high precision, while simultaneously inverting that signal in a circuit which utilizes a minimum amount of power and which presents the lowest possible load or impedance to the circuit being monitored. While the above mentioned precision is possible with the use of large and expensive electrical and electronic components, the cost and size of those components quickly removes the economic incentive for a user to purchase a meter using such components. As such, a need exists for a universally usable AC sensor circuit design having phase inversion or mark-space-modulation capabilities which can be fabricated from small low cost components and which design provides for virtually powerless sensing of the magnitude of the current of an AC signal.
SUMMARY OF THE INVENTION
The present invention fulfills the above needs by the provision of a low cost electronic sensor circuit suitable for fabrication in monolithic integrated circuit form.
The sensor circuit of the present invention provides, in combination, a small low impedance current transformer terminated in an active load amplifier circuit through a polarity switch which can be used for modulation and/or phase inversion of a sensed AC signal.
Through the combined use of a low input impedance amplifier and a substantially zero resistance polarity switch for connecting the current transformer to the input of the amplifier, the current transformer continuously operates virtually short circuited regardless of the position of the switch. By virtue of this short circuit operation, the potential or voltage difference across the input terminals of the amplifier is always negligible. Because of this low voltage difference, it is possible to use low voltage inexpensive transformers, analog switches and components in the present invention. Further, the low potential difference substantially reduces or eliminates switching voltage transients which normally occur at the switched inputs of amplifiers of the type contemplated for use in the present invention.
The foregoing advantages afforded by the present invention provide a circuit capable of virtually powerless precision monitoring of large AC currents to obtain a phase controllable output voltage from the amplifier which is directly proportional to the magnitude of the monitored current.
In view of the preceding, it is therefore an object of the present invention to provide an alternating current sensor circuit having enhanced operating characteristics.
It is another object of the present invention to provide a sensor circuit capable of virtually powerless precision monitoring of alternating current.
A still further object of the invention is to provide a sensor circuit suitable for applications requiring the precision sensing and/or measurement of alternating current signals which does not load the circuit being monitored.
Yet another object of the present invention is to provide a switch operated phase inversion-modulation sensor circuit capable of accurately generating an output voltage proportional to sensed current whereby the output voltage is proportional to monitored current and has a phase and/or modulation characteristic determined by the switch position and/or the duty cycle of a control signal applied to the switch.
It is still a further object of the present invention to provide a sensor circuit for monitoring alternating signals of large current magnitude capable of being fabricated from low cost, small size current and voltage components.
BRIEF DESCRIPTION OF THE DRAWING
The preceding objects, including other objects and advantages of the invention, will be more clearly appreciated by reading the following detailed description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a schematic diagram of an electronic sensor circuit in accordance with the basic teachings of the invention;
FIG. 2 is an improved embodiment of the invention of FIG. 1, utilizing additional amplifier circuitry for virtually eliminating the need for a low resistance switch in the invention;
FIG. 3 is still another embodiment of the invention and is an improvement over the embodiment of FIG. 2; and
FIG. 4 is similar to FIG. 1, however, utilizing a switched feedback technique which allows the elimination of certain electronic components.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first illustrated embodiment of the invention is shown in the schematic diagram of FIG. 1, wherein a current transformer CT is connected to an alternating current power source (not shown) for monitoring or sensing an AC-current I 1 . As shown, the primary winding of the transformer is a single wire carrying the AC-current I 1 . The secondary winding of the transformer consists of many windings or turns for transforming the primary current I 1 to a desired secondary current shown as I 2 .
The secondary winding of the transformer CT is connected to inverting (-) and non-inverting (+) input terminals of a transresistance amplifier OA1 via a double pole double throw switch illustrated as SW1 and SW2. There are any number of different types of amplifiers suitable for use with the present invention. One such amplifier is a type uA741 high performance integrated circuit operational amplifier manufactured by Fairchild Semiconductor, a division of Fairfield Camera and Instrument Corporation, 313 Fairchild Drive, Mountain View, California.
A conventional power supply is provided having a circuit ground or reference potential for providing two bias voltages +V1 and -V2 to amplifier OA1.
Still referring to FIG. 1, the aforementioned switch (SW1 and SW2) serves as an analog switch for switching the polarity of the input current I 2 applied to the first (-) and second (+) input terminals of OA1. While that switch may be a mechanical switch as diagrammatically shown, those in the art will recognize that in actual practice SW1 and SW2 may be realized as a plurality of active electronic switch elements controlled by an electronic control signal applied to a control terminal D. Preferably, the switch (SW1 and SW2) is realized as a low cost low voltage C-MOS device such as conventionally available in the art, or as C-MOS elements which are integrally formed in a single monolithic integrated circuit together with the other circuitry of FIG. 1.
As shown in FIG. 1, SW1 is comprised of switch contacts or terminals A1, B1 and C2 and SW2 has similarly associated terminals A2, B2, and C2. Terminals A1 and B2 of SW1 and SW2 respectively are secured together as output terminals and connected to the inverting (-) input terminal of OA1 at a summation point S3. In a similar fashion, output terminals B1 and A2 of SW1 and SW2 respectively are connected to the non-inverting (+) input terminal of OA1. As shown, the + input terminal of OA1 also serves as a ground return for current to flow from the amplifier OA1 through the CT secondary winding during circuit operation.
As previously mentioned, the polarity of the secondary current I 2 is switch controlled for application to the input terminals of OA1. As seen by observation of FIG. 1, this control is provided by the connections of SW1 and SW2, where the secondary winding of the CT is connected to the input terminals C1 and C2 of the analog switch. With the switch contacts C1, A1 and C2, A2 in the positions shown, an output voltage Vz is generated at an output terminal C of OA1 which is in phase with the line current I 1 and which has an amplitude proportional to the magnitude of that current. When the switch contacts are changed to connect B1 and B2 to C1 and C2 respectively, the polarity of the current I 2 applied to the input terminals of OA1 is changed. This results in a change in the phase of the output voltage Vz with respect to the line current I 1 . With the switch contacts in this latter position, the amplitude of Vz is still proportional to the magnitude of I 1 .
Two feedback resistors R1 and R2 are also connected from the output terminal C of OA1 to the input terminals of OA1 (via SW1 and SW2) for controlling the gain of the amplifier. As shown in FIG. 1, the resistors R1 and R2 are terminated at corresponding summation points S1 and S2 respectively. With the switch contacts C1, A1 and C2, A2 in the positions shown, the gain of OA1 is controlled by feedback resistor R1, which is connected to the - input terminal of OA1 via the contacts C1, A1 of SW1. When the switch is changed to close contacts C1, B1 and C2, B2 of SW1 and SW2 respectively, R2 serves to control the gain of OA1 by being connected to the - input terminal of OA1 via SW2.
The operating principles of the invention will be disclosed with reference to FIG. 1. However, as an aid to an understanding of some of those principles, reference is made to my prior U.S. Pat. No. 3,815,013. That patent is entitled "Current Transformer With Active Load Termination" and it is assigned to the same assignee of the present invention. This patent provides a detailed analysis and an operational description of a current transformer, similar to transformer CT, operating directly into a low impedance or transresistance amplifier similar to OA1 of FIG. 1.
Some of the analytical details of the circuit described in my aforementioned U.S. Pat. No. 3,815,013 are applicable to an understanding of the present invention. However, those details will not be discussed herein, except as necessary to a complete understanding of the present invention. For that reason, that patent is incorporated herein as reference material for information purposes.
To understand the operation of the present invention, it is considered advantageous to make a few observations. First, as described in my U.S. Pat. No. 3,815,013, the transformer CT is considered as an ideal AC-current source having a very low (neglible) output or source impedance at the operating frequency of I 1 (eg. 60 Hz line voltage). Also, amplifier OA1 has a very low input impedance Z i which may be expressed by the following approximation:
Z.sub.i =R.sub.f /A.sub.0 (equation 1)
Where R f represents a feedback impedance, such as the resistance of R 1 or R 2 , connected between points C and S 1 or C and S 2 respectively, and Ao represents the open loop gain of amplifier OA1. This expression (equation 1) neglects any resistance in the contacts C1, A1 and C2, A2. The effects of this resistance will be described in the ensuing description.
Because of the low source impedance of transformer CT and the low input impedance of amplifier OA1 (see U.S. Pat. No. 3,815,013), the secondary winding of the transformer is virtually short circuited. This results in an ideal (short circuit) current transformer operating condition.
Also, as contemplated by the present invention, the line current I 1 is an alternating current sign wave which goes through positive and negative half cycles. Thus, by reference to FIG. 1, it can be seen that I 2 will flow first in one direction through the secondary winding of CT during one half cycle (eg. positive), and then in the opposite direction during the other half cycle (eg. negative) for a complete cycle of I 1 and I 2 .
With the previous observations in mind, reference is now made to FIG. 1. During the positive half cycle of I 2 (and I 1 ), I 2 flows into the summing points S 1 in the direction of the arrow head as illustrated. From S 1 , I 2 flows through resistor R 1 into the output terminal C of amplifier OA1. Amplifier OA1 is now functioning as a current sink for a load not shown. Under this condition I 2 flows through OA1, and out of the -V2 terminal back to the power supply, where the current path is completed to ground at point M to return back to the CT secondary winding via contacts C2, A2 of SW2.
On the next half cycle (negative) of I 2 (and I 1 ) the direction of current flow reverses through the secondary winding of the CT and now flows out of terminal C of OA1, through R1 into S1 to the CT secondary winding. Under this condition, OA1 is now operating as a current source for the load whereby current is being provided to OA1 via the +V1 terminal of the power supply, with the current return path to the power supply being through the secondary winding to poing M (ground).
It should be noted that summing point S3 is at the same potential as summing point S1. As described in my U.S. Pat. No. 3,815,013, because R1 is connected between the inverting (-) input (via SW1) and the output C of OA1, the potential of S3 (and S1) is virtually at zero volt, with a typical value being 0.5 millivolt or less. Further, the impedance between S1 (and S3) and M (ground) is very low. Typically, this impedance is 0.2 ohm or less. Thus, the potential between M (ground) and S1 (and S3) is substantially the same (ie. zero). As a result, the summing point S3 (or S1) conducts no current to point M (ground). In other words, the input current to the inverting (-) input terminal at S3 of OA1 is so insignificant that it can be neglected.
The output voltage V z , as measured between points C and M (ground), is proportional to I 1 or I 2 and can be calculated from the following expression:
V.sub.z =-I.sub.2 ·R.sub.1 (equation 2)
Utilizing typical values in the above equation 2 as an example, if I 2 =2 ma and R1=10K ohms, then V z =-10 volts. The negative sign appears in equation 2 and this example because V z is inverted 180° in phase with respect to I 1 or I 2 . Other values for R 1 can also be used, depending upon the magnitude of I 1 (or I 2 ) and the amplitude desired for V z .
Still referring to FIG. 1, let it now be assumed that the switch (SW1 and SW2) contacts are changed to close contacts C1, B1 and C2, B2 whereby, contacts A1 and A2 are open. The transformer secondary is now grounded at S1 via C1, B1 of SW1 to point M (the + input of OA1) and the other end of the secondary is applied to S3, the (-) input of OA1 via summation point S2 and C2, B2 of SW2. As can be seen, the polarity of the current I 2 applied to OA1 is now reversed 180°. This in turn causes a 180° phase reversal of the output voltage V z . It should also be noted, that resistor R1 is removed from the circuit and replaced by resistor R2 to now provide the aforementioned feedback path around OA1 as previously described.
With the SW1 and SW2 contacts in the last described position, the invention operates in the same manner as when those contacts are in the C1, A1 and C2, A2 closed positions. Further, the preceding expression for the calculation of input impedance (Zi) and the output voltage (V z ) also apply, if R2 is substituted for R1.
Still referring to FIG. 1, it will be noted that, as SW1 and SW2 are switched between positions A1, B1 and A2, B2 respectively, the resistors R1 and R2 are alternately grounded at one end at S1 and S2 via the respective switch contacts. If it is assumed that there is no resistance between any of the contacts of SW1 and SW2, which would be the case if a mechanical switch is employed, then points S1 and S2 will alternately be at ground (zero potential). Thus, as previously described, the secondary winding of the CT is always short circuited by the low input impedance of OA1 via SW1 and SW2.
It is known, however, that solid state analog switches, such as the C-MOS type, do present a finite resistance between their respective contacts. This resistance, when this type of switch is utilized in the embodiment of FIG. 1, causes a slight voltage drop to occur between the contacts of SW1 and SW2.
With the switch contacts in the position shown in FIG. 1, the end of R2 at point S2 is normally considered to be at virtually ground potential, however, due to the resistance of contacts C2, A2 of SW2, point S2 is at some finite potential above ground. It has been found that the contact resistance of a typical C-MOS type switch is approximately 10 ohms. Neglecting any currents which flow in the circuit, except that current which flows through contacts A2, C2 of SW2, and assuming I 2 =1 ma and Ron=10 ohms (Ron is the resistance of contacts C2, A2), then the voltage drop across A2, C2, or the potential of S2 with respect to ground, is 10 millivolts (ie, 1 ma of current is flowing through C2, A2 contacts).
An additional current is caused to flow through C2, A2 contacts by virtue of the presence of R2, which causes an additional voltage drop across those contacts. This additional current flow can be understood by assuming that I 2 at S1 is in a positive half cycle. This causes I 2 to now flow through R 1 into OA1 at C as previously described. Also, note that S1 is positive with respect to point C, because of the negative output (-V z ) of OA1. It is further significant to note that, even though the resistance of contacts C1, A1 of SW1 is also approximately 10 ohms, that resistance has a negligible affect on the potentials of S1 and S3. This is because virtually no current is flowing into the inverting (-) input of OA1. All of I 2 is being diverted through R1, thus causing S1 to be at virtually zero volt (eg. 0.5 millivolt). Also, in the embodiment of FIG. 1, R1 and R2 are preferably matched resistors of the same value.
With the preceding assumption and understanding, reference is now made to point S2 of FIG. 1. As shown, a second current I 2 ' is shown flowing from S2 through R2 into point C of OA1. Using the preceding value where I 2 =1 ma, I 2 ' also equals approximately 1 ma. That is, the current I 2 ' flowing through R2 is I 2 '≈V z /R2+Ron (where Ron is the C2, A2 contact resistance). This second current (I 2 ') is due to the contact resistance of SW2, and it is added to I 2 , in the following manner. I 2 ' now flowing into the output of OA1 exits the amplifier through the -V2 terminal with I 2 with a combined current of 2 ma (I 2 +I 2 ') to the power supply where the added currents return via ground to point M through contacts C2, A2 of SW2. This double current (I 2 +I 2 ') now presents a voltage drop across C2, A2 or a potential at S2, of 20 millivolts instead of 10 millivolts as previously described.
From the preceding, it can be seen that a very small potential exists between points S1 and S2. Assuming that S1 is at 0.5 millivolts and S2 is at 20 millivolts, the potential across the secondary winding of the CT is only 19.5 millivolts, which is negligible, thus still providing a substantially short circuit operating condition for the transformer.
While the preceding description dealt with the direction of current flow through SW2 when I 2 was in a positive half cycle, no further description is believed necessary for how the circuit operates when I 2 is in a negative half cycle, for it is believed that those skilled in the art can analyze the circuit operation by the mere reversal of the direction of current flow through the various circuit components as previously described.
Further, it should be recognized that, when contacts C1, B1 of SW1 and C2, B2 of SW1 are closed, contacts C1, B1 of SW1 present the Ron resistance previously described in connection with SW2. The circuit operates in the same manner as previously described except that I 2 flows through R2, I 2 ' flows through R1 and (I 2 +I 2 ') flows through C1, B1 of SW1.
In view of the foregoing, it can now be seen how the invention functions as a virtually powerless current sensing switch controlled inverter circuit.
As previously mentioned, the invention also operates to perform a basic time-division or amplitude-mark-space modulation function. Still referring to FIG. 1, this function is provided when an alternating or pulsating control signal is applied at terminal D of the analog switch (SW1 and SW2). A representative input signal at D may be a pulsating signal such as that provided by a pulse width modulator 22 as disclosed in my aforementioned U.S. Pat. No. 3,955,138. That signal has a duty cycle proportional to sensed voltage, wherein the instantaneous pulse width is proportional to the corresponding instantaneous magnitude of a sensed input voltage variable applied to the pulse-width-modulator. When a signal of this type is applied to terminal D to rapidly switch SW1 and SW2 (eg. at a 10,000 Hz rate, as compared to the 60 Hz line frequency of I 1 ) the output voltage Vz is a pulsating signal which is a product of the current I 1 (or I 2 ) and the control signal applied to terminal D, with that product being equal to power (eg. kwhr) consumption.
While the present invention contemplates its application in a watthour meter or the like, it also has application in most any environment where large AC-current has to be sensed or measured accurately without loading the circuit being measured. To that end, when the invention is applied as a switch controlled polarity reversal circuit, the output voltage or signal V z is proportional to the magnitude of the current I 1 (or I 2 ). Also, when the invention is applied as a pulse width modulator, the output voltage V z is a pulsating signal with an amplitude proportional to I 1 (or I 2 ) and a pulse width proportional to the duty cycle of the signal applied to terminal D of the analog switch.
Reference is now made to FIG. 2 which illustrates an improved embodiment of the invention. In this embodiment, two operational amplifiers OA2 and OA3, with corresponding feedback resistors R4 and R3, are added to the basic circuit of FIG. 1. Amplifiers OA2 and OA3 may be of the same type as OA1.
As shown in FIG. 2, summing point S1 is connected to the inverting (-) input of OA3, with summing point S2 similarly connected to the inverting (-) input of OA2. Also, the non inverting (+) inputs of OA1, OA2 and OA3 are connected together to a common potential source or ground at point M.
The operation of the embodiment of FIG. 2 is basically the same as that previously described for FIG. 1, except for the inclusion of OA2 and OA3. For that reason, only that portion of the embodiment of FIG. 2 comprising OA2 and OA3 will be described.
The advantage of FIG. 2 is that the use of OA2 and OA3 eliminates the need for low contact resistance analog switches. With the switch contacts C1, A1 of SW1 and C2, A2 of SW2 in the positions shown, the amplifier OA2, in conjunction with its resistor R4, functions as a feedback circuit with the "on" resistance Ron of C2, A2 in a feedback loop to summing point S2 and the - input of OA2.
The input impedance of OA2 is very low, with the impedance between S2 and point M equal to (R4+Ron)/Ao, where Ao is the open loop gain of the amplifer OA2. The potential between S2 and M is thus very low. A typical value being much less than one millivolt.
Reference is now made to OA3 and OA1 of FIG. 2. It will be noted that contacts C1, A1 of SW1 are closed to complete the circuit to point S3 to allow OA1 to function as previously described. Also, with the switch contacts as shown, OA3 has no affect on the operation of the circuit. This is because contacts C1, B1 are open, thus removing the amplifier as a feedback circuit via R3 and the "on" resistance of contacts C1, B1 of SW1.
As previously described in connection with FIG. 1, point S1 of that embodiment, and of FIG. 2, is always at substantiately zero volt with respect to point M. As a result, as can be seen in FIG. 2, the potentials of S1 and S2 with respect to point M are both very small, with a typical measurement being less than one millivolt. The secondary of the transformer CT is thus terminated on both ends in an ideal substantially zero impedance. As a result, and in keeping with the teachings of the invention, the embodiment of FIG. 2 provides a virtually non-loading or powerless sensing circuit for monitoring the current I 1 .
Still referring to FIG. 2, if SW1 and SW2 are switched to close contacts C1, B1 and C2, B2 respectfully, amplifier OA3, in conjunction with R3 and the "on" resistance of contacts C1, B1 provide the feedback closed loop circuit in the manner just described for the amplifier OA2. In this case, OA2 is now isolated from the circuit via contacts C2, A2 as previously described for OA3. Further, it will be noted that contacts C2, B2 are closed to thus reverse the polarity of V z with respect to I 2 .
FIG. 3 is similar to the embodiment of FIG. 2, but including an additional set of switch contacts A3, B3 and C3 generally shown as SW3 to form a triple pole double throw switch. This embodiment operates in the same manner as FIG. 2, with the exception that total isolation is provided by the contacts of SW3 at the outputs of amplifiers OA2 and OA3. As shown in FIG. 3, the output of amplifier OA3 is grounded at point M via contacts C3, A3 to isolate OA2 from OA3, while contacts C2, A2 are closed to complete the feedback path around OA2. In a similar fashion, the output of OA2 is grounded at point M and OA3 is isolated from OA2 when contacts C3, B3 are closed along with contacts C1, B1 and C2, B2. In this embodiment, SW3 ensures that any small voltage gradient present at the output of the amplifier (OA2 or OA3) not being used does not affect the potential of the input of the amplifier connected in feedback configuration. This is effected by absolutely grounding the output terminal of the presently unused amplifier while isolating the presently used amplifier from the unused amplifier. Also, in the embodiment of FIG. 3, the - input of OA1 is connected to ground (point M).
In the embodiments of FIGS. 2 and 3, while it is preferable that the resistors R1, R2, R3 and R4 be of the same value, those resistors do not have to be matched as preferred for the FIG. 1 embodiment. This is because of the use of amplifiers OA2 and OA3 which allow the use of non-low contact resistance switches in the aforementioned feedback loops to keep the potentials of S1 and S2 at virtually zero volts.
FIG. 4 is a similar embodiment to that of FIG. 1, incorporating SW3 as a switchable feedback element with R1 around OA1, which eliminates R2. This embodiment operates in the same manner as heretofore described for FIG. 1, except for the control of feedback current by SW3. With the switch contacts in the position shown, current I 2 is allowed to flow from point S1 through SW3 contacts A3, C3 and R1 into point C and back to S1 as previously described. When the switch (SW1, SW2, SW3) contacts are switched to the bottom positions of FIG. 4, current I 2 is then allowed to flow from S2 through R1 via SW3 contacts B3, C3 into OA1 at point C. Current from OA1 is also allowed to flow back to point S2 through this same path with a change in the polarity of I 1 or I 2 in the same manner that it flows into point S1 from the OA1 output at point C.
In embodiment of FIG. 4, there is some slight "on" resistance Ron across contacts C2, A2 and C1, B1 when they are closed causing a small voltage drop across those respective contacts. I 2 ' is not present in this embodiment, thus, if I 2 =1 ma and Ron=10 ohms, then the potential of S1 or S2 is approximately 10 millivolts. This causes a small voltage across the secondary winding of 9.5 millivolts (ie, the potential of S2-10 millivolts minus the potential of S1=0.5 millivolts equals 9.5 millivolts and visa virsa).
In each of the embodiments of FIGS. 1-4, two reverse parallel connected diodes D1 and D2 are connected across the terminals of the secondary winding of the transformer CT. These diodes serve to provide over voltage or surge current protection for the transformer and the amplifiers connected directly across the secondary winding. Diodes D1 and D2 are normally "off" (non-conducting), as the potential between S1 and S2 and ground is normally low enough to prevent conduction of the diodes. The diodes utilized in the present invention are designed to conduct when a potential of 500 millivolts is applied across the diodes from S1 to S2. When either D1 or D2 conducts (depending on the polarity of I 2 ) the transformer secondary winding and the amplifier inputs are shorted out to thus prevent damage to the circuitry. These diodes also provide protection for the circuitry should some component failure cause the potential of either S1 or S2 to rise above the prescribed diode conduction level.
Although this invention has been described with respect to a few particular exemplary embodiments, those in the art will appreciate that it is possible to modify many features of the exemplary embodiments without departing from the new and improved teachings and features of this invention. Accordingly, all such modifications are intended to be incorporated within the scope of the present invention. | A circuit for sensing the magnitude of an AC signal applied to the circuit includes control means for reversing the polarity of the AC signal to thereby generate an output signal which is proportional in amplitude to the magnitude of the AC signal and which has a phase, with respect to the phase of the AC signal, determined by the control means. The control means also provides the capability of generating output pulses from the circuit which have an amplitude proportional to the magnitude of the AC signal and a pulse-width-spacing proportional to the duty cycle of a pulsating control signal applied to the control means. | 6 |
RELATED APPLICATION
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/136,378 entitled METHOD AND APPARATUS FROM DETERMINING BODY FAT PERCENTAGE FROM A BODY MASS INDEX, filed on May 27,1999, the contents of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to artificial intelligence and more particularly to a method and apparatus for estimating body fat percentage of a person
BACKGROUND OF THE INVENTION
With the steady increase in worldwide rates of obesity, the National Institutes of Health (NIH) and the World Health Organization (WHO) have recently adopted similar body weight standards for diagnosing overweightness and obesity. For example, a person is considered overweight according to these standards if the person's body weight adjusted for height, referred to a body weight index (BMI=weight/height 2 ), is greater than 25 kg/m 2 and obese if the BMI is greater than 30 kg/m 2 . Conversely, being underweight is defined as having a BMI less than 18.5 kg/m 2 . Practitioners have been using these body weight guidelines in diagnosing the presence of excessive adiposity and prescribing treatment for their overweight patients.
Lately, there has been increasing interest in quantifying a person's total body fat or the person's body fat percentage rather than BMI as a direct measure of obesity. The main assumption of the BMI standards is that body mass, adjusted for stature, is associated with body fatness and consequent morbidity and mortality. However, there some individuals who are overweight according to the BMI standards, but not overfat (e.g. body builders), Similarly, there are some lean individuals such as marathon runners who are not “underweight” in accordance with the BMI standards but who have a very low body fat content Due to the variations among the population, there is at present no accepted consensus on how BMI and body fat are linked.
Accordingly, several approaches have been developed for measuring body fat, but all of these approaches require special equipment. For example, am underwater or hydrostatic weighing technique compares a person's weight in air and the person's weight in water and, taking the person's lung volume into account, computes the person's body volume and density The body fat percentage is then estimated from the calculated body density. This technique, however, requires special equipment for weighing a person .underwater such as stainless steel water tanks.
Another body fat measurement technique is known as “dual energy X-ray absorptiometry” (DXA), in which a person is irradiated with X-rays to measure the bone mineral content and body fat percentage by differences in the X-ray absorption rates. This technique, too, requires special equipment to produce and measure the X-rays. Still another technique includes drinking heavy water comprising D 2 O or 3 H 2 O and calculating the deuterium or tritium dilution to determine the total body water, from which the body fat percentage can be estimated. This approach require special ingredients, equipment, and expertise.
Bioelectronic impedance analysis (BIA) can also be used to estimate body fat percentage from measuring the electrical impedance of a person and correlating the impedance with the person's standing height and body weight In contrast with the previous techniques, the BIA can be performed with relatively inexpensive pieces of equipment.
In all of these techniques, however, some additional equipment is required, ranging from the X-ray machines to bioelectronic impedance measurement devices. here is a need for a method and apparatus for estimating the body fat percentage, which is simple to apply and does not require special equipment or expertise. In fact, there is a need for a technique that can be performed over the Internet without requiring the user to purchase special equipment.
SUMMARY OF THE INVENTION
These and other needs are addressed by the present invention in which the body fat percentage for a person is estimated from the BMI of the person. The present invention stems from the discovery that the models for body fat percentage can be developed using a multiple regression analysis with the reciprocal of the BMI (1/BMI) as the independent variable. Use of the 1/BMI terms advantageously linearizes the data and avoids the need for logarithmic conversion or inclusion of power terms and therefore simplifies the computing apparatus and programs. Preferably, other potentially independent and easily obtained variables such as age, sex, and ethnicity are also used to provide precise estimates of the body fat percentage. All of such variables can readily be determined without the use of special equipment or expertise.
One aspect of the invention relates to an apparatus, a machine-implemented method, and software for estimating a body fat percentage of a person put indicating data concerning the person is received, and the body fat percentage of the person is then estimated based on a reciprocal of a body mass index (BMI), which is the quotient of the weight of the person divided by the square of the height of the person. Then the estimated body fat percentage is output to the user, Various embodiments of the apparatus include a body fat calculator, a personal computer programmed to estimate body fat percentage, a web server that provides a web site for estimating body fat percentages, and a scale that is equipped to weigh a person and use the measured weight to estimate the body fat percentage.
Still other objects and advantages of the present invention will become readily apparent from the following detailed description, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 depicts a body fat calculator in accordance with one embodiment of the present invention.
FIG. 2 depicts an electrical block diagram of the body At calculator depicted in FIG. 1 .
FIG. 3 is a flowchart illustrating the operation using the body fat calculator depicted in FIG. 1 .
FIGS. 4 ( a ), 4 ( b ), 4 ( c ), 4 ( d ), 4 ( e ), 4 ( f ), and 4 ( g ) depict screens displayed by the body fat calculator depicted in FIG. 1 .
FIG. 5 depicts a scale in accordance with one embodiment of the present invention.
FIG. 6 depicts an electrical block diagram of the scale depicted in FIG. 5 .
FIG. 7 is a flowchart illustrating the operation using the scale depicted in FIG. 5 .
FIG. 8 depicts a screen displayed in one mode by the scale depicted in FIG. 5 .
FIGS. 9 ( a ), 9 ( b ), 9 ( c ), 9 ( d ), 9 ( e ), 9 ( f ), and 9 ( g ) depict screens displayed in another mode by the scale depicted in FIG. 5 .
FIG. 10 is a diagram of a computer network that can be used to implement one embodiment of the present invention.
FIG. 11 is a flowchart illustrating the operation using the computer network depicted in FIG. 10 .
FIG. 12 is a diagram that depicts a computer system that can be used to implement one embodiment of the present invention.
FIG. 13 is a graph of BMI plotted against body fat percentage,
FIG. 14 is a graph of the reciprocal of BMI plotted against body fat percentage.
FIG. 15 is a graph of 1/BMI and sex plotted against body fat percentage.
FIG. 16 is a graph of 1/BMI, age, and sex plotted against body fat percentage.
FIG. 17 is a graph of 1/BMI and age plotted against body fat percentage.
FIG. 18 is a graph of 1/BMI, age, sex, and ethnicity plotted against body fat percentage.
FIG. 19 is a graph of body fat percentage measured by DXA plotted against body fat percentage as determined by the 4-Compartment approach for males.
FIG. 20 is a graph of body fat percentage measured by DXA plotted against body fat percentage as determined by the 4-Compartment approach for females.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Methods and apparatuses for estimating body fat percentage are described. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the present invention.
CONCEPTUAL OVERVIEW
In accordance with one aspect of the present invention, a study was conducted to develop formulas for expressing body fat percentage in terms of BMI and other potential independent variables such as age and ethnicity. Although the present application describes formulas that were developed from a particular battery of experiments by way of example, it is to be understood that the present invention is not so limited and may be used with results from other experimental configurations.
Accordingly, three groups of experimental subjects were recruited in New York City, USA, Cambridge, UK, and Jekei, Japan. The body fat of the subjects was measured by DXA at all three centers, and, in addition, tritium dilution volume and body density were quantified in the USA and UK sites to the body fat percentage by the 4-Compartment method. Subjects were a convenience sample recruited through advertisements in local newspapers, posted flyers, or through referral for body weight evaluation. The subject pool consisted of 1626 healthy adults, ranging in age, body weight, and ethnicity. In this experiment, three ethnic groups were evaluated: African American at the USA cite, Caucasian at the USA and UK sites, and Asian at the Japan site.
Once passing the screening evaluation, the BMI for the subjects was calculated, and the subjects completed all the available the direct body fat measurements on the same day. FIG. 13 is a graph of the subjects' BMI plotted against the measured body fat percentages of the subjects. Females are marked in the graph with a solid circle and males are indicated by a square. By inspecting the graph, there is a relationship between the body fat percentage and BMI, with the body fat percentage being distributed over a curve for both the males and females.
Next, the reciprocal of the BMI (1/BMI) was plotted against the body fat percentage, which resulted in the graph shown in FIG. 14. A linear relationship between 1/BMI and the body fat percentage was derived by a regression model, which finds a line that minimizes the square of the errors. Therefore, the body fat percentage can be estimated from the reciprocal of the BMI according to the following equation:
Body Fat %= A−K ×1/BMI, (1)
where A and K are constants, and BMI is the body mass index. The precise values of the A and K derive from the experiment results and will differ, depending on the experiments that were performed. In this model, the correlation coefficient is 0.576.
It was observed that, in general, females have a higher body fat percentage than corresponding males. Thus, the correlation in the model of equation (1) can be improved by taking the sex of the subjects into account, using the following equation, for example:
Body Fat %=− K ×1/BMI− B ×sex+ C ×sex×1/BMI, (2)
where A, B, C, and K are constants, “sex” is a variable that indicates the sex of the person (e.g. 0 for females and 1 for males), and BMI is the body mass index of the person. The precise values of A, B, C, and K derive from the experiment results and will differ from implementation to implementation, depending on the experiments that were performed. In this model, a graph of which is illustrated in FIG. 15, the correlation coefficient raises to 0.885.
Furthermore, it was found that older subjects tend to have a higher body fat percentage than their younger counterparts. Thus, the correlation can be improved by taking the age of the subjects into account, using the following equation, for example:
Body Fat %= A−K ×1/BMI− B ×age− C ×sex+ D ×sex×age+ E ×sex×1/BMI, (3)
where A, B, C, D, E, and K are constants, “sex” is a variable that indicates the sex of the person (e.g. 0 for females and 1 for males), “age” is a variable that indicates the age of the person, and BMI is the body mass index of the person. The precise values of A, B, C, D, E, and K derive from the experiment results and will differ from implementation to implementation, depending on the experiments that were performed In this model, a graph of which is illustrated in FIG. 16, the correlation coefficient raises to 0.889.
If only the age but not the sex of the person was considered, this scenario can be modeled with the following equation:
Body Fat %= A−K ×1/BMI− B ×age, (4)
where A, B, and K are constants, “age” is a variable that indicates the age of the person, and BMI is the body mass index of the person. The precise values of A, B, and K derive from the experiment results and will differ, depending on the experiments that were performed. In this model, a graph of which is illustrated in FIG. 17, the correlation coefficient is 0.576.
Since the sex of the person has a stronger influence on the body fat percentage, it is possible to take sex into account into the age model of equation (4) with two sex-specific regression formulas, one for males and the other for females, rather than employing sex as a variable. In this case, the following equations may be used, in which the corresponding constants A 1 vs. A 2 and B 1 vs. B 2 are different:
Body Fat % (male)= A 1 − K 1 ×1/BMI− B 1 ×age, (5)
Body Fat % (female)= A 2 − K 2 ×1/BMI− B 2 ×age, (6)
Further improvements in the correlation can be attained by taking the ethnicity of the subjects into account For example, it has been found that Asian tended to have a higher body fat percentage for a given BMI than did African Americans or Caucasians, particularly at the lower age ranges. Thus, the correlation can be improved by taking the ethnicity of the subjects into account, using the following equation, for example:
Body Fat %= A−K ×1/BMI−B×sex− C ×age+ D ×asian×1/BMI+ E ×asian×age+ F ×sex×age+ G ×sex×1/BMI, (7)
where A, B, C, D, E, F, G. and K are constants, “sex” is a variable that indicates the sex of the person (e.g. 0 for females and 1 for males), “age” is a variable that indicates the age of the person, “asian” is a variable that indicates whether the person is belongs to an Asian ethnic group, and BMI is the body mass index of the person. The precise values of A, B, C, D, E, F, G, and K derive from the experiment results and will differ from implementation to implementation, depending on the experiments that were performed. In this model, a graph of which is illustrated in FIG. 18, the correlation coefficient raises to 0.896.
In the experiment, two measurements of body fat were performed at the USA and UK sites, one based on DXA and the other using a 4-Compartment technique, which uses the measured mineral mass, total body water (which requires drinking heavy water), and body density/volume values for a person These measurements were also regressed in males and females (see FIGS. 19 and 20, respectively) to develop the following equation:
4- C Body Fat % (4- C )= A−K ×DXA Body Fat %, (8)
where A and K am constants and “DXA Body Fat %” is the body fat percentage based on the DXA technique is the body mass index of the person. The correlation constant for males in this experiment is 0.9364 and 0.934 for females, showing a high correlation for between the DXA technique and the 4-C approach. The 4-C body fat percentage can be reliably estimated from the DXA body fat percentage, without having the subject drink heavy water.
BODY FAT CALCULATOR
One aspect of the present invention relates to a simple device for estimating the body fat percentage for a person FIG. 1 depicts a body fat calculator 1 in accordance with one embodiment of the present invention, which does not require the use of special or expensive equipment, such as X-ray machines, or exotic chemicals, such as heavy water.
Various components are disposed on the front face of the body fat calculator 1 , including a power switch 2 , an up key 3 , a down key 4 , an enter key 5 , and a display screen 6 . The power switch 2 is provided for turning the body fat calculator 1 on and off. The up key 3 and the down key 4 permit a user to enter data about the user by incrementing or decrementing a display value corresponding to the user's standing height body weight, sex, age, and ethnicity. The display screen 6 can be a liquid crystal display (LCD), or LED display, etc., for displaying numbers and icons to the user in the course of operation.
FIG. 2 is an electrical block diadem of one implementation of the body fat calculator 1 . This implementation of the body fat calculator 1 includes a microcontroller (or CPU) 7 that is coupled to the input elements of the body fat calculator 1 , including the up key 3 , the down key 4 , and the enter key 5 . The power switch 2 is coupled to the microcontroller 7 and to a power supply 8 , which can be a battery disposed within the body fat calculator 1 , for switching power on and off to the microcontroller 7 . The display screen 6 is also coupled to the microcontroller 7 through a display driver (not shown).
FIG. 3 is a flowchart, illustrating the operation of using the body fat calculator 1 in accordance with one embodiment of the present invention. When a user begins to use the body fat calculator 1 , the user presses the power switch 2 , which connects the power source 8 to the microcontroller 7 . Upon application of power, the microcontroller 7 undergoes an initialization sequence (step 1 ), which sets up the display screen 6 to display an initial display screen. By way of example, one initial display screen is shown in FIG. 4 ( a ), but it is to be understood that the present invention is not so limited and various screens may be shown.
In the illustrated embodiment, by way of example, the initial display screen 400 includes areas for indicating the sex, age, height, weight, and ethnicity of the user. In other embodiments, additional and/or fewer areas for corresponding variables may be employed. In the initial display screen, default values for the age (25 years), height (170 cm), weight (55 kg) are displayed, and all supported values of sex (male or female) and ethnicity (Asian, black, white) arc shown. Areas are also reserved for outputting the BMI, body fat percentage, and body fat mass, but these values are displayed later after being calculated.
At step 2 , the user presses the up key 3 to indicate that he is a male or the down key 4 to indicate that she is a female. In response, only the corresponding icon is displayed (with the other icon being turned off). For example, if the user pressed the down key 4 to indicate that she is female, then the female icon is displayed and the male icon is turned off, as illustrated in screen 402 of FIG. 4 ( b ). Upon reaching the desired value for sex, the user presses the enter key 5 , which is tested at step 3 , and execution proceeds to step 4 .
At step 4 , the user repeatedly presses the up key 3 or the down key 4 to add one or subtract one, respectively, from the displayed age, until the desired age is reached. In the example, illustrated as screen 404 in FIG. 4 ( c ), the age has been incremented to 27 years. Upon reaching the desired age, the user presses the enter key 5 , which is tested at step 5 , and execution proceeds to step 6 .
At step 6 , the user repeatedly presses the up key 3 or the down key 4 to add a predetermined amount (such as 5 cm) or subtract the predetermined amount, respectively, from the displayed height, until the desired height is reached. In the example, illustrated as screen 406 in FIG. 4 ( d ), the height has been decremented to 165 cm. Upon reaching the desired height, the user presses the enter key 5 , which is tested at step 7 , and execution proceeds to step 8 . Although metric units are depicted in this example, U.S. customary units such as inches may also be employed.
At step 8 , the user repeatedly presses the up key 3 or the down key 4 to add a predetermined amount (such as 1 kg) or subtract the predetermined amount, respectively, from the displayed weight, until the desired height is reached. In the example, illustrated as screen 408 in FIG. 4 ( e ), the weight has been changed to 53 kg Upon reaching the desired weight, the user presses the enter key 5 , which is tested at step 9 , and execution proceeds to step 10 . Although metric units are depicted in this example, U.S. customary units such as pounds may also be employed.
At step 10 , the user repeatedly presses the up key 3 or the down key 4 to select one of the supported ethnicitics. In the example, illustrated as screen 410 in FIG. 4 ( f ), the user has selected the Asian ethnicity and presses the enter key 5 , which is tested at step 11 for continuation to step 12 .
At step 12 , the information that was received from the user is used to calculate the BMI, body fat percentage, and body fat mass. In this implementation the BMI is calculated as the weight/height 2 , and the body fat percentage is calculated using equation (7) explained herein above. The body fat miss is calculated as the product of the body fat percentage and the weight This information is displayed on the display screen 6 , as illustrated in the output display screen 412 of FIG. 4 ( g ). After a preset period of time, for example 30 seconds, as determined by an internal timer of microcontroller 7 , the body fat controller 1 automatically shuts itself off to conserve power.
BODY FAT CALCULATOR SCALE
One embodiment of the present invention is a scale that can estimate the body fat percentage of a person. Referring to FIG. 5, a scale 11 comprises an under body 12 and an upper body 13 . Disposed on the top face 13 A of the upper body 13 include a power switch 14 , a mode key 15 , an up key 16 , a down key 17 , an enter key 18 , and a display screen 19 . The power switch 15 is provided to turn the scale 11 on and off. The mode key 15 , the up key 16 and the down key 17 permit a user to enter data about the user such as the user's standing height, sex, age, and ethnicity. The display screen 19 can be a liquid crystal display (LCD), or LED display, etc., for displaying numbers and icons to the user in the course of operation.
FIG. 6 is an electrical block diagram of one implementation of the scale 11 . This implementation of the scale 11 includes a microcontroller (or CPU) 20 that is coupled to the input elements of the scale 11 , including mode key 15 , the up key 16 and the down key 17 . The power switch 14 is coupled to the microcontroller 20 and to a power supply 22 , which can be a battery disposed within the scale 11 , for switching power on and off to the microcontroller 20 . The display screen 19 is also coupled to the microcontroller 20 through a display driver (not shown). Furthermore, the microcontroller 20 is coupled to an electronic weight scale 21 , which is configured for providing weight information to the microcontroller 20 when a person is standing on the upper body 12 .
FIG. 7 is a flowchart, illustrating the operation of using the scale 11 in accordance with one embodiment of the present invention. When a user begins to use the scale 1 1 , the user presses the power switch 14 , which connects the power source 22 to the microcontroller 20 . Upon application of power, the microcontroller 20 undergoes an initialization sequence (step 20 ), which initialization the scale 11 .
At step 21 , the microcontroller 20 check to determined if the user has presses the fat mode button 15 . If the user has not pushed the fat mode button 15 , the scale 11 then measures the person's weight using the weight scale 21 (step 22 ) and displays the result in a display screen shown in FIG. 8 (step 23 ), in which, for example, the user weights 60 kg (about 132 lbs). After 30 seconds, tested in step 24 , the microcontroller 20 shuts the scale 11 off to converse power.
If, on the other hand, the fat mode button 15 , was pressed, then the microcontroller 20 sets up the display screen 19 to display an initial fat display screen 900 . By way of example, one initial display screen 900 is shown in FIG. 9 ( a ), but it is to be understood that the present invention is not so limited and various screens may be shown.
In the illustrated embodiment, by way of example, the initial fat display screen 900 includes areas for indicating the sex, age, height, weight, and ethnicity of the user. In other embodiments, additional and/or fewer areas for corresponding variables may be employed. In the initial display screen, default values for the age (25 years), height (170 cm), weight (55 kg) are displayed, and all supported values of sex (male or female) and ethnicity (Asian, black, white) are shown. Areas are also reserved for outputting the BMI, body fat percentage, and body fat mass, but these values are displayed later after being calculated.
At step 25 , the user presses the up key 16 to indicate that he is a male or the down key 17 to indicate that she is a female. In response, only the corresponding icon is displayed (with the other icon being turned off). For example, if the user pressed the down key 17 to indicate flat she is female, then the female icon is displayed and the male icon is turned off, as illustrated in screen 902 of FIG. 9 ( b ). Upon reaching the desired value for sex, the user presses the enter key 18 , which is tested at step 26 , and execution proceeds to step 27 .
At step 27 , the user repeatedly presses the up key 16 or the down key 17 to add one or subtract one, respectively, from the displayed age, until the desired age is reached. In the example, illustrated as screen 904 in FIG. 9 ( c ), the age has been incremented to 27 years. Upon reaching the desired age, the user presses the enter key 18 , which is tested at step 28 , and execution proceeds to step 29 .
At step 29 , the user repeatedly presses the up key 16 or the down key 17 to add a predetermined amount (such as 5 cm) or subtract the predetermined amount, respectively, from the displayed height, until the desired height is reached. In the example, illustrated as screen 906 in FIG. 9 ( d ), the height has been decremented to 165 cm. Upon reaching the desired height, the user presses the enter key 18 , which is tested at step 30 , and execution proceeds to step 31 . Although metric units are depicted in this example, U.S. customary units such as inches may also be employed.
At step 31 , the user repeatedly presses the up key 16 or the down key 17 to select one of the supported ethnicities. In the example, illustrated as screen 908 in FIG. 9 ( e ), the user has selected the Asian ethnicity and presses the enter key 18 , which is tested at step 32 for continuation to step 33 . At step 33 , the scale 11 then measures the person's weight using the weight scale 21 . The result is then displayed (step 34 ) in screen 91 shown in FIG. 9 ( f ), in which the user weights 53 kg. Although metric units are depicted in this example, U.S. customary units such as pounds may also be employed.
At step 34 , the information that was received from the user is used to calculate the BMI, body fat percentage, and body fat mass. In this implementation, the BMI is calculated as the weight/height 2 , and the body fat percentage is calculated using equation (7) explained herein above. The body fat mss is calculated as the product of the body fat percentage and the weight This information is displayed on the display screen 6 , as illustrated in the output display screen 912 of FIG. 49 ( g ). After a preset period of time, for example 30 seconds, as determined by an internal timer of microcontroller 20 in step 24 , the scale 11 automatically shuts itself off to conserve power.
BODY FAT ESTIMATION OVER A NETWORK
Another embodiment of the present invention related to performing body fat estimation over a network, such as a local area network (LAN), a wide-area network (WAN), or the Internet. FIG. 10 depicts a computer network in which a personal computers 20 is coupled, via a hub 31 , to a server 32 In this arrangement, a user at personal computer 30 desires to obtain the user's body fat percentage based on simple variables by interacting with server 32 over a computer network.
FIG. 11 illustrates the operation of this embodiment, in which the user obtains access to personal computer 30 (for example by login and password procedures) and then to server 32 , for example, by accessing a web site maintained at server 32 (step 1102 ). When the server 32 received a request for the web site, typical via a hypertext transfer protocol (HTTP) GET command with a URL designating the address of the web site. The server 32 receives the request (step 1104 ), fetches web page or other generates an input display image (step 1106 ) and transmits the web page to the personal computer 30 .
In response, the person computer receives and displays the web page (step 1108 ), which typically includes a form for inputting data. At step 1110 , the user enters the requested data, such as sex, age, height, weight, and ethnicity (or even BMI directly), and transfers the entered information to the server 32 , for example, by an HTTP POST command. In response, the server 32 receives the information, and makes the appropriate calculations to determine, inter alia, the body fat percentage based on at least some of the input variables, for example, by applying the above-explained regression equations (step 1112 ). The calculation results are then assembled into an output web page (step 1141 and transmitted to the user's personal computer 30 and displayed (step 1116 ).
HARDWARE OVERVIEW
FIG. 12 is a block diagram that illustrates a computer system 1200 , such as personal computer 30 , upon which an embodiment of the invention may be implemented. Computer system 1200 includes a bus 1202 or other communication mechanism for communicating information, and a processor 1204 coupled with bus 1202 for processing information. Computer system 1200 also includes a main memory 1206 , such as a random access memory (RAM) or other dynamic storage device, coupled to bus 1202 for storing information and instructions to be executed by processor 1204 . Main memory 1206 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 1204 . Computer system 1200 further includes a read only memory (ROM) 1208 or other static storage device coupled to bus 1202 for storing static information and instructions for processor 1204 . A storage device 1210 , such as a magnetic disk or optical disk, is provided and coupled to bus 1202 for storing information and instructions.
Computer system 1200 may be coupled via bus 1202 to a display 1212 , such as a cathode ray tube (CTR), for displaying information to a computer user. An input device 1214 , including alphanumeric and other keys, is coupled to bus 1202 for communicating information and command selections to processor 1204 . Another type of user input device is cursor control 1216 , such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 1204 and for controlling cursor movement on display 1212 . This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y), that allows the device to specify positions in a plane.
The invention is related to the use of computer system 1200 for estimating body fat percentage. According to one embodiment of the invention, estimating body fat percentage is provided by computer system 1200 in response to processor 1204 executing one or more sequences of one or more instructions contained in main memory 1206 . Such instructions may be read into main memory 1206 from another computer-readable medium, such as storage device 1210 . Execution of the sequences of instructions contained in main memory 1206 causes processor 1204 to perform the process steps described herein. One or more processors in a multi-processing arrangement may also be employed to execute the sequences of instructions contained in main memory 1206 . In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement the invention. Thus, embodiments of the invention are not limited to any specific combination of hardware circuitry and software.
The term “computer-readable medium” as used herein refers to any medium that participates in providing instructions to processor 1204 for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical or magnetic disks, such as storage device 1210 . Volatile media include dynamic memory, such as main memory 1206 . Transmission media include coaxial cables, copper wire and fiber optics, including the wires that comprise bus 1202 Transmission media can also take the form of acoustic or light waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM any other memory chip or cartridge, a carrier wave as described hereinafter, or any other medium from which a computer can read.
Various forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to processor 1204 for execution For example, the instructions may initially be borne on a magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a telephone line using a modem. A modem local to computer system 1200 can receive the data on the telephone line and use an e d transmitter to convert the data to an infrared signal. An infrared detector coupled to bus 1202 can receive the data carried in the infrared signal and place the data on bus 1202 . Bus 1202 carries the data to main memory 1206 , from which processor 1204 retrieves and executes the instructions. The instructions received by main memory 1206 may optionally be stored on storage device 1210 either before or after execution by processor 1204 .
Computer system 1200 also includes a communication interface 1218 coupled to bus 1202 . Communication interface 1218 provides a two-way data communication coupling to a network link 1220 that is connected to a local network 1222 . For example, communication interface 1218 may be an integrated services digital network (ISDN) card or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface 1218 may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented In any such implementation, communication interface 1218 sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.
Network link 1220 typically provides data communication through one or more networks to other data devices. For example, network link 1220 may provide a connection through local network 1222 to a host computer 1224 or to data equipment operated by an Internet Service Provider (ISP) 1226 . ISP 1226 in turn provides data communication services through the worldwide packet data communication network, now commonly refereed to as the “Internet” 1228 . Local network 1222 and Internet 1228 both use electrical, electromagnetic or optical signals that carry digital data streams. The signals through the various networks and the signals on network link 1220 and through communication interface 1218 , which carry the digital data to and from computer system 1200 , are exemplary forms of carrier waves transporting the information.
Computer system 1200 can send messages and receive data, including program code, through the network(s), network link 1220 , and communication interface 1218 . In the Internet examples a server 130 might transmit a requested code for an application program through Internet 1228 , ISP 1226 , local network 1222 and communication interface 1218 . In accordance with the invention, one such downloaded application provides for estimating body fat percentage as described herein. The received code may be executed by processor 1204 as it is received, and/or stored in storage device 1210 , or other non-volatile storage for later execution. In this manner, computer system 1200 may obtain application code in the form of a carrier wave.
While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended clams. | The body fat percentage for a person is estimated from the BMI of the person by employing a multiple regression analysis using the reciprocal of the BMI (1/BMI) as the independent variable. In other embodiments, potentially independent and easily obtained variables such as age, sex, and ethnicity are also used in conjunction to provide precise estimates of the body fat percentage. Devices for estimating the body fat percentage can be implemented as calculators, smart scales, and Internet web sites. | 0 |
BACKGROUND
1. Technical Field
Embodiments of the present disclosure generally relate to connectors, and particularly, to an electrical adapter assembly for hard disk drives.
2. Description of Related Art
Hard disk drives are widely used as mass storage devices in computers. To transfer information/data from a first hard disk drive to a second hard disk drive using a computer, the two hard disk drives must be coupled to a motherboard of a computer and the operating system of the computer must be used to transfer the information/data. After the information/data is transferred and if one of the two hard disk drives is to be used on a second computer, the hard disk drive must be detached from the first computer and coupled to the motherboard of the second computer. As can be seen, this is a tedious and time consuming process.
Therefore, a need exits for providing an electrical adapter assembly that can conveniently and repeatedly connect hard disk drives to each other without interfacing to a motherboard.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of an electrical adapter assembly in accordance with an exemplary embodiment, the electrical adapter assembly includes a loading member.
FIG. 2 is an exploded perspective view of the electrical adapter assembly of FIG. 1 .
FIG. 3 is an isometric view of the loading member of the electrical adapter assembly of FIG. 1 .
FIG. 4 is an isometric view of the electrical adapter assembly connecting a second hard disk drive and supporting a first hard disk which is about to be connected thereon.
FIG. 5 is an isometric view of the electrical adapter assembly connecting the second hard disk drive to the second hard disk and supporting the first hard disk thereon.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2 , an electrical adapter assembly 100 in accordance with an exemplary embodiment is configured for electrically connecting a first 1.8 inch hard disk drive 60 (shown in FIG. 4 ) to a second 3.5 inch hard disk drive 70 (shown in FIG. 4 ). The electrical adapter assembly 100 includes a connector 10 , a printed circuit board (PCB) module 20 , a loading member 30 , a pressing member 40 , and two fixing members 50 . The connector 10 is electrically connected with the PCB module 20 , and is fastened on the loading member 30 by the pressing member 40 and the fixing members 50 .
The connector 10 is a rectangle-shaped printed circuit board. The connector 10 includes 1.8 inch first golden fingers 11 , 1.8 inch second golden fingers 12 , and two fixing portions 13 . The first golden fingers 11 and the second golden fingers 12 are disposed at opposite edges of the connector 10 correspondingly. The two fixing portions 13 are respectively disposed at another two opposite edges of the connector 10 . The first golden fingers 11 and the second golden fingers 12 are electrically connected with each other. Each of the fixing portions 13 defines a fixing hole 131 .
The PCB module 20 includes a 1.8 inch first socket 21 and a 3.5 inch second socket 22 . Each of the first socket 21 and the second socket 22 includes a plurality of pins (not shown). The first socket 21 electrically connects the second golden fingers 12 , and the second socket 22 electrically connects to the second hard disk drive 70 . The PCB module 20 further includes a chip 23 , and circuits 24 for electrically connecting the chip 23 to the first socket 21 and the second socket 22 . The chip 23 is used for controlling data transfer between the first hard disk drive 60 and the second hard disk drive 70 .
The loading member 30 is used for docking the first hard disk drive 60 . Referring to FIG. 3 , the loading member 30 includes a rectangle-shaped base 31 , and a fastening portion 32 extending along one shorter side of the base 31 . The base 31 includes four positioning poles 311 a , 311 b , 311 c , 311 d . The positioning poles 311 a , 311 b are arranged on one longer side of the base 31 , and the positioning poles 311 c , 311 d are arranged on another longer side of the base 31 . Two fastening holes 321 are defined in opposite sides of the fastening portion 32 . The two fastening holes 321 correspond to the two fixing holes 131 of the connector 10 .
The loading member 30 further includes a first guiding wall 33 a , a second guiding wall 33 b opposite to the first guiding wall 33 a , two long narrow-shaped supporting portions 35 a and 35 b , and four guiding portions 39 a , 39 b , 39 c , 39 d (referring to FIG. 4 ).
The first guiding wall 33 a and the second guiding wall 33 b are disposed at the two long sides of the base 31 , and curve around the four positioning poles 311 a , 311 b , 311 c , 311 d correspondingly. The first guiding wall 33 a includes a stopper 333 a , and the second guiding wall 33 b also includes a stopper 333 b . The stoppers 333 a and 333 b extend from top sides of the first guiding wall 33 a and the second guiding wall 33 b respectively towards each other. The stoppers 333 a and 333 b are adjacent to the fastening portion 32 , and parallel with the base 31 .
The supporting portions 35 a and 35 b extend from the base 31 between the first guiding wall 33 a and the second guiding wall 33 b and parallel with the long side of the base 31 . The supporting portions 35 a and 35 b face the stopper 333 a , 333 b respectively, and the supporting portions 35 a and 35 b are configured for guiding the first hard disk drive 60 and to decrease contact area between the loading member 30 and the first hard disk drive 60 .
Each of the four guiding portions 39 a , 39 b , 39 c , 39 d has a smooth cylindrical outside surface, and further defines a through hole 391 to allow the four guiding portions 39 a , 39 b , 39 c , 39 d to be sleeved on the four positioning poles 311 a , 311 b , 311 c , 311 d respectively.
The pressing member 40 is a flat-shaped board for pressing the connector 10 to the fastening portion 32 of the loading member 30 . The pressing member 40 defines two through holes 41 in the board corresponding to the two fixing holes 131 of the connector 10 . The two fixing members 50 are inserted through the two through holes 41 and the two fixing holes 131 sequentially, and engage with the two fastening holes 321 correspondingly, so as to fix the connector 10 onto the fastening portion 32 of the loading member 30 . The two fixing members 50 may be screws and the two fastening holes 321 may be threaded.
Referring also to FIGS. 4 and 5 , in assembly, first, the connector 10 is disposed on the fastening portion 32 of the loading member 30 , and the two fixing holes 131 of the connector 10 are aligned with the two fastening holes 321 of the fastening portion 32 . Then, the pressing member 40 is disposed on the connector 10 , and the two through holes 41 are aligned with the two fixing holes 131 of the connector 10 correspondingly. After that, the two fixing members 50 are correspondingly inserted through the two through holes 41 and the two fixing holes 131 , and screwed into the two fastening holes 321 to fix the connector 10 on the fastening portion 32 of the loading member 30 . Finally, the second golden fingers 12 are inserted into the first socket 21 to electrically connect the connector 10 to the PCB module 20 .
When the electrical adapter assembly 100 is used for connecting the first hard disk drive 60 to the second hard disk drive 70 , the first hard disk drive 60 can be disposed between the first guiding wall 33 a and the second guiding wall 33 b and supported by the supporting portions 35 a , 35 b . And then, the first hard disk drive 60 is pushed along a first direction D 1 , such that, opposite side surfaces of the first hard disk drive 60 contact the guiding portions 39 a , 39 b and the guiding portions 39 c , 39 d correspondingly and movement along a second direction D 2 substantially perpendicular to the first direction D 1 limited, and apply a frictional force to the guiding portions 39 a , 39 b , 39 c , 39 d to allow the guiding portions 39 a , 39 b , 39 c , 39 d to rotate around the four positioning poles 311 a , 311 b , 311 c , 311 d respectively. Finally, the one end of the first hard disk drive 60 slides under the two stopper 333 a and 333 b , the first golden fingers 11 are inserted into a hard disk connector (not shown) of the first hard disk drive 60 . The second socket 22 of the PCB module 20 can be inserted into a hard disk connector (not shown) of the second hard disk drive 70 .
Therefore, the electrical adapter assembly 100 electrically connects the first hard disk drive 60 to the second hard disk drive 70 , thereby the first and second hard disk drives 60 , 70 can transfer data between each other under control of the chip 23 of the PCB module 20 . Because the guiding portions 39 a , 39 b , 39 c , 39 d are rotatably disposed on the positioning poles 311 a , 311 b , 311 c , 311 d respectively, the first hard disk drive 60 will be protected from wear and tear due to sliding between the guiding portions 39 a , 39 b , 39 c , 39 d . In addition, the two stoppers 333 a , 333 b , the supporting portions 35 a , 35 b , may cooperately prevent the first hard disk drive 60 from falling out of the base 31 in the up-down direction.
It is to be understood, however, that even though numerous characteristics and advantages of the present disclosure have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the present disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | An electrical adapter assembly for connecting a first hard disk drive and a second hard disk drive is provided. The electrical adapter assembly includes a connector capable of electrically inserting into the first hard disk drive, a printed circuit board (PCB) module electrically connecting the connector, and a loading member for loading the first hard disk drive. The PCB module includes a chip for controlling data transfer between the first hard disk drive and the second hard disk drive. The loading member includes a base and at least two guiding portions pivotally attached on the base to allow the first hard disk drive to be able to slide between the at least two guiding portions. | 7 |
BACKGROUND OF THE INVENTION
For the coating of a moving base, such as a paper board web, with a coating agent, various size presses are commonly used. In size presses, the paper or board web is passed through a nip formed by size press rolls, in which nip the coating agent is transferred onto the face of the paper or board web.
In the prior art, a number of size presses of different types are known, of which one application, which has been in use for a long time, is one in which the rolls in the size press are arranged substantially on the same horizontal level so that the paper or board web runs through the size press nip substantially vertically from the top downwards. In such an application, as a rule, in the nip between the size press rolls, there is a size pond, through which the paper or board web runs. When the web passes through the pond, the size adheres to both sizes of the web, whereupon, in the nip, the size press rolls spread and smooth layers of suitable thickness onto the web faces.
A second embodiment of a size press is one in which, by means of some suitable coating means, such as bar or blade coaters, size films of suitable thickness are first spread onto the faces of the size press rolls, from which said size films are then transferred onto the web faces in the roll nip. A third prior art embodiment of a size press is a so-called gate roll size press, which is, in two-sided surface sizing of a paper, composed of size rolls, which are in nip contact with each other. A gate roll size press first comprises applicator rolls proper, the web being passed through the nip between said rolls. Size films are spread onto the faces of said applicator rolls by means of gate rolls, which comprise a metering roll and a transfer roll. The transfer roll is in nip contact both with the metering roll and with the applicator roll proper. The coating agent is fed into the nips between the gate rolls, i.e. between the metering rolls and the transfer rolls, where it forms a pond. From both ends of the ponds, as a rule, an overflow is provided to the return circuit. By the effect of hydrodynamic forces, coating agent passes through the nip between the metering rolls and the transfer rolls, forming size films both on the metering rolls and on the transfer rolls. The size film placed on the transfer roll is transferred into the nip between the transfer roll and the applicator roll, which nip smooth and thins the film onto the applicator roll. In the nip between the applicator rolls, the film are transferred further onto the web.
The present invention is expressly related to the size presses of the last-mentioned gate roll type. The construction of conventional gate roll size presses is usually such that one of the applicator rolls is journalled fixedly on the size press frame, whereas the other applicator roll is arranged displaceable so that its bearing bracket is linked pivotally to the frame of the size press. The transfer roll that is in nip contact with the fixed applicator roll is linked pivotally to the size press frame by the intermediate of a loading arm and, further, the metering roll that is in nip contact with said transfer roll is linked pivotally to the size press frame by the intermediate of a loading arm and, further, the metering roll that is in nip contact with said transfer roll is linked pivotally to the bearing bracket or loading arm of the transfer roll by the intermediate of its own loading arm. In a corresponding way, in conventional solutions, the transfer roll that forms a nip with the displaceable applicator roll is linked pivotally to the bearing bracket or loading arm of the applicator roll by the intermediate of its own loading arm or by its bearing bracket and, further, the metering roll that is in nip contact with said transfer roll is linked pivotally to the bearing bracket or loading arm of the transfer roll. On the other hand, the loading cylinders of each roll are linked to the loading arm of search roll and, at the opposite end, to the machine member to which the roll concerned is linked pivotally.
In wide and high-speed paper machines in particular, the prior art solutions are associated with considerable problems of vibration of the gate rolls, resulting from the mode of linkage of conventional gate rolls. For example, the metering roll at the side of the displaceable applicator roll, i.e. the outermost roll in the system, is fixed to the frame by the intermediate of a chain formed by three separate articulated joints. By means of the construction concerned, it is very difficult to provide a sufficiently rigid fastening of the rolls in view of vibrations. Besides wear of the constructions of the frame, the vibrations also cause quality defects in the coating band an increased wear of the roll coatings. The wear of the roll coatings is one of the most important problems of the gate roll size presses.
OBJECTS AND SUMMARY OF THE INVENTION
An object of the present invention is to provide an improvement over the construction of the prior art size presses.
Accordingly, the present invention is related to a device for metering of a coating agent onto a moving base, such as a paper or board web. The device comprises a coating nip formed by soft-faced applicator rolls, through which nip the web is passed. A first applicator roll from among a plurality of applicator rolls is journalled as fixed on a frame of the device. A second applicator roll is linked to the frame of the device pivotally by the intermediate of a loading arm or equivalent. At least one of said applicator rolls is in nip contact with a hard transfer roll. The hard transfer roll is further in nip contact with a soft-faced metering roll, whereby, in a metering nip between the metering roll and the transfer roll, a pond comprising a coating agent is located. As the rolls revolve, the coating agent from the pond is fitted to be transferred through the metering nip onto the face of the transfer roll and from there further, through a transfer nip formed by the transfer roll and the applicator roll, onto the face of the applicator roll from which the coating agent is fitted to be transferred onto the web in the coating nip.
An important aspect of the device in accordance with the invention is that the metering roll and the transfer roll placed next to the fixed applicator roll and/or the metering roll and the transfer roll placed next to the mobile applicator roll are linked pivotally to the same member of the machine on the frame of the device.
By means of the device in accordance with the invention, a number of remarkable advantages are obtained over the prior art devices. It is one important advantage of the invention that the construction in accordance with the invention is considerably less susceptible to vibrations, because of the mode of linkage of the rolls. Moreover, in the invention, the regulation of the linear loads in the nips in the size press can be accomplished considerably more accurately than in the prior art solutions.
A further remarkable advantage obtained by the invention is that it is now possible to employ adjustable-crown rolls without the associated problems with the same found in the prior art. In particular, adjustable-crown rolls were not employed in the prior art gate roll size press constructions, partly because of the high weight of the rolls.
By means of the adjustable crown metering rolls employed in conjunction with the present invention, it is readily possible to regulate the profile of the coating quantity during operation of the machine. In contrast, in conventional size processes (in which an adjustable crown roll could not be used), the profile of coating quantity could be affected exclusively by means of the camber of the rolls.
Further advantages and characteristic features of the invention are set forth in the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
FIG. 1 is a schematic side view of a first embodiment of the device in accordance with the invention.
FIG. 2 is an illustration corresponding to FIG. 1 of a second embodiment of the device in accordance with the invention.
DETAILED DESCRIPTION
In FIG. 1, the device in accordance with the invention is denoted generally with the reference numeral 10. The device 10 comprises a frame 1, which is mounted on a foundation B, e.g. a floor. Applicator rolls 11,21 have been mounted on the frame 1, of which rolls the bearing bracket 12 of the first applicator roll 11 is mounted on the frame 1 in a stationary manner. The bearing 12 of the first applicator roll 11 is mounted on the frame 1 in a stationary manner, whereas the bearing bracket 22 of the second applicator roll 21 is mounted on an applicator roll loading arm 24, which is mounted on the frame 1 pivotally by means of an articulation shaft 25 transverse to the machine direction.
The applicator rolls 11,21 define a coating nip N 1 between them, through which nip the web W is passed. The web W is passed onto the coating nip N 1 guided by a leading roll 2, and after the coating nip N 1 the web W is passed to further processing as guided by a guide roll 4. The bearing bracket 3 of the leading roll 2 is supported on the frame 1 in a suitable way, but, for the sake of clarity of the illustration, these constructions are not shown in FIG. 1.
At the side of the stationary applicator roll, i.e. the first applicator roll 11, gate rolls are provided in the device 10, which gate rolls comprise a first metering roll 31 as well as a first transfer roll 41. The first metering roll 31 and the first transfer roll 41 are in nip contact with one another and define a first metering nip N 2 between them. Correspondingly, the first transfer roll 41 is in nip contact with the first applicator roll 11, while these rolls define a first transfer nip N 3 between them. The coating agent is fed into the first metering nip N 2 so that a first point P 1 is formed in said nip out of the coating agent. By the effect of hydrodynamic forces, coating agent passes through the first metering nip N 2 so that films of coating agent are formed on the faces of the first metering roll 31 and the first transfer roll 41. When the rolls revolve, the film placed on the face of the first transfer roll 41 is transferred into the first transfer nip N 3 , which smooths and thins the film onto the face of the first applicator roll 11. In the coating nip N 1 the film is then transferred from the face of the first applicator roll 11 onto the web W.
The bearing bracket 32 of the first metering roll 31 is mounted on a first metering roll loading arm 34, which is supported on the frame 1 of the device pivotally by means of an articulation shaft 35 transverse to the machine direction. In a corresponding way, the bearing bracket 42 of the first transfer roll 41 is also mounted on a first transfer roll loading arm 44 of its own, which is supported on the frame 1 of the device pivotally in a corresponding way by means of an articulation shaft 45 transverse to the machine direction.
In the first transfer roll loading arm 44 a loading cylinder 46 is attached by means of an articulated joint, and the opposite end 48 of said cylinder 46 is supported on the frame 1. The first metering roll loading arm 34 is also provided with a loading cylinder 36, the first end 37 of which is attached to said loading arm 34 by means of an articulated joint, whereas the other end 38 of the first metering roll loading cylinder 36 is attached to the first transfer roll loading arm 44.
In the embodiment shown in FIG. 1, the parts of the loading arms 34 and 44 of the first metering roll 31 and the first transfer roll 41 that are placed at the side of the rolls, i.e. the distances between the articulation shafts 35 and 45 and the axes of rotation 33 and 43 of the rolls are equally large as compared with one another and, in a corresponding way, the parts of the loading arms 34 and 44 placed at the side of the loading cylinders 36,46, i.e. the distances between the articulation points 37,48 of the loading cylinders 3 and 46 and the articulation shafts 35,45 of the loading arms are equally large as compared with one another.
Such an embodiment can be considered optimal for the invention, for in such a case, any adjustments taking place in the linear loads in the first metering nip N 2 and the first transfer nip N 3 do not affect each other, and opening or closing of the transfer nip N 3 does not produce a change in the length of the loading cylinder 36 or, thus, a pulse in the linear load of the metering nip N 2 . Such a pulse in the linear load would occur if there were a change in the stroke length of the loading cylinder 36.
As stated above, the bearing bracket 22 of the second applicator roll 21 is mounted on the applicator roll loading arm 24, which is supported on the frame 1 of the device by means of an articulation shaft 25 transverse to the machine direction. The applicator loading arm 24 is provided with a loading cylinder 26, which is, at its first end 27, attached to said applicator roll loading arm 24 by means of an articulated joint and, at its second end 28, to the frame 1 of the device. The second transfer roll 61, which forms the second transfer nip N 5 together with the second applicator roll 21, is supported on the frame 1 in a way similar to the first transfer roll 41. Thus, the bearing bracket 62 of the second transfer roll 61 is mounted on the second transfer roll loading arm 64, which is mounted pivotally on the frame 1 by means of an articulation shaft 65 transverse to the machine direction.
In a corresponding way, the second metering roll 51, which forms the second metering nip N. together with the second transfer roll 61, is supported on the frame 1 so that the bearing bracket 52 of said metering roll is mounted on a second metering roll loading arm 54 of its own, which is mounted on the frame 1 by means of an articulation shaft 55 transverse to the machine direction.
The second meter roll loading arm 54 is provided with a loading cylinder 56, whose first end 57 is linked to said second metering roll loading arm 54 by means of an articulated joint, whereas its second end 58 is linked to the second transfer roll loading arm 64 of by means of an articulated joint.
In a corresponding way, the second transfer roll loading arm 64 is provided with a loading cylinder 66 of its own, which is supported on the loading arm by means of an articulated joint at the same point with the second end 58 of the loading cylinder of the second metering roll. In a corresponding way, the second end 68 of the loading cylinder of the second transfer roll is linked to the applicator roll loading arm 24 by means of an articulated joint.
The dimensional proportions of the loading arms 24,64,54 have been arranged so that the parts of each of the loading arms placed at the side of the rolls, i.e. the parts between the axes of rotation 23,53,63 of the rolls and the articulation shafts 25,55,65, are equally large as compared with each other. In a corresponding way, the parts of the loading arm 24,64,54 placed at the side of the loading cylinders, i.e. the parts between the articulation shafts 25,65,55 and the articulation points 57,58,68 of the loading cylinders 56,66 are equally large as compared with each other. Owing to the mutual proportions of the dimensioning of the parts of the loading arms 24,54,64 in this case as well, adjustments taking place in the linear loads in the various nips N 1 ,N 4 ,N 5 and/or opening and closing of the nips do not affect the linear loads in other nips.
Typical linear loads in the various nips are, e.g. in the nips N 2 ,N 5 between transfer rolls and applicator rolls from about 10 to about 30 kN/m, and in the nips N 1 between applicator rolls from about 25 to about 40 kN/m. All the rolls 11,21,31,41,51,61 in the device 10 are separate driven. Separately drive is needed, because the speeds of rotation of the rolls are different. In particular, in a situation in which the transfer rolls 41,61 are smooth-faced rolls, typical circumferential velocities of the rolls in relation to the web speed are on the applicator rolls 11,21 about 100% of the web speed, on the transfer rolls 41,61 about 80% of the web speed, and on the metering rolls 31,51 about 25% of the web speed. Owing to the separate drives of the rolls, the roll speeds can also be regulated individually when desired.
The metering rolls 31,51 and the applicator rolls 11,21 are coated rolls. The metering rolls 31,51 are provided with a coating of rubber or equivalent, and the applicator rolls 11,21 are, as a rule, provided with rubber or polyurethane coating.
The transfer rolls 41,61 are hard rolls, and, in view of improving the wear resistance, they are commonly provided with a hard coating, in particular chromium coating.
In order to improve the wear resistance further, in a size press in accordance with the invention, on the transfer rolls 41,61, it is possible to employ a ceramic coating, whose wear resistance is very good. Instead of smooth-faced transfer rolls 41,61, it is also possible to employ mat-faced transfer rolls, in which case, the circumferential velocities of the various rolls in the size press are, as a rule, substantially equal to reduce the wear of the roll coatings.
Besides the reduced susceptibility of vibration, a remarkable advantage of the mode of linkage of the rolls illustrated in FIG. 1, compared with the prior art, is the fact that the control of the loading cylinders can be arranged precise, because the roll weights do not have an essential effect on the linear loads. The linear loads in each of the nips N 1 -N 5 in the size press shown in FIG. 1 can be regulated individually by means of the loading cylinders 26,36,46,56,66 so that adjustments of the linear loads in the various nips have no effect on the linear loads in the other nips. The embodiment as shown in FIG. 1 can be also accomplished so that each of the loading cylinders 36,46,56,66 of the gate rolls, i.e. metering rolls 31,51 and the transfer rolls 41,61 is linked directly to the frame 1 of the size press. In such case, the size press rolls communicate with each other exclusively through the frame 1 of linkage of the loading cylinders, however, requires a substantially more accurate and precise system of regulation of the loading cylinders, because the adjustments made in the linear loads in the various nips also affect the linear loads in the other nips. The mode of linkage of the rolls as shown in FIG. 1 also makes it easily possible to employ adjustable-crown rolls as the metering rolls 31,51.
In conventional gate roll size press constructions, it has not been possible to employ adjustable-crown rolls as metering rolls, because their weight is considerably high as compared with ordinary rolls. By means of adjustable-crown metering rolls 31,51 it is easily possible to regulate the profile of coating quantity during operation of the machine. In conventional gate roll size presses, the profile of coating quantity can be affected during operation but regrinding of the rolls.
In FIG. 2, a second embodiment of the invention is illustrated. The device shown in FIG. 2 is denoted generally with the reference numeral 11. In respect to the first applicator roll 11 and the gate rolls 31,41 placed at the side of the first applicator roll, the embodiment of FIG. 2 is identical with FIG. 1, and therefore the same reference numerals are used for corresponding components. Thus, the embodiment of FIG. 2 differs from FIG. 1 in respect of the linkage of the second applicator roll 21 and the gate rolls 51,61 placed at the side of said second applicator roll. The applicator roll loading arm 124 is linked to the frame 1 of the device 110 by means of an articulation shaft 125 transverse to the machine direction in a way similar to that used in the embodiment of FIG. 1. Further, the linkage of the loading cylinder 26 both to the frame 1 of the device and to the applicator roll loading arm 124 corresponds to FIG. 1.
In the embodiment of FIG. 2, the second metering roll loading arm 154 and second transfer roll loading arm 164 have not been linked directly to the machine frame 1 in a way corresponding to FIG. 1, but in the embodiment of FIG. 2, the arrangement is such that the second metering roll loading arm 154 and the second transfer roll loading 164 are linked to the applicator roll loading arm 124 by means of articulation shafts 155, 165 transverse to the machine direction.
The mode of linkage of the loading cylinders 156 and 166 of the second metering roll 51 and the second transfer roll 61 is similar to that shown in FIG. 1, so that the first end 157 of the loading cylinder 156 of the second metering roll 51 is linked to the second metering roll loading arm 154, and its second end 158 is linked to the second transfer roll loading arm 164.
In a corresponding way, one end of the loading cylinder 166 of the second transfer roll 61 is linked to the applicator roll loading arm 124, whereas the opposite end is linked to the second transfer roll loading arm 164 on the same articulation shaft with the loading cylinder 156 of the second metering roll 51.
In a corresponding way, one end of the loading cylinder 166 of the second transfer roll 61 is linked to the loading arm 124 of the second applicator roll 21, whereas the opposite end is the metering rolls 51, 61 are the side of the second applicator roll articulation shaft 125, but the coating nip N 1 can be readily opened to a higher extent than in the embodiment of FIG. 1 to facilitate the replacement of the second applicator roll.
The embodiments shown in FIGS. 1 and 2 can also be used for one-sided coating of the web W. In such a case, as compared with FIGS. 1 and 2, the solution has been simplified so that, for example, the gate rolls 31 and 41 at the side of the first applicator roll 11 are omitted completely in the solution. In such a case, in the coating nip N 1 , the size film that is applied from the second size pond P 2 through the second metering nip N 4 and the second transfer nip N 5 onto the face of the applicator roll 21 and from it further into the coating nip N 1 is spread onto one side of the web W only. In such a solution as well, by means of the suspension of the gate rolls, the same advantages are achieved as in the embodiments shown in FIGS. 1 and 2.
The device in accordance with the invention may be modified in many ways from what is shown in the figures in the drawing. Thus, compared with the figures, the run of the web W may be arranged in the opposite direction, i.e. so that the web W runs from below upwards. In such a case, of course, the senses of rotation of the rolls 11,21,31,41,51,61 are opposite to those shown in the figures, and the ponds P 1 ,P 2 of coating agent have also been arranged below the metering nips N 2 , N 4 .
Further, an alternative embodiment different from the figures is one in which the transfer rolls 41,61 are not loaded separately, but the linear loads in the transfer nips N 3 ,N 5 are provided by means of loading of the metering rolls 31,51. In such a case, differing from the figures, the loading cylinder 36 of the first metering roll 31 is linked, by one of its ends, directly to the frame 1 of the size press, and the loading cylinder 46 of the first transfer roll 41 has been omitted in the construction.
In a corresponding way, in such a case, the loading cylinder 56,156 of the second metering roll 51 is linked, by one of its end, to the applicator loading arm roll 24, 124 or directly to the frame 1 of the size press. In such a case, of course, the loading cylinder 66 or 166 of the second transfer roll 61 has been omitted in the construction. Then, the linear loads can, however, not be regulated equally individually as in the embodiments shown in the figures.
Above, the invention has been described by way of example with reference to the figures in the drawing. The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims. | The invention concerns a device for metering of a coating agent onto a moving base, such as a paper or board web. The device includes first and second soft-faced applicator rolls defining a coating nip, through which nip a web is passed. The first applicator roll is journalled as fixed on a frame of the device, and the second applicator roll is linked to the frame of the device pivotally by the intermediate of a loading arm or the equivalent. At least one of the applicator rolls is in nip contact with a hard transfer roll, which is further in nip contact with a soft-faced metering roll. A pond of coating agent is located in a metering nip between the metering roll and a transfer roll. As the rolls revolve, the coating agent is transferred through the metering nip onto the face of the transfer roll and from there further through a transfer nip formed by the transfer roll and the applicator roll onto the face of the applicator roll. From the applicator roll, the coating agent is transferred onto the web in the coating nip. The metering roll and the transfer roll placed next to the fixed applicator roll and/or the metering roll and the transfer roll placed next to the mobile applicator roll are pivotally linked to the same machine member on the frame of the device. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority of Taiwanese application No. 098100689, filed on Jan. 9, 2009.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a method of making a substrate for a semiconductor device, more particularly to a method of making a substrate with a rough surface for growth of a semiconductor device thereon.
[0004] 2. Description of the Related Art
[0005] A light-emitting device usually includes a substrate, an n-type semiconductor layer, a light-emitting layer, a p-type semiconductor layer, and electrodes. Light generated from recombination of electrons and holes is emitted in the light-emitting layer.
[0006] When light enters an interface between the p-type semiconductor layer and the electrodes at an angle larger than a critical angle, the light is reflected to propagate laterally in the semiconductor layers. However, the light loses its energy during the propagation, thereby lowering the external quantum efficiency. An existing method is generally carried out by processing a light-emitting diode chip to be of a hemispherical form or of a pyramidal form such that light enters the interface at an angle less than the critical angle so as to reduce light reflection. However, such processing is difficult and may damage the chip.
[0007] Another existing method includes roughening the surface of the light-emitting diode. However, the p-n junction may be damaged and the light-emitting efficiency may be adversely affected.
[0008] A conventional semiconductor device includes a substrate having recesses or protrusions for scattering light generated in the light-emitting layer, thereby increasing the external quantum efficiency. The recesses or protrusions in the substrate are created by mechanical polishing or etching. Since the recesses or protrusions are randomly generated, the crystallinity of the grown nitride semiconductor structure is lowered, which adversely affects the light-emitting efficiency. In addition, the method of making the substrate is complicated and incurs high labor and manufacturing costs.
[0009] U.S. Pat. No. 6,870,191 discloses a substrate provided with recesses/protrusions with a specific shape so as to increase crystallinity of the grown nitride semiconductor layers by virtue of the different growth rates of lateral and vertical growth of crystals. However, defects are easily produced at the interfaces of the nitride layers.
[0010] U.S. Patent Application Publication No. 2005/0179130 discloses a semiconductor device and a method of making the same. The semiconductor device includes a substrate formed with recesses/protrusions each of which includes at least two surfaces having different inclination angles. However, the method is complicated and incurs high manufacturing costs.
SUMMARY OF THE INVENTION
[0011] Therefore, an object of the present invention is to provide a method of making a rough substrate for growth of a semiconductor device that can address the problems encountered in the aforesaid prior art.
[0012] According to the present invention, a method of making a rough substrate comprises: (a) forming a first oxide layer on a substrate layer; (b) coating a photoresist layer on the first oxide layer; (c) exposing and developing the photoresist layer to form a plurality of spaced-apart photoresist regions; (d) etching parts of the first oxide layer uncovered by the photoresist regions such that portions of the substrate layer are exposed and such that parts of the first oxide layer shielded by the photoresist regions are formed into a plurality of spaced-apart sacrificial protrusions on the substrate layer; (e) removing the photoresist regions on the sacrificial protrusions; (f) depositing on the substrate layer and the sacrificial protrusions a second oxide layer; (g) etching the second oxide layer so as to expose the sacrificial protrusions and portions of the substrate layer and so as to leave rounded lateral portions of the second oxide layer which surround the sacrificial protrusions, respectively, and which have a rounded surface profile; and (h) etching additionally the sacrificial protrusions and the substrate layer which have been exposed, and the rounded lateral portions of the second oxide layer which respectively surround the sacrificial protrusions until a plurality of flat recess bottom faces are formed in the substrate layer, thereby producing substrate protrusions protruding from the flat recess bottom faces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of this invention, with reference to the accompanying drawings, in which:
[0014] FIGS. 1 a to 1 h are sectional views to illustrate consecutive steps of the first preferred embodiment of a method of making a rough substrate according to this invention;
[0015] FIG. 2 is a sectional view of the rough substrate made by the first preferred embodiment;
[0016] FIGS. 3 a to 3 f are sectional views to illustrate consecutive steps of the second preferred embodiment of a method of making a rough substrate according to this invention;
[0017] FIG. 4 is a sectional view of the rough substrate made by the second preferred embodiment;
[0018] FIG. 5 a is a top view of protrusions arranged in a matrix array; and
[0019] FIG. 5 b is a top view of the protrusions arranged in a random pattern.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Before the present invention is described in greater detail with reference to the accompanying preferred embodiments, it should be noted herein that like elements are denoted by the same reference numerals throughout the disclosure.
[0021] FIGS. 1 a to 1 h illustrate the consecutive steps of a method of making a rough substrate for growth of a semiconductor device according to the first preferred embodiment of this invention. The semiconductor device includes a plurality of semiconductor layers.
[0022] Referring to FIGS. 1 a and 1 b, a first oxide layer 11 is formed on a substrate layer 10 .
[0023] Referring to FIG. 1 c, a photoresist layer 12 is coated on the first oxide layer 11 , and is exposed and developed to form a plurality of spaced-apart photoresist regions 121 .
[0024] Referring to FIG. 1 d in combination with FIG. 1 c, parts 111 of the first oxide layer 11 uncovered by the photoresist regions 121 are etched such that portions 101 of the substrate layer 10 are exposed and such that parts of the first oxide layer 11 shielded by the photoresist regions 121 are formed into a plurality of spaced-apart sacrificial protrusions 112 protruding from the substrate layer 10 .
[0025] Referring to FIG. 1 e, the photoresist regions 121 on the sacrificial protrusions 112 are removed.
[0026] Referring to FIG. 1 f, a second oxide layer 12 is deposited on the substrate layer 10 and the sacrificial protrusions 112 .
[0027] Referring to FIG. 1 g, the second oxide layer 12 is etched so as to expose the sacrificial protrusions 112 and portions 105 of the substrate layer 10 and so as to leave rounded lateral portions 122 of the second oxide layer 12 which surround the sacrificial protrusions 112 , respectively, and which have a rounded surface profile. The rounded lateral portions 122 of the second oxide layer 12 are spaced apart from each other. The etching in this step may be wet etching or dry etching.
[0028] Referring to FIG. 1 h in combination with FIGS. 1 f and 1 g, the sacrificial protrusions 112 and the portions 105 of the substrate layer 10 which have been exposed, and the rounded lateral portions 122 of the second oxide layer 12 which respectively surround the sacrificial protrusions 112 are additionally etched until a plurality of flat recess bottom faces 100 are formed in the substrate layer 10 , thereby producing substrate protrusions 102 protruding from the flat recess bottom faces 100 . The etching in this step may be dry etching.
[0029] The substrate layer 10 may be made from a suitable transparent or non-transparent material, or a conductive or nonconductive material. In this embodiment, the first and second oxide layers 11 , 12 are made from silicon dioxide (SiO 2 ) or silicon nitride (SiN). The substrate layer 10 is made from a material selected from the group consisting of silicon (Si), sapphire, silicon carbide (SiC), spinel (MgAl 2 O 4 ), aluminum nitride (AlN), copper tungsten (CuW), and combinations thereof.
[0030] It is worth mentioning that the sacrificial protrusions 112 and the rounded lateral portions 122 can serve as a mask for buffering the action of etching. Accordingly, when etching is conducted in step ( 1 g ) to etch the substrate layer 10 , the portions 105 of the substrate layer 10 uncovered by the sacrificial protrusions 112 and the rounded lateral portions 122 are etched first and recessed. Portions of the substrate layer 10 below the sacrificial protrusions 112 and the rounded lateral portions 122 are etched next and formed into the substrate protrusions 102 . The substrate protrusions 102 have a rounded surface profile corresponding in shape to the rounded lateral portions of the second oxide layer 12 .
[0031] Preferably, the substrate protrusions 102 have the shape of a circle, an oval, a triangle, a quadrangle, a hexagon, a rhombus, or a polygon, when viewed from a top side of the substrate protrusions 102 .
[0032] It is worth mentioning that each of the sacrificial protrusions 112 of the first oxide layer 11 and the rounded lateral portions 122 of the second oxide layer 12 can be varied in shape according to a desired light emitting power of the semiconductor device.
[0033] Referring to FIG. 2 , the rough substrate made by the first preferred embodiment of the method includes a plurality of the substrate protrusions 102 protruding from the flat recess bottom faces 100 . Each of the substrate protrusions 102 has a planar top surface 104 , and a rounded sidewall 103 that extends annularly and downwardly from the planar top surface 102 to a contiguous one of the flat recess bottom faces 100 . The substrate protrusions 102 are spaced apart from each other by a distance (A) ranging from 0.5 μm to 5 μm. The planar top surface 104 has a largest width (C) ranging from 0.5 μm to 5 μm. The rounded sidewall 103 has a top end 1031 meeting the planar top surface 104 and a bottom end 1032 meeting an adjacent one of the flat recess bottom faces 100 . The rounded sidewall 103 has a length from the top end 1031 to the bottom end 1032 that produces a projected length (B) when projected onto a projection plane parallel to the flat recess bottom face 100 . The projected length (B) is about 1-2 times a distance (A) between adjacent ones of the substrate protrusions 102 . Moreover, the rounded sidewall 103 has a tangent line intersecting the bottom end 1032 of the rounded sidewall 103 . The tangent line is inclined with a plane coplanar with the flat recess bottom faces 100 by an angle (θ) of about 25°-75°. The rounded sidewall 103 has a chordal line interconnecting the top and bottom ends 1031 , 1032 thereof. The chordal line is inclined with a plane coplanar with the flat recess bottom faces 100 by an angle (θ m ) which is smaller than 45°.
[0034] By virtue of the substrate protrusions 102 , defects of the semiconductor device can be reduced, thereby enhancing the external quantum efficiency and the light extraction efficiency.
[0035] FIGS. 3 a to 3 f illustrate the consecutive steps of a method of making the rough substrate according to the second preferred embodiment of this invention.
[0036] Referring to FIGS. 3 a and 3 b , a photoresist layer 12 ′ is coated on a substrate layer 10 ′.
[0037] Referring to FIG. 3 c , the photoresist layer 12 ′ is exposed and developed to form a plurality of spaced-apart photoresist regions 121 ′ on the substrate layer 10 ′.
[0038] Referring to FIG. 3 d , a reflective layer 13 is deposited on portions of the substrate layer 10 ′ uncovered by the photoresist regions 121 ′ and on the photoresist regions 121 ′.
[0039] Referring to FIG. 3 e in combination with FIG. 3 d , the photoresist regions 121 ′ are lifted-off such that the reflective layer 13 on the photoresist regions 121 ′ is removed and the reflective layer 13 left on the substrate layer 10 ′ is formed into a plurality of space-apart protrusions 131 protruding from a surface 101 ′ of the substrate layer 10 ′.
[0040] Referring to FIG. 3 f , the protrusions 131 are oxidized to produce oxidized skin layers 14 on the protrusions 131 , respectively.
[0041] Preferably, the protrusions 131 have the shape of a circle, an oval, a triangle, a quadrangle, a hexagon, a rhombus, or a polygon, when viewed from above the protrusions 131 .
[0042] Preferably, the reflective layer 13 is made of a material selected from the group consisting of aluminum (Al), silver (Ag), and combinations thereof. Alternatively, the reflective layer 13 can be a distributed Bragg reflector.
[0043] Preferably, the substrate layer 10 ′ is made from a material selected from the group consisting of silicon (Si), sapphire, carbon silicon (SiC), spinel (MgAl 2 O 4 ), aluminum nitride (AlN), copper tungsten (CuW), and combinations thereof.
[0044] Referring to FIG. 4 , the rough substrate made by the second preferred embodiment of the method includes a plurality of the protrusions 131 . The protrusions 131 are spaced apart from each other by a distance (A′) ranging from 0.5 μm to 5 μm. Each of the protrusions 131 has a planar top surface 211 , and a truncated cone-shaped sidewall 212 extending annularly and downwardly from the planar top surface 211 . The planar top surface 211 has a width (C′) ranging from 0.5 μm to 5 μm. The truncated cone-shaped sidewall 212 has a top end 2121 meeting the planar top surface 211 and a bottom end 2122 meeting the surface 101 ′ of the substrate layer 10 ′. The truncated cone-shaped sidewall 212 has a length from the top end 2121 to the bottom end 2122 thereof, that produces a projected length (B′) on a projection plane coplanar with the surface 101 ′ of the substrate layer 10 ′. The projected length (B′) is 1-2 times a distance (A′) between adjacent ones of the protrusions 131 .
[0045] In this embodiment, an inclining angle (θ m ′) of the truncated cone-shaped sidewall 212 with respect to the surface 101 ′ of the substrate layer 10 ′ is smaller than 45°.
[0046] Likewise, by virtue of the protrusions 131 , defects of the semiconductor device can be reduced, thereby enhancing the external quantum efficiency and the light extraction efficiency.
[0047] In addition, by oxidizing the protrusions 131 , the oxidized skin layers 14 on the protrusions 131 can be the same material as the substrate layer 10 ′.
[0048] For example, the substrate layer 10 ′ is sapphire (Al 2 O 3 ) and the reflective layer 13 is made of aluminum (Al). When the reflective layer 13 is oxidized to produce the oxidized skin layer 14 , the oxidized skin layer 14 is aluminum oxide (Al 2 O 3 ) which is identical to the material of the sapphire substrate layer 10 ′. Therefore, the rough sapphire substrate has a surface layer that contains aluminum oxide (Al 2 O 3 ) like the remaining part of the rough sapphire substrate.
[0049] Referring to FIG. 5 a , the substrate protrusions 102 made by the first preferred embodiment, or the protrusions 131 made by the second preferred embodiment have a circular profile when viewed from a top side and are arranged in a matrix array.
[0050] Referring to FIG. 5 b , the substrate protrusions 102 or the protrusions 131 can be arranged in a random pattern.
[0051] It is worth mentioning that when the substrate protrusions 102 or protrusions 131 are regularly formed, external extraction efficiency of the light-emitting device can be increased and crystal defects in the semiconductor layers can be prevented when grown on the substrate of this invention.
[0052] With the invention thus explained, it is apparent that various modifications and variations can be made without departing from the spirit of the present invention. It is therefore intended that the invention be limited only as recited in the appended claims. | A method of making a rough substrate includes: (a) forming a first oxide layer; (b) coating a photoresist layer; (c) exposing and developing the photoresist layer; (d) etching parts of the first oxide layer such that parts of the first oxide layer are formed into a plurality of sacrificial protrusions; (e) removing the photoresist regions; (f) depositing on the substrate layer and the sacrificial protrusions a second oxide layer; (g) etching the second oxide layer so as to leave portions of the second oxide layer; and (h) etching additionally the sacrificial protrusions, the substrate layer, and the portions of the second oxide layer, thereby producing a plurality of flat recess bottom faces, and substrate protrusions. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
The Applicants claim the benefit of provisional patent application No. 62/231,860 filed on Jul. 17, 2015.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an electronic control system and method of operation for an automatic motorized gate operator. The invention provides for connection of a plurality of switching safety edges and photo eye obstruction detection systems to control a motorized gate operating unit which has fewer monitored control inputs than the number of monitored edges required in an application.
2. Description of the Related Art
Motorized doors and gates are used for everything from residential garages to industrial moving, rolling or sliding doors and gates. In this disclosure, any reference to the term “gate” or “gate systems” also applies to “door” or “door systems.” For many years, it has been a best practice and frequently a legal safety requirement to provide an obstruction protection mechanism to stop a motorized gate moving along a given track when the gate has an obstruction that will strike the gate if the motor driving the gate is not stopped. Many automatic doors or gates, particularly those such gates used in industry, have a gate operating unit which controls the power to the motor to open or close the motorized gate along its normal path.
The most common devices used to detect obstructions are photo beams and safety edges. Photo beams monitor a continuous path between a light emitter and a light receiver. Constant presence of the light beam between the transmitter and receiver signals no obstruction in the path, and an interrupted beam would indicate an obstruction or possibly failed sensor. It is desirable in monitored systems to recognize either event. Likewise, safety edges are switching devices placed along leading edges of moving doors or gates which change switching states upon obstruction contact to any portion of the switch.
To detect a fault in the switch as a fail-safe requirement, the switch is monitored to confirm continuity of the switch as a closed circuit. Upon activation from contact with an obstruction, the switch changes electrical state. Typical normal state continuity resistance is set to ten thousand ohms (“10KΩ”). Compression of typical edge switches along its length measures a short circuit and an open circuit measurement signals a fault in the edge or the associated wiring.
Monitoring for safety by detecting obstructions in the path of gates or moving doors is not new, but changes in safety regulations or best practices have required new methods of monitoring and an evolution in hardware to do so. There are recent changes in recognized standards for monitoring motorized gates in particular. Underwriters Laboratories® (“UL”) and the American Society for Testing and Materials® (“ASTM”) are the most well know examples of standard promulgating entities that have presented a need to increase monitoring of the number of possible entrapment areas in a moving gate.
A new UL 325 standard is a safety standard for door, drapery, gate, louver, and window operators and systems. Specifically, it applies to electric operators for doors, draperies, gates, louvers, windows and other opening and closing appliances. Similarly, ASTM F2200 is a standard that pertains to automated vehicular gates. ASTM F2200 recognizes five gate classifications: horizontal slide, horizontal swing, vertical lift, vertical pivot, and overhead pivot. UL325 was updated to require additional obstruction detecting devices for most gate installations. These updates became effective Jan. 12, 2016. The present disclosure relates to a system that addresses a need to interface more edge and obstruction monitoring sensors using existing gate operators which have less sensor inputs than the number of sensor required.
In the case of a garage door, a photo beam can detect the presence of an obstruction near the floor, while a safety edge can detect obstructions anywhere along the path of travel. The entrapment area is always the door opening, and is only of concern when the door is moving in the closing direction. A garage door closing may contact an obstruction or hazard on the way down, closing a switch when contacted the obstruction. Photo eye beams break continuity when the obstruction is present breaking the beam.
Alternately, a gate installation will likely have multiple entrapment areas, each of which may need to be guarded by entrapment protection devices. These entrapment zones may be further complicated as both directions of travel (opening and closing) need to be considered. Examples of the applications to which the invention is applied are found in standards publications such as an application drawing found at DASMA ASTM F2200. In the most complicated case, six entrapment detection devices may be required to guard all of the entrapment zones of a motorized gate.
In motorized, moving gate systems particularly, the direction of travel of the moving gate, laterally in relation to the ground in most instances, requires protecting several different areas around the gate to sense obstructions. Typically both edge sensors and photo eye type sensors are employed. With motorized gates, more than one of each type sensor is needed to protect up to four or five areas, such areas of the gate traveling in a reversible lateral direction. Leading and trailing edges of a gate need be protected and the gate movement area in each instance also need be protected from obstruction before an edge switch might contact an obstruction. Similar situations exist for swing gates and vertical lift gates. An interface device is needed to provide for such multiple inputs from safety edge or obstruction devices protecting a moving or motorized gate.
Accordingly, a device and method is needed in which the user of a motorized gate safety sensing system can use multiple sensor inputs ranging from edge sensing switch devices to photo eye devices commonly used in the industry. A system which allows retrofitting of existing gate operating units which provide for fewer sensor inputs than required for a multi sensor application would be useful. Such a conversion must maintain the safety conditions afforded by monitoring the operational readiness of the several switching edge protection devices while also monitoring multiple photo eye sensors, all controlling the same door operator.
It is the object of the present invention to provide an interface device which will allow a motorized gate operating unit to accept the application of a plurality of edge or area protecting devices without changing or modifying an existing gate operating unit which does not provide for a sufficient number of inputs. The disclosed invention could be used in new installations or to update existing installations.
It is further the object of the present invention to provide a conversion device to allow a motorized gate operator with a limited number of inputs to accept inputs from more device controlling or protecting gate edges in each operational direction by the door operating unit.
It is also the object of the present invention to provide a method of retrofitting an existing installation of a motorized gate or door with obstruction protection having a motor controller with insufficient input ports to accommodate multiple sensor edges and photo-eye type protective devices.
It is a further object of the present invention to accept multiple devices each of which use different signaling technologies and all of which require monitoring without the requirement of changing the controller or applying different power requirements.
SUMMARY OF THE INVENTION
The Underwriter's Laboratory® (“UL”) standard for safety entrapment devices used on commercial doors and gates sets standards to enhance the safety of the public when using such motorized doors. While compliance to the standard is voluntary, the majority of commercial door and gate operators have modified their products in order to be in compliance with the new standard, considered best practices in the industry.
The most significant change to the standard requires gate operators, sometimes also referred to as gate controllers, (the mechanical linkages, motors and control circuits) to have at least one “monitored” external entrapment device. The term “monitored” defines a device that generates a unique signal such that the monitoring equipment, i.e. the operator, can determine that the device is connected and working properly. A monitored entrapment device for motorized gates therefore applies a fail-safe protocol to assure that the safety device itself is always operational, and stops the system if the safety device reports a failed condition of the device. Current best practices include protecting a motorized gate or door at multiple locations for each direction of travel.
Since motorized gates present possible hazards when opening and closing, use of multiple edge protection switching devices as well as photo eye obstruction devices may require four or five inputs to a motor controller for a single application. Different types of edge protection devices use different operational technologies and signaling characteristics. Though it is possible to design a motor door operator or controller which would provide input ports all of which are designed to monitor each separate protection device, a typical motorized gates controller may have only one or two inputs, typically one for each direction of travel. If five or six edge protection devices are used in a given installation, monitoring each protection device and controlling the gate operator becomes an issue.
In order to solve this problem, it would be desirable to have a multi-input interface device for motorized gates operators that would allow monitoring of multiple edge or area protection devices, switches or photo eye, but connect to an operator with less inputs than required for the gate or door being protected. The optimum design would be a system or device consisting of apparatus which serves as a solution to the described problem. Both a method and a system of retrofitting existing installations would be very advantageous.
In summary, the apparatus and method described both monitors a plurality of door or gate switch edge for its termination and checks the edge for activation. The invention controls a motorized door or gate operator with fewer than the required input ports in the same fashion as if the control provided adequate ports for monitoring many different protection edge devices including photo eye area monitoring. A firmware program operates a typical microprocessor to run through a learning mode to poll the edge devices and learn the signaling characteristics of each type connected. For each type of device, an output port can be selected by the user.
A failed termination device or other change of the electrical conditions of the switch because of failure or an activation of the switch result in the loss of signal to the operator and the door or gate stops and/or opens depending on the programmed set up of the door operator. The invention is a field replacement system for an existing switching edge and/or photo eye monitored automatic gate which functions with the existing monitored gate operator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating available input configuration of a typical device used for one of the inputs of the invention.
FIG. 2 is a block diagram illustrating a typical configuration for use of the invention with different entrapment protection device formats and the six device input ports which can be associated with two separate outputs ports.
FIG. 3 is a block diagram of an auxiliary relay used to control power to a typical normally closed monitoring device used with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The general description of the Multi-Input Module (“MIM”) provided below may be considered with reference to the Figures in which like numerals relate to like parts. FIG. 1 is a block diagram of one entrapment protection device used with the invention. FIG. 2 is a block diagram of the invention's architecture demonstrating connection of two or more devices to the invention with at least two output ports for connection to a motorized door or gate operator. The example presented has six inputs for entrapment protection devices and two outputs to a motorized gate (or door) operator. Though not widely needed, it can be appreciated that more than two outputs ports can be configured in an embodiment. In general, any combination where there are more devices than operator control inputs can use the invention. An embodiment of the invention made strictly for the motorized door industry might only have two inputs and one output. However, motorized gates now require more devices for suitable entrapment protection.
Most current gate operators do not have enough inputs to accept more than one or two devices in each direction. The current UL 325 requirements may create situations where more devices are required than can be accepted by the operator. The present disclosure will make it possible to connect more devices. The invention also accounts for unused inputs in the event less than all the inputs are actually used in a given installation. In the preferred embodiment shown in FIG. 2 , there are six universal input ports for up to six entrapment sensing devices 12 , 14 , 16 , 18 , 20 and 22 . These will accept normally closed (“NC”), pulsed, and resistor terminated devices. Each input can be associated with either of the two outputs 26 or 28 . The outputs can be set for resistor terminated, pulsed or NC mode each of which will have different characteristics for a motorized gate operator. The invention is housed in a metal chassis which is intended to be mounted inside the chassis of a gate operator.
As to requirements for a power supply, this device will be connected to the standard operator voltages (typically 12 VDC to 24 VAC). DC power can be available to the accessory devices. Each input port will have four connections: two for power 42 and 36 and two for signal out from the entrapment sensing device 38 and 44 . A 10KΩ pull-up resistor 32 is sufficient for the NC and pulsed logic levels, and provides the range needed to monitor a resistor termination via an analog to digital converter. There is one LED associated with each input to indicate operation.
The outputs 26 and 28 will be either opto-relays or mechanical relays. They can be selected as either NC, resistor terminated or pulsed (independently), via a dual inline package) (“DIP”) switch selected by the user, or other user input selection methods. There is an LED for each output that indicates a fault mode. Each input can be assigned to either output A 26 or B 28 . This will be done via a DIP switch in the user selectable input/output association 24 . FIG. 2 discloses the relationship of each entrapment device to the MIM inputs 50 through 60 inclusive.
After installation of the preferred embodiment and it is configured properly and there are no faults from any of the devices, the installer can initiate a sequence to execute a program in firmware which will examine each input 12 , 14 , 16 , 18 , 20 , and 22 to determine which type of device is connected to a given input: NC, pulsed, resistive, or absent. A status LED can be configured to blink to indicate that this is in process. Once complete, the input channel information determined by the firmware routine will be stored in an EEPROM and normal operation will begin. Prior to this configuration procedure, the outputs 26 and 28 will be in a fault mode, and the microprocessor will continuously scan the inputs to assist the installer with the setup.
During a learn mode, any input that is near Vcc/2 will be considered a resistive termination, in the United States typically 10KΩ is used. With configured firmware set up to do so, any input that is HI for 10 ms will be considered not connected. The remaining inputs will be examined for pulsed or NC. During normal operation, any active input that is HI for more than 10 ms will be considered in fault. If a resistive input is LO, it will be considered a fault.
There are two aspects of the innovation in the MIM disclosed as a preferred embodiment. The first is an input design that allows for automatic recognition of any of the three common monitored input interfaces: normally closed, pulsed, and a typical 10KΩ termination. The invention takes advantage of the flexibility found in many microprocessors which allows a single pin to be configured as an analog or digital input. This allows the invention to identify and monitor the three different types of interfaces with a single set of hardware. As described above, the invention can also detect whether a device is not connected or is faulty.
The second aspect of the invention is using computer firmware in a microprocessor to logically detect the type of each device and then to generate an appropriate output signal for the gate operator. The output signal will report a fault condition if any of the inputs are in fault. Restated, in order to report a “good” condition to the operator, every input must also report a “good” condition.
In the preferred embodiment, the invention provides for up to six device inputs and two outputs for the operator. The user can associate the inputs with the outputs via DIP switches. Also, the user can select one of two output formats via different DIP switched. For example: an installation may require five entrapment protection devices, two in the gate close direction and three in the gate open direction. Reference is made to FIG. 2 and the example presented below. The installation table would present as follows:
Input #
Device Type
Location
Output A/B
1
Normally Closed
Photo-eye
A
(Close)
2
Pulsed (Wireless
Leading edge
A
switch)
(Close)
3
Normally Closed
Photo-eye
B
(Open)
4
10K Edge
Draw-in post
B
edge (Open)
5
Pulsed (Wireless
Trailing edge
B
Switch)
(Open)
6
Not used
The User would set the DIP switch to associate channels 3, 4, and 5, ( 16 , 18 , 20 ) to Output B 28 . After executing a learn firmware routine, the MIM would recognize that Input 6 ( 22 ) is not used.
Every input has a 10K pull-up resistor 32 and is connected to an analog-to-digital converter (“ADC”) within microprocessor 25 . Firmware which operates microprocessor 25 checks each input to determine if the observed voltage is HI, LO, or in the Middle. If the device connected to the input has a 10KΩ resistance to ground, it will read in the Middle. The MIM firmware is configured to have two modes: learn and run. The first time the invention is powered-up, it defaults to learn mode. In learn mode, each input is checked for HI, LO, or Middle. If the input reads Middle, it is assigned as a 10KΩ device. If the input is LO, it is assigned as a Normally Closed device. If the input is HI, it is assigned as No Connect. These inputs are checked several times, and if an input toggles between HI and LO, it is re-assigned as a pulsed device. When all of the external devices are connected and configured to be in a good (functioning) state, the user will press a learn button (or a software command, or other user input method). These settings will be saved into non-volatile memory, (“saved mode”), and then the MIM will go into the beginning of run mode.
In run mode, the MIM repeatedly checks each input against the set up parameters entered in the saved mode. On power-up, certain extra steps are required for the normally closed interface. To confirm the presence of this type of device, an auxiliary relay 40 is used to control the power to the devices. This type of relay 40 to power input devices is shown in FIG. 3 . Relay control is part of the operating firmware and processor 25 can activate relay 40 though relay control pin 46 as shown.
First, this power is kept off (relay open) and each normally closed device input is checked to make sure it reads HI, indicating that the external device is in fault mode (open). If any of these inputs read LO (short), an error is flagged, as the external device is considered faulty. The MIM is configured to stop at this point, and no further actions will occur.
If all of the normally closed inputs read HI, then the auxiliary relay 40 is closed, providing power to devices 12 , 14 , 16 , 18 , 20 and 22 . Normal operation continues at this point, where any LO signal is considered good, and any middle or high signal is considered Fault. The pulsed and 10KΩ termination inputs do not do anything special on power-up. For 10KΩ devices, any input that is HI (disconnected) or LO (active) is considered a fault.
For pulsed devices, the input state must change from HI to LO, or LO to HI within a defined period (usually 10 ms). If the state does not change in this period, it is considered a fault. Note that in all cases, a missing external device will cause a continuous HI input, which will be reported as a fault. Inputs marked as not used are ignored. In the preferred embodiment, a method is provided to allow for reconfiguration through user inputs by selecting the learn mode. It can be appreciated that this procedure can be made to be complicated enough that a user cannot easily disable the input to a device inadvertently.
Although the invention has been described in accordance with the preferred embodiment, it will be appreciated by those skilled in the art that the application of the present invention is useful in a variety of configurations and designs not specifically described above. All such designs and applications are considered to be within the scope of the present disclosure, and the invention is applicable across a wide variety of applications. Such applications are considered within the scope and spirit of the present invention. In so far as the description above and the accompanying drawings disclose any additional subject matter that is not within the scope of the claims, the inventions are not dedicated to the public and the right to file one or more applications to claim each such additional inventions is reserved. | A system and method which allows automatic recognition of any of three common monitored motorized door or gate safety edges or other entrapment protection devices. The invention allows retrofitting existing motorized door operators without enough monitored input ports to allow for more monitored entrapment devices required on laterally moving motorized gates. The system interfaces with obstruction monitoring devices in normally closed, pulsed, or resistive termination operating environments found in entrapment protection systems. Firmware logically analyzes the state of each edge or entrapment protection device to select and direct an appropriate output signal for a motorized gate operator. An operational example is disclosed which provides for up to six different device inputs and two separate outputs for the motorized door operator, which can be configured through dual inline package switches allowing field configuration. | 4 |
FIELD OF THE INVENTION
The present invention relates to detergent compositions, and methods of making them, that are useful for warewashing (i.e., washing of tableware, cutlery, etc.), particularly in large-scale commercial food service operations.
BACKGROUND OF THE INVENTION
Traditionally, food service equipment, tableware, serving utensils and other reusable food service items have been cleaned with solutions of alkaline detergents in a spray washing type machine, typically a dish washing machine or a pan washing machine. The cleaning operation is fairly straightforward and requires adequate water temperature and pressure, in combination with alkaline builders and other detergent ingredients to effectively emulsify the greases and oils and loosen and suspend the soils that are present and to allow them to be freely rinsed away from the tableware with a final rinse.
Presently available solid cast alkaline detergent compositions provide a uniform formulation throughout the life of the product (see for example those disclosed in U.S. Pat. Nos. RE32,818 and 32,763). However, providing a constant concentration of all formulation components can provide significant disadvantages.
Aside from mechanical operating conditions and limitations, including temperature, the greatest detriment to proper adequate cleaning and bright clean, spot-free, film-free results on the tableware has been water hardness. Other aspects of cleaning such as soil load, etc., are usually handled by increasing or varying the balance of alkaline components within the basic formulation. The results gained are not appreciably different with any alkaline component, be it an alkali metal hydroxide, an alkaline silicate or, for that matter in many cases, an alkaline phosphate or carbonate. The detrimental effects of hard water are handled in institutional and commercial warewashing and spray washing operations by either putting a water conditioning system in place before the cleaning operation or formulating the product to contain high levels of water conditioning agents. The most effective of these water conditioning agents are the complex phosphates which offer the benefits of synergistic enhancement of hard surface detergency and water softening.
However, the use of constant and sustained high levels of phosphates has significant disadvantages. For example, (1) high phosphate concentrations have a negative environmental impact; (2) high levels of complex phosphates are expensive components of a detergent formulation; and (3) the high level of phosphate required to effectively control or eliminate a lime/scale buildup are often high enough to unbalance the formula away from the effective cleaning material (i.e., the alkaline builder) toward the low alkalinity complex phosphate which is being used to control water hardness.
In practice, a commercial or institutional warewashing operation using hard water must periodically descale their washing machines with an acidic compound, which dissolves the lime/scale and restores the machine to its original bright finish. All acidic descalers have a corrosive effect on machine parts and/or plumbing. Unfortunately, this method does not eliminate film and buildup which may occur on the actual tableware and be highly noticeable on glass and crystal. To enhance results and offer film removal and reduced streaking on these types or surface, it is not unusual to use extremely high detergent concentrations to over condition the water or to use acidic or conditioning rinse aids which are substantially more costly than the ordinary sheeting agents used to accelerate the drying of tableware in machine washing operations. Furthermore, the washing equipment must be shut down during the deliming/descaling process, resulting in a loss of productive washing time.
It would, therefore, be desirable to provide a warewashing detergent composition that provided adequate detergency while also removing lime and scale from the washing equipment in which it is used. It would also be desirable to provides such a composition that would provide these deliming/descaling benefits without the need to shut down the washing equipment for the cleaning operation.
In many washing applications it may also be advantageous to provide varying degrees of active agents throughout the life of a detergent product. For example, it may be desirable to provide extra cleaning power at the end of product life before the detergent composition is changed in order to assure that alkalinity concentration is not depressed during the changeover process. It would therefore be desirable to provide detergent compositions which provided a heightened level of alkalinity as the product was used.
It may also be advantageous to periodically provide a strong dose of formulation components to provide other benefits. For example, use of high concentrations of silicates have been demonstrated to replenish glaze on the surface of china and other glazed table ware. It would therefore be desirable to provide detergent compositions in which the concentration of silicate is periodically increased to provide this replenishing effect.
It may also be advantageous to reduce the conductivity of the detergent solution produced by use of a solid cast alkaline detergent composition. Reducing the conductivity of late in the product life would cause the washing machine to increase the rate of dissolving the detergent composition, resulting in a higher concentration of active ingredient in the machine washing solution. It would therefore be desirable to provide a solid cast detergent product which would provide this type of variation in conductivity.
These and other advantages are provided by the present invention.
SUMMARY OF THE INVENTION
The present invention provides solid cast alkaline detergent compositions which are stratified (i.e., nonuniform) and provide a reproducible varying concentration of certain formulation components throughout the composition. In use, these detergent compositions provide an increasing or decreasing concentration of one or more formulation components as tile product is used.
Stratification of the detergent compositions is achieved by providing the formulation components to be stratified in granular (i.e. larger than about 100 mesh) form. The granular component or components are added to a molten detergent suspension comprising an active alkalinity source and water of hydration, in addition to other formulation components typically found in this type of composition, while maintaining the temperature of the suspension at a level sufficient to provide low viscosity. Because of its granular nature, the granular material will not completely dissolve in the saturated detergent composition and, because of its density relative to the suspension, will stratify to produce a variation in concentration from the top to the bottom of the composition.
Any material suitable for use in a solid cast alkaline detergent composition available in a granular form can be stratified in accordance with the present invention. In preferred embodiments, sodium tripolyphosphate (STPP), caustic, metasilicate, and sodium carbonate are stratified. More than one formulation component can be stratified, such as both STPP and caustic. Components may also be stratified in opposite orientations of the varied concentration gradient. For example, STPP may be stratified from top to bottom of a composition in increasing concentration, while caustic is stratified from bottom to top in increasing concentration.
In certain preferred embodiments, the solid cast detergent compositions of the present invention allow for the automatic, periodic deliming or descaling of both the washing machine and the tableware being washed therein. The solid cast alkaline detergent compositions of the invention are non-uniform in composition and provide an increasing concentration of water conditioning material as the composition is consumed. Thus, as the composition is used, the amount of water conditioning increases to the point where the concentration of conditioning materials is sufficient to delime/descale the washing machine while the composition is in use.
Any granular water conditioning material can be used in practicing the present invention, although complex phosphate materials are preferred. Suitable phosphate materials include, sodium tripolyphosphate (STPP), tetrasodium pyrophosphate (TSPP), sodium hexametaphosphate (SHMP), and sodium trimetaphosphate (STMP), along with their other alkali metal analogs, particularly potassium analogs (such as, for example, potassium tripolyphosphate). STPP is particularly preferred and can be used in any of its commercially available granular forms. Dense granular STPP in its coarsest commercially available forms is particularly preferred.
In certain preferred embodiments, the composition is cast within a jar or similar type disposable container (such as that shown in FIGS. 1 and 2). In such embodiments, the composition is manufactured such that there is a higher concentration of water conditioning material at the bottom of the container than at its top. The container is typically inverted during use, such that the opening in the top of the container is placed over a controlled spray stream of water (as shown in FIG. 3). The water spray impinges on the surface of the detergent composition, dissolving the solid to form a detergent solution. The detergent solution then flows into the wash tank of the machine. The initially dissolved solid contains a significantly smaller amount of water conditioning material than the bottom of the container, which will be the last part dissolved from the inverted container as the stream of water continues to dissolve the composition.
The water conditioner (such as for example, phosphate and/or other suitable materials) level throughout the jar preferably should be adequate to maintain balanced detergency and threshold water conditioning effect even where minimal conditioner concentrations are present. As the product is consumed, the conditioner concentration preferably increases so that during the consumption of the last about 20-25 percent of the container the concentration of conditioner is sufficient to not only condition the water but also to purge, clean and actually descale and delime both the machine and the tableware being washed. The phosphate concentration in the last portions of the composition is preferably high enough to, in most cases, completely eliminate or at the very least significantly reduce any film or scale buildup which may have occurred during the usage of the early part of the composition. The end result is to provide an effective product, minimizing raw material costs and adding the regular, periodic extra phosphate level needed to eliminate any detrimental effects of high water hardness levels without descaling.
Methods are also disclosed for making the compositions of the present invention. The stratification of phosphate content within the compositions is produced by controlling the viscosity of the molten detergent suspension which hardens into the solid cast detergent composition such that the phosphate components can stratify as the composition is cooled. Temperature control is the most important factor in producing the desired stratified effect, although other means for controlling viscosity and the stratification effect can also be used. Physical form, granulation and density of the formulation components can also have significant effects of the stratification of the resulting product.
In certain preferred embodiments, formulation components, including water and an active alkalinity source (such as an alkali metal hydroxide), are mixed. The temperature of the mixture is then adjusted to provide the desired viscosity of the molten detergent suspension. The granular material to be stratified is then added to the suspension. The appropriate viscosity is that which will provide the desired degree of stratification for a specific composition upon cooling. The molten suspension is then allowed to cool and solidify in a useable form (such as, for example, a cast block in a disposable jar).
Although formulation components can be mixed is any suitable order, typically the component to be stratified is added in its granular form as the last component to the molten detergent suspension. This allows greater maintenance of the granular form of the material, reducing dissolution of the material into the suspension. Dissolution of the granular material will, in most instances, result in reduction or elimination of the stratification of the granular material.
In certain preferred embodiments, the molten detergent suspension is also rapidly cooled in order to reduce or minimize degradation of the water conditioning material (such as for example, reversion of complex phosphates) to form degradation products (such as for example, orthophosphate). Reducing degradation of the water conditioning material maintains the water conditioning activity of the compositions.
In composition incorporating complex phosphate as the water conditioning material, it is preferred to prevent a substantial level of orthophosphate from forming the composition. Preferably less than 40% of the complex phosphate is allowed to revert. In certain particularly preferred embodiments the level of reversion is reduced to less than 20% and even less than 10% however, where the degradation product is orthophosphate, the composition may contain an average composition throughout of less than about 50% orthophosphate as a result of reversion of the complex phosphate.
Stratification of components other than STPP can also be accomplished in accordance with the present invention. Active alkalinity content can also be varied throughout a product such that more active alkalinity is provided in the initial stages of use of the composition. For example, in certain preferred embodiments which are cast in jars, the active alkalinity content is higher at the top of the jar (the portion used first) than at the bottom (the portion used last). This variation in active alkalinity content provides many advantages including more aggressive cleaning action at lower concentrations at the start of product use and deliming, defilming and reconditioning at the end of product use.. Variation of active alkalinity can be achieved when a variety of active alkalinity sources are used, including alkali metal hydroxides (such as for example sodium hydroxide and potassium hydroxide), silicates (such as for example alkali metal metasilicates), carbonates (such as for example alkali metal carbonates) and simple phosphates (such as for example orthophosphate). In addition, higher active alkalinity levels can be achieved at the end of the jar by stratifying the active alkalinity source (such as for example an alkali metal hydroxide or an alkali metal silicate) in granular form instead of or in addition to the water-conditioning material.
Although any desired level of active alkalinity can be used in compositions of the present invention, preferably the compositions contain about 5% to about 65%, more preferably about 10% to about 50%, average active alkalinity by weight. Both higher alkalinity compositions (such as those containing about 25% to about 50%) and lower alkalinity compositions (such as those containing about 5% to about 25%) may be made in accordance with the present invention.
Compositions of the present invention can also be designed to provide a variation in the conductivity of the washing solution circulated in a machine during use. For example, providing an increased concentration of STPP or decreased concentration NaOH at the end of product life will reduce the conductivity of the solution of dissolved detergent in the machine, resulting in an increased rate of dissolution. This increased dissolution will automatically result in an increased concentration of the composition being dispensed without adjustment of the concentration (conductivity) control, enhancing the composition's benefits with higher concentration.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1 and 2 depict a solid cast detergent production of a preferred embodiment of the present invention. FIG. 2 is a cross-sectional view of the container shown in FIG. 1 taken along line 2--2.
FIG. 3 depicts the preferred embodiment of FIGS. 1 and 2 in position for use in a ware washing machine.
FIG. 4 depicts a method for sampling a composition of the present invention for chemical analysis to determine the amount of stratification.
FIG. 5 is a photograph of the interior of a commercial ware washing machine which had used a prior art solid uniformly cast alkaline detergent composition.
FIG. 6 is a photograph of the interior of the same machine after use of a preferred composition of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Compositions of the present invention are non-uniform, cast solid alkaline detergent manufactured by heating an aqueous suspension primarily of water and alkaline hydratable materials (such as alkali metal hydroxides, carbonate, silicates and phosphates) together with organic additives of value in a detergent composition (such as surfactants, chelates, organic water conditioning materials, defoamers and a chlorine releasing compound (e.g.,an inorganic hypochlorite or an organic chlorine source)). The components are mixed and temperature adjusted to be just high enough to reduce the viscosity of the suspension to a point where the controlled stratification desired will occur. STPP, the active alkalinity source or other component to be stratified is preferably added last to reduce chemical (such as for example reversion) or physical (such as for example dissolving) degradation which may occur. This temperature will vary based upon the components, their percentage in the product, physical form and density which may be tailored for the optimum desired effect for the product application. Preferably, the temperature is adjusted to from about 130° F. to about 195° F., preferably from about 148° F. to about 163° F., or about 135° F. to about 168° F. most preferably from about 153° F. to about 158° F. Below 148° F. it may become more difficult to achieve repetitively uniform stratification. Below this temperature some formulations may be more viscous or tend to entrain air resulting in a lower fill weight, which may be desirable under some circumstances. However, the product will still be stratified below this temperature. Temperatures above 163° F. are higher than needed to maintain the reduced viscosity of many formulations. However, these higher temperatures may be required in certain formulations (such as those containing EDTA, carbonate or low density STPP in amounts more than about 10%) to maintain lower viscosity and higher fluidity of the molten detergent suspension during mixing. Prolonged exposure to these higher temperature may also result in deterioration or degradation of some formulation components.
In preferred embodiments, the compositions of the invention are essentially non-uniform (stratified) hydrated alkaline materials which have been cast in the container in which they are meant to be sold, transported and dispensed. The materials are designed to stratify upon standing and solidify as a non-uniform cast solid material. By incorporating components of selected particle size, shape, surface area, density and hydration characteristics, it is possible to create, on a repetitive basis, this unique solid cast composition with highly desirable characteristics. In preferred manufacturing processes the viscosity of the molten detergent material to be reduced to the point where the later sequential addition of some of the components lead to rapid stratification within the container. In the case of complex phosphates, in one preferred embodiment high density granular sodium tripolyphosphate is added as one of the last components to the composition once the molten detergent suspension has reached a relatively low viscosity after the other components have been added. Earlier additions may include other phosphate materials which are not necessarily designed to become part of the highly stratifying component.
The reduction in viscosity of the detergent suspension may be accomplished by any method known to those skilled in the art. Such methods include without limitation (1) adjusting the temperature of the suspension to the point that the material becomes readily flowable, (2) adding dispersing materials (such as lignosulfonates and certain surfactants or organic compounds) which have a viscosity reducing effect, and (3) varying particle size or physical form of formulation components. Controlling temperature is the preferred method of producing the desired viscosity.
Since higher complex phosphate is subject to reversion to pyro- or orthophosphate in a fluid, aqueous, highly alkaline environment at elevated temperatures, it is also important in certain embodiments to add last and quickly cool the molten detergent suspension to a temperature at which it will solidify at a sufficiently rapid rate to reduce or prevent reversion, yet at which the desired stratification process will occur.
Appropriate temperature ranges for providing stratification and reducing reversion will be dictated by the nature of the components and the relative amounts in which they are found in any given composition. For a given composition formulation, an appropriate temperature, if necessary, can be determined by trial and error; the formulation can be mixed, maintained at various temperatures, cooled and then examined to determine whether the degree of stratification and reversion is within the desired parameters. Temperatures of from about 135° F. to about 168° F. have been found to produce stratification without significant reversion in typical formulations. Temperatures of from about 148° F. to about 163° F. provide particularly desirable results. Temperatures above about 170° F. have been found to produce significant reversion in many formulations; however, such temperatures can be used for a particular formulation if the desired stratification and reduced reversion characteristics are produced. Extended mixing time at elevated temperatures can increase component degradation. In compositions having lower active alkalinity content (such as for example, those containing about 5% to about 25% average active alkalinity), the temperature range useful for providing the desired stratification effect may be lowered, even to as low as about 115° F.
The compositions of the present invention can include any of the components typically found in alkaline warewashing compositions. For example, any source of active alkalinity can be used to provide the desired alkalinity to the compositions. The alkali component of appropriate formulations is typically provided by an alkali metal hydroxide, such as sodium or potassium hydroxide. The alkali metal hydroxide can be used in any available liquid or solid form, although solid form is preferred. If solid metal hydroxide is used, any particle size can be used; however, commercially available beads (pellets) of medium size have been found to provide desirable results. Particularly, dissolving of metal hydroxide pellets is an exothermic process which can be harnessed to elevate the temperature of the resulting molten detergent suspension. Adjusting the particle size of the metal hydroxide may also contribute to adjustment of the viscosity of the molten detergent suspension. 0.75 mm sodium hydroxide pellets (bulk density 1,150 kg/m 3 or about 73 lb./ft 3 ) have been found to provide desirable results. Alkali metal silicates, such as anhydrous sodium metasilicate, can also be used as an active alkalinity source to replace some or all of the metal hydroxide. In larger bead or granular form, sodium hydroxide and/or alkaline silicate (such as for example anhydrous metasilicate) may be used as stratified components.
The compositions can also contain a source of available halogen. Any organic or inorganic material which provides active halogen, particularly chlorine (such as in the form of hypochlorite or Cl 2 ), can be used. Examples of appropriate chlorine sources include alkali metal and alkali earth metal hypochlorite, hypochlorite addition products, chloramines, chlorimines, chloramides, and chlorimides. Compounds of this type include sodium hypochlorite, potassium hypochlorite, monobasic calcium hypochlorite, dibasic magnesium hypochlorite, chlorinated trisodium phosphate dodecahydrate, potassium dichloroisocyanurate, trichlorocyanuric acid, sodium dichloroisocyanurate, sodium dichloroisocyanurate dihydrate, 1,3-dichloro-5, 5-dimethylhydantoin, N-chlorosulfamide, Chloramine T, Dichloramine T, Chloramine B and Dichloramine B. Stability is maximized when these materials are used in granular form and added last before the component(s) to be stratified. Encapsulated chlorine sources may also be used to provide better in-processing and storage stability.
The compositions may also contain surfactants, including nonionic surfactants, anionic surfactants, amphoteric surfactants and cationic surfactants. Preferred materials for machine spray washing application are those nonionic surfactants with defoaming characteristics (such as those sold under the "Triton CF" series by Union Carbide). Preferred surfactants include alkali metal alkyl benzene sulfonates, alkali metal alkyl sulfates, and mixtures thereof. Nonionic surfactants can also be used alone or in combination with anionic, amphoteric or cationic surfactants. Suitable nonionic surfactants include polyethylene condensates of alkyl phenols, products derived from the condensation of ethylene oxide with the reaction product of propylene oxide and ethylene diamine, the condensation product of aliphatic fatty alcohols with ethylene oxide as well as amine oxides and phosphine oxides. Products sold under the tradename "Pluronic" provide desirable results.
The compositions of the present invention may contain a supplemental water conditioning agent to enhance performance by sequestering calcium and/or magnesium ions at lower phosphate levels or to replace phosphate where its presence is undesirable. These include organic chelating/sequestering agents (such as gluconates, citrates, glucoheptanates, phosphonates, EDTA, nitrilo triacetate (NTA), polyacrylic acid of molecular weight of about 1,000-4,000 or greater in the useful range of sequestrants alone with copolymers and blends of the acrylic/maleic or other forms. These materials may be incorporated at any useful level from less than 1% to more than 15%. In addition, the compositions of the invention may contain any functional defoamer which may or may not have surface active properties.
The compositions of the invention can be made by combining the components of the formulation in suitable mixing equipment. Preferably, any source of complex phosphate is added last to reduce the time in which the material is exposed to elevated temperatures. As mixing occurs the temperature of the detergent suspension is adjusted to the desired range. In formulations employing solid metal hydroxide as an active alkalinity source, dissolution of the metal hydroxide is exothermic and generates heat, Minimal heat is required to be supplied from external sources. When liquid alkali metal hydroxide or other source of active alkalinity are used heat may need to be supplied. Heat may be applied by usual means, such as a steam-heated mixer jacket. The temperature of the detergent suspension may also be cooled, if necessary, to provide the desired temperature. Any known cooling means can be used, including a water-cooled mixer jacket. When the detergent suspension has reached the desired temperature, the molten suspension is poured into a mold (such as a disposable container) where it is allowed to cool. Formation of a stable hydrate by the water of hydralion in the alkali material causes the molten suspension to form a solidified mass.
The following examples demonstrate certain preferred embodiments of the compositions and methods of the present invention.
EXAMPLE 1
300 g samples were prepared according to the following formulations:
______________________________________sample I II III IV______________________________________water 26.3 (wt %) 24.8 23.25 21.7sodium hydroxide (solid) 58.7 55.2 51.75 48.3STPP (dense granular) 15.0 20.0 25.0 30.0______________________________________
The samples were prepared by adding the required amount of water to a beaker, followed by the addition of bead (pelletized) sodium hydroxide with mixing. The hydration reaction of the sodium hydroxide was exothermic and the solution was continually mixed as the sodium hydroxide dissolved. The temperature was then adjusted to 150° F. The required amount of dense granular sodium tripolyphosphate (density: 62 lb./ft 3 ; particle size: >95% on 100 mesh (U.S.) and >75% on 0.5 mm (metric)) was then added quickly and mixed for approximately one minute. The temperature was then verified to be just below 150°. The molten detergent suspension was then poured into an eight ounce straight sided cylindrical bottle with a thirty eight millimeter cap, the dimensions of the cylindrical portion of the bottle being approximately five and one quarter inches high by approximately two inches in diameter. The portion of the three hundred gram sample which was poured into the bottle and did not adhere to the beaker occupied approximately three and one half inches of vertical height of the bottle. The samples were then capped as they were made and immersed to a depth of approximately four and one half inches in a large sink of tap water at approximately 58°. The samples solidified relatively quickly and were allowed to remain in the water to cool to room temperature.
After approximately two hours, the physical appearance of the samples was observed in front of a bright light. Each sample showed marked stratification to the naked eye. The appearance of stratification was visibly noticeable based upon the fact that the top portion of the samples was extremely uniform and almost translucent while the lower portion of the stratified material showed the granular texture of the sodium tripolyphosphate being evident and opaque in appearance. This opaque area, which showed as a dark shadow in front of a bright light, appeared to represent the highly stratified portion of the sample. Its height in the container varied from a little over one inch for the sample containing fifteen percent sodium tripolyphosphate to nearly two inches for the sample containing thirty percent sodium tripolyphosphate.
EXAMPLE 2
Samples were prepared including sodium metasilicate and sodium carbonate according to the following formulations:
______________________________________ A B C D E F______________________________________water 23.25 (wt %) 23.25 23.25 23.25 23.25 23.25sodium hydroxide 51.75 51.75 51.75 51.75 51.75 51.75(bead)STPP 20.0 20.0 20.0 5.0 5.0 10.0(dense granular)anhydrous sodium 5.0 -- -- -- -- --metasilicatesodium carbonate -- 5.0 -- -- 5.0 15.0(light soda ash)sodium carbonate -- -- 5.0 -- -- --(dense soda ash)sodium hydroxide -- -- -- 20.0 15.0 --(bead)______________________________________
The components were mixed as described above, with the second listed portion of sodium hydroxide being added last. Samples A-E showed visible stratification. Stratification of sample F was not apparent to the naked eye, but a chemical analysis of the sample was not performed to determine the degree of stratification.
EXAMPLE 3
Samples were made incorporating organic water-conditioning materials according to the following formulations:
______________________________________ A B C D E F G H______________________________________water 23.25 23.25 23.25 23.25 23.25 23.25 23.25 23.25sodium 51.75 51.75 51.75 51.75 51.75 51.75 51.75 51.75hydroxide(bead)STPP 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0(densegranular)polyacrylic 5.0 -- -- -- -- -- -- --acid(4500 MW)acrylic maleic -- 5.0 -- -- -- -- -- --copolymer(SoKolanCP5)citric acid -- -- 5.0 -- -- -- -- --gluconic -- -- -- 5.0 -- -- -- --acid (50%)sodium -- -- -- -- 5.0 -- -- --glucohep-tanatetrisodium -- -- -- -- -- 5.0 -- --nitrilotriacetatetetrasodium -- -- -- -- -- -- 5.0 --EDTAphosphonate -- -- -- -- -- -- -- 5.0(Dequest2000)______________________________________
The inclusion of these additives did not appear to appreciably change the stratification characteristics on a visible basis seen in prior samples without the additives.
EXAMPLE 4
Samples were made including surfactants and defoamers to the following formulations:
______________________________________ A B C D E F______________________________________water 23.25 23.25 23.25 23.25 23.25 23.25sodium hydroxide 51.75 51.75 51.75 51.75 51.75 51.75(bead)STPP (dense granular) 20.0 20.0 20.0 20.0 20.0 20.0polyacrylic acid 5.0 3.0 3.0 3.5 3.5 4.0(4500 MW)nonylphenol ethoxylate -- -- -- 1.5 -- --(N-95)ethylene oxide- -- -- -- -- 1.5 --propylene oxide(Pluronic L)modified aryl aloxylate -- -- -- -- -- 1.0(Triton CF)dodecyl benzene 2.0 -- -- -- -- --sulfonic acid(anionic)Miranol JEM -- 2.0 -- -- -- --(amphoteric)BTC 2125M (quaternary -- -- 2.0 -- -- --aryl)______________________________________
The inclusion of these additives did not visibly affect the observed stratification.
EXAMPLE 6
A production-sized batch (1000 lbs.) of the following formulation was made:
______________________________________NaOH (50% soln.) 427 lbs.sodium carbonate 30(light soda ash)polyacrylic acid 60(MW 4500)NaOH (solid) 260Triton CF76 8antifoam 1.5sodium glucoheptanate 15STPP (dense granular) 200______________________________________
The batch was made according to the general steps described in Example 4. In this batch, the temperature was adjusted to 153°-158° F. before dumping the suspension out of the kettle.
Finished samples were taken from this batch for chemical analysis. 127 8-pound jars (approximate weight) were produced in this batch. The 29th (early stage), 67th (intermediate stage) and 111th (late stage) jars were taken as samples for analysis. Each jar was sliced into five slices designated top, top-middle, middle, middle-bottom and bottom (see FIG. 4). Cores were then taken from each slice at center, middle and outside positions (see FIG. 4). Each core was then analyzed for total Na 2 O, active Na 2 O, % orthophosphate, and % total P 2 O 5 . % NaOH and % STPP were calculated from analytical values.
The results of the analysis are reported in the following table. "C","M" and "O" denote center middle and outside core samples.
__________________________________________________________________________Samp- % Total % Active % Ortho- % Totalling Sample Na.sub.2 O Na.sub.2 O % NaOH phosphate P.sub.2 O.sub.5 % STPPTime Layer C M O C M O C M O C M O C M O C M O__________________________________________________________________________Early top 44.1 45.5 45.2 41.7 43.3 42.8 57.4 58.4 58.5 0.85 0.81 0.62 1.9 4.00 2.50 1.82 5.55 3.27 top- 44.4 44.3 43.5 40.5 40.5 40.0 56.6 56.8 55.6 0.90 0.92 0.93 4.8 4.22 4.10 6.79 5.74 5.52 middle middle 41.9 43.6 44.4 36.9 39.6 40.4 52.3 54.1 56.3 1.34 1.58 1.47 7.43 8.80 5.54 10.6 12.5 7.08 mid- 39.7 40.8 40.0 33.4 35.1 34.0 47.1 47.4 47.0 3.00 2.54 2.45 13.5 16.6 14.7 18.3 24.4 21.3 bottom bottom 36.4 37.7 34.5 28.5 30.2 26.4 40.9 42.0 38.3 3.00 3.00 2.90 18.3 20.0 18.6 26.6 29.7 27.3Inter- top 46.1 44.8 44.9 43.4 41.7 42.4 59.9 57.9 58.1 1.00 0.94 1.00 2.10 3.00 2.50 1.91 3.58 2.61med- top-mid 43.3 44.5 43.5 39.3 39.4 40.1 55.0 56.6 55.1 1.57 1.20 1.40 5.32 5.00 5.53 6.53 6.61 7.19iate middle 42.3 42.2 41.3 37.2 37.8 37.1 52.9 52.9 51.8 0.94 1.27 1.40 7.30 6.91 6.90 11.0 9.82 9.57 mid- 40.1 39.0 40.8 33.8 32.2 34.8 46.9 46.8 45.7 2.34 2.57 2.27 15.2 11.9 13.4 22.3 16.2 19.3 bottom bottom 38.3 34.4 52.4 31.9 25.7 40.8 42.8 44.0 62.6 3.00 2.89 3.25 19.9 3.34 16.7 29.4 0.78 23.5Late top 46.7 44.2 46.0 43.7 40.5 42.3 59.5 56.3 59.5 1.30 1.00 0.64 5.30 4.80 2.66 6.96 6.61 3.51 top-mid 43.8 42.9 43.6 39.7 39.2 39.9 55.3 54.2 55.6 1.51 1.50 1.20 5.94 6.00 4.70 7.71 7.83 6.09 middle 40.3 42.3 41.6 35.2 37.5 36.5 49.7 53.0 52.4 1.92 1.56 1.50 8.80 7.10 6.35 11.9 9.64 8.44 mid- 38.0 37.1 38.1 31.0 30.1 31.2 43.9 43.5 45.3 2.60 2.32 2.45 15.9 14.0 12.8 23.1 20.3 18.0 bottom bottom 35.1 34.0 36.7 27.6 24.2 30.0 38.6 37.6 40.8 3.33 3.10 3.14 20.0 18.8 19.8 29.0 27.3 28.9__________________________________________________________________________
The data show that the composition is stratified (i.e., non-uniform) from top to bottom within the jar with respect to each of the parameters tested. Of particular interest is the variation of the active Na 2 O and STPP. Using an average of the figures reported for the center, middle and outside samples in each top and bottom layer, active Na 2 O varies from top to bottom by 33.5% at early stages of production, by 22.8% at intermediate stages and by 35.3% at late stages. STPP varies from bottom to top by 87.2% at early stages of production, by 84.8% at intermediate stages and by 79.9% at late stages. Thus, the analytical data demonstrate that there is a broad range of variation of active Na 2 O and STPP in the stratified product.
EXAMPLE 8
Jars produced in Example 7 were tested in a commercial washing machine. FIG. 5 shows the condition of the washing machine after it had been routinely using a prior art high alkalinity solid cast ware washing detergent of the following formulation:
______________________________________water 14.5 (wt %)NaOH (bead) 48.5sodium carbonate 17.35(light soda ash)polyacrylic acid 4.26(MW 4500)tetrasodium EDTA 4.26STPP (light) 10.41surfactant (CF-76)/ 0.61defoamer______________________________________
This prior art product was uniformly cast. Heavy lime deposits and scaling can be seen on the vertical wall of the machine. A photograph was taken of the wash tank (FIG. 6) when use of the prior art product was discontinued before changeover. Use of the product was discontinued by removing the partial jar from the dispenser and replacing it with the composition of Example 6. No adjustment was made to any control devices or operating conditions or methods. No acid descaling or special steps were taken other than use of the composition of Example 6.
Normal washing procedures of the customer were followed using jars of the composition of the present invention made in Example 6. Near the end of the fourth jar of composition a second photograph was taken (see FIG. 6). This photograph shows that the heavy lime deposits and scaling have been removed as a result of the boost in phosphate content provided by the composition of the present invention. This cleaning result was achieved solely by use of the composition of the present invention in the normal course of operation of the machine. No down time was required. Dishes and glasses run through the machine after conversion to the composition of the present invention were examined and found to be spot free and had a bright, renewed appearance.
EXAMPLE 9
The effect of incorporation of other typical desirable detergent builders and components in the near monohydrate ratio sodium hydroxide solution was examined. Granular anhydrous sodium metasilicate was used in a formulation as follows:
______________________________________NaOH (50% wt soln.) 130 (gms)sodium carbonate 24(dense soda ash)LMW45 (surfactant) 18.2NaOH (solid bead) 75sodium glucoheptanate 6CF76 (surfactant) 1.5antifoam 0.3anhydrous sodium metasilicate 45______________________________________
This sample was prepared in the same manner described in Example 4, with the metasilicate being added in place of the STPP. This composition stratified in a manner similar to those described previously. | Stratified solid cast alkaline detergent compositions are disclosed in which the concentrations of an active alkalinity source and water of hydration which contain at least one granular material in varying concentration throughout the composition. Methods of making and using the disclosed compositions are also disclosed. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to microelectromechanical systems (MEMS) and, in particular, relates to the fabrication of electrically isolated MEMS devices using plating techniques.
[0003] 2. Discussion of the Related Art
[0004] Microelectromechanical systems (MEMS) components are being progressively introduced into many electronic circuit applications and a variety of micro-sensor applications. Examples of MEMS components are electromechanical motors, radio frequency (RF) switches, high Q capacitors, pressure transducers and accelerometers. In one application, the MEMS device is an accelerometer having a movable component that, in response to acceleration, is actuated so as to vary the size of a capacitive air gap. Accordingly, the current output of the MEMS device provides an indication of the strength of the external stimulus.
[0005] One current method of fabricating such components, often referred to as surface micro-machining, uses a sacrificial layer, such as silicon dioxide, that is deposited and bonded onto a substrate, such as single crystal silicon which has been covered with a layer of silicon nitride. A MEMS component material, for example polycrystalline silicon, is then deposited onto the sacrificial layer, followed by a suitable conductor, such as aluminum, to form an electrical contact with the ambient environment. The silicon layer is then patterned by standard photolithographic techniques and then etched by a suitable reactive ion etching plasma or by wet chemistry to define the MEMS structure and to expose the sacrificial layer, which may comprise silicon dioxide. The sacrificial layer is then etched to release the MEMS component. This leaves only a single material, the structural material.
[0006] One significant disadvantage associated with current surface fabrication techniques involves the lack of electrical isolation that is achieved. The present inventors have discovered that a MEMS device may be used as a current or voltage sensor, in which the device may receive high voltages at one end of the device, and output an electrical signal at the other end of the device to, for example, a sensor. The output could be a function of the capacitance of the MEMS device, as determined by the position of a movable MEMS element with respect to a stationary element. However, because the entire movable MEMS element achieved using conventional surface fabrication techniques is conductive, the input and output ends of the MEMS device are not sufficiently isolated from one another, thereby jeopardizing those elements disposed downstream of the MEMS output.
[0007] Another significant disadvantage associated with current surface fabrication techniques is that the process is inherently limited to thin structural layers (on the order of 1 to 2 μm) due to stresses which may be introduced during the fabrication. The thinness of the layers limits the amount of capacitance that can be obtained in the sensor portion of the MEMS device, and thus limits the magnitude of any output signal. This in turn limits the overall resolution obtainable
[0008] It is therefore desirable to provide a method for fabricating a MEMS device using surface fabrication techniques having greater thickness than that currently achieved to enhance sensitivity, while providing sufficient electrical isolation for the device.
BRIEF SUMMARY OF THE INVENTION
[0009] The present inventors have recognized that a MEMS device may be fabricated using an insulating material, a sacrificial material, a mold material, and a conducting mechanical structural layer that may be plated onto an insulating substrate.
[0010] In accordance with one aspect of the invention, a method for fabricating a MEMS device, comprising the steps of providing a substrate having an upper surface, and depositing a sacrificial layer onto the upper surface of the substrate. A nonconductive layer is then deposited onto the upper surface of the sacrificial layer. Next, a mold is deposited onto the substrate, wherein the mold has at least one void aligned with the insulating layer. A conductive material is then deposited into the at least one void to form conductive elements extending from the nonconductive layer. Finally, the mold and sacrificial layer are removed to release a movable element including the nonconductive layer and conductive layer from the substrate.
[0011] The conductive material may be electroplated or electrolessplated onto the nonconductive layer.
[0012] All of the aforementioned aspects are not necessary to carry out the invention. Furthermore, these and other aspects of the invention are not intended to define the scope of the invention for which purpose claims are provided. In the following description, reference is made to the accompanying drawings, which form a part hereof, and in which there is shown by way of illustration, a preferred embodiment of the invention. Such embodiment also does not define the scope of the invention and reference must be made therefore to the claims for this purpose.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Reference is hereby made to the following figures in which like reference numerals correspond to like elements throughout, and in which:
[0014] [0014]FIG. 1 is a schematic sectional side elevation view of a MEMS device constructed in accordance with a preferred embodiment of the invention;
[0015] [0015]FIG. 2 is a sectional side elevation view of a structure having a substrate, sacrificial layer, and insulating layer that is used to fabricate the MEMS device illustrated in FIG. 1 in accordance with one embodiment of the invention;
[0016] [0016]FIG. 3 is a sectional side elevation view of the structure illustrated in FIG. 2 having a portion of the insulating and sacrificial layers removed;
[0017] [0017]FIG. 4 is a sectional side elevation view of the structure illustrated in FIG. 3 having a plating mold attached thereto;
[0018] [0018]FIG. 5 is a sectional side elevation view of the structure illustrated in FIG. 4 after patterning the mold using standard photolithographic techniques; and
[0019] [0019]FIG. 6 is a sectional side elevation view of the structure illustrated in FIG. 5 after plating a material onto the insulating layer.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring initially to FIG. 1, a MEMS device 10 includes a stationary MEMS element 12 and a movable MEMS element 14 , both attached to a substrate 16 . The substrate 16 may be either conducting or insulating, depending on the intended application, and may comprise glass, high resistivity silicon, crystalline sapphire, crystalline silicon, polycrystalline silicon, silicon carbide, or ceramic such as alumina, aluminum nitride, and the like, or gallium arsenide. In fact, the substrate may comprise any material whatsoever that is suitable for supporting a MEMS device. In the embodiment shown in FIG. 1, the stationary MEMS element 12 comprises a pair of stationary conductive members 13 which extend outwardly from the substrate. The movable MEMS element 14 includes a base layer 17 which supports separated conductive members 18 that extend outwardly from the base 17 . Movable element 14 is disposed between the stationary members 13 . It should be appreciated by those having ordinary skill in the art that movable MEMS element 14 is a beam that is supported at its distal ends by, for example, the substrate such that the middle portion of element 14 is free and movable relative to the stationary members 13 , as illustrated.
[0021] It should be appreciated by one having ordinary skill in the art that FIG. 1 illustrates a portion of a MEMS structure 10 , and that inner MEMS element 14 is connected to substrate 16 at its two distal ends, as disclosed in patent application Ser. No. 09/805,410 filed on Mar. 13, 2001 and entitled “Microelectricalmechanical System (MEMS) Electrical Isolator with Reduced Sensitivity to Internal Noise” the disclosure of which is hereby incorporated by reference. Accordingly, while the outer portions of movable element 14 are connected to the substrate, an elongated section of element 14 is suspended and free from the substrate, thereby permitting deflection of the free portion of the movable MEMS element with respect to the substrate 16 . The stationary members 13 are separated from the moveable MEMS element 14 by a variable size gap 19 , which could be the gap between the adjacent plates of a detection capacitor, as will become more apparent from the description below. The size of gap 19 changes as the movable element deflects in response to a stimulus.
[0022] In the MEMS device 10 illustrated in FIG. 1, there are two different structural materials that remain after the movable element 14 is released from the substrate 16 . In particular, an insulating material that forms the base layer 17 and a conducting layer that forms the other portions of the device 13 and 18 . As such, fabrication of devices of this type utilizes at least three unique materials, in addition to the substrate: a conducting material, an insulating material, and at least one sacrificial material.
[0023] If base layer 17 is formed utilizing an insulating material, as is the case in accordance with the preferred embodiment, the conductive members 18 become electrically isolated from each other, thereby minimizing the risk that an electrical input will conduct across the device 10 , which would jeopardize those elements disposed downstream of the MEMS output, in a useful circuit application. The insulation layer 17 thus provides sufficient electrical isolation across the movable element 14 , thereby rendering the device 10 usable, for example, as a current or voltage sensor.
[0024] The MEMS device 10 could therefore perform any function suitable for a MEMS application. For example, the device could comprise an accelerometer whose movable MEMS element 14 is a beam that deflects in response to the external stimulus, such as an acceleration or vibration of the device 10 . Accordingly, as the size of the gaps 19 vary, so will the output capacitance, thereby providing a measurement of the amount of deflection of the movable MEMS element 14 . A measurement of the amount of acceleration may thereby be obtained by measuring the capacitance of the device. The device 10 constructed in accordance with the present invention could furthermore incorporate a wafer level cap and electrical traces connected to the stationary members 13 , as is described in U.S. patent application filed on Sep. 26, 2001 and entitled “Method for Constructing an Isolated Microelectromechanical System (MEMS) Device Using Surface Fabrication Techniques” the disclosure of which is hereby incorporated by reference as if set forth in its entirety herein.
[0025] The MEMS device 10 schematically illustrated in FIG. 1 may be fabricated in accordance with several embodiments of the invention that utilize plating processes, as will now be described.
[0026] In particular, referring now to FIG. 2, the fabrication process begins by providing a substrate 16 that is insulating and comprises either glass or high resistivity silicon in accordance with the preferred embodiment. Other materials, including conducting materials, could be substituted for the substrate material, depending on the intended application of the MEMS device. Several layers are subsequently deposited onto the substrate 16 . The first layer 20 to be deposited will ultimately form a sacrificial release layer and comprises silicon nitride in the preferred embodiment. A skilled artisan will appreciate that any alternative material that is selectively etchable could also be used. The second layer 22 to be deposited will form an insulating base layer and comprises silicon dioxide in the preferred embodiment. The deposition of these materials is well known, and could be achieved by chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), or similar techniques well known to those skilled in the art. The thickness of each layer is selected in anticipation of the desired height of the final MEMS device, and may be on the order of 1-3 microns.
[0027] Referring now to FIG. 3, once the layers 20 and 22 are deposited, they are patterned by standard photolithographic techniques. In particular, photoresist is applied to the top surface of the structure and patterned. The insulating layer 22 is selectively anisotropically etched, followed by selective anisotropic etching of the sacrificial layer 20 , and finally the photoresist is removed which reveals the insulating base 17 , lying on top of patterned sacrificial layer 20 .
[0028] In preparation for an electroplating step, the top surface of the structure may be coated with a shorting layer that is compatible with the metal which will be electroplated. The shorting layer will later facilitate the plating process. For example, when electroplating gold, a tin/gold or a chromium/gold bilayer shorting layer is used. This electrically connects regions where metal deposition is desired. After plating, the gold shorting layer can be removed with a short KI 3 solution and the tin, for example, can be removed using a buffered HF solution.
[0029] In preparation for an electrolessplating step, the top surface of the structure may be coated with a pre-treated catalyst to induce the electroless plating reduction reaction.
[0030] Referring to FIG. 4, the structure is now coated with the mold material 24 , which may comprise a photoresist or other photoactivated polymer material in accordance with the preferred embodiment. Because the plating process is a relatively low temperature process, a high temperature material like that needed for the sacrificial layer is not required for the mold material. In addition, commercial photoresists exist that can be applied to thickness up to and above 10 microns. This increased thickness is beneficial as it will allow the plated conductive layer to achieve a greater thickness. A skilled artisan will appreciate that the mold material could also be an inorganic material, such as the same material employed for the sacrificial material. However, the thickness of such materials is generally limited to 1-3 microns which will limit the overall height of the final conducing layer.
[0031] The photoresist is then patterned with standard photolithographic processes to result in a mold pattern. That is, the photoresist is removed in the areas where the plating is desired, as shown in FIG. 5. Gaps are thereby formed in the mold 24 that will provide the structure for the fabrication of conductive members 18 .
[0032] Referring now to FIG. 6, the conducting material is plated onto the insulating layer 22 using standard plating processes. Conducting material is further plated onto the surface of substrate 16 to form the stationary conductive members 13 . The conducting material could be nickel, gold, copper, or any other suitably conductive metal which can be plated. The metal fills the cavities in the mold and attaches to layers 22 and substrate 16 . Finally the mold material 24 is etched away and the sacrificial layer 20 is etched away using standard techniques, thereby leaving the final released structure depicted in FIG. 1.
[0033] It should be appreciated that the embodiments described herein comprise various layers of conductive and nonconductive materials. While these materials are identified in accordance with the preferred embodiment, it should be appreciated that any alternative materials suitable for use in the intended MEMS application, and that are selectively etchable if necessary, could be substituted for the disclosed materials. For example, sacrificial layer 20 could be silicon dioxide and the insulating layer 22 could be silicon nitride with no change in functionality.
[0034] The above has been described as preferred embodiments of the present invention. It will occur to those that practice the art that many modifications may be made without departing from the spirit and scope of the invention. For example, it is appreciated by one having ordinary skill in the art that the structure of the movable MEMS element 14 may differ so long as it is electrically isolated and includes a conductive member that is operable to create, for example, a capacitance that varies in accordance with the motion. Accordingly, variations of the embodiments described herein will become apparent to those having ordinary skill in the art, and such variations are within the scope of the present invention, as defined by the following claims. | A method is presented for fabricating an electrically isolated MEMS device having a conductive outer MEMS element, and an inner movable MEMS element spaced apart from the conductive outer MEMS element. The inner element includes a nonconductive base having a plurality of conductive structures extending therefrom. The conductive components are formed by plating a conductive material into a pre-formed mold which defines the shape of the conductor. | 1 |
FIELD OF THE INVENTION
This invention relates, generally, to treatment of liquids and, more particularly, to an improved method and apparatus for the removal of particles from water or wastewater by means of an enhanced sedimentation system.
BACKGROUND OF THE INVENTION
The oldest and most widely used treatment procedure for water as supplied to municipalities or industrial sites or for wastewater as produced by these same entities, is to subject the liquid to a sedimentation process. Such systems usually comprise a confined area or basin with means for regulating the inflow of liquid thereto as well as to collect and carry away the treated effluent after a nominal detention time in the basin, during which suspended matter is given an opportunity to settle or separate by gravity from the liquid being treated.
The surface loading rate of conventional sedimentation basins can be dramatically increased by installing inclined parallel plates which effectively increase the surface area on which suspended particles may settle. These devices also promote laminar and stable flow conditions, which leads to a very high degree of separation. Conventional settling basins can be retrofitted with a plurality of inclined, parallel plates or baffles between which the influent is directed to encourage the separation of particles from the liquid. These particles impinge upon the baffle surfaces, congregate with other particles as they slide down the baffle surfaces, form larger particles and eventually fall by gravity to the basin bottom wherein they are periodically removed as a sludge product.
Several shortcomings have been apparent with many existing inclined plate settlers. The baffles or plates themselves are relatively expensive and the usual rigid construction of glass fiber reinforced plastic results in a member which accordingly must be limited in size and which tends to warp, become brittle and break off into pieces over time. Manipulation of such plates during installation, removal and repair is quite awkward. Also, settler plates are mounted in a fixed manner, thereby precluding ready variation of the angle of inclination to maximize sedimentation rates under altering conditions. The cleaning or replacement of any of the plates is a tedious procedure resulting in a significant amount of down-time.
DESCRIPTION OF THE RELATED ART
Examples of settlers employing a plurality of inclined plates or the like will be found in U.S. Pat. Nos. 3,482,694 issued to Rice et al, 3,706,384 issued to Weijman-Hane, 3,768,648 issued to Anderson et al and 4,783,255 issued to Bogusch. The alternate plate construction and adjustable mounting as proposed by the present invention is not seen to be suggested in any of the prior art of which applicant is aware.
SUMMARY OF THE INVENTION
By the present invention, an improved method and apparatus for obtaining the gravity separation of particles from a liquid is presented and which includes a plurality of uniquely attached or mounted inclined partitions or baffles whereupon an operator of the system may quickly and easily simultaneously vary the angle of inclination of all of the baffles to achieve the most efficient output of treated effluent in accordance with the characteristics of the influent. Additionally, an alternate baffle construction using stretchable membranes is proposed, which can be used in plate settlers with either fixed or adjustable mountings.
The instant mounting and fabrication of the substantially planar settler members permits the separation of individual members from adjacent members to allow for inspection and replacement in addition to permitting the ready adjustment of the angle of inclination thereof to optimize the sedimentation process. Such adjustment includes the ability periodically to dispose the settler members in a true upright or vertical manner, thereby encouraging accumulated materials to slough off the surfaces of the members.
By utilizing baffles or settler members comprising stretchable membrane material, the cost, bulk and ease of assembly are noticeably enhanced. With thinner, lightweight members, the compactness and efficiency of a high-rate sedimentation basin is significantly increased since a larger number of such baffles may be installed within any one basin, with the same usual nominal spacing therebetween of say, 2 inches, thereby increasing the total number of effective treatment zones as provided by each pair of adjacent settler members. Likewise, the overall transverse extent or length of the members may be increased over the known existing settler baffles without the need for intermediate structural support elements spanning the basin beneath the baffles, and which can interfere with the operation of associated mechanical sludge removal equipment. Moreover, a variety of membrane materials with low coefficients of friction are available and can be used to improve the removal of settled materials as they slide down the membrane surfaces, counter to the flow of liquid being treated.
The present system readily lends itself to the provision of a high-rate settler apparatus, whether newly constructed or as a retrofit to existing conventional basins.
Accordingly, one of the objects of the present invention is to provide an improved high-rate settler system including a plurality of baffles of unique construction.
Another object of the present invention is to provide an improved high-rate settler system including a basin containing transverse baffles comprising stretchable membranes.
A further object of the present invention is to provide an improved high-rate settler system including a mounting mechanism for the ends of transverse baffles permitting quick, simultaneous alteration of the inclination thereof.
Still another object of the present invention is to provide an improved high-rate sedimentation system including settler members spanning a basin with a manifold delivering influent through a plurality of ports spaced along the axial extent of the basin.
Another object of the present invention is to provide an improved high-rate settler system including a plurality of baffle members each having opposite ends attached to a support rod in turn having roller devices slidably contained within longitudinal trackways.
Yet another object of the present invention is to provide an improved high-rate sedimentation system including flexible baffle members having opposite ends attached to support rods allowing variation of the tension as applied to individual baffle members.
With these and other objects in view which will more readily appear as the nature of the invention is better understood, the invention consists in the novel combination and assembly of parts hereinafter more fully described, illustrated and claimed with reference being made to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a sedimentation system according to the present invention;
FIG. 2 is a vertical sectional view of the apparatus of FIG. 1;
FIG. 3 is an enlarged vertical sectional view through one of the barrier assembly support and adjustment channels;
FIG. 4 is a horizontal sectional view through the support and adjustment mechanism shown in FIG. 3;
FIGS. 5 and 6 are enlarged side elevation views illustrating alternate positions of the adjustably mounted settler member support rods;
FIG. 7 is an end elevation, partly in section, of one of the settler member support rods;
FIGS. 8 and 9 are horizontal sectional views illustrating alternate positions of the settler member support rods during installation or adjustment of the tension of flexible settler members; and
FIGS. 10 and 11 are vertical sectional views showing alternate embodiments of the support and adjustment mechanism as shown in FIG. 7.
Similar reference characters designate corresponding parts throughout the several figures of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, particularly FIGS. 1 and 2, the present invention will be seen to relate to a sedimentation system, generally designated S and which includes a structural tank or basin 1. As a minimum, the basin 1 is provided with a bottom 2 and one or more peripheral walls, such as the illustrated opposed end walls 3,4 and side walls 5,6. It is well known to provide sedimentation basins having rectangular, square or circular configurations to accommodate the attendant operating structure and demands imposed by the nature of the intended influent.
Inasmuch as the present apparatus utilizes a plurality of baffles or settler members comprising parallel, substantially planar members, between which the influent is directed in order to capture solid particles contained in the influent, the preferred configuration comprises an elongated, rectangular basin as shown in the drawings. Generally speaking, but with certain constraints, it is desirable to employ the greatest number of settler members possible in order to maximize the degree of achieved sedimentation with the ultimate fluid flow rate through the apparatus. With the present type of settler members, the adjustable mounting means and the manner of admitting the influent into the basin, it will be appreciated that an elongated, rectangular configuration is preferable wherein the parallel side walls 5,6 are substantially longer than the parallel end walls 3,4.
The sedimentation action is accomplished by means of a plurality of transversely disposed baffles or settler members 8 substantially spanning the width of the basin interior 9, throughout the majority of its length. In the conventional settling apparatus, these baffles comprise rigid plates made of fiberglass, asbestos-cement or wood and have their opposite ends fixedly attached to the basin side walls. The mass of such members usually limits the length thereof and also necessitates the inclusion of underlying support beams and columns which obviously impede the free falling of sediment particles and can interfere with the operation of mechanical sludge removal equipment.
The baffles 8 of the present invention comprise relatively lightweight members preferably made of flexible stretchable membranes. When the system S is operational, the basin interior contains liquid defining a top surface 10 which will be seen from FIG. 2 to be disposed well below the top 11 of the basin 1. The baffles 8 are retained within the liquid with their top edges 12 in a plane spaced beneath this liquid surface 10 with effluent collection and removal means disposed intermediate the baffle top edges 12 and liquid surface 10. This collection and removal means comprises submerged effluent launders or overflow weirs. The preferred means includes a plurality of laterally spaced apart perforated pipes 13 extending longitudinally of the basin interior 9 from the leading end wall 3 to downstream end portions, communicating with individual effluent ports 14 through the trailing end wall 4. To support the pipes 13 and maintain their full length in a horizontal disposition, a plurality of transverse beams or supports 15 span the tops 11 of the two side walls 5,6. Hangers 16 suspended from these beams 15 are then suitably connected to the pipes 13.
Liquid to be treated by the present apparatus is preferably admitted into the basin interior 9 through a plurality of influent ports 17 formed in one side wall 6, at a level below that of the bottom edges 18 of the settler members 8. Supplying these ports 17 is an influent manifold or channel 19 extending longitudinally adjacent the basin side wall 6, and preferably with a tapered cross-section to promote uniform flow distribution through influent ports 17.
As an alternative to the longitudinal disposition of the effluent pipes 13, such discharge means may comprise a plurality of transversely arranged perforated pipes (not shown), spanning the two side walls 5,6 and which would have outlet ports through a side wall opposite that containing the influent ports 17. In this manner, in view of the shorter length of such pipes, support beams and hangers will not be required.
The sedimentation process itself is well known. Influent is admitted into the basin to the lower liquid area 20 beneath the baffles 8 while a corresponding volume of effluent is displaced and drawn off from the upper liquid area 21 adjacent the liquid top surface 10. As the influent migrates from the lower area to the upper area, it passes through the intermediate area 22 containing the settler members 8. To enhance the settling of particles on the stationary baffles 8, the latter are mounted at an inclination with their top edges 12 directed toward the discharge or trailing end wall 4. Thus, it will be understood that as long as new influent is being delivered into the basin, at least a minimal amount of the liquid will be directed, in an upward manner, through the laminar passageways 23 formed between each two adjacent baffles 8. As suspended solids progress through the laminar passageways, they are subjected to two force vectors. One is the gravity force pulling the particles downwardly and the other is the flow velocity vector forcing the particles upwardly and along the length of the baffle. By inclining the baffles in close proximity to each other, the settling distance is greatly reduced so a larger number of solid particles can impinge upon the inclined upwardly facing surfaces 25 of the opposed baffles. The majority of these particles will continue to descend, sliding down the respective baffle surfaces 25, aggregating with adjacent particles to form larger and heavier particles, and thence settling adjacent the basin bottom 2.
Clean-out means is included within the basin to permit continuous removal of accumulated sludge in the lower area 20 and may take the form of the sludge collector assembly 26 shown in FIG. 2. An automated removal process is provided by endless chains 27 driven by sprockets 27A adjacent each basin side wall connected to common shafts 27B and having transverse flights 28 thereupon. As the chains are operated by suitable motor means (not shown) in a clockwise direction as viewed in FIG. 2, sludge collected upon the basin bottom 2 is driven towards the leading end wall 3. A sump or hopper 29 receives the delivered sludge for subsequent removal from the system by means of a drain 30.
After the liquid has been drawn through the passageways 23 between the various settler members 8 and passes the top edges 12 thereof, it is relatively free of solid particles and is collected within the perforated pipes 13 forming the effluent launders. Since these pipes are level and disposed at an elevation slightly below that of the influent level 31 within the influent channel 19 it will follow that the force of gravity will insure that treated liquid is collected uniformly through the pipe perforations 13A, providing a constant discharge of the effluent from the ports 14 in the trailing end wall 4. These ports will be seen to communicate with an outlet channel 32 adjacent the exterior of the basin end wall 4.
With the above described operation it will be appreciated that an improved sedimentation process is achieved in view of the distribution of the influent as transversely directed into the basin lower area 20 through the plurality of spaced influent ports 17 extending throughout the basin interior beneath the bottom edges 18 of the assembly of settler members 8. In this manner, equally divided flows of the particle-containing influent are treated by separate adjacent groups of the baffles 8 for a most efficient treatment. This is in contrast to existing sedimentation basins wherein the entire influent flow is usually admitted to the basin interior, in a longitudinal direction, through the leading end wall 3, which generally induces a very poor pattern of flow distribution between the settler members.
Notwithstanding the above, the improved baffle construction presented by this invention, together with adjustable mounting means, therefore will be understood to vastly enhance the sedimentation process whether applied to existing conventional basins as a retrofit installation or incorporated in a basin as proposed herein.
The settler members 8 are retained in the use position by means of a separate support rod 33 to which each end or side edge 34 of every baffle 8 is attached. As previously described, the baffles may comprise substantially rigid planar members constructed of any suitable composition such as glass fiber reinforced plastic, although the preferred material will be a flexible, stretchable composition. Any well known resilient material such as synthetic rubber or nylon fabric may be utilized and which lends itself to at least a nominal stretching, in a membrane fashion. Such flexible baffles are shown in the drawing figures about to be described.
FIGS. 3-9 depict the attachment of the baffle ends 34 to the respective support rods 33 and the mounting of these rods to the basin side walls 5,6 in a manner to permit the ready adjustment of the inclination angle of the supported baffles 8. Each support rod 33 comprises an elongated pipe provided with a longitudinal slot 35 communicating with the pipe central bore 36. The baffle ends 34 are formed with a closed loop 37 adapted to receive a dowel 38 with these latter two components defining a diameter less than that of the pipe bore 36, initially to permit the free insertion of the dowel-equipped baffle ends into the support rods 33 as shown in FIG. 8. The dowel 38 extends into the upper reaches of support rod 33 so that it may be removed through the top end of the support rod during replacement of a baffle 8, as will be further discussed hereinafter.
The support rods 33 at both ends of all of the baffles 8 are adapted in turn to be mounted with their opposite ends respectively supported by a top channel 39 and bottom support member 40 affixed to the inner surface 41 of each basin side wall 5,6. To attach each support rod 33 to the top channel 39, a roller assembly 42 having a horizontal mount rod 43 is provided for each end of each baffle 8. As will be seen most clearly in FIG. 7, the roller assemblies 42 are captively retained within the confines of the top channel 39, between its top wall 44, bottom wall 45 and the two vertical inner walls 46,46. The roller assemblies 42 bear against anti-friction surfaces 42A,42A mounted on the inner walls 46,46, and will be understood to provide for minimal frictional attachment of the top end 47 of the support rods 33 to the basin top channel 39. Each roller assembly mount rod 43 includes an outer collar or nut 48 adapted to surround and engage the threaded top end 47 of a support rod 33 and is joined to an axle 49 slidably disposed within the throat as defined between two flanges 50,50 directed inwardly from the top channel inner walls 46,46. This axle 49 is journalled within a vertical roller axle 51 having a pair of horizontal rollers 52,52 in turn journalled at its ends. The inner end of certain ones of the axles 49 will be understood to be equipped with a vertical sheave or pulley 53, the purpose of which will be discussed hereinafter.
The lower end 54 of each support rod 33 includes a bushing 33A which is threadedly attached to the support rod and can be removed to allow the insertion of a baffle 8 and dowel assembly 38 through the bottom of the support rod. A depending guide rod 55 is in turn, threadedly attached to the bushing 33A and its lower end is inserted through a selected one of a plurality of spaced apart openings 56 formed in the bottom support member 40. These openings 56 are configured to permit an unimpeded axial sliding movement of the guide rod 55 as well as allow an angular displacement thereof as the inclination of the support rods 33 is altered.
With a baffle 8 and dowel 38 inserted through the bottom of a support rod 33 and retained within bore 36 by a bushing 33A, the guide rod 55 is passed through one of the bottom support member openings 56 and thence, the top threaded end 47 of the support member is screwed into and through the collar 48 of a roller assembly 42. With both ends 34,34 of any one baffle 8 thusly attached, the membrane is stretched to provide a substantially planar or taut condition by rotating the respective support rods 33 such as shown in FIG. 9. To facilitate this operation, appropriate tool-engaging means such as bores 57, may be provided in the top end 47 of each support rod. When the desired degree of tautness is achieved, a jam or lock nut 58 is secured against the top of mount rod collar 48 to retain the stretched condition. Installation or replacement of the baffle ends may otherwise be achieved with the support rods 33 already attached to the roller assemblies by initially inserting a baffle end loop 37 through the support rod slot 35 and thence lowering the dowel into the loop. Thereafter, the support rod is rotated to obtain the desired tautness following which the lock nut 58 is tightened against the mount rod collar 48.
The longitudinal sectional views of FIGS. 3 and 4 most clearly depict the relationship between adjacent ones of the roller assemblies 42 and wherein it will be seen that the periphery of the horizontal rollers 52,52 are in abutment. Accordingly, the diameter of these rollers will define and consistently maintain the resultant spacing between the plurality of settler members 8. It will be noted that the lateral extent, or width, of the mount rod collars 48 must necessarily be less than the diameter of the rollers 52 to insure that these rollers remain in abutment with one another and thus constantly maintain the supported baffles 8 in the proper, equi-spaced disposition. As mentioned above, selected ones of the horizontal axles 49 are provided with an endmost pulley or sheave 53. These sheaves provide support for an endless chain or cable 60, the ends of which are sheaved about a drive sprocket 61, located adjacent each basin end wall, as shown in FIGS. 1-4. At least two removable connecting links 62 are carried by the top run of the chain 60 and are joined to the end of the first and last roller assembly axles 49 as shown in FIGS. 3 and 4. These links 62 serve to transmit horizontal displacement of the chain 60 and a corresponding horizontal movement of all of the roller assemblies 42 associated therewith.
The two drive sprockets 61 are simultaneously driven by means of a common transverse shaft 63 located adjacent one end wall, such as the leading end wall 3, and having a suitable operating mechanism 64 as shown in FIGS. 1 and 2. Thus, by manipulating the operating mechanism 64, the two sprockets 61,61 are actuated, along with the respective drive chains 60,60 to longitudinally displace all of the roller assemblies 42. This displacement produces an alteration of the inclination of the plurality of support rods 33 and attached settler members 8 such as between the two extremes shown in FIGS. 5 and 6.
In the alternative embodiments of FIGS. 10 and 11, modified roller assemblies are employed to adjustably retain the same baffle support rods 33 relative to the two top channels in the basin. With the roller assembly 65 as shown in FIG. 10, the pulleys 66 are carried by a selected number of the mount rod axles 67, intermediate the channel inner walls 68,68 and mount rod collar 69. With this arrangement, smaller top channels 70 are required in view of the disposition of the pulleys 66 exteriorly of the channels and accordingly, the rods 33 and attached baffles or membranes 8 will extend a greater width across the basin or, closer to the side walls 5,6.
In the case of the roller assembly 71 as shown in the modification of FIG. 11, the pulleys and chains as utilized in the previous embodiments may be eliminated altogether. To secure the roller assemblies 71 and joined support rods 33 at the desired inclination, the two endmost mount rod axles 72 and selected intermediate ones are provided with a bearing washer 73 and adjacent bearing nut 74. In this manner, the adjusted support rods 33 are secured in position by the tightening of the bearing nuts 74, thereby sandwiching the channel inner walls 68,68 between the rollers 52,52 and bearing washers 73. Alteration of the baffle or membrane inclination is readily achieved by loosening the bearing nuts 74 and moving the top portion of one of the endmost support rods 33, whereupon the abutting rollers 52 within the slotted channels 70 produce a simultaneous displacement of all of the roller assemblies 71. To facilitate this displacement of the support rods, an appropriate tool, such as the rod or lever 75, may be affixed to or removably attached to the top portion of the two endmost support rods 33.
The above described adjustable mounting of the baffles 8 permits the positioning of the baffles at a precise angle of inclination in order to maximize the sedimentation process in accordance with the liquid parameters at hand. In this manner, flow rates and settling velocities of the particles to be removed from the liquid may be taken into consideration and the baffle inclination selected accordingly. Also, the procedure of clearing the baffle surfaces of accumulated solid particles is facilitated as the adjustment mechanism may be operated to position the baffles in the true vertical plane as shown in FIG. 5, thereby encouraging such particles to fall by gravity to the lower reaches of the basin. If more thorough cleaning, or inspection of individual baffles is required, the connecting links 62 of drive chain 60 can be released from the roller assembly axles 49, thereby allowing the top ends of one or more support rods 33 to be spread apart for inspecting the baffles. In the case of the embodiment shown in FIG. 11, the bearing nut 74 may be loosened to provide free movement of the support rods and inspection of the baffles.
The replacement of individual baffles 8 can be accomplished without materially interfering with the operation of the settler unit. After loosening of the lock nut 58 and allowing the support rods 33 to rotate as the tension at each end of a baffle is relieved, the respective dowels 38 are pulled from the closed loop 37 of the baffle and removed from the top end of the support rod 33. The baffle ends are then free to be pulled through the support rod slots 35. Replacement of any baffle is accomplished by a reversal of the foregoing procedure. Should additional baffles be needed, these can be inserted at one end of the top channels 39 with the last baffle securely fastened to the drive chains 60 by means of connecting links 62 or alternatively, by using the bearing nuts 74 on the mount rod axles, as in FIG. 11.
It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims. | A sedimentation process for the collection and removal of solid particles from a liquid includes a basin provided with a plurality of planar baffles or settler members each having opposite ends attached to support rods, with the latter obviating the need for any beams or the like, to support the lower edges of the settler members. Manipulation of an adjustment mechanism permits simultaneous alteration of the inclination of all of the settler members without halting operation of the process. Influent is directed into the basin through a plurality of ports spaced longitudinally of one side wall thereof to more evenly distribute the influent throughout the bottom expanse of the settler members. Preferably, the settler members comprise stretchable membranes with the support rods including a shiftable, lockable mechanism permitting quick installation and variation of the tension as applied to the settler members. | 1 |
FIELD OF THE INVENTION
This invention relates to a device for continuously cleaning yarn and more specifically, for removing lubricants and contaminants during the processing of fibers used to make surgical sutures.
BACKGROUND OF THE INVENTION
The removal of processing lubricants and associated contaminants is a significant aspect in the processing of surgical ligatures such as braided sutures, woven tapes and yarns. The difficulty in cleaning the surgical ligatures stems from the fact that the contaminants and lubricants can be trapped between the individual filaments of the yarn bundle in these surgical ligatures. In order to clean the ligature, a cleaning agent or solvent must permeate the crevices between the filaments of the yarn bundle. Typically, surgical ligatures have been cleaned by various batch methods, where the ligature is immersed in a bath for a predetermined amount of time sufficient to remove lubricants and contaminants from the fibers.
The present invention provides a solution to the above-mentioned problem by providing a device that continuously cleans yarn fibers, and which does not require any stoppage or interruption in the yarn manufacturing process in order to clean such ligatures.
Venturi devices, such as that disclosed in U.S. Pat. Nos. 3,097,412; 3,462,813; 3,545,057; 3,577,614; 3,863,309; 3,881,231; 3,969,799; 3,979,805; 4,041,583; 4,096,612; 4,104,770; 4,157,605; 4,189,812 and 4,290,177; all incorporated herein by reference, have been used for texturizing yarns, but not for cleaning lubricants and contaminants from yarns.
It is therefore an object of the present invention to provide a device for continuously cleaning a ligature.
Another object of the present invention is to provide a device for removing lubricants and contaminants during the processing of surgical ligatures.
Still another object of the present invention is to provide a method for continuously cleaning surgical ligatures moving through a device.
A further object of the invention is to provide a method for removing lubricants and contaminants during the processing of surgical ligatures.
These and other objects and advantages of the invention will become more fully apparent from the description and claims, which follow or may be learned by the practice of the invention.
SUMMARY OF THE INVENTION
The present invention is directed to a method and apparatus for continuously cleaning a surgical ligature moving through the device. A first scouring body has a yarn entrance and a yarn exit connected by a central cavity. Moving fluid is introduced through the surgical ligature while the surgical ligature is positioned within and moving through the central cavity.
In a particularly preferred embodiment, a device in accordance with the present invention further comprises an inlet in fluid communication with the central cavity of the scouring body, and a venturi situated within the central cavity. The venturi is preferably positioned at the exit. The venturi devices listed in the background, and incorporated by reference, would all be used in the present invention. In one preferred embodiment, a needle is slidably mounted into the central cavity through the entrance of the venturi. The needle includes a passage there through for introducing ligature through the central cavity and, at least one flange and a cap. The flange of the needle has at least one opening to allow movement of the fluid from the solvent inlet to the central cavity. This preferred device further comprises at least one cover for holding the needle securely within the central cavity of the scouring body and at least one adjustment nut for adjusting movement of the needle within the central cavity. The cover is in direct contact with the adjustment nut. The device also preferably includes ceramic eyelets situated adjacent to the entrance of the scouring body. In an alternative preferred embodiment, the cleaning device has a baffle for guiding the ligature. The baffle is slidably mounted on a bracket affixed to the scouring body at the exit. A turning pin may also be provided for holding the baffle in the bracket. The entrance and exit are preferably located on opposing sides of the scouring body.
A ligature cleaning system in accordance with the present invention preferably includes two of the scouring bodies described above. Like the first scouring body, the second scouring body has a entrance and exit connected by a central cavity and a means for introducing fluid through the ligature while the ligature is positioned within and moving through the central cavity of the second scouring body. The first and second scouring bodies are arranged in tandem. Each of the first and second scouring bodies has an axis defined by its entrance and exit. The axis of the first and second scouring bodies can be co-axially aligned along a common axis when the system is in its thread-up state. The axes of the first and second scouring bodies are then aligned at a non-zero angle in order to bring the system into a scouring state. The angle between the axes of the first and second scouring bodies is from about 45° to about 90°. When the system is used to clean thinner ligature, the non-zero angle varies from about 60° to about 75°. Separation of the liquid stream containing contaminants and lubricants from the ligature fiber occurs when the ligature fiber is guided away from the exit of a scouring body at an angle. A plurality of scouring bodies can be aligned to continuously clean surgical ligatures.
The ligature cleaning system can also include a housing for encasing a scouring body and a rotatable mounting device for attaching the scouring body within the housing. The housing comprises eyelets for introducing and removing ligature. The housing can also include a fume hood for removing vapors emitted by the cleaning fluid.
The device of the present invention can also comprise a fluid reservoir and a connecting means for transporting solvent from the reservoir to a scouring body. The preferred cleaning fluid is ethyl acetate and the ligature fiber is a suture strand.
The present invention also relates to a method of continuously cleaning a ligature moving through a device. The method comprises the following steps: (a) guiding ligature through a scouring body having a entrance and exit connected by a central cavity, and (b) introducing fluid through ligature positioned within and moving through the central cavity. Before employing step (a), a needle can be slidably mounted into the central cavity and the ligature can be introduced into the central cavity using a needle. After the needle is mounted, the movement of the needle can be adjusted with an adjustment nut. Before employing step (b), the ligature can be moved through a second scouring body having entrance and exit connected by a central cavity, and then the first and second scouring bodies can be aligned at a non-zero angle. The angle between the first and second bodies can vary from about 45° to about 90°.
The method of the present invention can also include the following steps of: (a) axially aligning at least two scouring bodies during a thread-up state; (b) guiding ligature through the central cavity of the scouring bodies utilizing an axially slidable needle; (c) rotatably adjusting the scouring bodies creating a non-zero angle; and (d) introducing fluid through the central cavities of the scouring bodies while moving the ligature through the central cavities of the scouring bodies, thereby cleaning the ligature of contaminants and undesired lubricants during a scouring state.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the manner in which the above-recited and other advantages and objects of the invention are obtained and can be appreciated, a more particular description of the invention briefly described above will be rendered by reference to a specific embodiment thereof which is illustrated in the appended drawings. Understanding that these drawings depict only a typical embodiment of the invention and are not therefore to be considered limited of its scope, the invention and the presently understood best mode thereof will be described and explained with additional specificity and detail through the use of the accompanying drawings.
FIG. 1 is a cross-sectional view of a scouring body for continuously cleaning a surgical ligature as it travels through the central cavity of the scouring body, in accordance with a preferred embodiment of the present invention.
FIG. 2 is a diagram showing the operation of an overall system for cleaning surgical ligature, in accordance with a preferred embodiment of the present
FIG. 3 a is a diagram showing two scouring bodies in a thread-up position.
FIGS. 3 b and c are diagrams showing scouring bodies in different scouring positions, in accordance with alternative preferred embodiments of the present invention.
FIG. 4 is a cross-sectional view showing a baffle fixed with relation to the exit of a scouring body, in accordance with another preferred embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a baffle free to seek a force balance position with respect to the exit of a scouring body, in accordance with another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly, to FIGS. 1, 4 and 5 wherein a ligature cleaning device in accordance with the present invention, generally designated 1 , comprises a scouring body 10 having an entrance 12 and an exit 13 connected by a central cavity 15 . The device 1 further comprises an inlet 16 in fluid communication with the central cavity 15 , and a venturi 18 situated within the central cavity 15 near the exit 13 . The cleaning device 1 also has a needle 20 slidably mounted into the central cavity 15 through the entrance 12 ; the needle 20 has a passage 22 therethrough for introducing ligature 5 through the central cavity 15 . The needle 20 has at least one flange 24 and a cap 25 . The flange 24 of the needle 20 has at least one opening 26 for allowing movement of fluid 7 from the inlet 16 to the central cavity 15 . The device further comprises at least one cover 27 for holding the needle 20 securely within the central cavity 15 , and at least one adjustment nut 28 for adjusting the position of the needle 20 within the central cavity 15 . The cover 27 is in direct contact with the adjustment nut 28 . The device can also have ceramic eyelets 29 for protecting the ligature 5 ; the eyelets 29 are situated adjacent to the entrance 12 of the scouring body 10 .
FIG. 2 shows an overall system 100 for cleaning a surgical ligature. System 100 includes a second scouring body 30 which is substantially the same as scouring body 10 , and thus includes an entrance 32 and an exit 33 connected by a central cavity. The first and second scouring bodies, 10 and 30 respectively, rotatably mounted within and are encased by the housing 40 . The housing 40 comprises eyelets 42 and 43 for introducing and removing ligature 5 from housing 40 . The housing 40 also has a fume hood 45 for removal of toxic gases emitted by the fluid 7 . The system 100 also has a fluid reservoir 46 and a connecting means 47 for transporting fluid 7 from the reservoir 46 to the scouring bodies, 10 and 30 , respectively.
FIGS. 3 a, b and c show system 100 in a thread-up position and scouring positions. The thread-up position is used to thread ligature 5 through device 100 prior to the initiation of cleaning or scouring operations. In the thread-up position (FIG. 3 a ), the yarn entrances and exits of the first and second scouring bodies, 10 and 30 respectively, are rotated until they are aligned along a common axis A within a housing 40 . The housing 40 has eyelet entrance 42 for introducing and removing ligature 5 . During the threadup operation, the ligature 5 is guided from the eyelet entrance 42 of the housing 40 to the entrance 12 of the first scouring body 10 through its central cavity 15 and out its exit 13 . The yarn is then introduced to the entrance 32 of the second scouring body 30 through its central cavity 35 and out its exit 33 and through the eyelets exit 43 of the housing 40 .
FIGS. 3 b and c show the scouring bodies, 10 and 30 respectively, in different scouring positions. After the thread-up operation is complete, scouring bodies 10 and 30 are then preferably rotated until they are aligned in one of the scouring positions shown in FIGS. 3 b and 3 c . Each of the first and second scouring bodies, 10 and 30 , has an axis 50 or 51 , defined by a line passing through its entrance, 12 or 32 , and its exit, 13 or 33 . In the scouring positions shown, the axes of the first and second scouring bodies, 50 and 51 , are aligned at a non-zero angle. The angle (a) between the axis of the first and second bodies is from about 45° to about 90°, and may be varied depending on the thickness of the yarn suture. For example, FIG. 3 b shows a scouring used for cleaning thicker (i.e., 3 to 0 braided suture) ligature, and FIG. 3 c shows a scouring position used for thinner (i.e., 1/0 to 8/0 braided suture) ligature. The scouring position in FIG. 3 is preferred for thinner ligatures because the angle of ligature 5 relative to axes 51 and 52 is smaller, thus creating less tension on the ligature and minimizing the likelihood of breaking or damaging the ligature.
In accordance with an alternative preferred embodiment, FIG. 4 shows a cross-section of the device 1 with a baffle 60 installed adjacent to the venturi 18 and the exit 13 in accordance with the teachings of Breen, U.S. Pat. No. 2,852,906 incorporated herein by reference. The baffle 60 is slidably mounted in bracket 62 , which in turn is affixed to the scouring body 10 at the exit 13 . A turning pin 63 holds the baffle 60 in place in the bracket 62 and when released, the baffle 60 can be moved from the exit end of the device 1 for ease of thread-up.
In accordance with an alternative preferred embodiment, FIG. 5 shows the cleaning device 1 with a baffle 70 movable about a hinge pin 72 according to the teachings of Kozlowski, U.S. Pat. No. 3,835,510, incorporated herein by reference. Hinge pin 70 is mounted off-center of cylinder 74 , which is rotatable in bracket 76 , which is attached to the scouring body 10 . A knob (not shown) is used to rotate cylinder 74 , thus providing an eccentric motion for varying the position of the baffle 70 for optimum operating conditions. A layer of wear-resistant ceramic material 77 may be attached to the surface of baffle 70 facing the outlet end of the device 1 .
To thread-up the device 1 , ligature 5 is presented to the entrance 12 of the device 1 with the assistance of the needle 20 . The cover 27 is moved inwardly away from the head of the adjustment nut 28 , from a preset operating position to a string-up position so that an aspirating effect draws the ligature 5 through the entrance 12 and out through the passage 22 . When the ligature 5 emerges from the venturi 18 , the cover 27 is allowed to return to its preset operating position against the adjustment nut 28 under the force of pressure against the needle 20 in the reduced region of the yarn needle. In this manner, pressure in communication with piston and cylinder arrangement of the needle 20 and scouring body 10 in the central cavity 15 is relied on to return the needle 10 back to the present operating position after string-up. The ligature is then guided through the venturi and out of the device 1 at an angle. Once thread-up is complete, pressurized fluid 7 is then introduced from the inlet 16 to the central cavity 15 , thus cleaning the ligature 5 positioned within and moving through the central cavity 15 of the scouring body 10 .
For the purpose of this invention, a surgical ligature includes yarns, braided constructs and woven or knitted tapes. The fluid used to clean the ligatures should be an appropriate liquid to remove the desired contaminants and/or clean the ligature. Generally the fluids will be cleaning solutions (detergents, surfactants, emulsifiers, wetting agents and combinations thereof) or solvents (i.e., ethyl acetate, acetone, toluene, trichloroethane, water and/or steam). If absorbable sutures are being cleaned aqueous cleaning solutions should be avoided. The fluids used to clean the ligatures may be applied at elevated temperature to facilitate cleaning.
Additionally, the present invention can be combined with conventional ligature cleaning techniques such as scouring baths (which have moving fluids or agitation such as mechanical, sonic or ultrasonic) and/or rinsing procedures. The present invention may be combined with other conventional post cleaning steps such as drying, heat stretching, coating, sterilization and packaging.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore understood that within the scope of the appended claims appended hereto, the invention may be practiced otherwise than as specifically disclosed herein. | A method and apparatus for continuously cleaning a yarn moving through the device. A first secouring body has a yarn entrance and a yarn exit connecting by a centeral cavity. Pressurized fluid is introduced through the yarn while the yarn is positioned within and moving through the central cavity. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to an electron beam inspection apparatus in which a plurality of inspection points are moved to shorten the inspection time.
The inspection points are arranged by the user arbitrarily and hence in an inefficient order of inspection. To assure efficiency, a method is also available to arrange the inspection points in the form of bellows. In this arrangement in bellows form, however, the inspection time is not necessarily minimized. The inspection time is increased conspicuously due to the increased distance in the inspection of a wafer having a diameter as large as 300 mm. Therefore, the optimization of the order of inspection is required and has not been realized due to the failure to establish an algorithm which completes the calculation in practical calculation time.
SUMMARY OF THE INVENTION
The object of this invention is to provide an electron beam inspection apparatus in which the calculation function for determining the order of inspection is realized to shorten the inspection time. The calculation should desirably be completed in a practicable range of not longer than 30 seconds. The order of inspection is determined by shortening the total time including the moving time and the inspection time as well as the distance covered.
According to this invention, there is provided an electron beam inspection apparatus wherein the function to optimize the order of inspection is realized at the time of preparing a recipe to determine the inspection points and the order of inspection. The inspection apparatus has the function not only to determine the order of inspection for shortening the distance covered but also to optimize the order of inspection of inspection points in accordance with the carrying-out position and other prevailing situations. After determining the inspection points, the order of inspection is changed using the order changing function. The formula used to change the order of inspection is automatically selected in accordance with the number of inspection points involved.
As described above, the inspection time is shortened by changing the order of inspection of the inspection points in an electron beam inspection apparatus thereby to contribute to an improved throughput.
Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the process for preparing a recipe.
FIG. 2 shows an outline of the process for calculating an optimum route.
FIG. 3 shows the process of calculation to determine an optimum route.
FIG. 4 shows the process of calculation to determine an optimum route.
FIG. 5 shows the normal order of inspection.
FIG. 6 shows the order of inspection in the shortest distance.
FIG. 7 shows the order of inspection in bellows type (return type).
FIG. 8 shows an outline of a measuring SEM.
FIG. 9 shows a route determined taking the alignment end point and the wafer carrying-out position into consideration.
FIG. 10 shows an optimum route for each of two wafer carrying-out positions.
FIGS. 11A and 11B show an example in which an optimum route is acquired for each of two wafer carrying-out positions taking the alignment point into consideration.
FIGS. 12A , 12 B and 12 C show an example using an optical microscope for alignment.
FIGS. 13A and 13B show the calculation of the moving time to determine the optimum route.
FIGS. 14A and 14B show an example in which the time other than the moving time can be shortened by the route.
FIG. 15 is a diagram showing a general configuration of a scanning electron microscope according to an example of the invention.
FIG. 16 shows the selection by calculation of an optimum route.
FIG. 17 shows a screen to store the route information.
FIG. 18 shows an example of the trapezoidal control operation of the stage speed.
DESCRIPTION OF THE INVENTION
A basic operation flow of the invention is shown in FIG. 1 . In the conventional recipe preparation process, the inspection points are determined arbitrarily by the user, and the apparatus performs the inspection in accordance with the procedure thus determined. According to this invention, the recipe begins to be prepared (S 0001 ), the contents of inspection are determined (S 0002 ) and the inspection points are determined (S 0003 ), after which an optimum route calculation menu ( 102 ) is selected (S 0004 ) from an optimum route calculation and select screen ( 100 ) shown in FIG. 16 . Upon selection (S 0004 ) of the optimum route calculation menu ( 102 ), the calculation of the optimum route is started (S 0005 ). The optimum route is calculated automatically. After calculation of the optimum route, the order of inspection of the optimum route is indicated on an inspection point list ( 101 ). The change in the order of inspection is selected (S 0006 ), and an OK button ( 106 ) is selected (S 0007 ) on the route information storage confirmation screen ( 105 ) thereby to determine the optimum route. No route information is stored in the case where the “cancel” button ( 107 ) is selected. Steps S 0004 to S 0007 represent new steps added by the invention. The selection of the optimum route calculation start menu, the route information storage confirmation, etc. are conducted by use of an input device ( 52 ) while watching a CRT ( 53 ) shown in FIG. 15 . The route information, together with the recipe information, are stored in a storage unit ( 51 ).
The calculation process of the optimum route is shown in FIG. 2 . Strictly, the optimum route cannot be determined without calculating all the combinations of the inspection orders. With the increase in the inspection points, however, the number of combinations increases and all the combinations cannot be calculated within a practical calculation time. According to this invention, the calculation algorithm is changed in accordance with a predetermined number of measurement points. In the case where the number of measurement points is smaller than n 1 and n 2 , all the route combinations are calculated to calculate the optimum route strictly (S 0008 , S 0009 , S 0010 ). In the case where the measurement points exceed n 1 and n 2 , on the other hand, an optimum route is calculated approximately by the optimization calculation algorithm or the bellows-type route calculation (S 0011 , S 0012 ).
An example of the algorithm to calculate an optimum route is shown in FIG. 3 . According to this algorithm, continuous inspection points in a predetermined order of inspection are changed and the inspection time is compared. Then, the order of inspection which shortens the inspection time is selected. First, an initial value n is set to 1 (S 0013 ). Then, the calculation result of the total covered distance is stored as A 1 (S 0014 ). The inspection order n is replaced with the inspection order n+ 1 and the total covered distance is calculated, the result of which is stored as A 2 (S 0015 ). In the case where A 1 is larger than A 2 , the inspection order n is replaced with n+1 so that n is set to 1 and the process is returned to S 0014 (S 0016 , S 0017 ). In this case, n is set to 1 at S 0017 and the process is returned to S 0014 . Nevertheless, n may be alternatively set to n−1 at S 0017 . In the case where A 2 is larger than A 1 , on the other hand, n is set to n+1, and in the case where n coincides with the number of inspection points, the inspection is completed. Otherwise, the process is returned to S 0014 (S 0018 , S 0019 ).
The route after calculation follows exactly the same order as before calculation or the order with a shorter inspection time than before calculation. The calculation time is also comparatively shortened. Since only the continuous inspection points are replaced for comparison, however, the route after calculation considerably depends on the route before calculation. Depending on the manner in which the route before calculation is selected, therefore, the optimum route may fail to be determined. For this reason, this algorithm is more effectively used only after determining an approximately optimum route by another algorithm to determine the optimum route.
Next, another example of the algorithm to calculate the optimum route is shown in FIG. 4 . In this calculation method, the starting and ending points are defined first of all, and using them as an inspection route, inspection points are added (inserted) in the inspection route. The candidate points to be added (inserted) are those not yet added to the route, and inspection points minimizing the inspection time for the whole route are inserted in the order minimizing the inspection time. In FIG. 4 , points u 1 −1, u 1 , u 1 +1, u 1 +2 are already added to the inspection route, and points v, v 1 , v 2 , v 3 candidates to be added to the route. Specifically, the following procedure is followed.
Assume that the input is a weighted complete graph G at the position p with the side weight satisfying the triangle inequality w(u, v)+w(u, w)≧w(v, w) at arbitrary three input points u, v, w. The output is assumed to be a Hamilton closed path C of appropriate weight.
1. Select uεV (G), and regard u as 1 minus closed path C 1 . (i←1) 2. If i=p, end as C=Cp. 3. If i≢p, select a point v where w(u 1 , v)+w(v, u 1 +1)−w(u 1 , u 1 +1) is minimum out of points adjacent to continuous points u 1 , u 1 +1 on Ci but not on C. 4. By setting i←i+1, repeat the processes 2 to 4 above.
As a result, in the case of FIG. 4 , w(u 1 , v)+w(v, u 1 +1)<w(u 1 , v 1 )+w(v 1 , u 1 +1), and therefore v is inserted in the route.
This calculation is repeated until all the inspection points are added to the route. This method, as compared with the method of FIG. 3 , has the feature that the calculation time increases with the number of inspection points. Since this method is hardly affected by the initial route, however, a route comparatively near to the optimum route can be calculated. An effective method is to use this algorithm and then the algorithm of FIG. 3 .
This invention is not limited to the aforementioned algorithms, but can use, for example, TSP (traveling salesman problem) or the nearest inspection algorithm in public domain as a method of calculating the optimum route.
The result of calculation of the optimum route is explained with reference to the examples shown in FIGS. 5 to 7 . FIG. 5 shows a case in which the inspection is conducted in the ascending order of both X and Y coordinates. This order of inspection is often determined arbitrarily by the user. In this inspection order, the total distance between inspection points is not shortest, and therefore the total inspection time can be reduced by changing the order of inspection. FIG. 6 shows the result of determining the optimum route using the functions of the invention. The optimum route is not necessarily determined uniquely, and this route is an example of the optimum route. The average covered distance is 3.66 chips for the route shown in FIG. 5 , while the figure for the optimum route is 2.31 chips or about 40% shorter. This example assumes that the covered distance is proportional to the inspection time. In actual calculations, however, parameters other than the covered distance can be used, as described in detail later. FIG. 7 shows an example of a bellows-type route. The inspection is conducted in the ascending order of X coordinate as in FIG. 5 , while the ascending order and the descending order are alternated with each other in Y direction. As a result, the number of reciprocations in Y direction can be reduced. Thus, the total covered distance and hence the total measurement time can be reduced. The average covered distance along the route shown in FIG. 7 is 2.87 chips. In this case, as compared with FIGS. 5 and 7 , the average covered distance is reduced by about 20%.
This invention is effectively applicable to the measuring SEM and the review SEM in which as shown in FIG. 8 , the inspection is conducted on a sample 8 moved by moving an X table 2 and a Y table 3 controllable while at the same time radiating an electron beam 9 . Also, apart from the inspection apparatus using an electron beam, the invention is effectively applicable to a case in which the inspection range is narrow and the inspection points are moved while moving the sample 8 . Although the XY stages are used to move the sample 8 in the case under consideration, the invention is also applicable to a Rθ stage having a rotary shaft and an axis to move the stage or a case in which the stage moves along one axis and the electron beam along an axis perpendicular thereto. Further, in FIG. 8 , 1 denotes a base, 4 denotes an X-axis motor, 5 denotes a Y-axis motor, 6 denotes a sample chamber, and 7 denotes a main body.
FIGS. 9 to 11B show an application of the invention to the measuring SEM. In the measuring SEM, before moving the inspection points to conduct the inspection, an image is recognized at a predetermined alignment point to adjust the wafer coordinate. The moving time from the alignment point before moving to the inspection points, therefore, is also a factor contributing an increased total measurement time. Also, after the last inspection session, the sample 8 is moved to a wafer carrying-out position before moving to a preliminary exhaust chamber. In optimization of the total moving time, therefore, the moving time from the last inspection point to the wafer carrying-out position is also preferably included in the calculation. FIG. 9 shows a case in which the movement from the alignment end point to the inspection point and the movement from the last inspection point to the wafer carrying-out position are also included in the calculation. In the optimum route of FIG. 9( a ) in which only the inspection points are considered in the calculation, the average covered distance is 2.77 chips, while the average covered distance is 2.17 chips or about 20% smaller for the route shown in FIG. 9( b ) in which the movement from the alignment end point to the inspection points and the movement from the last inspection point to the wafer carrying-out position are included in the calculation.
FIG. 10 shows an application to a plurality of preliminary exhaust chambers. In this apparatus, the optimum route for the carrying-out position 1 is not necessarily the optimum route for the carrying-out position 2 . In the route shown in FIG. 10( a ), the average covered distance is 2.17 chips for carrying out to the carrying-out position 1 , and 2.68 chips for carrying out to the carrying-out position 2 . In the case where the route shown in FIG. 10( b ) is followed, however, the covered distance is 2.17 chips for the carrying-out position 2 . In this way, a plurality of optimum routes are prepared using the algorithm of the invention, and in accordance with the wafer carrying-out position for inspection, an appropriate one of the optimum routes is selected. Thus, the optimum route can be inspected in keeping with the conditions.
The example shown in FIGS. 11A and 11B represents a case in which the sequence of a plurality of alignment points is also taken into account for optimization. A plurality of alignment points are generally used. In the measurement sequence from the wafer carrying-in position (normally the same as the carrying-out position) through all the alignment points and all the inspection points to the carrying-out position, therefore, the route shortest in inspection time is calculated as an optimum route.
In the case where alignment is carried out using an optical microscope, the calculation is further required taking the offset into consideration. As shown in FIG. 12C , the optical axes of the optical microscope and the electron microscope are offset from each other, and in the case where a point AL 1 is inspected under the optical microscope, the point AL 1 is moved to the axial position of the optical microscope. Under this condition, a chip OL 1 is located at the position on the optical axis of the electron microscope. This chip is moved to OL 1 in terms of the coordinate system observed under the electron microscope. In the coordinate of the alignment points for calculating the optimization, therefore, the offset is required to be automatically calculated while the moving position is regarded as OL 1 for calculation. The offset amount is unique to each apparatus, and defined in advance. Therefore, this distance can be used for conversion. In the case where the alignment is conducted using the same chip AL 1 under electron microscope, on the other hand, as shown in FIG. 12A , conversion from the chip AL 1 is required, while the alignment using the optical microscope requires the conversion to the position of OL 1 as shown in FIG. 12B before optimization calculation. In this way, the optimum route is calculated in FIG. 12B .
The foregoing explanation concerns a case in which the total inspection time is minimized by minimizing the total covered distance. In this case, the moving time T is proportional to √{square root over ( )}((ΔX) 2 +(Δy) 2 ) in FIG. 13A . In the stage adapted to move in X and Y directions independently of each other, the total moving time is that along X or Y direction, whichever is longer. On such an XY stage, therefore, the moving time in X direction and the moving time in Y direction are calculated from the coordinates before and after movement, so that the moving time is determined from the longer one of the distances. In such a case, the moving time T is proportional to MAX(ΔX, ΔY). Generally, in FIG. 13B , assume a weighted complete graph G at the input position p with the side weight satisfying the triangle inequality w(u, v)+w(u, w)≧w(v, w) at arbitrary three input points u, v, w. Then, the optimum route can be calculated using the optimization algorithm. The moving time, etc. which satisfy the equation above, can be used for calculation.
FIG. 14 shows a case in which the parameters other than the covered distance are controlling over the measurement time. In the case where the sample surface is known to be charged like a contour and the time required for correction is longer than the moving time of the sample, for example, the total inspection time can be minimized by conducting the inspection in such an order as to minimize the correction amount. The optimum route in terms of the covered distance shown in FIG. 14A is accompanied by a total of eight potential variations, while the optimum route along the equipotential line shown in FIG. 14B has a total of two potential variations. Also in this case, the optimum route can be calculated following the procedure according to the invention by expressing the correction time due to the potential difference between the inspection points in numerical values.
The process of minimizing the total inspection time with the wafer height change Δh as a parameter is explained with reference to FIGS. 15 and 18 . Generally, the height of each inspection point on a wafer 20 is varied by a least 100 μm even on the stage 25 , and since the focal depth of the SEM is less than 1 μm, the focusing is impossible. In view of this, a height detecting laser 26 is applied to the wafer 20 , and the reflection thereof is detected by a laser detector 27 to measure the height. Based on the height information obtained by the measurement, the current for an objective lens 17 is controlled by an objective lens control power supply 33 through a computer 50 to attain the focusing. The objective lens 17 reacts to the set current with a predetermined time constant (delay). Specifically, the larger the change of the current, the longer the time required to set a target focal point. Further, while the objective lens current is directly changed, the image is picked up and the sharpness is determined. Thus, the automatic focusing operation (AF) is conducted by setting an objective lens current associated with the highest sharpness.
Further, in FIG. 15 , 11 denotes a cathode, 12 denotes a first anode, 13 denotes a second anode, 14 denotes an electron beam, 15 denotes a first convergence lens, 16 denotes a second convergence lens, 18 denotes an aperture plate, 19 denotes a scanning coil, 21 denotes an orthogonal electromagnetic field (E×B) for separating secondary signals, 22 denotes the secondary signals, 23 denotes a detector for secondary signals, 24 denotes an amplifier, 30 denotes a power supply for controlling a high voltage, 31 denotes a power supply for controlling the first convergence lens, 32 denotes a power supply for controlling the second convergence lens, 34 denotes power supply for controlling the scanning coil, 35 denotes an image memory, 41 denotes a power supply for controlling an aligner for the objective lens, and 61 denotes an aligner for the objective lens.
In executing the recipe, let Ts be the stage moving time to move the stage to an inspection point, and T 1 the reaction waiting time due to the objective lens current width from the previous inspection point based on the laser measurement of the wafer height at the particular position. The processing time Tt from a measurement session to the next measurement session is given as
Tt=Ts+T 1 +Tap
where Tap is the sum of the pattern recognition time and the AF execution time and substantially constant. In the case where the stage speed is controlled in a simple trapezoidal fashion, Ts which is a function of the distance d between the two measurement points is given as, when d<Vmax*Vmax/2*(1/α 1 +1/α 2 ),
Ts=√{square root over ( )}(2d*(1/α1+1/α2)) and, when d≧V max* V max/2*(1/α1+1/α2)
Ts=d/V max+ V max/2*(1/α1+1/α2)
where Vmax is the maximum stage speed, α 1 the acceleration, and α 2 the deceleration. Also, using the height change Δh, T 1 is expressed as
T 1 =A* exp(Δ h/τ )
where A and τ are constants unique to the lens.
These time values are determined for each route so that the total measurement time can be minimized at the time of optimization calculation.
The foregoing description concerns CD-SEM as an example. This invention, however, is not limited to the CD-SEM but applicable also to various electron beam inspection apparatuses with equal effect.
It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims. | An electron beam inspection apparatus in which the order of inspection is determined to shorten the inspection time is disclosed. The order of inspection is determined by minimizing the total of the moving time and the inspection time as well as by simply optimizing the covered distance. At the time of preparing a recipe to determine the inspection points and the order of inspection, the sequence of a series of inspection points sequentially inspected is changed to optimize the order of inspection. Not only the sequence which minimizes the covered distance is determined but also the order of inspection of the inspection points is optimized in accordance with the charged state, warping of the wafer, the delivery position and other situations. | 6 |
This is a divisional application of U.S. Pat. application Ser. No. 09/422,612 filed on Oct. 21, 1999 now U.S. Pat. No. 6,294,060.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to apparatus and methods for conveying and electroplating a substrate. More particularly, the present invention is generally directed to a conveyorized electroplating device having an anode positioned proximate to a plurality of absorptive applicator assemblies that apply a plating solution to the substrate and a conveyor device that grips the substrate thereby isolating the electrical contact from the plating solution.
2. Description of the Invention Background
Many conventional electroplating devices typically employ mechanisms for moving substrates through a series of large baths or large tanks containing a plating solution. One of the disadvantages of this type of electroplating device is the lengthy amount of time to complete the electroplating process. For example, electroplating one (1) mil of copper in holes contained within a substrate may take in excess of one (1) hour. Another disadvantage of this type of conventional electroplating device is the relatively low exchange of metallic ions at the substrate surface due to the limitations of the bath circulation and the off contact nature of the anode/cathode positions.
Some conventional horizontal electroplating conveyor systems that deliver electrical power to the substrate include a driven roller type conveyor system and a non-driven roller type conveyer system. The driven roller type conveyor system includes solid or disk type rollers to convey the substrate through the plating area The non-driven roller system grips the substrate at its edges by spring loaded contacts and pulls the substrate through the plating area. Both of these systems suffer from the problem of exposing electrified metallic surfaces to plating solution which necessitates the removal of the resulting undesired plating from the roller assemblies thus, preventing them from acting as reliable and dimensionally stable electrical contacts so that current can be delivered to the substrate.
Thus, the need exists for a conveyorized electroplating device that can electroplate a substrate in a relatively short time while providing a high exchange of metallic ions at the substrate surface resulting in a substrate that has a uniform electroplated surface.
The need also exists for a conveyorized electroplating device that minimizes the need to recondition the electrical contacts that are exposed to plating solution thus, assuring a more reliable and repeatable contact point and a more stable process.
Yet another need exists for a conveyorized electroplating device that has the ability to handle substrates of various sizes and thickness without the need for mechanical adjustment.
SUMMARY OF THE PRESENT INVENTION
One form of the present invention provides a conveyorized electroplating device that electroplates a substrate in a relatively short time and exhibits a relatively high exchange of metallic ions at the substrate resulting in a uniform electroplated surface.
The present invention may also include a conveyorized electroplating device comprising a fluid bed assembly having a manifold and an anode, a conveyor device adjacent to the fluid bed assembly, and a plurality of absorptive applicator assemblies wherein the plurality of absorptive applicator assemblies are adjacent and in close proximity to the anode and in fluid communication with the fluid bed assembly.
The present invention may also include a fluid bed assembly having a plurality of baffles received within the manifold such that the plating solution will flow uniformly from the fluid bed assembly.
The present invention may comprise a conveyorized electroplating device that includes a plurality of absorptive applicator assemblies, a conveyor device and an anode, wherein each of the plurality of absorptive applicator assemblies has a profile and defines a fluid passageway that delivers plating solution thereto, and wherein the anode has a profile that corresponds to the profiles of the absorptive applicator assemblies.
Another embodiment of the present invention provides for a conveyor device that isolates the electrical contacts from the plating solution and that is able to handle various sizes and thicknesses of substrates. The conveyor device of the present invention may include a drive assembly and a gripper assembly connected thereto, wherein the gripper assembly has a non-metallic housing, a metallic member slideably mounted within a cavity defined by the non-metallic housing, an arm pivotably mounted to the housing and forming a passageway, and a seal mounted adjacent to the arm.
The present invention further provides for a modular conveyorized electroplating device, wherein multiple modular conveyorized electroplating devices are used together depending on the specific needs of the application. Furthermore, the modular conveyorized electroplating device makes it easy for the user to maintain and replace one or more of the modular conveyorized electroplating devices.
The present invention may also comprise a method of conveying and electroplating a substrate, comprising gripping the substrate at the edges thereof, electrifying the substrate, moving the substrate on or between a plurality of absorptive applicator assemblies, pumping a plating solution in contact with the absorptive applicator assemblies and onto the substrate, and isolating the electrical contact at the substrate from the plating solution.
Other details, objects and advantages of the present invention will become more apparent with the following description of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For the present invention to be readily understood and practiced, various embodiments will be described in conjunction with the following figures wherein:
FIG. 1 is a perspective view of the conveyorized electroplating device of the present invention wherein several modules are placed end to end to create the desire length of the electroplating process;
FIG. 2 is a perspective view of one of the modules of the conveyorized electroplating device of the present invention, wherein a portion of the housing has been removed;
FIG. 3 is a perspective view of one of the modules of the conveyorized electroplating device of the present invention, wherein the entire housing has been removed;
FIG. 4 is an exploded view of a fluid bed assembly of the conveyorized electroplating device of the present invention shown in FIG. 3;
FIG. 5 is a cross-sectional view of a fluid bed assembly of the present invention shown in FIG. 4 and taken along line 5 — 5 ;
FIG. 6 is a perspective view of a drive assembly of the conveyorized electroplating device of the present invention shown in FIG. 3;
FIG. 7 is a perspective view of a gripper assembly of the conveyorized electroplating device of the present invention shown in FIG. 3;
FIG. 8 is a front view of the gripper assembly shown in FIG. 7;
FIG. 9 is a top view of the gripper assembly shown in FIG. 7;
FIG. 10A is a sectional view of the gripper assembly shown in FIG. 8 and taken along line 10 — 10 , wherein the extension is in the unengaged position and no substrate is being gripped;
FIG. 10B is another sectional view of the gripper assembly, wherein the extension is in the intermediate position and a substrate is being gripped;
FIG. 10C is another sectional view of the gripper assembly, wherein the extension is in the fully engaged position and a substrate is being gripped;
FIG. 10D is another sectional view of the gripper assembly, wherein the extension is in the intermediate position and no substrate is being gripped;
FIG. 11 is a perspective view of an upper roller assembly of the conveyorized electroplating device of the present invention shown in FIG. 3;
FIG. 12 is a right side view of the upper roller assembly shown in FIG. 11;
FIG. 13 is a longitudinal sectional view of the upper roller assembly shown in FIG. 12 and taken along line 13 — 13 ;
FIG. 14 is a perspective view of the lower roller assembly of the conveyorized electroplating device shown in FIG. 3;
FIG. 15 is a right side view of the lower roller assembly shown in FIG. 14;
FIG. 16 is a longitudinal sectional view of the lower roller assembly shown in FIG. 15 and taken along line 16 — 16 ;
FIG. 17 is a diagrammatical top view of the drive assembly and gripper assemblies of the conveyorized electroplating device of the present invention shown in FIG. 3;
FIG. 18 is a diagrammatical multiple layer sectional view of the conveyorized electroplating device of the present invention shown in FIG. 3;
FIG. 19A is a diagrammatical sectional view of the drive assembly and gripper assemblies of the present invention shown in FIG. 17 and taken along line 19 — 19 ;
FIG. 19B is a diagrammatical sectional view of another embodiment of the drive assembly and gripper assembly of the present invention having a cleaning device;
FIG. 20 is a sectional view of the gripper assemblies illustrating the movement of the gripper assemblies during the process of plating the substrate and also illustrating an alternative embodiment of the first contact;
FIG. 21 is an exploded perspective view of another embodiment of the conveyorized electroplating device of the present invention;
FIG. 22 is another exploded perspective view of the conveyorized electroplating device of the present invention shown in FIG. 21, wherein the absorptive applicator assemblies have been removed;
FIG. 23 is an exploded view of the fluid bed assembly of the conveyorized electroplating device of the present invention shown in FIG. 21;
FIG. 24 is a sectional view of another embodiment of the coveyorized electroplating device of the present invention having absorptive applicator assemblies;
FIG. 25 is a perspective view of yet another embodiment of the conveyorized electroplating device of the present invention;
FIG. 26 is a sectional view of the conveyorized electroplating device shown in FIG. 25;
FIG. 27 is a top view of the conveyorized electroplating device shown in FIG. 25;
FIG. 28 is a perspective view of another embodiment of the conveyorized electroplating device of the present invention;
FIG. 29 is a sectional view of the conveyorized electroplating device of the present invention shown in FIG. 28;
FIG. 30 is a top view of the conveyorized electroplating device of the present invention shown in FIG. 28;
FIG. 31 is a perspective view of yet another embodiment of the conveyorized electroplating device of the present invention;
FIG. 32 is a sectional view of the conveyorized electroplating device of the present invention shown in FIG. 31;
FIG. 33 is a top view of the conveyorized electroplating device of the present invention shown in FIG. 31;
FIG. 34 is a perspective view of yet another embodiment of the conveyorized electroplating device of the present invention;
FIG. 35 is a sectional view of the conveyorized electroplating device of the present invention shown in FIG. 34;
FIG. 36 is a top view of the conveyorized electroplating device of the present invention shown in FIG. 34;
FIG. 37 is an enlarged view of the conveyorized electroplating device of the present invention shown in FIG. 34 illustrating the anode and the absorptive applicator assemblies;
FIG. 38 is a side view of one of the absorptive applicator assemblies of the conveyorized electroplating device of the present invention shown in FIG. 34;
FIG. 39 is a sectional view of the absorptive applicator assembly shown in FIG. 38;
FIG. 40 is side view of another embodiment of the absorptive applicator assemblies of the conveyorized electroplating device of the present invention;
FIG. 41 is a sectional view of the shaft of the absorptive applicator assembly shown in FIG. 40;
FIG. 42 is a side view of yet another embodiment of one of the absorptive applicator assemblies of the conveyorized electroplating device of the present invention; and
FIG. 43 is an enlarged sectional view of the absorptive applicator assembly shown in FIG. 42 .
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below in terms of apparatuses and methods for electroplating and conveying a circuit board. It should be noted that describing the present invention in terms of electroplating and conveying a circuit board is for illustrative purposes and the advantages of the present invention may be realized using other structures and technologies that have a need for an apparatus and a method for electroplating and/or conveying a substrate.
It is to be further understood that the Figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, other elements and/or descriptions thereof found in a typical conveyorized electroplating device. Those of ordinary skill in the art will recognize that other elements may be desirable in order to implement the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein.
FIG. 1 is a perspective view of the modular conveyorized electroplating device 100 of the present invention, wherein several modules 102 can be placed end to end to create the desire length of the electroplating process. Although the illustrated modular conveyorized electroplating device system 100 of FIG. 1 comprises three modules, any number of modules 102 can be placed end to end. The modular conveyorized electroplating device system 100 has an input station 104 and an output station 106 such that a circuit board substrate (not shown) is loaded into the modular conveyorized electroplating device system 100 at the input station 104 and exits at the output station 106 after being electroplated. The housing 108 of the modular conveyorized electroplating device system 100 may have several removable panels such that the internal mechanisms of the modular conveyorized electroplating device 110 can be easily accessed for maintenance.
FIG. 2 is a perspective view of one of the modules 102 of the modular conveyorized electroplating device system 100 of the present invention, wherein part of the housing 108 has been removed for clarity. The module may include an input section 103 and an output section 105 if used alone. The modular configuration of the conveyorized electroplating device system 100 allows for the fluid bed assembly 112 , the conveyor device 114 and the absorptive applicator assemblies 116 to be easily removed from the module 102 for maintenance and replacement thereof. Each of the modules 102 of the conveyorized electroplating device system 100 comprises one or more fluid bed assemblies 112 , a conveyor device 114 and absorptive applicator assemblies 116 , each of which are discussed in greater detail below.
FIG. 3 is a perspective view of a single conveyorized electroplating device 110 of the present invention, wherein the housing 108 has been completely removed for clarity. The fluid bed assembly 112 extends across and above some of the absorptive applicator assemblies 116 . One of the longitudinal edges of the fluid bed assembly 112 is parallel and adjacent to the longitudinal axis of the conveyor device 114 . The absorptive applicator assemblies 116 comprise upper roller assemblies 118 and corresponding lower roller assemblies 120 . The lower roller assemblies 120 define a track 119 for the circuit board substrate to travel thereon. The upper and lower roller assemblies 118 and 120 are rotatably supported at their ends by bearing blocks 121 . The longitudinal edge of the conveyor device 114 is adjacent and parallel to the longitudinal edge of the absorptive applicators assemblies 116 . The conveyor device 114 also includes a drive assembly 150 and a gripper assembly 124 .
FIGS. 4 and 5 illustrate a fluid bed assembly 112 of the conveyorized electroplating device 110 shown in FIG. 3 . The fluid bed assembly 112 comprises a manifold 130 , a plurality of baffles 132 and an anode 134 . In this embodiment, the manifold 130 is substantially rectangular and defines several receptacle portions 135 each having an inlet 136 and a plurality of stand offs that take the form of rod members 138 . The inlets 136 are in fluid communication with a plating solution reservoir 111 , as shown in FIG. 3 . The plating solution is pumped to the inlets 136 through conduit 101 by pump 109 , as shown in FIG. 3 . Each of the rod members 138 define a recess (not numbered) for supporting the plurality of baffles 132 . The shelf 144 extends inwardly from the vertical walls of the manifold 130 and around the periphery of each of the receptacle portions 135 . The shelf 144 acts to redirect the plating solution so that the plating solution exits the anode holes 148 uniformly. Other types of mechanisms that may be used to redirect the plating solution are diffuser cones. The manifold 130 further has a plurality of mounting claws 140 defining holes (not numbered) for mounting the manifold 130 securely onto the housing 108 using any conventional fasteners such as screws. The manifold 130 also has a seal 142 around its periphery at 141 where it is connected to holes 359 located around the periphery of the anode 134 with suitable fasteners such as stainless steel, titanium or plastic screws or a clamping system. The manifold 130 may be made of polyvinylchloride as well as a variety of other materials which will be apparent to one of ordinary skill in the art. The seal 142 may be a hard rubber gasket, a silicone sealer or any other material that is compatible with the fluid bed assembly 112 .
The baffles 132 are substantially rectangular members having several pins 145 extending from the top surface of the baffles 132 and defining a second recess (not numbered) for receiving fasteners 143 extending through holes 361 located within the periphery of the anode 134 thus, attaching the anode 134 to the baffles 132 . Thus, the baffles 132 are received within the manifold receptacles 135 and are supported by the rod members 138 and are connected to the rod members 138 by fasteners 146 such as stainless steel screws. The baffles 132 may be made from polyvinylchloride as well as a variety of other materials, which will be apparent to one of ordinary skill in the art. Although not illustrated, the shape of the baffles 132 may take a variety of configurations that will be apparent to one of ordinary skill in the art. Also the conveyorized electroplating device of the present invention may be made without baffles 132 , as will be described below.
The anode 134 is a planar member having a substantially rectangular shape and a defining plurality of holes 359 and 361 extending through the anode 134 . As stated above, fasteners 143 such as stainless steel screws extend through the holes 361 and connect to the pins 145 . See FIG. 5 . The anode 134 is further supported by the manifold 130 in that the anode 134 rests on the manifold's periphery at 141 and is attached by stainless steel screws being received in holes 359 . The anode 134 further comprises slots 148 through which the plating solution passes. The fluid bed assembly 112 attaches to the housing 108 at its mounting claws 140 . The fluid bed assembly 112 is positioned such that the anode 134 is in sufficiently close proximity to the absorptive applicator assemblies 116 (FIG. 3) in order to provide a relatively high metallic ion exchange between the anode 134 and the substrate 217 . The anode 134 may be titanium, copper, tin, a precious metal, or an inert metal depending on the application.
FIG. 6 is a perspective view of a drive assembly 150 of the conveyorized electroplating device 110 shown in FIG. 3, which illustrates part of the conveyor device 114 of the present invention. The drive assembly 150 comprises an actuator in the form of a chain 152 with mounting attachments 154 connected thereto, a drive frame 156 , a drive mechanism 158 , a driven mechanism 160 , a chain tension block 162 , chain guides 164 and an actuator drive 126 . The chain 152 moves along the length of the drive frame 156 and around the drive mechanism 158 and driven mechanism 160 . Mounting attachments 154 attached to the chain 152 are substantially planar members that are rigid and have a somewhat square shape with rounded edges. The drive frame 156 is fixedly attached to the housing 108 by any conventional fastening method. The drive mechanism 158 and the driven mechanism 160 are rotatable. The driven mechanism 160 is rotated by the actuator drive 126 which results in the movement of the chain 152 . The chain tension block 162 allows for the tightening or loosening of the chain 152 (i.e., decreasing or increasing the slack in the chain). The chain guides 164 provide that the chain 152 move in a substantially straight path along the length of the drive frame 156 . The actuator drive 126 comprises a drive motor 122 and gear box. The drive assembly may alternatively comprise pneumatics, electrical and hydraulic components.
FIGS. 7-10 illustrate one of the gripper assemblies 124 of the conveyorized electroplating device 110 of the present invention shown in FIG. 3 . The gripper assembly 124 comprises a non-metallic housing 166 , a metallic member 168 , a pivotable panel support 172 which takes the form of an arm, and a seal 176 . The non-metallic housing 166 comprises a T-shaped member 178 and a second member 180 (FIGS. 7 and 8 ). The T-shaped member 178 has a trunk 182 and two branches 184 extending substantially perpendicular from the trunk 182 . The trunk 182 is a substantially elongated rectangular member and has a cavity 186 therein (FIG. 10 A). The cavity 186 slidably receives the metallic member 168 . The second member 180 of the housing 180 also defines a passage 170 which receives the trunk 182 of the T-shaped member 178 . The second member 180 further defines a mounting portion 190 having a plurality of holes 192 , shown in hidden lines in FIGS. 10A-10D. The mounting portion 190 is connected to the mounting attachments 154 by stainless steel screws or other appropriate fasteners. A housing biasing member 194 extends between each branch 184 of the T-shaped member 178 and the second member 180 of the housing 166 (FIG. 8) and are received within cavities 185 (shown in hidden lines) of the second member 180 of the housing 166 . The housing 166 may be made of a variety of non-metallic materials such as polypropylene or polyethylene as well as any other non-metallic materials that are compatible with plating solution and the operating temperature of the electroplating device of the present invention that will be apparent to one of ordinary skill in the art. The housing biasing members 194 may be coil springs; however, other biasing members can also be used as will be apparent to one of ordinary skill in the art.
Referring to FIGS. 10A through 10D, the metallic member 168 comprises a first contact 197 , a second contact 199 , a first biasing member 200 , a second biasing member 202 , flexible contact wire 204 and a roller 206 . The contact wire 204 may also take the form of a braided or multi-stranded wire. The first contact 197 is a substantially elongated rectangular member having the roller 206 rotatably connected thereto by a set screw 208 such that the set screw 208 transverses the longitudinal axis of the first contact 197 . The first contact 197 also defines an opening 198 . The second contact 199 is a substantially elongated rectangular member, defining an opening 210 therein, and having an extension 212 extending therefrom and through an opening 214 in the T-shaped member. The first biasing member 200 is between the first and second contacts 197 and 199 . The contact wire 204 is connected to and extends between the first contact 197 and the second contact 199 . The contact wire 204 is attached to the first and second contacts 197 and 199 by set screws 218 . The second biasing member 202 is positioned at the base of the cavity 186 . The first and second biasing members 200 and 202 may be coil springs; however, a variety of other biasing members can be used which will be apparent to one of ordinary skill in the art. The first and second biasing members 200 and 202 have a greater stiffness than the stiffness of the housing biasing members 194 . The first and second contacts 197 and 199 , the first and second biasing members 200 and 202 , contact wire 204 and the roller 206 , may be made form a variety of metallic materials such that electrical current will be easily conducted therethrough.
The pivotable panel support 172 is a substantially L-shaped arm member having one leg thereof pivotally connected to the housing 166 by a pin 213 and the other leg of the L-shaped member free to swing in an arc and thus form a passageway 174 with the housing 166 .
The seal 176 is attached to the exterior of the trunk 182 and adjacent the pivotable panel support 172 by any conventional fasteners such as adhesive, pins, or clips. The seal 176 is a conical compressive seal fabricated from, for example, EDPM such that after the seal 176 is compressed (FIGS: 10 B, 10 C and 10 D), the seal 176 will spring back to its original form (FIG. 10 A). The length of the free leg of the pivotable panel support 172 is sized such that when the pivotable panel support 172 is pivoted about pin 213 toward the seal 176 , the seal 176 forms a fluid tight seal therewith (FIG. 10 D).
The absorptive applicator assemblies 116 take the form of upper roller assemblies 233 and lower roller assemblies 253 . FIGS. 11-13 illustrate an upper roller assembly 233 . Each of the upper roller assemblies 233 may comprise a solid shaft 235 or hollow shaft (not shown) that has a roll bushing 237 pressed thereon at each of its end portions 240 . Another shaft bushing 246 is pressed onto the intermediate portion 242 of the shaft 235 . As can be seen in FIG. 13, bushings 237 and 246 are received within a liner 245 that is pressed into an elongated roller 247 . It will be appreciated that bushings 237 and 246 rotatably support solid shaft 235 within liner 245 . An upper roller assembly 233 further comprises a bushing 250 pressed onto the shaft 235 at one of the end portions 240 . A flange member 239 is pressed onto the other end of the solid shaft 235 and extends perpendicular thereto. The flange member 239 further includes a projection 251 which is supported by the bearing blocks 121 and prevents the solid shaft 235 from rotating. The shaft 235 and the bushings 237 , 246 and 250 are rotatably received within the roller 247 and the liner 245 such that the roller 247 can rotate relative to the shaft 235 . The elongated roller 247 may be made of a woven mesh made from polypropylene, polyethylene or polyvinyl alcohol; however, a variety of materials can be used for the roller 247 as will be apparent to one of ordinary skill in the art. The shaft 235 may be made of polyvinylchloride; however, it will be apparent to one of ordinary skill that other materials may be used as well. Bushings 237 , 246 and 250 may be made of polypropylene; however, any material having suitable mechanical and chemical properties could also be used for the bushings 237 , 246 and 250 . The shaft 235 is supported at its end portions 240 to the bearing block 121 wherein the solid shaft 235 and the flange member 239 are received within recesses of the bearing blocks 121 , shown in FIG. 3 .
FIGS. 14-16 illustrate a lower roller assembly 253 of the conveyorized electroplating device 110 shown in FIG. 3. A lower roller assembly 253 may include a solid shaft 255 , two roll bushings 261 , a shaft bushing 263 , a sprocket 265 , a liner 267 , and a roller 269 . The solid shaft 255 has two end portions 257 and an intermediate portion 259 . The roll bushings 261 are pressed onto the two end portions 257 of the shaft 255 . Similarly, the shaft bushing 263 is pressed onto the intermediate portion 259 . The sprocket 265 is pressed onto one end portion 257 . A liner 267 is pressed into a coaxial passage in roller 269 and is rotatably supported on the bushings 263 and 261 . The roller 269 may be made from woven mesh of polypropylene, polyethylene or polyvinyl alcohol or a variety of other materials apparent to one of ordinary skill in the art. The shaft 255 , the liner 267 , and the bushings 263 and 261 also may be made of the materials for the like parts stated above. The end portions 257 of the shaft 255 are received within recesses in the bearing block 121 (FIG. 3) and the sprocket 265 is engaged and rotated by a chain (not shown) to drive lower roller assemblies 253 . However, other conventional drive mechanisms can be used to drive the lower roller assemblies 253 . The chain is driven by a lower roller drive assembly 128 . The lower roller drive assembly 128 may be a DC motor, an AC motor, a stepper motor or a servo motor,
FIG. 17 is a top view of a drive assembly 150 and gripper assemblies 124 . FIG. 18 is a multiple layer longitudinal sectional view of the drive assembly 150 and gripper assemblies 124 shown in FIG. 17 . FIG. 19A is a horizontal sectional view of the drive assembly 150 and gripper assemblies 124 of the present invention shown in FIG. 17 and taken along line 19 — 19 in FIG. 17 . FIG. 20 is a sectional view of the gripper assemblies 124 illustrating the movement of the gripper assemblies 124 when the substrate 217 is being fed through the conveyorized electroplating device 110 . In FIGS. 18, 19 A and 20 , the gripper assemblies 124 are illustrated as a simplified form for clarity. In operation, a circuit board substrate 217 is inserted into the conveyorized device 110 at the input station 104 (shown in FIG. 1 ), fed onto the track 119 of one of the modules 102 (shown in FIG. 3) and is gripped along the length of one of its edges 219 by the gripper assembly 124 (FIGS. 17, 18 , 19 A and 20 ). As shown in FIG. 17, as the gripper assemblies 124 a round the corner of the drive assembly 150 , the substrate 217 is gripped by the gripper assembly 124 a and is carried in direction A due to the motion of the chain 152 . As the gripper assembly 124 a is about to turn at the opposing end of the drive frame 156 following the path of the chain 152 , the gripper assembly 124 a will release the substrate 217 having carried the substrate 217 the length of the drive frame 156 .
Referring to FIGS. 18 and 20, for the pivotable panel support 172 of the gripper assembly to grasp the circuit board substrate 217 , the roller 206 engages a ramp 223 which is inclined in the downward direction B (FIG. 20 ). The ramp 223 is a bus bar 221 . As the gripper assembly 124 moves further in the direction A, the ramp 223 forces the roller 206 in direction B, which results in the T-shaped member 178 exerting a force on the housing biasing members 194 and being compressed in a direction B (see FIGS. 8, 10 B, 10 C and 10 D). FIG. 10A illustrates the gripper assembly 124 before it engages the ramp 223 . When the gripper assembly engages ramp 223 and even before a substrate 217 enters passageway 174 the seal 176 engages the pivotal panel support 172 . (FIG. 10 D). The housing biasing members 194 will compress before the first and second biasing members 200 and 202 because the housing biasing members 194 are weaker. As the ramp 223 (FIG. 20) further increases in a downward direction B, the force exerted on the roller 206 (FIGS. 8, 10 B, 10 C and 10 D) compresses the first and second biasing members 200 and 202 , resulting in the extension 212 moving from an unengaged position without a substrate 217 (FIG. 10 D), to an intermediate position (FIG. 10B) to a fully engaged position ( 10 C), wherein the extension 212 extends from opening 214 and makes contact with the substrate 217 which is received within passageway 174 (FIG. 10 C). Because the housing springs 194 are less stiff than the first and second biasing member 200 and 202 , the T-shaped member 178 will be compressed in direction B initially. Having the two different strength springs allows for the T-shaped member 178 to move in direction B resulting in the seal 176 , engaging the pivotal panel support 172 and the extension member 212 to remain within cavity 186 and thus, be protected from the plating solution until the substrate 217 is received within passageway 174 at which time the substrate 217 will engage the seal 176 (FIG. 10C) and thus isolate extension 212 from the plating solution. The extension 212 is in the unengaged position (FIG. 10A) when no force has been applied to the housing biasing members 194 on the first and second biasing members 200 and 202 . The extension is an unengaged position without a substrate when the roller engages the ramp 223 but no substrate 217 is present in the passageway 174 (FIG. 10 D). The extension 212 is in the intermediate position (FIG. 10 B), when the housing biasing members 194 are being compressed. The extension is in the engaged position when it is extending from the opening 214 (FIG. 10 C).
At the same time that rollers 206 of the gripper assemblies 124 are engaging the ramp 223 , the pivotable panel support 172 is riding across ledge 225 such that the ledge 225 supports the pivotable panel support 172 in the C direction. See FIG. 20 . Furthermore, when the roller contacts the ramp 223 , which is a bus bar 221 , electricity is supplied to the roller 206 . The electricity flows through the metallic roller 206 , through the first contact 197 , through the contact wire 204 , through the second contact 199 and through the extension 212 . When the extension 212 contacts the substrate 217 , the substrate is then electrified. While the gripper assemblies are gripping the substrate, moving it in direction A and electrifying the substrate, the plating solution is being pumped through the fluid bed assembly 112 from plating reservoir 111 (FIGS. 3 - 5 ). The plating solution enters inlet 136 and is diffused by the baffles 132 and forced through the electrified anode slots 148 where it then is applied to the upper roller assemblies 233 which are in contact with the substrate 217 and is transferred thereby to the substrate 217 which is in contact with the upper roller assemblies 233 . Both a DC current electroplating method may be used to plate the substrate or a pulse plating method may be used. One example of a pulse plating system that may be used is manufactured by Chemring Plating Systems of Kennett Square, Pa. 19348. The baffles 132 forces the plating solution to be evenly distributed along the anode 134 and exiting the anode evenly along the surface thereof. Without the baffles 132 , the plating solution would enter the inlet 136 and move directly to the closest holes 148 thus exiting the anode 134 at concentrated areas.
FIG. 19B is a diagrammatical sectional view of another embodiment of the drive assembly and gripper assembly having a cleaning device 350 for the extension 212 , which is the electrical contact. The cleaning device 350 comprises an abrasive disk 356 , a motor 352 and a spring loaded vertical actuator 354 . The abrasive disk 356 can be substantially comprised of a diamond dust mounted on a structure; however, many other abrasive surfaces may be used. The motor 352 may be an electrical motor, a pneumatic motor or other types of motors apparent to one of ordinary skill in the art. The spring loaded vertical actuator 354 may be a coil spring or other members that will absorb the downward force of the device 350 . The cleaning device is mounted on the return pass of the drive assembly 150 . As the gripper assembly 124 rides along the ramp 358 , the extension 212 is forced passed the seal 176 while at the same time the abrasive disk 356 is moved into contact in the direction F with the extension 212 by the spring loaded vertical actuator 354 . This contact results in the removal of unwanted plating or oxidation from the extension 212 .
This embodiment of the present invention places a relatively large amount of absorptive applicator assemblies 116 in contact with the substrate 217 and both the assemblies 116 and the substrate 217 in close proximity with the anode 134 which results in a high metallic ion exchange. Furthermore, the relatively large number of assemblies 116 in contact with the substrate provides for the desired plating of holes and/or openings in the substrate 217 .
As can be seen in FIG. 20, a ski-shaped device 227 can be substituted for the roller 206 . The ski-shaped device 227 can be made of a variety of metallic materials such as copper.
FIGS. 21-23 illustrate another embodiment of the conveyorized electroplating device 110 of the present invention. The conveyorized electroplating device system 100 comprises two fluid bed assemblies 112 , a lower anode assembly dam 277 , upper and lower bearing block supports 121 , absorptive applicator assemblies 116 , and portions of housing 108 . The conveyor device 114 previously discussed is also used in this embodiment; however, it has been omitted from FIGS. 21-23 for clarity purposes. The fluid bed assembly 112 shown in FIG. 23 comprises a manifold 130 and an anode 134 . The manifold 130 is a substantially rectangular member having an inlet 271 , a receptacle portion 131 and a mounting flange 273 (not shown) on opposing sides of the manifold 130 . The anode 134 consists of a substantially rectangular planar member fabricated from a material suitable for the material of the substrate having holes 148 extending therethorough. For example, if the substrate is to be plated with copper, the anode 134 may be copper and the plating solution may be a copper acid bath. Also the anode may be, for example, titanium or titanium with a coating. Furthermore, the anode 134 may be non-sacrificial and inert such as titanium or titanium with a coating and the plating solution may be a tin bath. However, one of ordinary skill will appreciate that a variety of anodes and plating solutions may be used. The anode 134 is connected to the manifold 130 at its periphery by stainless steel screws 275 and the fluid bed assembly 112 is then connected to the housing (not shown).
The lower anode assembly dam 277 , shown in FIG. 21, comprises four vertical walls forming a rectangular shape, wherein the opposing side walls define recesses 279 . The shafts 235 and 255 of the upper and lower roller assemblies 233 and 253 are received with the recesses 279 . The lower anode assembly dam 277 also has a cut-out portion 281 at one end thereof that receives the tubular inlet member 271 of the manifold 130 . The lower anode assembly dam 277 is supported by the fluid bed assembly 112 and connected to the anode 134 by fasteners (not shown). The vertical walls are notched to be received within the upper and lower bearing block supports 121 . See FIG. 22 .
The upper and lower roller assemblies 233 and 253 , shown in greater detail in FIGS. 11-16 and described above, are rotatably received within upper and lower bearing blocks supports 121 . The upper bearing blocks 121 have recesses 283 that rotatably receive a corresponding shaft 235 and flange member 239 of the upper roller assemblies 233 . Similarly, the lower bearing blocks 121 have recesses 183 (not shown) that are adapted to receive corresponding shaft 235 and flange member 239 of a corresponding lower roller assembly 253 . The lower and upper bearing block supports 121 are rigidly connected to the housing 108 by any conventional fasteners, including screws, bolts, rivets, etc. In operation, plating solution enters the fluid bed assembly 112 through inlet 271 of the manifold 130 and exits the fluid bed assembly 112 through the anode holes 148 and is applied to the roller assemblies 233 and 253 of the absorptive applicator assemblies 116 , wherein the plating solution will be transferred to both sides of the substrate as it moves over the absorptive applicator assemblies 116 . The lower anode assembly dam 277 prevents the plating solution from spilling over the sides of the fluid bed assembly 112 as it exits the anode holes 148 thus, redirecting the solution onto the absorptive applicator assemblies 116 . The lower anode assembly dam 277 creates a reservoir for the plating solution thus, keeping the roller assemblies 116 wet with the plating solution. This results in the substrate 217 also remaining wet with plating solution thus preventing “burning” of the substrate 217 . Burning is when the substrate 217 after being electroplated has darkened, uneven deposits associated with high current densities or a lack of metals to be plated or a combination of both. This burning can be prevented by keeping the substrate wet with plating solution.
FIG. 24 is a sectional view of another embodiment of the conveyorized electroplating device 110 of the present invention having absorptive applicator assemblies 116 in the form of strip or block members 285 . This embodiment comprises the lower roller assemblies 253 , as described above, positioned below the substrate 217 and block members 285 made of absorptive material being mounted over the holes 148 of the anode 134 such that the plating solution that is pumped through the fluid bed assembly 112 will exit the holes 148 in the anode 134 and be delivered to the substrate. The block members 285 may be made from polyethylene, polypropylene or polyvinyl alcohol or any other material that is flexible and absorbent and chemically compatible. In this embodiment, the block members 285 are in direct contact with the substrate; however the block members 285 may be spaced from the substrate.
FIGS. 25-27 illustrate another embodiment of the conveyorized electroplating device 110 of the present invention, wherein driven absorptive applicator assemblies 116 engage the bottom of the substrate 217 (FIG. 26) and the plating solution is applied from the bottom of the substrate 217 through the anode 134 . In this embodiment, only one fluid bed assembly 112 and one row of absorptive applicator assemblies 116 are used. The substrate 217 moves over the track 119 defined by the absorptive applicator assemblies 116 . The absorptive applicator assemblies 116 are positioned above the fluid bed assembly 112 . The fluid bed assembly 112 comprises a manifold 130 , several baffles 132 and an anode 134 , as described previously. The plating solution is pumped through the fluid bed assembly 112 exiting the anode 134 at the anode holes 148 and is applied to the absorptive applicator assemblies 116 . As can be seen in FIG. 26, the absorptive applicator assemblies 116 are spaced from the anode 134 ; however, the absorptive applicator assemblies 116 may also contact the anode 134 .
FIGS. 28-30 illustrate another embodiment of the conveyorized electroplating device 110 of the present invention, wherein the substrate 217 is positioned between two rows of the absorptive applicator assemblies 116 and the plating solution is applied to the top and bottom of the substrate 217 . This embodiment of the conveyorized electroplating device 110 comprises two fluid bed assemblies 112 , two rows of absorptive applicator assemblies 116 , the upper roller assemblies 233 and the lower roller assemblies 253 , wherein the lower roller assemblies 253 are driven members and the upper roller assemblies 233 are free to rotate. Each fluid bed assembly 112 comprises a manifold 130 , a plurality baffles 132 and an anode 134 , all of which have been described above. The substrate 217 is driven by the lower roller assemblies 253 and the conveyor device 114 (not shown for clarity purposes). The plating solution is applied to both sides of the substrate 217 by the fluid bed assemblies 112 . The solution is pumped out of the holes 148 of the anodes 134 onto the absorptive applicator assemblies 116 , which are in contact with the substrate 217 . Alternatively, the plating solution may be pumped through only one of the two fluid bed assemblies 112 thus, electroplating only one surface of the substrate 217 . This embodiment also includes two spray bars 248 each having spray nozzles 249 for wetting the substrate 217 with the plating solution prior to engaging the absorptive applicator assemblies 116 . By soaking the substrate prior to electroplating the substrate, the substrate is not susceptible to being depleted of solution during the electroplating process and thus, having an uneven “burnt” electroplated surface as a result. The spray bars 248 have nozzles 249 connected thereto which spray the plating onto the substrate 217 . The spray bars are fluidly connected to the plating solution reservoir 111 .
FIGS. 31-33 illustrate yet another embodiment of the conveyorized electroplating device 110 of the present invention, wherein the substrate 217 is positioned above the driven absorptive applicator assemblies 116 and the plating solution is supplied through the anode 134 positioned above the substrate 217 . In this embodiment, the conveyorized electroplating device 110 comprises one fluid bed assembly 112 positioned adjacent to the roller assemblies 116 . The plating solution is pumped through the fluid bed assembly 112 exiting the anode holes 148 onto the roller assemblies 116 which come in contact with the substrate 217 .
FIGS. 34-37 illustrate yet another embodiment of the conveyorized electroplating device of the present invention, wherein the substrate 217 is between upper and lower roller assemblies 233 and 253 and the plating solution is supplied through a fluid passageway defined by the upper and lower roller assemblies 233 and 253 . In this embodiment of a conveyorized electroplating device 110 , the plating solution is transported to the absorptive applicator assemblies 116 through a supply tubing system 300 such that the plating solution enters a fluid passageway 301 of the absorptive applicator assemblies 116 (FIG. 37) and is dispersed radially with respect to the absorptive applicator assemblies 116 . The anode 302 has a profile that conforms with the absorptive applicator assemblies 116 such that the anode 302 is in contact with absorptive applicator assemblies 116 or spaced a relatively small distance away therefrom. For example, in one embodiment of the present invention, the anode 302 can be spaced approximately 0.125 inches to 0.25 inches away from the absorptive applicator assemblies. This embodiment eliminates a manifold and baffles. The absorptive applicator assemblies 116 form two rows of absorptive applicator assemblies 116 , the upper and lower roller assemblies 233 and 253 , wherein the substrate 217 is fed therethrough and the lower roller assemblies 233 are driven. The tubing system 300 comprises multiple tubes 303 that supply plating solution to each of the upper roller assemblies 233 from a main line 304 . Although the plating solution is only being supplied to the substrate 217 through the upper roller assemblies 233 , the solution may also be supplied to the substrate 217 from both the upper and lower roller assemblies 233 and 253 .
FIGS. 38 and 39 illustrate upper roller assemblies 233 of the conveyorized electroplating device of the present invention shown in FIGS. 34-37. The upper roller assembly 233 is a tubular member defining a fluid passageway 306 . One of the multiple tubes 303 is connected to the fluid passageway 306 such that plating solution can be delivered from the plating solution source (not shown), through the main tube line 304 , through the multiple tubes 303 and into the fluid passageway 306 . The tubular member is made from porous plastic such as polyvinylchloride or ceramic such that the plating solution entering the fluid passageway 306 is dispersed radially through the tubular member to the substrate 217 .
FIGS. 40 and 41 illustrate another embodiment of an absorptive applicator assembly 116 of the conveyorized electroplating device 110 of the present invention having bristles 310 protruding from the circumference thereof and defining a fluid passageway 308 therethrough for delivering the plating solution to the substrate 217 . This embodiment of the absorptive applicator assembly 116 comprises a hollow shaft member 309 and a plurality of radially extending brush bristles 310 . The brush bristles 310 extend around the entire circumference of the shaft 309 . The brush bristles 310 comprise a U-shaped elongated channel member (not shown) within which the bristles extend. The channel member is crimped such that it is connected to the bristles and the elongated member is then wound around the shaft 309 where the channel member can be connected thereto by adhesive, clips or other fasteners. The tubes 303 supplying the plating solution are in fluid communication with the fluid passageway 308 . The plating solution is delivered to the fluid passageway and is dispersed outwardly onto the substrate 217 which is in contact therewith. The shaft 309 is made from a porous plastic that allows for the plating solution to be dispersed radially outward and through the plastic. The bristles 310 then supply the plating solution to the substrate. The bristles 310 may be made from polypropylene or any other suitable material.
FIGS. 42 and 43 illustrate yet another embodiment of an absorptive applicator assembly 116 of the conveyorized electroplating device 110 of the present invention having a flat brush and defining a fluid passageway 316 therethrough for delivering plating solution. In this embodiment, the absorptive applicator assemblies 116 each comprise a tubular member 314 defining a fluid passageway 316 and a longitudinal slot 318 that extends the length of the tubular member 314 . The absorptive applicator assemblies 116 further include a plurality of brush bristles 320 that extend radially from the tubular member 314 and cover a portion of the circumference of the tubular member 314 thus forming a flat brush. The plating solution is supplied from the multiple tubes 303 , to the fluid passageway 316 of the tubular member 314 and it is directed to the brush bristles 320 by the slotted portion 318 of the tubular member 314 . The bristles 320 engage the substrate 217 and apply the plating solution thereto. It will be appreciated that all of the absorptive applicator assemblies 116 illustrated in FIGS. 38-43 may be manufactured without a fluid passageway therein and thus, be adapted to be used in the embodiments of the present invention illustrated in FIGS. 1-33.
Although the present invention has been described in conjunction with preferred embodiments thereof, it is expected that many modifications and variations will be developed. This disclosure and the following claims are intended to cover all such modifications and variations. | A conveyorized electroplating device having an anode positioned proximate to a plurality of absorptive applicator assemblies that apply a plating solution to a substrate and a conveyor device that grips the substrate thereby isolating the electrical contact from the plating solution. The conveyorized electroplating device has a fluid bed assembly with a manifold and an anode, a conveyor device adjacent to the fluid bed assembly, and a plurality of absorptive applicator assemblies, wherein the plurality of absorptive applicator assemblies are adjacent and in close proximity to the anode and in fluid communication with the fluid bed assembly. The conveyor device isolates the electrical contacts from the plating solution and is able to handle various sizes and thicknesses of substrates. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to an FDMA (Frequency Division Multiple Access) transmitter-receiver and more particularly to an FDMA transmission/reception method for use in a digital radio communication system which is capable of changing a communication channel bandwidth, and a transmitter-receiver employing the FDMA transmission/reception method.
2. Description of the Related Art
A digital radio communication system is generally designed in such a way that a plurality of local stations transmit/receive the respective radio waves to/from a base station and the communication is established between the local stations via the base station. Therefore, the base station needs to multiplex the signals on all the call channels or communication channels which are assigned to the communication system of interest in order to transmit/receive the resultant radio wave. As such multiplexing communication methods, there are known the Time Division Multiple Access (hereinafter, referred to as "a TDMA" for short, when applicable) method in which multiplexing is carried out in time domain and the Frequency Division Multiple Access (hereinafter, referred to as "an FDMA" for short, when applicable) method in which multiplexing is carried out in frequency domain.
On the other hand, the promotion of the multi-media in recent years results in the demand of carrying out communication between terminals having various data rates being developed. In order to cope with the promotion of the multi-media, it is desired that the rate of data which can be transmitted/received by the communication system can be changed.
SUMMARY OF THE INVENTION
In the above-mentioned TDMA method, since the call channels or communication channels are assigned in time domain, it is relatively easy to set the call channels having the different data rates. On the other hand, in the above-mentioned FDMA method, since multiplexing is carried out in frequency domain, it is necessary to provide a demultiplexing filter for every channel. In addition, in order to cope with the variable data rate, it is required that a plurality of filter banks having different bandwidths corresponding to the various data rates are prepared and also switching control is carried out so as for the frequency ranges of the channels not to overlap each other. In order to achieve the switching function in the FDMA method, frequency conversion needs to be carried out multiple times. As a result, the hardware scale becomes large and also the control thereof becomes necessarily complicated.
In the light of the foregoing problems associated with the prior art, it is therefore an object of the present invention to provide a transmission/reception method and a communication apparatus employing the method for use in a communication system of an FDMA mode which is capable of changing bandwidths of call channels or communication channels.
It is another object of the present invention to provide a communication system of an FDMA mode which is capable of changing bandwidth of call channels or communication channels.
It is still another object of the present invention to provide a channel switching method for use in an FDMA communication system.
In order to attain the above-mentioned objects, it is a concentrable method that a plurality of filter banks constituted by band-pass filters having different bandwidths are prepared, and these filter banks are switched. In this connection, since an amount of hardwares is increased if those filter banks are constructed in a usual manner, in the present invention, a trans-multiplexer (hereinafter, referred to as "a TMUX" for short, when applicable) is employed.
The FDM-TDM conversion as a reverse operation is realized by a trans-demultiplexer (hereinafter, referred to as "a TDMUX" for short, when applicable) in which the structure of the TMUX is reversed. If the number of channel multiplexings is changed in both the TMUXs and the TDMUXs while maintaining a sampling frequency fs constant, it is possible to construct the filter banks having different passband-widths.
Specifically, an FDMA mode transmitter-receiver according to one aspect of the present invention is arranged such that an FDMA signal from a reception circuit is converted to a time-division multiple access signal stream (hereinafter referred to as TDMA signal stream) by a TDMUX, the TDMA signal stream received is demultiplexed by a channel signal demultiplexing/multiplexing circuit connected to receive the TDMA signal stream from the TDMUX in order to extract a signal on each communication channel and the signals thus extracted are channel-reassignably remultiplexed to produce a different TDMA signal stream. The different TDMA signal stream is received by a TMUX by which the different TDMA signal is converted to a different FDMA signal.
More specifically, for example, the FDMA multiple signal which has been received, is converted into TDMA signal streams by a plurality of TDMUXs having different passband-widths. The signals on the channels in communication are extracted from each of the TDMA signal streams on the basis of information contained in the signal on a control channel and fed to the TMUXs having corresponding passband-widths. In the TMUXs, the TDMA signals are converted into FDMA signals. In such a way, the FDMA signals which have been produced by conversion in a plurality of the TMUXs are added and multiplexed in order to be transmitted.
As described above, when constructing a plurality of filter banks having different passband-widths, by employing TMUXs and TDMUXs, configuration can be made simpler as compared with the case where discrete filters are combined with each other, and hence an amount of hardwares can be reduced. In addition, since the control of changing the passband-width can be carried out in the TDMA signal domain, such control can be more readily processed as compared with the case where the control of changing the passband-width is carried out in the FDMA signal domain, and in addition thereto, it is possible to realize a switching function.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects as well as advantages of the present invention will become clear by the following description of the preferred embodiments of the present invention with reference to the accompanying drawings, wherein:
FIG. 1 is a block diagram showing a configuration of an FDMA transmitter-receiver of an embodiment according to the present invention;
FIG. 2 is a spectrum view useful in explaining the operation of the FDMA transmitter-receiver of the embodiment shown in FIG. 1;
FIG. 3 is a schematic view useful in explaining the principle of a trans-multiplexer employed in the present invention;
FIG. 4 is a block diagram showing an example of a configuration of the trans-multiplexer shown in FIG. 3;
FIG. 5 is a schematic view useful in explaining the principle of a trans-demultiplexer employed in the present invention;
FIG. 6 is a block diagram showing an example of a configuration of the trans-demultiplexer shown in FIG. 5;
FIG. 7 is a block diagram, partly in circuit diagram, showing an example of a configuration of a communication signal demultiplexing/multiplexing circuit and a call control circuit which are employed in the present invention; and
FIG. 8 is a schematic view of a sequence of transmitting/receiving a signal which is useful in explaining the operation in the case where a call bandwidth of a local station is changed in the communication system of an embodiment according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will hereinafter be described in detail with reference to the accompanying drawings.
Referring first to FIG. 1, there is illustrated a block diagram showing a configuration of an embodiment in which an FDMA transmitter-receiver of the present invention is applied to a communication apparatus for a base station of an FDMA radio communication system.
In the figure, reference numeral 1 designates a transmission/reception antenna; reference numeral 2, a circulator; reference numeral 3, a reception circuit; reference numeral 4, a transmission circuit; reference numeral 5, a TDMUX for two-channel multiplexing, for example; reference numeral 6, a TDMUX for six-channel multiplexing, for example; reference numeral 7, a TMUX for six-channel multiplexing, for example; reference numeral 8, a TMUX for two-channel multiplexing, for example, reference numerals 9 and 11, call signal demultiplexing/multiplexing circuits; reference numeral 10, a call control circuit; and 12, an adder. The TDMUXs 5 and 6 and the TMUXs 7 and 8 may have at least one channel, respectively.
Call signals which have been respectively transmitted from a plurality of local stations are received through the transmission/reception antenna 1 so as to be inputted to the reception circuit 3 through the circulator 2. The reception circuit 3 receives in a lump all the signals (which are different in frequency from one another and are received in the form of frequency-division multiplexing) from a plurality of local stations in order to frequency-convert all the signals having high frequency bands to an FDMA multiple signal having a base band. On the other hand, an FDMA multiple signal which will be transmitted from the base station to a plurality of local stations on the reception side is converted from the signal having the base band to signals having higher frequency bands in order to be transmitted through the transmission/reception antenna 1 via the circulator 2.
Now, before the description proceeds to the operation of the FDMA transmitter-receiver shown in FIG. 1, both the TMUX and the TDMUX which are employed in the present invention will hereinbelow be described in detail.
The TMUX is a device which serves to convert a time division multiple (TDM) signal stream into a frequency division multiple (FDM) signal without involving a demultiplexing process. As for the known examples relating thereto, there are "A Modulation Type Converter" disclosed in JP-A-1-117437, and the like for example.
While the principle of the TMUX is described in detail in JP-A-1-117437 and an article of "Application of Digital Signal Processing" edited by THE INSTITUTE OF ELECTRONICS AND COMMUNICATION ENGINEERS OF JAPAN, Chapter 5 (Signal Conversion Processing in Communication), pp.121 to 134 (issued on 1981), the main points thereof will hereinbelow be described with reference to FIG. 3.
The TMUX can also be considered to be a technology for constructing filter banks in which the passband characteristics are identical to each other and the central frequencies are arranged at fixed intervals. Since quadrature modulation wave signals are handled here, all signals are treated as complex signals. For the frequency shift carried out in the TDM-FDM conversion, both a sampling frequency fs (as an example, this sampling frequency fs is, with the channel width of 6.25 kHz, 37.5 kHz for the six channel multiplexing) and a shift frequency fk of each channel are selected so as to fulfill the relationship of fk=k˜fs/M (refer to FIG. 3(b)) where M represents the number of channel multiplexing. A signal spectrum of each of the channels of the input TDMA signal stream is as shown in FIG. 3(a). Then, let us consider that the signal spectrum is frequency-shifted to a channel k of the FDMA signal as indicated by a dotted line as shown in FIG. 3(a). If the TDMA signal stream is demultiplexed through a demultiplexing switching circuit, then the sampling frequency is decreased down to fB=fs/M, and alias components appear as indicated by a dotted line of FIG. 3(b). The frequency component to be shifted (i.e., the signal on the channel k indicated by a solid line) has only to be extracted among these alias components.
Next, the filter banks are comprised of a group of band-pass filters which have the same passband width fB and in which the respective central frequencies are separated at intervals of fB (refer to FIG. 3(c)). Therefore, the frequency characteristics of the k-th filter Hk(z) are obtained by shifting the frequency characteristics of the original filter Ho(z) having the same frequency characteristics by the frequency of k˜fB, and hence can be expressed by the following expression (1): ##EQU1## where W=exp(-j2π/M). This expression (1) is obtained in such a way that f in a delay operator z=exp(j2πf/fs) of the original filter Ho(z) is replaced with (f-k˜fB). That is, an expression (2) is established.
Hk(z)=H.sub.0 (zW.sup.k) . . . (2)
Now, an arbitrary filter can be expressed by an expression (3) on the basis of a poliphase filter which has the sampling frequency divided by M.
H(z)=ΣH.sup.i (z.sup.M)z.sup.-i . . . (3)
As a result, by poliphase-decomposing the k-th filter Hk(z) and also using the relationship of an amount of frequency shift of k˜fB, the following expression is obtained.
Hk(z)=ΣH.sub.k i(z.sup.M)z.sup.-i =H.sub.o.sup.i (-z.sup.M)z.sup.-i W.sup.-ik . . . (4)
where W.sup.-ik =exp(j2Σik/M) . . . (5).
Then, all the output signals from respective k-th filter are added, thereby obtaining the FDMA signal (refer to FIG. 3(d)).
From expression (4), it is clearly understood that the filter bank of the FDMA mode can be realized on the basis of multiplication of the matrix W -ik of expression (5), the poliphase filter (refer to expression (3)) and the delay operator z. Since the multiplication of the matrix W -ik is the butterfly operation used in the FFT (Fast Fourier Transform) by which DFT (Discrete Fourier Transform) can be speedily calculated, the high speed operation can be promoted with the same algorithm. In addition, since all the M poliphase filters which are obtained by expanding the M filter banks are common, reduction of the hardware can be attained.
Thus, it is understood that the TDM-FDM conversion can be realized by the TMUX as shown in FIG. 4. In the figure, reference numeral 41 designates a time division separation switch, reference numeral 42 designates an inverse DFT butterfly operation circuit, reference numerals 430 to 43M-1 designate poliphase filters, respectively, reference numerals 440 to 44M-1 designate delay devices, respectively, and reference numeral 45 designates an adder.
The FDM-TDM conversion as the inverse operation is realized by a TDMUX (trans-demultiplexer) which is obtained by reversing the configuration of the TMUX shown in FIG. 4. But, since all the signals on the k-th channels of the FDMA signal are shifted to d.c. signals (their frequencies are zero), the operation W -ik of the inverse DFT is replaced with the operation W ik of the DFT, and also the order of the poliphase filters and the FFT butterfly operation are reversed. Here, the operation of the trans-demultiplexer will now be described by taking a spectrum view shown in FIG. 5 as an example. FIG. 5 shows an example in which the FDMA signals on two channels are converted into the TDMA signal. In order to extract the signal on the k-th channel of the FDMA signal (refer to FIG. 5(a)), the filter Hk(z) which has the frequency characteristics indicated by a solid line in FIG. 5(b) is employed. The frequency characteristics of the filter Hk(z) are obtained by shifting those of the original filter Ho(z) indicated by a dotted line in FIG. 5(b) by the frequency of fB=fs/2, and hence can be expressed by the following expression: ##EQU2## where W=exp(-j2π/M). That is, expression (6) is obtained in such a way that f in the delay operation z=exp(j2πf/fs) of the original filter Ho(z) is replaced with (f+(k+1/2).fB.
A point of difference of expression (6) from expression (1) is that the term of exp(jπ/M) is additionally contained therein. This results from that an amount of frequency shift is equal to half the frequency interval fB of the filter bank. By substituting expression (6) into expression (3), an expression (7) is obtained, instead of the expression (4) in the case of the TMUX.
Hk(z)=ΣH.sub.k.sup.i (z.sup.M)Z.sup.-i =ΣH.sub.0.sup.i (-z.sup.M)˜z.sup.-i ˜W.sup.ik ˜exp(jπi/M) . . . (7)
The output signal from each k-th filter has the spectrum indicated by a dotted line in FIG. 5(c) and it is shifted to a d.c. signal (its frequency is zero) with the DFT operation W ik .
The TDMUX as discussed above can be configured as shown in FIG. 6. In the figure, reference numerals 610 and 611 designate delay devices, respectively, reference numerals 620 and 621 designate phase rotation circuits, respectively, reference numerals 630 and 631 designate poliphase filters, respectively, reference numeral 64 designates a DFT butterfly operation circuit, and reference numeral 65 designates a time division multiple switch.
Then, if the number of channel multiplexing is changed with both the above-mentioned TMUXs and TDMUXs while maintaining the sampling frequency fs constant, then the filter banks having different passband-widths can be constructed. Then, the FDMA multiple signal which has been received is converted into TDMA signal streams by a plurality of TDMUXs having different passband-widths. Signal on channels in communication are extracted on the basis of the information contained in the signal on the control channel in order to be transmitted to the TMUXs having corresponding passband-width. In the TMUXs, the TDMA signal streams are converted into FDMA signals. The FDMA signals which have thus been obtained by the conversion in a plurality of the TMUXs are added and multiplexed so as to be transmitted.
Next, an embodiment of the present invention will hereinbelow be described with reference to FIGS. 1 and 2. Note that the outline of the configuration of the FDMA transmitter-receiver shown in FIG. 1 is as already described above.
Referring to FIG. 2, there is illustrated a spectrum view useful in explaining the operation of the present embodiment shown in FIG. 1. Firstly, the arrangement of the communication channels of the present embodiment will be described with reference to FIG. 2.
The frequency characteristics of the filter bank constituted by both the TDMUX 6 and the TMUX 7 are shown in FIG. 2(a). Five communication channels are respectively provided by the band-pass filters each having the passband-width fB. While the sampling frequency fs of the TMUX is given by fs=6˜fB and hence the six communication channels can be set, the 6-th channel is not used. Next, the frequency characteristics of both the TDMUX 5 and the TMUX 8 are shown in FIG. 2(b). As apparent from FIG. 2(b), two band-pass filters each having the passband-width 2fB are provided. By adopting the frequency arrangement as described above, it is possible to set the channels ranging from the first channel up to the seventh channel as shown in FIGS. 2(a) and 2(b). The arrangement of the communication channels which is available to the FDMA communication system of the present embodiment is shown in FIGS. 2(c), 2(d), 2(e) and 2(f), respectively. Note that the channels 1 and 2 and channel 6 can not be used at the same time. In addition, the channels 4 and 5 and channel 7 also can not be used at the same time. The channel 3 can be used in even any channel arrangements. For this reason, the channel 3 is used as the control channel for the FDMA communication system.
Next, the description will hereinbelow be given by taking the situation in which in the embodiment shown in FIG. 1, both channels 1 and 4 are in use, and a local station A (not shown) using the channel 1 doubles the communication bandwidth (e.g., when communication is switched from speech signals to higher rate data of a facsimile, a computer or the like), as an example with reference to FIGS. 1 and 8.
FIG. 8 is a sequence diagram of a signal transmission/reception in the situation described above. In the figure, time elapses from upper to lower. In Step 1, both the communication signal on the channel 1 from the local station A and the communication signal on the channel 4 from the local station B are respectively transmitted to the base station. In the apparatus of the base station, both the signal on the channel 1 and the signal on the channel 4 are converted into a TDMA signal stream by the TDMUX 6, demultiplexed into signals corresponding to the associated channels and remultiplexed by the call signal demultiplexing/multiplexing circuit 9, and are constructed into an FDMA signal again by the TMUX 7 so as to be transmitted through the transmission/reception antenna 1. In FIG. 8, channel 1, channel 2 and channel 3 indicated by respective solid lines represent that the apparatus of the base station is in operation with respect to channels 1, 2 and 3, and also channel 2 and channel 6 indicated by respective broken lines mean that the apparatus is in pause with respect to the channels 2 and 6 and hence no communication channel is set.
Then, in Step 2, the local station A sends a channel change request to the base station through the control channel (channel 3). The base station transmits the control signal on the channel 3 which has been outputted from the TDMUX 6 to the call control circuit 10 (cont), and checks the use status of the channels in Step 3. If it is judged from the use status of the channels that circuit assignment change is possible, then the control of channel switching is carried out in Step 4 so as to control both the communication signal demultiplexing/multiplexing circuits 9 and 11 to inhibit the use of the channel 1 and prepare for use of the channel 6. After completion of the preparation therefor, in Step 5, the base station transmits a channel change enabling signal to the local station A through the control channel (channel 3). In response to the channel change enabling signal, in Step 6, the local station A establishes the communication with the base station through the channel 6. The signal which has been received by the base station through the channel 6 is outputted through the TDMUX 5. The signal is sent to the TMUX 8 through the communication signal demultiplexing/multiplexing circuit 11, thereby completing the operation of changing the communication bandwidth of the local station A.
Next, the detailed description will herein-below be given with respect to both the configurations and operations of the communication signal demultiplexing/multiplexing circuits 9 and 11, and the call control circuit 10 with reference to FIG. 7.
FIG. 7 is a block diagram showing the configurations of the communication signal demultiplexing/multiplexing circuits 9 and 11 and the call control circuit 10.
In FIG. 7, reference numeral 91 designates a time division separation switch, reference numerals 921, 922, 924 and 925 designate memories, respectively, and reference numeral 93 designates a time division multiple switch. The communication signal demultiplexing/multiplexing circuit 9 is constituted by these constituent elements.
Reference numeral 111 designates a time division separation switch, reference numerals 1126 and 1127 designate memories, respectively, and reference numeral 113 designates a time division multiple switch. The communication signal demultiplexing/multiplexing circuit 11 is constituted by these constituent elements.
In addition, in FIG. 7, reference numeral 101 designates a decoder circuit, reference numeral 102 designates a CPU, and reference numeral 103 designates a coder circuit. The communication control circuit 10 is constituted by these constituent elements.
Since the signal which is inputted to each of the communication signal demultiplexing/multiplexing circuits is time-division data, switching of channel can be carried out by both the time division separation switch and the memories. For example, the input TDMA signal stream which has been inputted to the communication signal demultiplexing/multiplexing circuit 9 is separated into signals on the respective channels by the time division separation switch 91. Since the signal on the channel 3 is the control signal, it is inputted to the decoder circuit 101 in order to separate data sent from the associated local station so as to be inputted to the CPU 102. The CPU 102 monitors the assignment status of the multiple communication signal at all times so as to control both the time division switches 91 and 93, and carries out the switching of channel with respect to the communication signal as required. In addition, the CPU 102 sends the channel assignment enabling signal onto the channel 3 through the coder circuit 103 in order to integratedly control calls among the local stations.
The above-mentioned operation of the communication signal demultiplexing/multiplexing circuit 9 is also substantially applied to the communication signal demultiplexing/multiplexing circuit 11. Therefore, the description thereof will be omitted here for the sake of simplicity.
As described above, since in the present embodiment, the filter bank employed in the FDMA transmitter-receiver which is capable of changing the communication bandwidth is constituted by the TMUXs, it is possible to promote a great reduction in the hardware. In addition, while in the above-mentioned embodiment, description has been given with respect to a specific case where no change of communication channel is required when changing the communication bandwidth, in actuality, communication bandwidth can not be changed if call channel is not changed in many cases. In such cases, switching function of channel changing is required for the base station apparatus. With respect to TDMA signal, by changing only time positions of data, it becomes possible to realize the switching function. On the other hand, with respect to FDMA signal, the frequency needs to be shifted and hence the required configuration will be very complicated. However, in the present invention, since by employing both the TDMUXs and the TMUXs, FDMA signal is converted into TDMA signal, the switching function can also be readily realized, and also it is possible to enhance the use efficiency of the FDMA communication device.
As set forth hereinabove, according to the present invention, in the FDMA communication system which is capable of changing the passband-width of communication channels, a group of filters having different passband-widths can be readily configured with a less amount of hardwares. In addition, since the control of switching the filter and channel switching function can also be readily realized, it is possible to provide an FDMA communication device which is very excellent in adaptability. While in the embodiment, the description is given with respect to an example in which the present invention is applied to a base station apparatus of an FDMA radio communication system, it is to be understood that the present invention is not limited to the radio communication. In addition, it is to be understood that the present invention can be applied not only to a terminal for a local station but also to a base station.
Furthermore, since in the present invention, the overall FDMA transmitter-receiver can be realized on the basis of the digital signal processings, it is suitable for implementation in LSI. As a result, miniaturization of the apparatus, lower power consumption and lower cost can also be readily promoted.
While the present invention has been particularly shown and described with reference to the preferred embodiments and the specified modifications thereof, it will be understood that the various changes and other modifications will occur to those skilled in the art without departing from the scope and true spirit of the invention. The scope of the invention is therefore to be determined solely by the appended claims. | An FDMA (Frequency-Division Multiple Access) transmitter-receiver for use in an FDMA communication system which is capable of changing a bandwidth of a channel as required. The FDMA transmitter-receiver includes: a plurality of trans-demultiplexers which are different in the number of channel multiplexings from each other and each of which serves to convert the received FDMA signal into a TDMA signal; a communication signal demultiplexing/multiplexing circuit for subjecting the output communication channel signals from the trans-demultiplexers to demultiplex and channel-reassignable multiplex them; a plurality of trans-multiplexers which are provided in correspondence to the plurality of trans-demultiplexers and each of which serves to convert the output channel signal after demultiplexing and remultiplexing from the associated communication signal demultiplexing/multiplexing circuit into an FDMA signal; an adder for adding the FDMA signals outputted from the trans-multiplexers; and a transmission circuit connected to an output of the adder for transmitting therefrom the signal which has been obtained by adding the FDMA signals. The bandwidth per channel of each of the trans-demultiplexers and the trans-multiplexers is different in correspondence to the number of channel multiplexing. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 439,628, filed Feb. 4, 1974, now U.S. Pat. No. 4,038,373, which application is a continuation-in-part of both of the two co-pending patent application Ser. No. 45,527 filed June 11, 1970, now abandoned and application Ser. No. 127,351 filed March 23, 1971, now abandoned. Application Ser. No. 45,527 is a continuation-in-part of application Ser. No. 859,703 filed Sept. 22, 1969. Application Ser. No. 127,351 was a continuation-in-part of both the application Ser. No. 859,703 and application Ser. No. 45,527.
Reference is made to the following co-pending applications: Reactive Metals, Ser. No. 211,979 filed Dec. 27, 1971, now abandoned; Aluminum Hydrates and Salts of Carboxylic Acids, Ser. No. 255,757 filed May 22, 1972, now abandoned; Metal Hydrates and Salts of Carboxylic Acids, Ser. No. 255,758 filed May 22, 1972, now abandoned; and Composition of Matter and Apparatus and Method for the Same, Ser. No. 176,907 filed Sept. 1, 1971.
BACKGROUND OF THE INVENTION
The present invention relates to methods of forming selected aluminum halohydrates and to the aluminum halohydrates formed thereby.
The present invention relates more particularly to the methods of forming aluminum iodohydrate, aluminum chlorohydrate, aluminum bromohydrate, and aluminum fluorohydrate.
Generally, aluminum halohydrates have found substantial commercial usages in a wide variety of fields, including use as an active ingredient in body deodorants, tawing salts, and for this impregnation of textiles to impart water repelling properties. In addition, aluminum halohydrates are also used for the preparation of absorption agents or catalytically active substances. Many other commercial uses for the chemicals are well known.
Prior art methods for preparing aluminum halohydrates often include the step of reacting an aluminum halide salt, such as aluminum fluoride, aluminum chloride, aluminum bromide or aluminum iodide with water and metallic aluminum. The process described in the U.S. Pat. No. 3,476,509 includes the use of water soluble thallium compound with a pH of between 2.5 and 4.4 at an elevated temperature in the order of 70° C. to 105° C. The aluminum hydrate formed from an aluminum halide usually shows traces of the aluminum halide. This has been recognized to be a very serious problem especially for aluminum chlorohydrate when used as an antiperspirant because the aluminum chloride hydrolyzes to hydrochloric acid and results in severe skin irritation. The presence of the aluminum halide also tends to make the aluminum halohydrates hydroscopic.
The article entitled, "Basic Aluminum Compounds" by Hideo Tanabe in The American Perfumer and Cosmetics, Vol. 77, August 1962 pages 25-30 provides a review of known methods for preparing aluminum halohydrates. On page 26, Tanabe presents four methods by way of equations (5), (6), (7), and (8). The four methods are briefly given herein for reference:
1. More than an equivalent amount of metallic aluminum is reacted with an acid, or metallic aluminum is reacted with an aluminum salt with a catalyst of mercury, iron, or copper:
2. More than an equivalent amount of aluminum hydroxide is reacted with an acid;
3. An alkali is added to an aluminum salt solution; and
4. An aqueous solution of an aluminum halide is passed through an anion exchange resin.
On page 26, Tanabe presents the general formula Al 2+n OH 3n X 6 and indicates that when "n" is large, the soluton is slightly turbid but can be made clear by filtration with carbon powder. Tanabe continues with an analysis of the aluminum chlorohydrate and states that each of the four reactions results in a basic aluminum ion which condenses gradually into a polynuclear ion and this condensation is influenced by various conditions such as temperature, time and the the value of "n". Thus, the aluminum chlorohydrate reported by Tanabe appears to show instability with both temperature and time. An eariler Tanable article in Pharm. Soc. Japan, 75 page 868 (1955) is directed to the study of these instabilities.
Another earlier article by Tanabe, in Pharm. Soc. Japan, 74, page 868 (1954) states explicitly that the properties of aluminum chlorohydrate varies with the method of preparation.
SUMMARY OF THE INVENTION
One of the principal objects of the Invention is to provide a method for preparing aluminum iodohydrate, aluminum chlorohydrate, aluminum bromohydrate and aluminum fluorohydrate by the steps of first permeating aluminum having a purity by weight of at least 99.98% with mercury in the presence of a hydrogen ion source, such as an acid, and then contacting the permeated aluminum with an appropriate halogen ion source in the presence of an excess of water compared to the halogen, in accordance with the formula Al 2 (OH) 5 X where "X" corresponds to the selected halogen.
Another object of the present invention is to obtain novel aluminum iodohydrate, aluminum chlorohydrate, aluminum bromohydrate and aluminum fluorohydrate compounds exhibiting novel properties.
A further object of the present invention is a method of preparing selected aluminum halohydrates having a desired ratio between the aluminum and halogen atoms.
Yet another object of the present invention is to provide a method for preparing aluminum iodohydrate, aluminum chlorohydrate, and aluminum bromohydrate by the use of the corresponding gas in the presence of water.
Yet another object of the present invention is a method for preparing aluminum iodohydrate from iodine crystals in water.
Further objects and advantages of the invention will be set forth in part in the following specification and in part will be obvious therefrom without being specifically referred to, the same being realized and attained as pointed out in the claims hereof.
The present invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, all as exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims. Furthermore, the products obtained are novel and exhibit properties which are superior to known corresponding products. For example, the products obtained are water-clear when dried to a solid, are soluble in water, and are not hygroscopic. In addition, the aluminum iodohydrate, aluminum chlorohydrate, and aluminum bromohydrate exhibit superior bacterialcidal properties.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and object of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawings, in which:
FIG. 1 is an infrared spectra response for aluminum iodohydrate prepared according to the present invention;
FIG. 2 is an infrared spectra response for aluminum chlorohydrate prepared according to the present invention;
FIG. 3 is an infrared spectra response for an aluminum bromohydrate prepared according to the present invention; and
FIG. 4 is an infrared spectra response for an aluminum fluorohydrate prepared according to the present invention.
THE INVENTION
The present invention if focused on the utilization or the remarkable properties of a reactive aluminum described in application Ser. No. 211,979, now abandoned.
Generally, a reactive aluminum is prepared by permeating highly pure aluminum in the presence of a hydrogen ion source with mercury. The hydrogen ion source can be an inorgaic acid, such as hydrochloric acid or hydrobromic acid or the like, or an organic acid, such as citric acid or acetic acid, or the like. The reactive aluminum in an alkali solution such as water and sodium hydroxide will serve as an hydrogen ions source for the formation of another reactive aluminum.
It should be understood that the term "highly pure" herein means a purity greater than 99.98% by weight.
The concentration of the acid employed can cover the broadest range. The choice of the hydrogen ion source such as an acid will depend upon the product to be formed and the concern over impurities.
It is preferable to prepare a highly pure aluminum rod for the reaction by at least partially stripping the aluminum oxide coating which usually has formed on the surface due to exposure to air and moisture. Of course, other than a rod shape can be used. If the aluminum rod has been stripped, hot water can serve as a hydrogen ion source, although the reaction time is long. Otherwise, it may be desirable to start out with an acid to strip off the oxide coating on the aluminum rod in order to initiate the reaction as quickly as possible. Of course, the aluminum rod may be stripped mechanically with sandpaper or a file or the like.
The inter-reaction which occurs between the aluminum, the mercury and the acid, gives rise, at the start, to the formation of large bubbles which rise up to the surface through the acid. After a while, it will be observed that instead of large bubbles forming at the top of the aluminum rod and then breaking free and rising to the surface of the acid, tiny bubbles will be eminating from many parts of the upper surface of the rod. The occurrence of the multitude of tiny bubbles indicates that the rod is becoming converted to receive aluminum as herein used.
Generally, the rod will take up or absorb from 0.1% to 5% by weight of the mercury depending upon the length of time the reaction is permitted to continue. A range of 2% to 3% by weight of the mercury is satisfactory for many application. The maximum mercury content is about 5% by weight.
The reaction can be stopped on the one hand due to increase in weight or the rod due to the absorption of the metal or on the other hand due to the production of a multitude of tiny bubbles for a period of ten to fifteen minutes. Another basis is to test the rod by immersing it in water hydrolysis of the water to absence.
A reactive aluminum as described, displays surprisingly active catalytic properties not at all suggested by the prior art. The reactive aluminum possesses an altered physical structure and my be used as an activator or initiator. After grain alignment, the reactive aluminum becomes an open matrix where the boundaries have expanded.
The amount of the mercury in the aluminum can be varied in accordance with applications. In general, if a high percent of the mercury of weight is desired, quick cooling of the reactive aluminum after formation will prevent the squeezing out of the mercury due to an exothermic reaction and lattice expansion. Water or alcohol is convenient for this purpose. In cases where it is desired to reduce the amount of, mercury from several percent by weight to 0.1% by weight, for example the reactive aluminum can be heated to squeeze out the mercury.
Certain impurities such as copper and iron, inhibit the formation of a reactive aluminum and so should be avoided in the aluminum. Some of the impurities which inhibit or promote the reaction are given in the aforementioned Reactive Metals application. But, small amounts of the inhibitors can be tolerated for certain applications.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For a fuller understanding of the invention certain embodiments have been selected for more detailed description.
Generally, a reactive aluminum is reacted with water and a selected source of chlorine, bromine, iodine or fluorine. In many cases, it is convenient to use an acid form of the selected halogen. Sometimes, it is convenient to use a gaseous form of the selected halogen, such as chlorine gas, or bromine gas iodine vapors. A further possibility in the use of ground iodine crystals in water.
Basically, the amount of water present compared to the available halogen atoms can be determined from the formula: Al 2 (OH) 5 Q; Q corresponds to the halogen: chlorine, bromine, iodine of fluorine. It is preferable to use more water than the stoichiometric equivalent of the formula in order to be assured of having sufficient hydroxyl groups available.
The ratio of the aluminum atoms to the halogen atoms varies from the ratio of 2:1. It is highly significant that the ratio of 2.2:1 for aluminum chlorohydrate and 2.4:1 for aluminum bromohydrate can be obtained by the present invention. Also, a ratio of 2.7:1 for aluminum iodohydrate has been obtained by the present methods. Surprisingly, the product obtained by the present methods even for high ratios of aluminum to halogen is water clear.
In addition, the products obtained by the present methods show a stable pH of about 4.2 to about 4.3 in contrast to products obtained by prior art methods which have a pH of approximately 3.9.
In carrying out the present methods, it is desirable to cool the reaction to below 100° F. in order to avoid the incidental formation of an aluminum halide. The presence of an aluminum halide in prior art products is considered highly undesirable. However, products obtained by the present methods are non-hydroscopic and are therefore far more suitable for many applications where prior art products were unsuitable. For example, the present aluminum chlorohydrate is well suited use as an underarm deordorant even in for high concentrations, since the absence of aluminum chloride avoids the formation of hydrochloric acid and irritation to human skin. Tests with even relatively concentrated solutions have verified this for human use.
Another significant advantage of the present product is that the present products become micronized after spray drying and at least 99% will pass a 325 mesh. Prior art products require additional treatment in order to become micronized after spray drying. This may be related to the fact that prior art products have at least 14% moisture content after spray drying in contrast to the present products which have only about an 8% moisture content after spray drying.
The aluminum used in the present method preferably is high purity aluminum having a purity of 99.99% by weight and is readily available in rod form but, of course, other shapes can be used. It is preferable to prepare the reactive aluminum with the halogen acid corresponding to the aluminum halohydrate to be formed in order to maintain high purity. Repeated washing of a reactive aluminum can be used for cleansing the reactive aluminum of potential impurities. Usually, it is highly desirable to form the aluminum halohydrate with a high degree of assurance that no mercury will appear in the product. This can easily be achieved by using a reactive aluminum having a mercury content by weight such that the mercury by weight in the initial reactive aluminum corresponds to less than approximately 3% by weight of the reactive aluminum after completion of the reaction. It is known that the reactive aluminum retains mercury up to the approximate saturation point of about 5% by weight. Thus, calculations can show the amount of aluminum which will be consumed to obtain the desired aluminum to halogen ratio for the available halogen and these calculations can guide the selection of the total weight of the reactive aluminum used and the mercury content thereof. This is another surprising feature contributing to the high purity of the product obtained by the present methods.
The aluminum iodohydrate, aluminum bromohydrate, and aluminum chlorohydrate prepared by the present methods exhibit surprisingly good anti-microbial properties. Standard tests are used to determine the anti-microbial number, namely the concentration to completely destroy pseudomonas and aeruginosia in 10 minutes but not 5 minutes. The aluminum iodohydrate was effective at dilutions in the order of 1000:1 to 600:1 and the aluminum chlorohydrate was effective at a dilution in the order of 1000:1. The Aluminum bromohydrate was effective at a dilution of approximately 100:1. The aluminum iodohydrate showed suprisingly superior anti-microbial activity even compared to IOPREP (trademark), a well known pre-surgical antiseptic. The antimicrobial dilution of the aluminum iodohydrate against stabhylococcus and pseudomonas was 400:1 in each case as compared to the IOPREP which was 100:1 in each case. Furthermore, one part of a 25% concentration aluminum iodohydrate was combined with 4 parts of Ivory (trademark) soap and was found effective against staphylococcus even after being diluted 80 times. The solution was also effective against pseudomonas but only for a dilution of 40 times.
Therefore, a further step in the present invention includes using aluminum iodohydrate prepared in accordance with the present invention for its anti-microbial properties.
With regard to usual properties, it is noted that the aluminum bromohydrate is suprisingly well suited for fireproofing such things as wood, clothes and paper. The fireproofing properties can be imparted either by spraying a solution of the aluminum bromohydrate on the object or soaking the object therein. Naturally, other methods may be use.
After preparing an aluminum halohydrate according to the present methods, it may be desirable to enrich the hydroxyl content of the aluminum halohydrate. The enrichment of the hydroxyl content may be carried out by utilizing the product obtained as described in applicant's co-pending patent application Ser. No. 176,907. Briefly, the product of application Ser. No. 176,907 is obtained by placing highly pure aluminum in contact with mercury and an acid with a part of the aluminum exposed to air. The aluminum can be in the form of a rod with the mercury covering about half of the rod lying therein. A novel product forms on the aluminum exposed to the air. The temperature of the rod should preferably be maintained below 105° F. Cooling can be accomplished many different ways but one convenient way is to contact the aluminum with a large pool of mercury and use only a small amount of acid to just bearly cover the mercury. The mercury helps to conduct heat away from the rod and therefore cools the rod. An operating temperature of about 90° F. is preferable. The novel product obtained is extremely rich in hydroxyl groups and can be added to the aluminum halohydrate and mixed with or without heating to obtain a hydroxyl enriched aluminum halohydrate.
Sometimes it is desirable to obtain an aluminum halohydrate involving at least two different halogen atoms. This can be easily accomplished by the present methods by using, for example, two different acids such as hydrochloric acid and hydrobromic acid. Other variations include, for example, hydrofluoric acid with chlorine gas pumped therethrough in the presence of an immersed reactive aluminum.
The products obtained by the present method are polymeric in nature and the above noted formula should not be considered restrictive because the number of aluminum atoms in a unit may exceed the number two and can easily be 4 or 6 with a corresponding increase, but not necessarily proportional, number of hydroxyl and halogen atoms included. Furthermore, with regard to the formula, the hydroxyl content could be less than "5" depending upon the available quantity of hydroxyl groups.
Sometimes an alcohol soluble product is desired. Such a product can be obtained by the use of water and alcohol but some instabilities over extended periods of time have been noted for aluminum chlorohydrate.
EXAMPLES
Illustrative non-limiting examples of the practice of the invention are set forth below. Numerous other examples can readily be evolved in the light of the guiding principles and teachings contained herein. The examples are intended merely to illustrate the invention and not in any sense to limit the manner in which the invention can be practiced. The parts and percentages recited herein and all through this specification, unless specifically provided otherwise, refer to parts by weight and percentages by weight.
EXAMPLE 1
The procedure for preparing an aluminum chlorohydrate illustrates some general rules. Typically, it is convenient to use a mass of aluminum equal to that needed to obtain a desired ratio. The aluminum chlorohydrate is prepared by first forming a mercury treated reactive aluminum rod and then reacting the reactive aluminum with hydrochloric acid. A rod of 54 grams of aluminum having a purity of 99.98% by weight is permeated in the presence of hydrochloric acid with mercury so that the permeated mercury is between 1% to 3% by weight of the rod. Then, the reactive aluminum is immersed in 87 grams of 1.5N hydrochloric acid. Generally, the acid can range between 0.5N and 2N or higher. It is preferable to maintain the temperature of the reaction below about 100° F. in order to avoid the possibility of forming aluminum chloride or a product which does exhibit a stable chemical property. Generally, a temperature of 200° F. or higher should be avoided so that halides are not formed.
EXAMPLE 2
The reactive aluminum rod of Example 1 is immersed in a solution of 126 grams of approximately 38% concentration hydrochloric acid and 300 grams of water. Again, the reaction temperature is maintained below 100° F. After approximately 72 hours, the liquor contains about 50% by weight solid aluminum chlorohydrate with the balance being water. The aluminum to chlorine ratio is approximately 2.04:1.
EXAMPLE 3
The reactive aluminum rod of Example 1 is immersed in 250 grams of 50% by weight methanol with the balance being water; then, 36 grams of chlorine gas is bubbled therethrough over a period of approximately 24 hours. The product obtained had an aluminum to chlorine ratio of approximately 1.86:1.
EXAMPLE 4
The reactive aluminum of Example 1 is immersed in 87 grams of 38% by weight concentration of hydrochloric acid mixed with 150 grams of methanol and 300 grams of water. The temperature is maintained below 100° F. by cooling. After 72 hours, the liquor contained approximately 50% by weight aluminum chlorohydrate with the balance being mainly methanol. The aluminum to chlorine ratio was approximately 1.92:1. When the liquor was permitted to dry, alcohol soluble crystals were obtained.
EXAMPLE 5
An aluminum chlorohydrate is prepared with the reactive aluminum of Example 1 is immersed in 250 grams of water which has been twice distilled and then chlorine gas is bubbled through the water, preferably so that the bubbles collide with the reactive aluminum. It may be desirable to recirculate the gas which has not been reacted. 36 grams of chlorine reacted over a period of approximately 72 hours producing a liquor having 46% by weight of aluminum chlorohydrate. A reactive aluminum of 59 grams yields a product with a ratio of aluminum to chlorine 2.2:1.
EXAMPLE 6
An aluminum iodohydrate is prepared by using 59 grams of the reactive aluminum of Example 1 in 435 grams of water and 127 grams of powdered iodine. The water and iodine are agitated so that the iodine contacts the reactive aluminum. A product with an aluminum to iodine ratio of 2.7:1 is obtained.
EXAMPLE 7
An aluminum bromohydrate is prepared by immersing a 64 gram reactive aluminum in 600 grams of water and introducing 80 grams of bromine gas into the water so that the bubbles contact the reactive aluminum. The gas flow should be regulated to occur over a period of several days. A product with an aluminum to bromine ratio of 2.4:1 is obtained.
EXAMPLE 8
An aluminum bromohydrate is prepared by immersing 59 grams a reactive aluminum in 307 grams of water and 162 grams of hydrobromic acid and continuing the reaction until an aluminum to bromine ratio of 2.0:1 is obtained. It is preferable to provide cooling.
EXAMPLE 9
An aluminum fluorohydrate is prepared by immersing a reactive aluminum of 54 grams in 307 grams of water and 40 grams of hydrofluoric acid and providing cooling. A teflon lined reactor is preferable.
EXAMPLE 10
A stable hydroxyl augmented aluminum chlorohydrate is formed by taking 150 grams of the aluminum chlorohydrate of Example 1 and combining it with 40 grams of the oxygen-bearing aluminum complex of application Ser. No. 176,907 and 40 grams of methanol. After the mixture is heated to approximately 200° F. a stable product is obtained. This product is soluble in alcohol.
EXAMPLE 11
An hydroxyl augmented aluminum chlorohydrate is obtained by adding to 150 grams of the aluminum chlorohydrate of Example 1 40 grams of the aforementioned oxygen-bearing aluminum complex, which is an aluminum complex including hydroperoxy groups. After mixing, the combination is left for 24 hours. Then, 10 grams of ethanol are added to the liquor and a reactive aluminum is immersed therein for between 12 to 24 hours. The resulting product is an aluminum oxychlorohydrate which is soluble in alcohol.
EXAMPLE 12
Example 12 is repeated except that no reactive aluminum is used after the ethanol has been added.
EXAMPLE 13
When the procedure of any of Examples 1 to 12 is repeated for an aluminum having a purity of at least 99.99% a purer product having a superior quality and preferable for pharmaceutical and like applications is obtained.
Examples 1 to 12 will result in elemental mercury at the bottom of the reactor. This mercury can be easily avoided by standard techniques for recovery the desired product. But, some mercury may be held in the liquor obtained and may be highly undesirable. A further step can be used to purge the mercury from the liquor. The purging can be accomplished by using a reactive aluminum having 500 to 2000 parts per million. Such a reactive aluminum accumulates and holds mercury so that the liquor purity is remarkably improved. | An aluminum halohydrate is formed by first preparing a reactive aluminum by permeating highly pure aluminum with mercury in the presence of a hydrogen ion source and then contacting the reactive aluminum with a source of iodine, chlorine, bromine or fluorine in the presence of water. The products obtained show high stability, uniformity from batch to batch, and a pH of about 4.3. | 2 |
FIELD OF THE INVENTION
[0001] The invention relates to bisphenols and more particularly to a method for their production.
SUMMARY OF THE INVENTION
[0002] A method for producing a bisphenol is disclosed. The method entails reacting in at least one first reactant selected from a first group consisting of phenol and substituted phenols with at least one second reactant selected from a second group consisting of ketones and diols, in the presence of hydrogen chloride catalyst and volatile sulphur compound having an SH bond as co-catalyst. The reaction product is a mixture that contains bisphenol, first reactant and second reactant. The catalyst and co-catalyst and water of reaction are separated by distillation. The high reaction rates and selectivities characterize the method.
BACKGROUND OF THE INVENTION
[0003] Bisphenols are raw materials for the production of polycondensation materials such as epoxy molding compounds, polyether sulphones, polyether ketones or polycarbonates. Bisphenols are generally produced by reacting phenol or substituted derivatives thereof with suitable ketones in the presence of acidic catalyst and with separation of water. The industrially most significant bisphenol is bisphenol A (BPA), produced from phenol and acetone. Bisphenols derived from cyclic alkanes, for example the condensation product of phenol and 3,3,5-trimethylcylohexanone (BP-TMC) are also very important in the production of polycarbonates.
[0004] Homogeneously dissolved acids such as hydrogen chloride or heterogeneous acid fixed-bed catalysts such as sulphonated cross-linked polystyrene resins (acid ion exchangers) are used as catalysts for the production of bisphenols. While the use of heterogeneous catalysts is to be preferred from certain viewpoints to the use of homogeneous catalysts, it may be found in EP-A 995 737 that inadequate reaction and selectivity is achieved with this type of catalyst for certain ketones. Therefore, the use of strong acids such as hydrochloric acid as a catalyst is to be preferred for a large number of ketones, in particular cyclic ketones. To further increase the ketone reaction and to raise the selectivity of the reaction, sulphur-containing organic compounds such as alkyl mercaptans, thiocarboxylic acids or dialkylsulphides, as described in U.S. Pat. No. 5,210,328, are used as cocatalysts. The use of specific alkane thiols is to be derived from U.S. Pat. No. 5,336,812, while EP-A 995 737 proposes the use of alkyl mercaptans with 1 to 12 carbon atoms.
[0005] Mixtures containing the desired bisphenol, isomers, intermediates and secondary products of the desired product, as well as unreacted raw materials and water, and the catalyst and cocatalyst used and optionally the reaction products thereof with the components of the reaction system are generally obtained as a result of the reaction of phenols and ketones under the above-mentioned conditions. To obtain bisphenol products of suitable quality for producing high-grade polymer materials, it is necessary to separate these by-products and reaction components as completely as possible from the reaction product bisphenol. For this purpose a combination of various standard purifying operations such as crystallisation, extraction or distillation are usually carried out. Various problems can occur in this process. The bisphenols obtained are thus generally thermally unstable in particular in the presence of catalytically active compounds, acids or bases. This is particularly problematical when using homogeneously distributed acids as catalysts which remain in the product mixture. It is disadvantageous in the neutralization with bases described in EP-A 995 737 or in the extraction of the acids by addition of water proposed in EP-A 679 151 that large quantities of organically loaded waste water are produced by these measures and have to be processed in expensive purification operations. It is also difficult in a procedure of this kind to carry out the reaction continuously with separation of the catalyst. It is also not ensured in a procedure of this type that the sulphur-containing cocatalyst used is also substantially separated from the reaction mixture. Residues of the cocatalyst in the purified bisphenol impair the suitability thereof for producing high-grade polycondensation materials.
[0006] A further problem in the production of bisphenols from phenols and in particular from ketones with more than 5 carbon atoms is that the reaction mixtures with high proportions of produced bisphenol can become solid owing to crystallisation of the product, so efficient continuous reaction control and separation of the catalyst is no longer possible. Subsequent melting of the reaction mixture or carrying out the reaction at elevated temperatures to avoid this problem leads to undesired side reactions and reduced selectivities. Reaction control with a high phenol excess or incomplete ketone reaction to avoid a high bisphenol product concentration is disadvantageous, as the space-time yield is thus reduced. Excess phenol and ketone also have to be separated when working up the reaction product. It is proposed in EP-A 995 737 to initially allow phenol and ketone to react in a prereaction until at least 90 mol % of the ketone has reacted and then to add a further quantity of phenol and/or aromatic hydrocarbon to the reaction mixture. A procedure of this type is awkward, does not solve the problem of separating the catalyst and may even introduce a further material into the method which later has to be separated.
[0007] The object of the invention is to provide a method for producing bisphenols with acid catalysis in the presence of a sulphur-containing cocatalyst which has a high space-time yield and high selectivity and supplies a product which can be fed to further purification without further expensive processing steps.
DETAILED DESCRIPTION OF THE INVENTION
[0008] This object is achieved by a method for producing bisphenols, by reacting phenols or substituted phenols with ketones or diols in the presence of hydrogen chloride and a volatile sulphur compound having an SH bond. The resulting bisphenol is separated from unreacted starting materials and catalysts by distillation.
[0009] According to the invention there is no neutralization, in contrast to known methods for producing bisphenol. Moreover, the separation of the product by distillation in the method for producing bisphenols is unknown. The reaction rate may be slowed or the reaction altogether stopped by adding water. Any volatile components such as catalyst, co-catalyst, water and unreacted raw materials having suitably high volatility may be separated from the reaction mixture by distillation.
[0010] The reaction rate is much higher than in known methods. The method according to the invention provides high selectivity with high space-time yields. The catalyst and cocatalyst may be substantially separated from the reaction product without cleavage or rearrangement reactions occurring to a noteworthy extent. By isolating and recirculating unreacted ketone the reaction may be carried out with partial ketone conversion with high selectivity, without the reaction mixture becoming solid, having to be diluted or ketone loss occurring.
[0011] Starting materials in the method according to the invention are phenol and a large number of phenol derivatives without substituents withdrawing electrons and with unsubstituted 2- and/or 4-position. Suitable phenol derivatives are for example 2-alkylphenols, such as o-cresol, 2-ethylphenol, 2-isopropylphenol or 2-tert.-butylphenol, 2,6-dialkylphenols, such as 2,6-xylinol, 2,6-diethylphenol, 2-methyl-6-i-propylphenol, 2-methyl-6-tert.-butylphenol, 2,6-di-i-propylphenol, 2,6-di-tert.-butylphenol and 2,4-dialkylphenols, such as 2,4-xylenol. Particularly preferably used are phenol or o-cresol. These compounds are, on the one hand, a starting material for the reaction mixture and, on the other hand, a solvent for the reaction mixture.
[0012] The further starting materials of the method according to the invention to be reacted with the above-mentioned starting materials are ketones or diols. These ketone or diol components may be cyclic or acyclic aliphatic or aromatic aliphatic ketone compounds. Suitable examples include acetone, butanone, 2-pentanone, 3-pentanone, cyclopentanone, 3-alkylcyclopentanone with an alkyl radical containing 1 to 12 carbon atoms, 3,3-dialkylcyclopentanone with an alkyl radical containing 1 to 12 carbon atoms wherein the alkyl radicals may be identical or different, 3,3,5-trialkylcyclohexanone, wherein the alkyl radicals have 1 to 12 carbon atoms and may be identical or different, cyclohexanone, 3-alkylcyclohexanone with an alkyl radical containing 1 to 12 carbon atoms, 4-alkylcyclohexanone with an alkyl radical containing 1 to 12 carbon atoms, 3,3-dialkylcyclohexanone with alkyl radicals containing 1 to 12 carbon atoms, wherein the alkyl radicals may be identical or different, 3,3,5-trialkylcyclohexanone with alkyl radicals containing 1 to 12 carbon atoms and which may be identical or different, acetophenone. Particularly preferred are cyclohexanones substituted with alkyl radicals, the alkyl radical of which has 1 to 5 carbon atoms. The ketone or diol components may be used in a concentration of 1 to 25 wt. %, preferably 1 to 20 wt. % based on the weight of the reaction mixture.
[0013] Suitable catalysts are highly volatile acids, such as concentrated hydrochloric acids and hydrogen chloride gas. Concentrated hydrochloric acid, hydrogen chloride, hydrobromic acid and trifluoroacetic acid are preferred. Volatile sulphur compounds having an SH bond are used as cocatalyst. Compounds of this type include hydrogen sulphide, methyl-, ethyl- and propylmercaptan. Hydrogen sulphide is preferred. The method according to the invention is particularly preferably carried out with hydrogen chloride gas and hydrogen sulphide as catalyst and cocatalyst. The concentration of the catalyst may be 0.3 to 5 wt. %, preferably 0.5 to 2 wt. % based on the weight of the reaction mixture. The concentration of the cocatalyst may be 50 ppm to 1 wt. %, preferably 100 ppm to 0.5 wt. %, based on the weight of the reaction mixture.
[0014] At the beginning of the process the starting materials may be placed in the reactor with concentrated acid. The catalyst and cocatalyst are then introduced, preferably while the reaction mixture is stirred. The cocatalyst may also be produced in situ. For this purpose ammonium bisulphide may be introduced into the acid reaction mixture.
[0015] The reaction may take place at atmospheric pressure or excess pressure. The reaction is preferably carried out at an excess pressure of 0.1 to 0.5 MPa (1 to 5 bar). The temperature of the reaction mixture may be 10 to 80° C., preferably 25 to 60° C. and particularly preferably 30 to 40° C.
[0016] Water is formed during the reaction. This reaction product decelerates the reaction rate, to maintain the rate additional catalyst has to be added. This also applies to the cocatalyst. Catalyst and cocatalyst may be added individually or mixed, in liquid, solid or gaseous form into the reaction mixture. The addition preferably takes place gaseously by blowing into the reaction mixture. The reaction mixture is preferably saturated with respect to catalyst and cocatalyst. The method according to the invention may be carried out continuously or discontinuously, preferably continuously.
[0017] The reaction solution may be withdrawn from the lower part of the reactor and conveyed either directly or via a receiver into a distillation device. During distillation, the catalysts, water and unreacted starting materials are separated from the reaction solution.
[0018] So that water may be completely evaporated at not too high temperatures, distillation may take place under vacuum and the vacuum may be adjusted in such a way that the base temperature does not lead to product damage. This will be the case at a temperature of 130° C. and lower. At about 130° C. the bisphenols are dissolved and evaporation takes place from the starting compounds such as phenols and cresols only to the extent that a homogeneous solution remains. This procedure allows the virtually complete removal of the water and the catalysts and cocatalysts and supplies a clean, concentrated product solution which may be cleanly and economically crystallised during cooling. The pressure in the distillation column is 50 to 120 mbar, preferably 90 to 110 mbar.
[0019] The product withdrawn from the bottom of the column contains, apart from the bisphenol product, phenol and possibly ketone, depending on the boiling point of the product, in amounts of 0 to 15 wt. %, based on the weight of the solution. The product at a temperature of 100 to 130° C. is transferred into a conventional crystallizer. Crystallization preferably takes place in a rotary crystallizer. Depending on the product obtained, recrysallization may take place one to three times, preferably once or twice. With TMC phenols a double crystallization is usually sufficient and with BPA a single crystallization is generally sufficient to obtain a very pure product. The recrystallization preferably takes place with phenol. Difficult to separate mixtures between phenol and other solvents are therefore avoided.
[0020] The crystallized product may then also be purified of phenol. The purification may be, for example by thermal desorption of the phenol at raised temperatures while blowing in nitrogen. As temperatures above 190° C. are required in this method, cleavage products are formed. According to a particularly preferred embodiment of the invention the crystallized product is therefore washed with water, and phenol is released in the process from the bisphenol/phenol adducts. The temperature of the water to wash the bisphenol may be 20 to 100° C., preferably 70 to 80° C. The filtered-off cake may be washed with warm water. The removal of phenol from the bisphenol/phenol mixed crystals with water prevents thermal damage to the bisphenol.
[0021] The method according to the invention may be carried out in a stirred-tank reactor, a loop reactor or a cascade reactor. Distillation may be continuous or discontinuous distillation. The reaction solution may be introduced into the distillation device between two separation stages with phenol removal with total reflux. The lower part of the distillation device is preferably equipped in such a way that water, catalyst and cocatalyst and optionally the starting material may be removed with phenol vapor.
[0022] Bisphenols (diphenols) obtained according to the invention are preferably those of formula (I)
[0023] A is a single bond, C 1 to C 2 -alkylene, C 2 to C 5 -alkylides, C 5 to C 6 -cycloalkylides, —O—, —SO—, —CO—, —S—, —SO 2 —, C 6 to C 12 -aryls on which further aromatic rings optionally containing heteroatoms may be condensed
[0024] or a radical of formula (II) or (III)
[0025] B is C 1 to C 12 -alkyl, preferably methyl, halogen, preferably chlorine and/or bromine respectively
[0026] x is 0, 1 or 2 respectively independently of one another
[0027] p is 1 or 0, and
[0028] R 5 and R 6 for each X 1 and independently of one another, represent hydrogen or C 1 -C 6 -alkyl, preferably hydrogen, methyl or ethyl,
[0029] X 1 is carbon and
[0030] m is an integer from 4 to 7, preferably 4 or 5 with the proviso, that on at least one atom X 1 , R 5 and R 6 are simultaneously alkyl.
[0031] Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis-(hydroxyphenyl)-C 1 -C 5 -alkanes, bis-(hydroxyphenyl)-C 5 -C c -cycloalkanes, bis-(hydroxyphenyl)-ether, bis-(hydroxyphenyl)-sulphoxides, bis-(hydroxyphenyl)-ketones, bis-(hydroxyphenyl)-sulphones and α,α-bis(hydroxyphenyl)-diisopropyl-benzenes) and the derivatives thereof brominated and/or chlorinated in the nucleus.
[0032] Particularly preferred diphenols are 4,4′-dihydroxydiphenyl, bisphenol-A, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1,1-bis-(4-hydroxyphenyl)-cyclohexane, 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4′-dihydroxydiphenylsulphide, 4,4′-dihydroxydiphenylsulphone and the di- and tetrabrominated or chlorinated derivatives thereof such as 2,2-bis(3-chloro-4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane or 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)propane.
[0033] The invention will be illustrated, but not limited, by the following examples.
EXAMPLES
Example 1
[0034] 500 g of reaction solution are placed in a stirred-tank reactor with a volume of 1 l. The reaction solution contains 95.5 wt. % phenol and 4.5 wt. % acetone. At the beginning of the reaction a 5 wt. % aqueous HCl is added. The gas phase is kept at a pressure of 2 bar by HCl gas. 3.3 l/h H 2 S gas are added to the gas stream. After about 30 minutes, 0.8 l/h reaction solution are continuously pumped into this reactor, the phenol/acetone ratio corresponding to the ratio given above. 0.8 l/h reaction solution are simultaneously pumped from the reactor to the distillation column. The volume in the reactor is controlled in such a way that 30 minutes residence time is reached. The temperature of the reaction mixture is 40° C.
[0035] The reaction solution is brought to about 113° C. by a heat exchanger. The vacuum in the distillation column is adjusted to 100 mbar. The reflux ratio is adjusted in such a way that only small amounts of phenol distil off overhead. The base of the column is brought to about 125° C. The volatile substances such as water, hydrogen chloride, hydrogen sulphide and the remainder of the unreacted acetone are condensed and worked up again.
[0036] The base of the distillation column then only still contains the reaction products and phenol. The adduct bisphenol/phenol crystallizes from the hot product solution (45° C.). The product is filtered off and washed with warm phenol. The mother liquor may be recycled. The washed adduct is then washed with hot water at a temperature of about 85° C. to separate phenol and bisphenol. The product is vacuum-dried after filtration.
[0037] Selectivity in the reaction solution is 95.5% pp BPA and product concentration after drying is 99.71%.
Example 2
Comparison
[0038] The reaction takes place under the same reaction conditions as in Example 1 but, no H 2 S was added. The reaction time was doubled. The acetone conversion nevertheless decreases by ⅓, but the selectivity drops to 86.6% pp BPA. The comparison example shows the importance of the cocatalyst for the method according to the invention.
[0039] Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations may be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims. | A method for producing a bisphenol is disclosed. The method entails reacting in at least one first reactant selected from a first group consisting of phenol and substituted phenols with at least one second reactant selected from a second group consisting of ketones and diols, in the presence of hydrogen chloride catalyst and volatile sulphur compound having an SH bond as co-catalyst. The reaction product is a mixture that contains bisphenol, first reactant and second reactant. The catalyst and co-catalyst and water of reaction are separated by distillation. The method is characterized by the high reaction rates and selectivities. | 2 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to solvent extractors commonly used for the removal of oils, fats and waxes from solid material such as oil-bearing seeds, hops, lignite, rice bran, etc. The solvent will depend on the component to be extracted. Hexane, alcohol, blend of alcohol and toluene, chlorinated solvent are typical. Water may be used where it is a satisfactory solvent for removing the extractable component, e.g. the extraction of proteins from meal. Generally, the present invention relates to extractors for extracting a component that can be soaked or leached out of a solid material.
More particularly, the present extractor is designed for use with material which does not lend itself to extraction by the so-called percolation method. Percolation extractors are dependent on granular material or material that has voids permitting the solvent or the leaching media to drain through the solids. Some materials are too finely divided resulting in a very dense bed that does not lend itself to the percolation or the transfer of solvents from the surface on through the bed of the material. This may also occur where the material is too high in moisture or too high in fat. Examples of materials with which the present extractor is designed for use are finely divided lignite (for Montan wax extraction), rice bran, hops, animal fat where the fat content of the meat scrap would be in excess of about 40%, etc. Oil seeds, for example, may be processed to screen the coarser material which may be processed through a conventional percolation extractor and the fine material processed through the present immersion extractor to increase the overall oil recovery and capacity of the plant. Similarly, in the case of lignite, the coarser material obtained by screening may be processed through a percolation extractor and the fine material would be processed in the present immersion extractor.
2. Description of Prior Art
Solvent immersion extractors are shown in U.S. Pat. Nos. 1,826,945; 2,227,605; and 2,703,274.
Of the three patents noted, the most pertinent is Swallen et al, U.S. Pat. No. 2,227,605, disclosing an apparatus for extracting zein (the alcohol soluble constituent of corn protein) from gluten meal using an alcoholic solvent and a series of settling vessels for the solvent through which the meal is moved by a series of conveyors. Each of the settling vessels is preceded by a mixing vessel having a rotating agitator for mixing the solid material with the solvent, the arrangement being that the mixture of solids and solvent thus made into a flowable mixture overflows a weir separating the mixing and settling chambers for deposit in the settling chamber. A drag conveyor is used to move the solid materials through the settling chamber and up and over an inclined bottom wall containing a screen for permitting solvent to drain back into the chamber. Each of the chambers has its own conveyor which returns overhead to re-enter at the opposite side of the chamber in an endless configuration. One of the disadvantages of the Swallen structure is that the drag conveyor moves up through the settling chamber on an inclined path and as it does so disturbs and agitates the surface of the miscella (alcohol and dissolved zein). A solvent immersion extractor depends upon the solid portion being heavier than the miscella so that it will settle to the bottom of the settling chamber and at the same time the miscella will float to the top of the solvent bath from where it is decanted. It is, accordingly, most important and forms a feature of the present invention that the surface from which the miscella is decanted is both clean and quiescent. Swallen et al depends on the obtaining of a homogenous mix overflowing the weir of the mixing chamber--a system which would not work with lignite where the heavy particles, including sand, would accumulate on the bottom.
SUMMARY OF THE INVENTION
The solvent immersion extractor of the present invention comprises a plurality of side-by-side settling chambers and a single drag conveyor which moves successively through the chambers and partitioning structure providing well defined entryways and exitways for the conveyor into and from the chambers while insuring the maintenance therebetween of a clean quiescent miscella surface. Baffling means are also used on the return leg of the conveyor for diverting solid material which may be released therefrom away from the quiescent surface and into one of the entryways.
Another and important feature of the present invention is the incorporation within what is basically an immersion extractor, of a percolation extractor and the inherent advantages provided thereby. The present apparatus combines the best features of the immersion-type extractor with the percolation-type extractor.
Another feature of the present invention is to provide an extractor of the character described which may be readily and thoroughly cleared of solid material at the end of a run.
The invention possesses other objects and features of advantage, some of which of the foregoing will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and forming part of this specification. It is to be understood, however, that variations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claims.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a front elevation, in a somewhat diagrammatic form and with the front wall removed, of a solvent immersion extractor constructed in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the accompanying drawing, the solvent immersion extractor of the present invention comprises, briefly, a structure providing a plurality of adjacent chambers 6, 7 and 8 for liquid solvent for extracting the desired component from solid material immersed in the solvent in the chambers; means 11, 12, 13, 14, 15 and 16 partitioning off substantially vertical entryways 21, 22 and 23 at one side of each of chambers 7-8, and substantially vertical exitways 26, 27 and 28 at the opposite side of the chambers, the partitioning means being effective to provide quiescent solvent surfaces 31, 32 and 33 between each pair of entryways and exitways; a continuous conveyor 36 for displacing the material through the chambers and being mounted for downward movement through entryways 21-23 and for upward movement through exitways 26-28 without disturbing the quiescent surfaces 31-33, conveyor 36 having a return leg 38 overhead of chambers 6-8; baffle means 41 mounted between surfaces 31-33 and return leg 38 and formed to divert falling solid material away from surfaces 31-33 and into one of the entryways 21-23; and the housing 43 providing the several chambers also including outlets 46, 47 and 48 on one side thereof at liquid levels 31-33 for decanting the miscella from the clean miscella surfaces. As will be observed from the drawing, partitioning means 11-16 extends from above surfaces 31-33 well down into the interior of chambers 6-8 and thus establish solvent columns isolated except at their bases from the fluid material in the chambers. Accordingly, the conveyor may move through these columns without significantly disturbing surfaces 31-33, and of particular importance any solid material falling off of the conveyor in the exitways will be deposited on the columns effectively shielded away from surfaces 31-33. Preferably and as here shown, the chambers are formed with arcuate bottoms and the partitioning walls making up the entryways and exitways 21-23 and 26-28 define elongated passageways; and the conveyor is formed with flights 56 which are mounted and dimensioned for movement through the passageways with the planes of the flights substantially perpendicular to the longitudinal axes of the passageways. At the same time, the conveyor is entrained about the sheaves 57, 58 and 59 for movement of flights 56 around an arcuate path conforming to bottoms 51-53 and with the flights supported substantially perpendicular to the container bottoms. As here shown, housing 43 is composed of a top wall 61, a bottom wall 62, end walls 63 and 64, a rear wall 65 and a front wall which is removed to show the interior parts. Chamber defining walls 67, 68 and 69 extend between the front and rear walls of the housing and walls 67 and 69 cooperate with end walls 63 and 64 to provide individually sealed chambers. Likewise, partition walls 11-16 and 41 extend between the front and rear walls to form their respective compartments and conveyor flights 56 similarly extend into proximity to the front and rear walls to most effectively drive the solvent and solid material mash through the chambers and the entryways and exitways connected thereto. It is desired that the vertical legs of the conveyor flights in the several exitways fit closely to the surrounding casing so as to most effectively transfer the mash from one chamber to the next. The liquid tends to drain from the mash as it is elevated and is permitted to return to the solvent column in the exitway via small clearance between the flights and the surrounding walls forming the exitway.
Solid material containing the component to be extracted is fed into the apparatus via a hopper 71 and feed conveyor 72 to a downwardly inclined chute 73 mounted on end wall 63 for delivery of material into the entryway 21 of the first stage where it is carried downwardly by conveyor flights 56 into chamber 6. A solvent delivery conduit 76 is connected to the feed conveyor for mixing the solid material with solvent as the two are delivered to chute 73 for passage into the first stage. Conduit 76 is here part of nozzle 77 and is connected by solvent line 78 to the outlet of a pump 109.
Another feature of the present invention is the incorporation within what has been heretofore described as an immersion extractor of a percolation extractor and the obtaining of the inherent advantages of this type of structure. This is accomplished by carrying the final discharge of solid material via conveyor leg 38 over a drainage support 81 and at the same time applying to the material fresh solvent for percolation therethrough. As here shown, support 81 comprises a series of parallel bars extending in the direction of conveyor travel with the slots between the bars permitting drainage therethrough of solvent leaching through the solid material carried by the conveyor. Fresh solvent 82 is applied to the solid material by a spray head 83 mounted at the upstream end of drainage support 81. Preferably, the drainage screen slopes upwardly slightly so as to prevent solvent from running into the spent solids discharge conveyor 86 positioned at the downstream end of the drainage support. Solids which are partially dried on the drainage support, drop onto discharge conveyor 86, here shown as a screw type, for movement out of the housing to a desolventizer. A pan 87 here forming part of the aforementioned baffle means 41 underlies the drainage support 81 for directing percolated solvent to entryway 23 of the final stage. Fresh solvent is added at the upper end of pan 87 by a spray head 88 which is connected by conduit 89 to spray head 83 and to a fresh solvent source, spray head 88 functioning to wash the fines deposited on pan 87 back into the entryway of the final stage. Accordingly, fresh and most potent solvent is deposited on and percolated through the substantially spent solid material to pick up the final bit of extractable component. In this operation, pan 87 cofunctioning with the partitioning means above described prevent any of the solid material from dropping onto and disturbing the quiescent miscella surfaces 31-33 in the several chambers. Similarly, partition means 41 underlies the endless conveyor as it passes from discharge conveyor 86 into the intake passage of the initial stage so that any solid material entrained on the conveyor and dropping therefrom will be diverted away from miscella surface 31 in the initial stage and be carried into the intake passage of the input stage.
Decanting of the miscella is here effected by outlets 46-48 formed in box-like structures 91, 92 and 93 mounted on rear wall 65 in registration with openings 46-48 and having outlets 96, 97 and 98 connected to drain conduits 101, 102 and 103, respectively. Decanted miscella is advanced from stage to stage in a reverse direction to the flow of material through the extractor. For example, drain conduit 103 of the final stage is connected to the intake of pump 106 which has its discharge connected to conduit 107 leading to a solvent spray head 108 positioned above entryway 22 of the second stage. Drain conduit 102 of the second stage is connected by pump 109 to nozzle 77 discharging miscella into the intake chute 73 of the first stage. Drain conduit 101 is connected to pump 111 which is, in turn, connected to conduit 112 for conducting the rich miscella to the evaporator for recovery of the solvent and extractable component. Additionally, drain openings 116, 117 and 118 are provided at the bottom of chambers 6-8 for draining the miscella at the end of a run. The present apparatus affords a unique advantage in clearing itself of solid material at the end of a run in the following manner. The flow of solid material through feed conveyor 72 and chute 73 is stopped. The conveyor continues to move and fresh solvent is supplied to spray heads 83 and 88 until the last of the main body of solid material is removed by discharge conveyor 88. The flow of fresh solvent is then stopped and conveyor operation continued until substantially all of the solid matter is removed from the system whereupon the solvent may be pumped out. This is here effected by first opening a valve 121 in conduit 122 leading from drain opening 118 to the intake side of pump 106, thus causing evacuation of the miscella from the third stage and delivering it to the second stage. When overflow ceases at opening 47, a valve 123 is opened in conduit 124 connecting drain 117 to the intake side of pump 109 for transfer of the miscella out of the second stage and into the intake of the first stage. When overflow from opening 46 ceases, a valve 126 is opened in conduit 127 leading from drain 116 to the intake side of pump 111 for transfer of the final miscella in the system from the first stage to the evaporator, via conduit 112.
While the present extractor is illustrated and described as a three stage extractor, it will be understood that more or less stages may be assembled in the manner illustrated. The conveyor illustrated more or less diagrammatically in the drawing is a standard drag conveyor composed of drive chains and flights. | The immersion extractor is designed for use with a solid material containing an extractable component and includes a plurality of adjacent chambers each formed to contain a liquid solvent bath for extracting the component from the material and a continuous conveyor for displacing the material through the chambers. Partitions are used to define substantially vertical entryways for the conveyor at one side of the chambers and substantially vertical exitways for the conveyor at the opposite side of the chambers thus maintaining between the entryway and exitway of each container a quiescent solvent surface which is decanted for removal of solvent and dissolved component. A single continuous conveyor is used and the return leg of the conveyor is structured to carry out a final percolation-type extraction of the extractable component. | 1 |
RELATED APPLICATIONS
The present application is based on, and claims priority from, French Application Number 07 02562, filed Apr. 6, 2007, the disclosure of which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
The invention relates to the field of optical information recording.
BACKGROUND OF THE INVENTION
In this field, it may be advantageous to provide recording media which can be neutralized irreversibly, for example, for limiting the number of read accesses in the case where it is desired to prevent an unauthorized use of the recorded data. In particular, in the optical disk (CDROM, audio CD, DVD, etc.) memory, irreversible erasing of the data or of some of the data may serve to protect against unauthorized copying of the information contained in the memory.
Optical data are, in principle, stored on the medium in the form of physical marks which are irregularities of control dimensions which present an optical contrast allowing them to be read by a laser beam detection system.
The physical marks may be impressions formed by molding a polycarbonate substrate (for example, DVD-ROM); they are then recorded once and for all; they may also be formed by recorded zones in layers that are sensitive to the action of a writing light beam; the recording may then be reversible (erasure is possible, even re-recording) or irreversible (no erasure possible nor overwriting).
Typically, in the case of an irreversible optical recording, the recording is carried out by irradiating, by means of a laser diode, a colored layer which is locally degraded when the power of the writing laser exceeds a threshold. This local degradation defines marks whose length is defined by the time during which the laser acts on the rotating disk, taking into account the rotational speed of this disk.
For rewritable disks, the writing is usually carried out by heating a material known as a “phase change material” using a writing laser diode. The material is, for example, initially in a crystalline phase; it locally changes into an amorphous state where the writing laser acts. The optical contrast (for example, in reflectivity) between the amorphous zones and the zones that remain crystalline is sufficient to enable the reading of information thus recorded. Erasing is carried out by again exposing these zones, via the laser diode, to a power greater than the power of the read laser but lower than the power of the laser for writing information. The zones that had become amorphous recrystallize, those that were crystalline remain crystalline, and the disk is ready for a new writing operation.
When it is sought to increase the density of information recorded on an optical disk, this objective is generally limited by the performance of the information read device. The basic principle is that the physical information written to the disk can only be read with great difficulty when its size is smaller than the resolution limit of the optical system which will be used to read this information. Typically, when reading with a red laser having a wavelength of 650 nm and a numerical aperture of 0.6, there is normally no hope of correctly reading information having a resolution below 0.4 microns, or at the limit 0.3 microns.
However, methods known as super-resolution methods have been devised for reading information whose physical size is smaller than, or even much smaller than, the wavelength. These methods are based on the non-linear optical properties of certain materials. The expression “non-linear properties” is understood to mean the fact that certain optical properties of the material change depending on the intensity of the light which they receive. The read laser itself will locally modify the optical properties of the material by thermal, optical, thermooptical and/or optoelectronic effects on dimensions smaller than the dimension of the read laser spot; due to the change in properties, a piece of information present in this very small volume becomes detectable whereas it would not have been detectable without this change.
The phenomenon which is exploited is mainly based on two properties of the read laser that will be used:
on the one hand, the laser is very highly focused so as to have an extremely small cross section (of the order of the wavelength) but whose power distribution is Gaussian, very strong at its center, very attenuated at the periphery; and on the other hand, a read laser power is chosen such that the power density over a small part of the cross section, at the center of the beam, significantly modifies an optical property of the layer, whereas the power density outside of this small cross section portion does not significantly modify this optical property; the optical property is modified in a direction that tends to allow the reading of information which would not be readable without this modification.
Everything then takes place as if a beam had been used that was focused on a diameter much smaller than that which its wavelength allows.
In a previous patent application, filed under the number FR 0700938 on 9 Feb. 2007, an optical storage structure was proposed operating in super-resolution. This structure comprises a substrate (preferably made of polycarbonate) equipped with physical marks whose geometrical configuration defines the information recorded, a superposition of three layers on top of the substrate marks, and a transparent protective layer on top of this superposition, the superposition comprising a layer of indium or gallium antimonide inserted between two dielectric layers of a zinc sulfide and silicon oxide (ZnS/SiO 2 ) compound.
This structure is favorable because it requires a relatively low read laser power to read the super-resolution information with a satisfactory signal/noise ratio. However, the question of the reading power is critical as, on the one hand, a sufficiently high power is necessary to obtain a super-resolution effect via a localized change of the optical properties, but, on the other hand, too high a power tends to gradually destroy the information recorded, limiting the number of read cycles possible whereas a number of read cycles that is as high as possible is desired.
By carrying out tests on these structures based on InSb or GaSb between two ZnS/SiO 2 layers, it was surprisingly observed that it was possible, at the same time:
to read correctly, without them degrading, the information recorded in super-resolution, by using a read laser with a first power P 1 ; and to irreversibly degrade the information recorded in super-resolution by reading them with a power P 2 less than P 1 .
This observation was made from repeated measurements on samples comprising regularly distributed marks, recorded in super-resolution.
Although this phenomenon has not been able, to date, to be adequately explained scientifically, the repetition of the observations has led to the conclusion that it would be possible to use this phenomenon industrially to neutralize, at will and irreversibly, the working contents of an optical disk recorded in super-resolution. The neutralization consists of a degradation of certain zones (determined or randomly distributed) that renders the disk unusable.
SUMMARY OF THE INVENTION
Consequently, a process is proposed according to the invention for intentional degradation of information recorded in super-resolution in a high-resolution optical information storage structure, the structure comprising a substrate equipped with physical marks whose geometrical configuration defines the information recorded, a superposition of three layers on top of the substrate marks, and a transparent protective layer on top of this superposition, the superposition comprising a layer of indium or gallium antimonide inserted between two dielectric layers of a zinc sulfide and silicon oxide (ZnS/SiO 2 ) compound, the process comprising a degradation operation consisting in making a laser beam, which has a power around 30% lower than the power of the read laser used to read the information recorded in super-resolution on the disk, pass over the physical marks.
As an example of use, it may be anticipated that the storage structure must not be read more than N times, and that the read system activates, after the N th reading, the application of a lower reading power which degrades sensitive information zones of the structure. The number N moreover may be contained in the structure itself and read by the system in order to activate a power modification of the read laser suitable for carrying out the desired degradation. When the storage structure is rewriteable, it is even possible to record therein the number of readings already carried out in order to manage the desired moment for the intentional degradation.
Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious aspects, all without departing from the invention. Accordingly, the drawings and description thereof are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF DRAWINGS
The present invention is illustrated by way of example, and not by limitation, in the figures of the accompanying drawings, wherein elements having the same reference numeral designations represent like elements throughout and wherein:
FIG. 1 represents the optical information storage structure used for implementing the invention;
FIG. 2 represents an atomic force microscope view of a substrate in which marks have been preformed having multiple dimensions of 80 nanometers spaced apart at multiple distances of 80 nanometers; and
FIG. 3 illustrates a process of degration according to the embodiment disclosed in the application.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1 , the general structure of the optical information storage medium used for implementing the invention is represented.
It comprises a substrate 10 , which is preferably an organic material, and notably polycarbonate conventionally used for optical disks. The substrate will, in practice, be in flat disk form and the information is conventionally written onto the disk along substantially concentric tracks; a read laser beam, symbolized by the arrow 20 , placed in front of the disk will see the information pass in front of it during the rotation of the disk.
The substrate 10 comprises physical marks that define the recorded information, and in this example, the physical marks are constituted in the form of a relief imprinted on the upper surface of the substrate. The relief is, for example, composed of pits whose width is more or less fixed for all the information written, but whose length and spacing, in the run direction of the information, define the contents of the written information. Reading of the information is carried out by analysis of the phase of the laser beam reflected by the structure, a phase which varies at the start and at the end of the pass by each physical mark. The pits may be prerecorded by pressing of the polycarbonate or of the plastic substrate for example using a nickel mold which has been produced from very high-resolution electron-beam etching tools.
The width, length, and spacing of the physical marks may be less than the theoretical optical resolution of the optical read system which will be used to read them. Typically, when it is a blue laser with a wavelength of around 400 nanometers, used with a focusing optic whose numerical aperture is 0.85, the theoretical physical resolution limit is around 120 nanometers when precautions are taken. Here, the marks may be prerecorded with a resolution, in the length or in the spacing, of less than or equal to 80 nanometers as will be seen.
The marks are covered with three layers composed, in order, of a dielectric layer 12 of ZnS/SiO 2 compound, a layer 14 of indium antimonide (InSb) or gallium antimonide (GaSb), and a dielectric layer 16 of ZnS/SiO 2 compound. The assembly is covered by a transparent protective layer 18 .
The layer 14 made of InSb or GaSb is a layer having non-linear optical properties, and it has been observed that the reflexivity of the three-layer structure, GaSb or InSb layer surrounded by the two ZnS—SiO 2 dielectric layers, may increase very substantially when it is illuminated by a laser beam having a power of 1 to 2 milliwatts (in practice, corresponding to a power density of around 7 milliwatts per square micron).
FIG. 2 recalls the manner in which the information prerecorded onto the substrate may be constituted, before deposition of the superposition of three layers 12 , 14 , 16 : blind holes of variable length and spacing. The arrow indicates the run direction of the substrate under the read laser.
The tests carried out have shown that the optimal thicknesses of the layers according to the invention are the following:
lower ZnS/SiO 2 layer: from 20 to 100 nanometers, preferably around 50 to 70 nanometers; GaSb or InSb layer: from 10 to 50 nanometers, preferably around 20 to 30 nanometers; and upper ZnS/SiO 2 layer: from 20 to 100 nanometers, preferably around 50 to 60 nanometers.
The preferred atomic composition for the ZnS—SiO 2 compound is around 80% ZnS per 20% SiO 2 . It may range from an 85/15 ratio to a 70/30 ratio.
The atomic composition of the InSb or GaSb layer is preferably around 45% to 55% antimony Sb; the proportion of indium or of gallium is then between 45% and the balance of the antimony proportion from 100%. An In 50 Sb 50 or Ga 50 Sb 50 stoichiometric compound is particularly suitable, but small deviations from stoichiometry are acceptable.
The deposition of the layers does not pose any particular problems; it may be carried out conventionally by sputtering from a target comprising the materials in question, both for the active layer and for the dielectrics, or by plasma-enhanced vapor deposition.
The invention is particularly applicable for reading information from a blue laser, typically with a wavelength of around 400 nanometers, the information prerecorded onto the optical disk possibly then having a resolution of 100 nanometers or less, that is to say four or five times less than the read wavelength.
The reading of the information will preferably be carried out using a read laser power of around 1.5 to 2 milliwatts. The wavelength of the laser is preferably around 400 nanometers. The focusing optic has a numerical aperture of around 0.85.
The voluntary degradation of the information will be carried out using a laser similar to the read laser, or the read laser itself, with a similar focusing optic or with the reading optic itself, but with a reduced laser power. The reduced power will be around 30% lower than the read power. When the laser being used to provide the intentional degradation of the information is the read laser itself, it will be operated with a lower supply current and/or voltage during the degradation operation than during the super-resolution reading operation.
The degradation may notably be observed by taking measurements of fluctuations in the length of the marks present in the output signal relative to the reference time period (“jitter” measurement) of the output signal. The reference time period is, for example, the time T corresponding to a reference distance of 80 nm scanned by the read laser beam during rotation of the disk. The degree of regularity of the marks read is measured as a ratio (as a percentage) of the periods actually detected in the read signal to the theoretical period of the signal, and it may be considered that the information recorded is degraded when the periodic fluctuation measured exceeds 10% whereas the information is precisely periodic on the disk. This is because, when the fluctuation exceeds 10%, sampling of the signal at the frequency 1/T, in order to detect the presence or absence of the marks, has a not-inconsiderable probability of giving a false result.
The practical measurement method consists in compatibilizing the durations of the successive recorded marks, determined from the output signal of the read head, and in establishing a histogram thereof (number of marks located having one length or another), then in determining the standard deviation of the length, this standard deviation representing the fluctuation relative to the reference time. The calculation may optionally be made by taking into account the fluctuations in the rotational speed of the recording medium when its rotational speed is not perfectly regular.
It is observed that
reading at low powers (below 1 mW) gave a low fluctuation relative to the reference time, less than 10% (the super-resolution information not however being able to be seen at a low power); the information read at a relatively high power for which the super-resolution effect applies, mainly around 1.5 to 2 milliwatts gives a low fluctuation, below 10%; the information read at a medium power (around 1.2 to 1.5 milliwatts, mainly around 30% less than the read power in super-resolution), gives a high fluctuation, which may reach close to 20%; and after reading at medium power, the super-resolution information could no longer be read by reestablishing the normal read power in super-resolution; it was affected by a high fluctuation, greater than 10% and this was observed repeatedly; the information is irretrievably degraded, the degradation being measured by a jitter value; observation with an atomic force microscope confirmed the fact that the recorded marks had deteriorated.
The observation was repeated multiple times, on structures that were different from one another and both when the phase change layer was indium antimonide and when it was gallium antimonide.
The tests were made on the following structures, given in the table below in which:
the lower ZnS/SiO 2 layer 12 deposited on the polycarbonate substrate 10 is denoted by layer C 1 ; the phase change layer 14 made of InSb or GaSb by layer C 2 ; the upper ZnS/SiO 2 layer 16 is denoted by layer C 3 ; the normal read laser power in super-resolution is denoted by P 1 ; and the power at which degradation was observed, irreversibly preventing reading in super-resolution is denoted by P 2 .
Layer C1
Layer C2
Layer C3
Read power
Degradation
ZnS/SiO 2
InSb or GaSb
ZnS/SiO 2
P1
power P2
75 nm
InSb 20 nm
40 nm
1.3 mW
0.9 mW
75 nm
InSb 20 nm
50 nm
1.5 mW
1.0 mW
75 nm
InSb 20 nm
70 nm
1.9 mW
1.3 mW
75 nm
InSb 20 nm
80 nm
2 mW
1.4 mW
75 nm
GaSb 20 nm
50 nm
2 mW
1.5 mW
The irreversible degradation process according to the invention is useful for limiting the number of accesses to a recorded media, or for limiting the abusive or fraudulent use of the recorded data.
FIG. 3 shows that the process of the degradation operation according to the disclosed embodiment. The degradation operation includes a step S 1 of making a laser beam, and a step S 2 of passing over physical marks.
It will be readily seen by one of ordinary skill in the art that the present invention fulfils all of the objects set forth above. After reading the foregoing specification, one of ordinary skill in the art will be able to affect various changes, substitutions of equivalents and various aspects of the invention as broadly disclosed herein. It is therefore intended that the protection granted hereon be limited only by definition contained in the appended claims and equivalents thereof. | The invention relates to the field of optical information recording. In order to prevent abusive or fraudulent use of storage media, the invention provides a process for intentional degradation of information by application of a laser power below the normal power for reading information recorded in super-resolution on the media. This process relies on the surprising observation that a laser power below the super-resolution read power produces an irreversible degradation of the information recorded. This observation has been made with regard to media composed of a three-layer structure comprising an InSb or GaSb layer between two ZnS/SiO 2 layers. Application for protecting sensitive data. | 6 |
BACKGROUND
Unmanned aerial vehicles (UAVs) comprise a variety of vehicles, from conventional fixed wing airplanes, to helicopters, to ornithopters (i.e., machines that fly like birds), and are used in a variety of roles. They can be remotely piloted by a pilot on the ground or can be autonomous or semi-autonomous vehicles that fly missions using preprogrammed coordinates, GPS navigation, etc. UAVs can include remote control helicopters and airplanes for the hobbyist, for example.
UAVs may be equipped with cameras to provide imagery during flight, which may be used for navigational or other purposes, e.g., identify a house address, etc. UAVs can also be equipped with sensors to provide local weather and atmospheric conditions, radiation levels, and other conditions. UAVs may also include cargo bays, hooks, or other means for carrying payloads.
Newer generation UAVs may also provide significant payload capabilities. As a result, UAVs can also be used for delivering packages, groceries, mail, and other items. The use of UAVs for deliveries can reduce costs and increase speed and accuracy. The range provided by current UAV technology, however, makes deliveries over a wide area—e.g., throughout a city, or even a portion of a city—difficult.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items or features.
FIG. 1A depicts an unmanned aerial vehicle (“UAV”) docking station on a convention streetlight, in accordance with some examples of the present disclosure.
FIG. 1B depicts a variety of UAV sizes, in accordance with some examples of the present disclosure.
FIG. 1C depicts a network of docking stations for UAVs, in accordance with some examples of the present disclosure.
FIGS. 2A-2C depict the UAV docking station of FIG. 1 equipped with a recharging station, in accordance with some examples of the present disclosure.
FIGS. 2D-2E depict the UAV docking station of FIG. 1 equipped with a refueling station, in accordance with some examples of the present disclosure.
FIGS. 3A-3C depict a first UAV hold-down system, in accordance with some examples of the present disclosure.
FIGS. 4A-4B depict a second UAV hold-down system, in accordance with some examples of the present disclosure.
FIGS. 5A-5B depict a UAV docking station with an integrated package locker, in accordance with some examples of the present disclosure.
FIGS. 6A-6B depict a UAV docking station with an integrated package system, in accordance with some examples of the present disclosure.
FIG. 7 depicts a UAV docking station with a plurality of communications accessories, in accordance with some examples of the present disclosure.
FIG. 8 depicts a UAV docking station incorporated into a cellular phone tower, in accordance with some examples of the present disclosure.
FIG. 9A depicts a method for routing a UAV to deliver a package, in accordance with some examples of the present disclosure.
FIG. 9B depicts a method for rerouting a UAV to avoid a weather event, in accordance with some examples of the present disclosure.
FIGS. 10A-10B depict a method for routing a second UAV to deliver a package when a first UAV has a problem, in accordance with some examples of the present disclosure.
FIGS. 11A-11B depict a third UAV hold-down system, in accordance with some examples of the present disclosure.
DETAILED DESCRIPTION
Examples of the present disclosure relate generally to unmanned aerial vehicles, or “UAVs,” and specifically to a system of docking stations for UAVs to increase the range and safety of UAVs. The docking stations may incorporate a number of features to enable UAVs to fly longer routes, to fly routes more accurately, and to provide shelter during adverse conditions. In some examples, the docking stations may also provide additional services to the communities in which they are installed. In some examples, the docking stations can also include various package handling abilities to facilitate package delivery. In some examples, the docking stations may be networked to provide central command and control for the UAVs.
To simplify and clarify explanation, the disclosure is described herein as a system and method for enabling UAVs to provide delivery and other services. One skilled in the art will recognize, however, that the disclosure is not so limited. While, the system may be described as a system to deliver packages, it should be understood that the system may just as easily be used to delivery groceries, mail, movies, prescriptions, and other items. In addition, the system is described herein for use with UAVs, but could also be applied to other vehicles using different form factors such as ground-based docking stations for autonomous delivery vans.
The vehicles, methods, and systems described hereinafter as making up the various elements of the present disclosure are intended to be illustrative and not restrictive. Many suitable vehicles, energy sources, navigational aids, and networks that would perform the same or a similar function as the systems described herein are intended to be embraced within the scope of the disclosure. Such other systems and methods not described herein can include, but are not limited to, vehicles, systems, networks, and technologies that are developed after the time of the development of the disclosure.
As shown in FIG. 1A , examples of the present disclosure can comprise a system 100 for providing a plurality of docking stations for one or more UAVs 105 . The docking station 102 portion of the system 100 is shown as installed on a conventional pole-mounted street light 110 . As discussed below, however, the system 100 could also be installed on other existing structures such as cell towers, church steeples, office buildings, parking decks, radio towers, telephone/electrical poles, and other vertical structures (collectively, “poles”). The system 100 can comprise an elevated landing platform 115 to enable one or more UAVs 105 to land. This can enable the UAVs 105 to, for example, avoid bad weather, recharge/refuel, drop off packages, pick-up packages, communicate with a central control system, reset navigation systems, and await further instructions, among other things.
In some examples, the elevated landing platform 115 can be sized and shaped to enable two or more UAVs 105 to land at the same time. In this configuration, the system 100 can also comprise one or more locating devices such as, for example, pressure sensors, laser scanners, video cameras, or other means to enable the system 100 to locate the drones 105 on the elevated landing platform 115 . This can enable the system 100 to ensure, for example, that a first drone 105 drops off a package, while a seconds drone 105 recharges and continues on.
As mentioned above, a limiting factor with current UAV technology is the relatively short range available when a UAV is carrying a heavy or large payload. In other words, while a UAV may have a range of several, or even tens of miles, unladen, this range can drop to less than a mile while carrying a package. Of course, larger UAVs with larger payloads and ranges are available, but the tradeoff between range and payload remains a significant concern in UAV system design.
To this end, as shown in FIG. 1B , in some examples, the system 100 can include a variety of different UAVs 105 . In some examples, the system 100 can comprise small UAVs 105 a , medium UAVs 105 b , and large UAVs 105 c . In some examples, the UAVs 105 can be categorized by payload capacity. For example, small UAVs 105 a could be capable of from approximately 0-5 lbs., while medium UAVs 105 b could be capable of carrying between 0-10 lbs., while the large UAVs 105 c could be capable of carrying up to 50 lbs. Of course, other payload capacities, including payloads up to 500 lbs and more are possible. These ranges are intended to be exemplary and are not in any way limiting.
In this manner, the system 100 can assign packages to a suitable sized UAV 105 . Small packages can be assigned to small UAVs 105 a , for example, to reduce costs and/or increase delivery speed. Larger packages, on the other hand, can be assigned to medium 105 b or large 105 c UAVs with larger payloads. In some examples, the packages can also be assigned to UAVs 105 based on prevailing weather conditions. In other words, a small or medium package can nonetheless be assigned to a large UAV 105 c due to strong winds, for example. Of course, the UAVs 105 can be classified in a number of ways including, but not limited to, size, energy efficiency, payload, range, and top speed.
As shown in FIG. 1C , in some examples, the system 100 can also comprise a plurality of networked docking stations 102 . The system 100 can comprise a central control 150 , which can comprise, for example, a networked computer or server to provide information and commands to the plurality of UAVs 105 . In some examples, the central control 150 can be in communication with the docking stations 102 via a wireless connection 160 , a wired connection 165 , or combinations thereof. In some examples, the central control 150 can be in constant communication with the UAVs 105 via a cellular, radio frequency (RF), or other suitably long-range wireless connection. In other examples, the central control 150 can be in communication with the UAVs 105 when they are on, or in sufficient proximity, to a docking station 102 .
In some examples, the central control 150 can also comprise an interne connection 155 . The central control 150 can also be in communication, via either the interne connection 155 or a dedicated connection, with a local or regional package handling center or central facility 170 . The interne connection 155 can enable the central control 150 to retrieve weather and package data, for example, to enable the system 100 to route UAVs 105 in an efficient manner, while avoiding bad weather when possible. In this manner, UAVs 105 can retrieve a package from a central facility 170 (or a docking station 102 ), and be routed in an efficient manner to their final destination via one or more docking stations 102 .
The route for the UAV 105 can be calculated by the central control 150 and can be, for example, the most direct path, the path with the most favorable atmospheric conditions (e.g., without headwinds), or the path that moves the UAV 105 from docking station to docking station without exceeding the UAV's 105 range. In some examples, the central control 150 can adjust the UAVs' 105 routes dynamically based on, for example, the package weight and/or size, changes in weather (e.g., increased headwinds), package priority, or traffic from other UAVs 105 or other air traffic.
The central control 150 can also be in communication with the docking stations 102 via a wired or wireless connection. This can enable the UAVs 105 to communicate with the central control 150 when they are proximate a docking station. In addition, as discussed below, the docking stations 102 can also comprise weather stations, for example, to provide weather data including local weather conditions. In addition, in some configurations, the docking stations 102 can also comprise automated package handling systems, which can be in communication with the central control 150 to indicate, for example, when a package arrives at the package handling system or when a package is retrieved from same.
In some examples, one or more of the central control 150 , the UAVs 105 , the central facility 170 , and the docking stations 102 can be equipped with GPS receivers in communication with one or more GPS satellites 175 . As mentioned below, in some examples, the docking stations 102 can act as reference points for adjustment and error reduction for the UAV 105 GPS systems. In some examples, the central control 150 can use GPS coordinates as waypoints for routing flight paths.
In some examples, to facilitate longer routes, the UAV docking stations 102 can comprise a recharging station 205 , as shown in FIGS. 2A-2C . As shown in FIG. 2A , the recharging station 205 can comprise a modular power source 215 for the UAV 105 , a power bay 220 located on the UAV 105 , and a recharging base 210 . As shown, in some examples, the recharging station 205 can comprise a battery charging base 210 and one or more batteries, or battery packs, 215 . In this configuration, the UAV 105 can be powered by a single battery 215 , for example, but can have a battery bay 220 configured for two or more battery packs 215 . As the UAV 105 approaches the docking station 102 , therefore, the UAV 105 can position itself to land on the recharging station 205 ( FIG. 2B ), drop off a discharged battery 215 and pick-up a charged battery 215 ( FIG. 2C ). Thus, the UAV 105 can take off almost immediately to continue its route and, when it takes off, the discharged battery 215 is left in the charging stand to charge.
In addition, while described as a battery pack 215 , the power supply for the UAV 105 could also be a hydrocarbon fuel, a fuel cell, solar energy, or other energy source. If, for example, the UAV 105 uses one or more nitromethane burning engines, the battery packs 215 could be replaced with modular fuel cells and the recharging station 205 could comprise a refueling station. As the UAV approaches the docking station 102 , therefore, it simply exchanges an empty fuel tank for a full one. Of course, the UAV could also use gasoline, diesel, Jet A, propane, methane, ethanol, methanol, or other hydrocarbon or alcohol based fuels. The use of appropriately spaced recharging (refueling) stations 205 can limitlessly extend the range of the UAV 105 .
In addition, while described above as a battery pack 215 , the energy source could also be a number of other electrical energy sources such as, for example, a fuel cell, a solar storage system, or a capacitor. In addition, there are myriad types of batteries and the battery packs 215 can comprise a variety of different battery types including, but not limited to, lithium ion, nickel cadmium, nickel metal hydride, lithium polymer, and combinations thereof. Using a capacitor, for example, can enable the battery pack 215 to be recharged quickly obviating the need for multiple battery packs. In addition, while a conventional contact type battery charger is discussed, other types of chargers such as, inductive, RF, and other non-contact charging systems are contemplated herein. Finally, docking stations 102 configured to enable more than one UAV 105 to land can comprise a plurality of recharging stations 205 to enable multiple UAVs 105 to be refueled/recharged at the same time.
As shown in FIGS. 2D-2E , in some examples, the UAVs 105 can be powered by liquid or gaseous fuels. In this configuration, the UAVs 105 can include fuel tanks 245 . In some examples, the power bay 220 can comprise two fuel tank receivers, similar to the battery bay 220 discussed above. In this manner, the UAV 105 can land, drop an empty fuel tank 245 , and pick up a full fuel tank 245 .
In other examples, as shown in FIG. 2D , the UAVs 105 may comprise a refueling probe 250 engageable with a refueling nozzle 255 on the platform 115 . The refueling nozzle 255 , in turn, can be in fluid communication with a fuel storage tank 260 in the platform 115 (or somewhere on the docking station 102 ). In some examples, the refueling nozzle 255 may comprise a cone-shaped receptacle to reduce the maneuvering accuracy required by the UAV 105 . When the UAVs 105 land (as shown in FIG. 2E ), the refueling probe 250 can engage with the refueling nozzle 255 to enable the system 205 to refill the fuel tank 245 .
In still other examples, the UAVs 105 can be stackable. In other words, two or more UAVs 105 can land in the same location on the platform 115 to both increase the capacity of the platform 115 and to provide charging to multiple UAVs 105 at the same time. In some examples, the UAVs 105 can be secured to one another and can include electrical contacts to enable two or more UAVs 105 to be charged by the same charging station 205 .
As shown in FIGS. 3A-3C , the docking station 300 can also comprise one or more UAV securing systems 305 . In some examples, the UAV securing system 305 can comprise a clamp to hold the UAV 105 securely when on the elevated platform 115 . This can enable the UAV 105 to offload packages 310 safely, for example, and can enable the UAV 105 to be secured during high winds and other adverse weather events.
The UAV securing system 305 can comprise one or more clamps 305 a stowed in one or more bays 305 b on the platform 115 . The clamps 305 a can be stowed in the bays 305 b when not in use, or can simply be in an open position, as shown in FIG. 3A . When the UAV 105 lands, the clamps 305 a can be closed to secure the UAV 105 to the platform 115 , as shown in FIG. 3B (and in detail in FIG. 3C ). In some examples, the clamps 305 a can be closed every time the UAV 105 lands. In other examples, the clamps 305 a can be closed only when conditions require it to stabilize the UAV 105 (e.g., during high winds). As shown, the clamps 305 a can be secured over one or more skids 105 d of the UAV 105 .
Of course, different UAV 105 landing gear designs (e.g., wheeled) or platform 115 designs may require a variety of designs to secure the UAV 105 . The UAV securing system 305 could also comprise a magnet, such as an electromagnet. In this configuration, the electromagnet may be energized when the UAV 105 is on the platform 115 , and de-energized prior to take-off, landing, and/or when no UAV 105 is present. In other examples, the elevated landing platform 115 could comprise a vacuum device, such as a suction cup or vacuum plate (i.e., a perforated plate in the platform to exert a vacuum on a portion of the UAV 105 ) to secure the UAV 105 to the platform 115 .
In some examples, as shown also shown in FIGS. 3A-3B , the elevated platform 115 may also comprise a turntable 325 . The turntable 325 can enable the UAV 105 to be rotated while on the platform 115 . Rotating the UAV 105 can enable the package 310 to be properly aligned, for example, for handling by the package handling system, discussed below. The turntable 325 can also enable the UAV 105 to be aligned with the recharging system 205 , or simply to enable a UAV 105 to take off and land into the wind as the wind shifts.
In other examples, as shown in FIGS. 4A and 4B , the platform 115 can include one or more slot-type hold-downs 405 . The slot-type hold-downs 405 can comprise opposing brackets 410 , for example, disposed on the platform 115 such that a slot 415 is defined therebetween. In this manner, as the UAV 105 approaches the platform 115 , it can fly such that its skids 105 d (also shown in FIG. 3C ) are substantially aligned with the slot 415 . As the UAV 105 lands, therefore, the skids are inserted between the brackets 410 and the UAV 105 substantially moves in straight and level flight, or translates, to fully engage the brackets 410 . Because the slot 415 is smaller than the diameter of the skids, however, the UAV 105 is secured to the platform. When taking off, the UAV 105 merely hovers slightly, backs off the platform 115 , until it clears the brackets 410 and then flies away normally. In some examples like the clamp-type system 305 , the brackets 410 can move between an open position and a closed position to decrease the accuracy required to land and engage the UAV.
In some examples, as shown in FIGS. 5A-5B , the system 500 can also comprise additional features for improved aesthetics, functionality, and profitability. In some examples, the system 500 can comprise signage 505 . This can include, for example, banners, signs, and display screens. In some examples, the signage 505 can comprise advertising to generate additional revenue for the provider. In other examples, the signage 505 can provide information, such as the location number for the docking station 102 to enable users to locate packages, for example, or GPS coordinates to enable users and UAV operators to calibrate their GPS equipment.
In still other examples, the system 500 can comprise a package transfer system 510 and/or a package locker storage system 515 . As the name implies, the package transfer system 510 can transfer packages from the UAV 105 , to the platform 115 , and then to a lower level (e.g., the ground level). In some examples, this can enable the UAV 105 to deliver items to a user or a delivery person on the ground. In other words, in some examples, the UAV 105 can deliver packages to the docking station 500 and the package either can be picked-up there by the addressee or can be delivered to its final destination by a delivery person in a truck, car, on a scooter, or using other transportation means. The package transfer system 510 can comprise, for example, a vacuum (or pneumatic) tube, dumbwaiter, elevator, or conveyor to transfer the package from the platform to the ground level without damage. In some examples, the package transfer system 510 can utilize gravity and can simply comprise a conduit with one or more gates 525 to direct packages to the correct location. The package transfer system 510 can comprise, for example, a large gate 525 a , a medium gate 525 b , and a small gate 525 c , such that packages of a certain size are routed to an appropriate location in a storage system, as discussed below.
In some examples, the system 500 can also comprise a locker storage system 515 . In some examples, the locker storage system 515 and the package transfer system 510 can be separate. In this configuration, packages can be transferred to the ground level by the package transfer system 510 . The packages can then be sorted and stored in the locker storage system 515 at the ground level. This can enable customers to pick up packages from the locker storage system 515 .
As shown in FIG. 5B , this configuration can also enable delivery personnel to retrieve packages—which can be presorted—from the locker storage system 515 and deliver them to their final destination. All packages in a particular locker 515 a , for example, can be addressed to the same zip code, neighborhood, street, or house to enable more efficient local delivery. In some examples, the use of local locker storage systems 515 can enable packages to be delivered without the use of large delivery trucks. In other words, personnel can retrieve packages from a centrally located locker storage system 515 . The worker can deliver all of the packages for a first location, and then return to the locker storage system 515 for the packages for a second location. This can enable packages to be delivered via compact car, scooter, or other more efficient means (i.e., more efficient than a large delivery truck), while minimizing the distances covered for delivery and delivery delays.
In other examples, the locker storage system 515 can be in communication with the package transfer system 510 and/or the central control 150 and can include an automated package sorting system. The automated package sorting system can use conveyors, robotics, or other known methods to automatically read and sort packages into an appropriate locker 515 a . In some examples, the package sorting system can sort packages based on commands from the central control 150 . They can be sorted, for example, in the order they arrive, because the central control 150 can in control of routing the packages and the UAVs 105 . In this manner, packages can be placed in an individual storage locker 515 a based on, for example, address, zip code, size, or weight.
In some examples, the lockers 515 a can comprise coded entry locks 515 b to enable users to pick up their package at the locker 515 a at a convenient time. Upon delivery to the locker storage system 515 , the recipient can be provided with the location of the docking station 500 , the locker 515 a number, and the code for the lock 515 b (e.g., an alphanumeric one-time use access code) via e-mail or text message, for example. The recipient can then retrieve the package at their convenience using the one-time use access code. The locker storage system 515 can then update the status of the locker 515 a to empty, assign a new access code to the lock 515 b , and the locker 515 a is ready for reuse.
In some examples, packages not retrieved within a predetermined timeframe (e.g., 10 days) can be returned to the central facility (i.e., the central facility 170 shown in FIG. 1C ) for reprocessing or return to the original sender. In some examples, the package can be returned to the platform 115 with the package transfer system 510 for retrieval by a UAV 105 . In other examples, the package can simply be returned by a delivery person.
In still other examples, the system 500 can also comprise a shelter 520 for the UAV 105 . The shelter 520 can be used instead of, or in conjunction with, the UAV securing system 305 . In some examples, the shelter 520 can be a small structure with a roof, as shown in FIG. 5A . In other examples, the shelter 520 can be a retractable tarp or awning, an inflatable shelter, or a mechanized top, similar to a convertible vehicle roof. In other words, in some examples, the shelter 520 can be a permanent structure, while in other examples it can be retractable or inflatable. As shown in FIG. 5A , in some examples, the shelter 520 can comprise a pivoting roof 520 a to enable the UAV 105 to more easily land in the shelter 520 (e.g., the UAV 105 can land vertically, horizontally, or a combination thereof).
As shown in FIGS. 6A and 6B , in some examples, the platform 115 can comprise an access door 610 to the package transfer system 510 . In some examples, as shown the access door 610 can comprise one or more trap doors. In other examples, the access door 610 can comprise, for example, a sliding door, a roll-up door, or other type of door to provide access to the package transfer system 510 , while reducing, or eliminating, the infiltration of water, dirt, and debris into the package transfer system 510 .
In some examples, the access door 610 can be spring-loaded and can open under the weight of the package. In other examples, the access-door 610 can be in short-range communication with the UAV 105 (e.g., RFID, wireless, etc.) and can open upon receiving a signal from the UAV 105 . In still other examples, as mentioned above, the central control 150 can track and control a plurality of UAVs 105 . In this configuration, the central control 150 can be in communication with the UAV 105 and/or the access door 610 and can send a signal to the access door 610 to open and close.
Prior to the arrival of a UAV 105 that has a package for that location, the access door(s) 610 can be closed, as shown in FIG. 6A . When the UAV 105 lands on the platform, communication between the UAV 105 and the access door 610 or the access door 610 and the central control can be initiated. Upon receiving the appropriate command, the access door 610 can open and the UAV 105 can drop the package 605 into the package transfer system 510 , as shown in FIG. 6B . Of course, in some examples, to prevent damage, the UAV 105 may lower the package into the package transfer system 510 or the package transfer system 510 may be padded or curved to reduce the impact.
In some examples, the UAV 105 can also comprise a camera 625 . The camera 625 can comprise a standard video camera and/or can comprise, for example, an infrared camera, a night vision camera, sonar receiver, and radar receiver. The camera 625 can enable the UAV 105 to, for example, locate the platform 115 , align with the package handling system 510 , and refuel/recharge. In some examples, the camera 625 can also provide remote video feeds to enable monitoring of weather and light conditions, crime, traffic, and other information.
As shown in FIG. 7 , to encourage municipalities, neighborhoods, and individuals to allow installations of multiple docking stations 102 , the docking stations 102 may also include a number of mutually beneficial features. In some examples, the docking station 700 can include a street light 705 . In selected examples, instead of being mounted on an existing street light, the service provider may include a new street light with the installation.
Similarly, the docking stations 700 can act as primary or supplementary (relay) cell towers. To this end, the docking stations can include cellular antennas 710 , switches, and other equipment to act as cell tower. In addition, in some cases, the docking stations 700 can also include wireless internet, or “Wi-Fi,” connections 715 . This can not only enable the UAV 105 to talk to the central control (i.e., the central facility 170 shown in FIG. 1C ) and the docking station 102 but also can provide local free or fee-based Wi-Fi services. This can enable cities to provide free Wi-Fi in public parks, buildings, and other public areas without bearing the burden of installing some, or all, of the necessary infrastructure.
In still other examples, the docking stations 700 can include video cameras 720 . These can be used by local authorities for traffic monitoring and crime prevention, among other things. In some configurations, the docking stations 700 can also include weather stations 725 . The weather stations 725 can provide wind speed and direction, temperature, and other weather related information to both the UAVs 105 , the central control 150 , and to local residents, businesses, and government entities. In this manner, the UAVs 105 and central control 150 can create efficient routes for the UAVs to avoid, for example, excessive winds, head winds (which can negatively affect flight range), and severe weather. Similarly, a networked series of docking stations 700 can provide highly granular weather reporting without the need for separate infrastructure.
In yet other examples, the docking stations 700 can further comprise one or more solar panels 730 . The solar panels 730 can be used, for example, to power the docking station 700 , the docking station accessories (e.g., the weather stations 725 ) or to provide energy to the recharging station 205 . In some examples, the solar panels 730 may be connected to an electrical grid as shown in FIG. 1A to offset the cost of system.
In still other examples, the docking station 700 can comprise one or more GPS receivers 735 . In some examples, the docking station 700 can send GPS coordinates to the UAV 105 when it is positioned on the platform 115 to enable the UAV 105 to calibrate or “zero-out” its navigational system. In other words, the location of the docking station 700 can be measured very accurately using a relatively sophisticated GPS receiver 735 , land surveying equipment, or other means. The docking station 700 can then provide this corrected GPS location to the UAV 105 , which may have a relatively simpler GPS system with some inherent error. This can provide a correction factor to the UAV 105 to increase the accuracy of the onboard GPS system.
In other examples, the docking station 700 can comprise the same type of GPS receiver 735 as that used on the UAV 105 . In that manner, the docking station 700 , which is stationary, can compare the GPS location provided by the GPS receiver 735 to the known GPS location, calculate a correction factor, and provide the correction factor to the onboard GPS receiver on the UAV 105 . In some examples, because all of the docking stations 700 are networked, the GPS receivers 735 on the docking stations 700 can provide a local area correction by combining the correction factor from two or more docking stations 700 .
As shown in FIG. 8 , the docking station 800 may be mounted on, or may include, a cell tower 805 . This can provide cell towers 805 in more remote locations than would otherwise be financially prudent, for example, because the cost of the tower can be absorbed, or at least shared, with the package delivery company using the UAVs 105 . So, for example, the company could either partner with a cell phone provider to share costs, or could enter cell phone market themselves to defray the costs of the docking stations 800 .
Examples of the present disclosure can also comprise a method 900 for routing UAVs to deliver packages. In some examples, the package can be received at a central facility, as shown at 905 . As mentioned above, the central facility can comprise, for example, a local or regional package sorting and handling facility. At the central facility, the central control can determine the size, weight, and final destination of the package can be determined, as shown at 910 . This information can be derived from the package ID, such as a tracking number or bar code.
The central control can then choose an appropriate UAV based on the size and weight of the package, delivery time, and weather conditions, among other things. The central control can then generate a flight plan, comprising one or more segments, for the chosen UAV, as shown at 915 . The flight plan can be chosen based on current wind and weather conditions, package delivery time, and UAV flight speed, among other things, and can include segments.
The central control can then ensure that the flight plan segments do not exceed the maximum range of the chosen UAV, as shown at 920 . If none of the segments exceeds the UAV's range, the central control can send the flight plan to the UAV for execution, as shown at 925 . In other words, if the UAV has sufficient range to deliver the package directly (e.g., the final destination is relatively close to the central facility, the UAV can fly directly to the final destination.
If any of the flight segments do exceed the maximum range of the UAV, on the other hand, the central control can add segments and stops at intervening docking stations, as necessary, as shown at 930 . The docking stations can enable the UAV to land, refuel/recharge, and then continue along the flight path to the final destination. When a sufficient number of intervening docking stations have been added to the flight plan to provide sufficiently short flight segments, the flight plan can be sent to the UAV for execution, as shown at 925 .
In some cases, the flight plan may need to be modified to account for changing weather conditions, as shown in FIG. 9B . As a result, examples of the present disclosure can also comprise a method 950 for rerouting UAV to avoid significant weather issues. In some examples, the central control can receive weather information from one, some, or all of the docking stations, as shown at 950 . In some example, each docking station can comprise a weather station. This can provide the central control with a very granular weather picture for the delivery area. This can enable the system to identify localized weather events such as, for example, thunderstorms, which tend to be fairly small and localized, but violent.
In some examples, the central control can determine if the weather event exceeds a certain threshold, as shown at 955 . In other words, the central control can determine, for example, whether the wind is in a certain direction (e.g., a headwind for the UAV) and/or exceeds a predetermined speed. If, for example, a UAV has a top speed of 10 mph (or 15 or 20 mph), then any headwind above this mark would prevent flight. In addition, the threshold can be set somewhat lower, such that any speed above 5 mph (or 10 mph or 15 mph, respectively) is deemed to inefficient to continue. Wind speed threshold can be set, for example, as an absolute value or a percentage of the top speed of the UAV.
Similarly, the UAV may be able to continue rather easily in a light rain, while rainfall above a certain rate (e.g., 1 inch/hour) makes flying inefficient or impossible. UAVs may also be unable to fly in extremely cold or extremely hot weather due to battery losses at these temperatures. As a result, the weather event thresholds can be set for each size and type of UAV, for a certain package size and/or weight, or other factors and combinations of factors.
If the system determines that the weather event is below the predetermined threshold, then system can continue to receive weather updates from the docking stations, as shown at 952 . If, on the other hand, the weather event exceeds the predetermined threshold, the central control can generate an alternative flight plan in an attempt to avoid the weather event, as shown at 960 . If, for example, the weather event is a fairly localized thunderstorm, the system can simply route the UAV around the weather event. If the weather event can be avoided, the alternate flight plan can be sent to the UAV for execution, as shown at 970 . As before, the flight plan can include a necessary number of docking stations to route the UAV to the final destination.
If, on the other hand, the weather event is more widespread, it may be impossible or impractical for the central control to route the UAV around the weather event. In this case, the central control can determine the current location of the UAV, as shown at 972 , and then determine the location of the closest docking station to the current location, as shown at 975 . In some examples, this can comprise the closest available docking station (e.g., the closest docking station may already be occupied). The central control can then send a “hold” flight plan to the UAV to fly to the closest docking station and hold for the weather to clear, as shown at 980 . In some examples, the UAV can take advantage of the UAV securing system 305 at the docking station to prevent damage during the weather event.
It is inevitable that UAVs with have electronic or mechanical failures in service. As a result, as shown in FIGS. 10A and 10B , in some examples the system can also include a method 1000 for rerouting UAVs to account for mechanical, electrical, or other technical issues. In some examples, the UAV can comprise an on-board diagnostic system comprising a plurality of error codes. These codes can refer to, for example, battery and motor overheating, low battery charge or fuel level, low motor RPM, and higher than normal power settings (e.g., the current from the battery is higher than normal for the current load and conditions).
Regardless of the problem, a first UAV can send an error code to the central control, as shown at 1005 . Upon receiving the error code, the central control can (1) determine the current location of the first UAV, as shown at 1010 and (2) determine a first docking station for the first UAV, as shown at 1015 . Of course, in some cases, the first docking station will be chosen because it is the closest docking station. In other cases, the closest docking station may be occupied, for example, and the first docking station can be the closest available docking station. In still other cases, such as when the stricken UAV cannot fly to a farther docking station, the central control can send a flight plan to a UAV that is occupying the closest docking station moving it to another docking station. After determining the appropriate docking station, the central control can generate an “emergency” flight plan for the first UAV from the UAV's current location to the first docking station, as shown at 1020 .
The central control can then send the emergency flight plan to the first UAV, as shown at 1025 . If the error is an unexpected loss of power such as a defective battery pack, for example, the first UAV may be able to receive a charged battery pack from the first docking station and continue on to the final destination. If, on the other hand, the UAV is unable to continue (e.g., one or more motors on the UAV have failed), then the central control can send an instruction to the first UAV to drop the package at the first docking station, as shown at 1030 .
As shown in FIG. 10B , if the first UAV is unable to continue, the method 1000 can continue with the central control determining the current position of a second UAV, as shown at 1050 . The second UAV may be the closest UAV to the first docking station, the closest available UAV, or the closest UAV with the appropriate carrying capacity for the package, for example. The central control can then generate a “back-up” flight plan for the second UAV to the first docking station, as shown at 1055 . If the back-up flight plan is determined to be within the range of the second UAV, as shown at 1060 , the central control can send the back-up flight plan to the UAV, as shown at 1065 .
If, on the other hand, the back-up flight plan is determined to exceed the range of the second UAV, as shown at 1055 , the central control can add docking stations to the flight plan, as necessary, as shown at 1075 . The central control can then send the modified back-up flight plan to the second UAV, as shown at 1065 . In some examples, the central control can also send instructions to the second UAV to pick up the package from the first docking station, as shown at 1070 . The second UAV can then be routed to the final destination, as discussed above.
As shown in FIGS. 11A and 11B , in some examples, the platform 115 can comprise one or more electromagnets 1105 and the UAV 105 can comprise one or more ferromagnetic components 1110 . In some cases, for example, some or all of the skids 1110 on the UAV 105 can comprise a ferromagnetic material. In some examples, the skids 1110 can comprise ferromagnetic pucks or strips. In this manner, when activated, the electromagnets 1105 can secure the UAV 105 to the platform 115 , but release the UAV 105 when deactivated. In some examples, the electromagnets 1105 can also comprise a battery back-up system to ensure the UAV 105 can be secured during power outages. This may be particularly relevant in weather related power outages, for example.
In some examples, the platform 115 can also include additional features. The platform 115 can comprise, for example, one or more landing patterns 1120 . In some examples, the landing patterns 1120 can comprise high contrast, reflective, or other markings, such as an X, which can be easily identified by the UAVs video camera 625 . The landing patterns 1120 can provide a target location for the UAV 105 and can align the UAV 105 with, for example, the package handling system 510 or the securing system 305 . In some areas, the platform 115 can also comprise pigeon spikes, scarecrows, artificial owls, overhangs, or other deterrents to limit wildlife interference with platform 115 operations.
In some examples, the platform 115 can also comprise one or more beacons 1125 . The beacons 1125 can comprise, for example, flashing landing lights, radio beacons, homing beacons, or other indicia to enable the UAV 105 to locate the elevated landing platform 115 . The beacons 1125 can enable the UAV 105 to locate the platform in adverse weather conditions, for example, or at night. In some examples, the beacons 1125 can comprise radio beacons to aid navigation in areas with high light pollution (e.g., in city centers), where landing lights may be difficult to distinguish from surrounding city lights. In still other examples, the beacons 1125 can comprise a glide slope, ILS, or other instrumentation to facilitate landing.
While several possible examples are disclosed above, examples of the present disclosure are not so limited. For instance, while a system of docking stations for UAVs to deliver packages is disclosed, other UAV tasks could be selected without departing from the spirit of the disclosure. In addition, the location and configuration used for various features of examples of the present disclosure such as, for example, the location of the package transfer system and lockers, the number and type of services provided by the docking station, and the locations and configurations of the docking station can be varied according to a particular neighborhood or application that requires a slight variation due to, for example, size or construction covenants, the type of UAV required, or weight or power constraints. Such changes are intended to be embraced within the scope of this disclosure.
The specific configurations, choice of materials, and the size and shape of various elements can be varied according to particular design specifications or constraints requiring a device, system, or method constructed according to the principles of this disclosure. Such changes are intended to be embraced within the scope of this disclosure. The presently disclosed examples, therefore, are considered in all respects to be illustrative and not restrictive. The scope of the disclosure is indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein. | Systems and methods for providing a series of multiuse UAV docking stations. The docking stations can be networked with a central control and a plurality of UAVs. The docking stations can include a number of services to facilitate both UAV guidance and maintenance and community acceptance and benefits. The docking stations can include package handling facilities and can act as a final destination or as a delivery hub. The docking stations can extend the range of UAVs by providing recharging/refueling stations for the UAVs. The docking stations can also include navigational aid to guide the UAVs to the docking stations and to provide routing information from the central control. The docking stations can be incorporated into existing structures such as cell towers, light and power poles, and buildings. The docking stations can also comprise standalone structures to provide additional services to underserved areas. | 0 |
BACKGROUND OF THE INVENTION
Related Patent Applications
Title “A Video Distribution System Using Segments with Disk Load Balancing,” Ser. No. 09/748,442, Filing Date Dec. 27, 2000, assigned to the same assignee as this invention.
Title “A Video Distribution System Using Dynamic Segmenting of Video Files,” Ser. No. 09/748,304, Filing Date Dec. 27, 2000, assigned to the same assignee as this invention.
Title “A Video Distribution System Using Dynamic Disk Load Balancing with Variable Segmenting,” Ser. No. 10/027,991, Filing Date Dec. 20, 2001, assigned to the same assignee as this invention.
“Streaming While Fetching of Video Objects,” Ser. No. 10/804,658, Filing Date Mar. 19, 2004, assigned to the same assignee as this invention.
Title “A Hardware Independent Hierarchical Cluster of Heterogeneous Media Servers,” Ser. No. 10/804,657, Filing Date Mar. 19, 2004, assigned to the same assignee as this invention.
Field of the Invention
This invention relates to the field of broadcasting quality video data over a packet switched network in such a way that the video is played in a smooth (not jerky) manner.
Description of Related Art
In the past video streaming servers required that a file be fully present before the sever could start streaming the file. This imposed a considerable restriction as typical DVD or broadcast quality videos may be several Gigabytes in size and thus imposed a large latency before a viewer could start viewing a video.
Video is the most dominant medium in entertainment and is rapidly becoming a critical part of computing as well. Video is often used in CD-ROM titles, for example, to mimic personal or virtual environments, increasing an application's appeal and usability. Video has a large information carrying capacity and is heavily used in capturing and conveying complicated situations such as news events, live interviews, scientific experiments, tourist attractions, and many others.
With the increasing availability of high bandwidth networks, video on-demand applications are gaining popularity on global digital communications networks such as the Internet as well as private and corporate digital communication internal networks commonly referred to as Intranets. Example applications include online training, news broadcasts, educational programming, corporate information, and virtual seminars directly to every desktop computing system or workstation. Similarly, video kiosks can be set up in enterprises and university campuses to display live video and up-to-the-minute news, without ever needing an on-site upgrade.
Video files, however, occupy huge amounts of space on computers. It requires about 10 MB to store one minute of video in most standard compression and decompression video formats, including Motion Picture Experts Group standard MPEG-1, the Apple Computer Inc. Indeo, Intel Corp. QuickTime, and Super Mac, Inc Cinepak. That translates into 1.2 GB of space for two hours of video, the length of an average feature film. These tremendous storage requirements make effective on-demand sharing of video files at least as important as conventional file sharing.
However, conventional file servers do not address video's unique requirements and cannot effectively support video sharing. Full-motion video, inherited from analog TV, is a sequence of images played out at constant intervals. The two most common analog video formats are the National Television Standards Committee (NTSC), used in the United States and Japan, and Phase Alternation Standard (PAL), used in Europe. NTSC plays video at 30 frames per second, while PAL plays it at 25 frames per second. The sequence of images in a video clip must be relayed at a constant interval, or else the perceptual quality degrades rapidly: the motion jumps and the sound breaks. This rigid periodic timing property is referred to as the isochronous requirement. Referring now to FIG. 1 , conventional file servers 10 are designed for minimal transfer latency. Files 15 are thus transferred to maintain the minimum latency and are transferred as quickly as possible. The files 15 will be interleaved with other digital communication traffic on the network and thus non-isochronously. Without explicit mechanisms to ensure isochronism, delivery rates are irregular, resulting in erratic playback quality at the client computing system 20 :
To avoid erratic playback, the usual approach is to download whole files 15 from the server 10 to the client computing system 20 before starting video playback. This approach results in unacceptable delays for most video files, which are large. For example, even with transfer rates as fast as 1.5 Mb/second, the initial start-up delay is 60 seconds for a one-minute video clip.
It is thus desirable to deliver video streams isochronously, as depicted in FIG. 2 , so that video playback is guaranteed to have smooth motion and sound. The file server 10 must now transfer or stream the files 25 such that the time between each section of the file is transferred at a period of time τ The even interval allows the file 25 to arrive isochronously with the first section to be displayed before any of the remaining sections of the file 25 have arrived at the client system 25 . This allows a video clip to begin practically instantaneously.
The rapid advances in the speeds of microprocessors, storage, and network hardware may give a false impression that video on-demand (VOD) solutions do not need special purpose video streaming software. Video streaming as shown in FIG. 2 allows efficient playback of full motion videos over networks with guaranteed quality using isochronous timing.
When an operating system's default file transfer mode is used to stream a video file, faster hardware may accelerate the operating system's transfer rate, but this improved hardware still cannot change the fundamental, erratic behavior of a file transfer as shown in FIG. 1 . By default, the file transfer process does not respect the isochronous nature of a video stream. This typically results in a jerky and poor-quality playback of a video stream. The dominant factors of a system's overall streaming performance are the higher level client/server and networking processes, and are not the raw power of the low level physical devices.
When an application at a Windows client accesses a file in a Windows NT server, the data are automatically cached by WFS at both Windows client and Windows NT server. This is a commonly used technique for reducing the amount of disk access when the cached data can be reused by subsequent requests. This technique does not work for most video-on-demand applications for two reasons. The first reason is that the cached data is hardly used again. VOD applications have very low “locality profile” because they tend to have high data rate and massive volume of videos for users' interactive playback. The second reason is that the constant video caching leads to intensive memory paging and, thus, severely limits performance.
U.S. Pat. No. 6,101,546 (Hunt) describes a method and system for providing data files that are partitioned by delivery time and data type. A file is logically partitioned into data channels where each data channel holds a sequence of data of a particular data type. The data channels are logically partitioned into delivery times. The format of the file explicitly sets forth the synchronization between the data channels and the delivery times of data held within the channels. The file format is especially well adapted for use in a distributed environment in which the file is to be transferred from a server to a client. Channel handlers are provided at the client to process respective data channels in the file. The channel handlers are data type specific in that they are constructed to process data of an associated data type. The data in the file may be rendered independently of the delivery time of the data.
U.S. Pat. No. 6,018,359 (Kermode, et al.) illustrates a system and method for multicast video-on-demand delivery system. The video-on-demand system divides video files into sequentially organized data segments for transmission and playback. Each segment is repeatedly transmitted in a looping fashion over a transmission channel. The rate of transmission is equal to or greater than the playback rate, and the lengths of the segments are chosen such that:
the receiver tunes into no more than a fixed number of channels (preferably two) at any one time; the receiver tunes into a new channel only after an entire segment has been received from a previous channel; and until a maximum segment length is attained, data is received from no fewer than two channels.
The segments are sequentially presented even as new segments are being downloaded. When the display rate is equal to the transmission rate, it is found that the foregoing conditions are satisfied when the relative lengths of the segments form a modified Fibonacci sequence.
U.S. Pat. No. 5,930,473 (Teng, et al.) discloses a video application server for mediating live video services. The video application server is to be used in a network including source clients and viewer clients connected to one or more shared transmission media. A video server is connected to one of the transmission media and is operative to control the broadcast and storage of multiple live or previously stored video streams. The control may be provided via remote procedure call (RPC) commands transmitted between the server and the clients. In one embodiment, a video presentation system is provided in which a video stream from a source client is continuously broadcast to a number of viewer clients. One or more of the viewer clients may be authorized by the source client to broadcast an audio and/or video stream to the other clients receiving the source video stream. In another embodiment, a multicast directory is provided to each of a plurality of viewer clients by transmitting directory information in a packet corresponding to a predetermined multicast address. The multicast directory indicates to a particular viewer client, which of a number of video programs are available for broadcast to that client.
U.S. Pat. No. 6,101,547 (Mukherjee, et al.) describes an inexpensive, scalable and open-architecture media server. The multi-media server provides client systems with streaming data requiring soft real-time guarantee and static data requiring a large amount of storage space. The servers use a pull-mode protocol to communicate with client systems through a real-time network. Separate data and control channels enhance the soft real-time capability of the server. The data channel conforms to an open standard protocol such as such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), or Real-time Transport Protocol (RTP). A switched data link layer for the control channel permits separate intrahost control messages that may be multicast and broadcast. The distributed file system selects a specific data block size based upon the compression technique employed to enhance soft real-time guarantee. A hierarchical data structure combined with merging empty data blocks minimizes disk fragmentation. Data blocks are striped across multiple disks to improve disk utilization. A local buffer and a queue for both read and write requests provides support for simultaneous read and write data streams.
U.S. Pat. No. 5,805,821 (Saxena, et al.) teaches a video optimized media streamer user interface employing non-blocking switching to achieve isochronous data transfers. The media streamer includes at least one control node; a user interface having an output coupled to the at least one control node; at least one storage node for storing a digital representation of at least one video presentation; and a plurality of communication nodes each having an input port for receiving a digital representation of at least one video presentation therefrom. The video presentation requires a time T to present in its entirety, and is stored as a plurality of N data blocks. Each data block stores data corresponding to a T/N period of the video presentation. Each communication nodes further has a plurality of output ports for outputting a digital representation. A circuit switch is connected between the at least one storage node and the input ports of communication nodes for coupling one or more input ports to the at least one storage node. The user interface includes a capability for specifying commands for execution, and the at least one control node is responsive to individual ones of the commands for controlling at least one of the at least one storage node and at least one of the plurality of communication nodes, in cooperation with the circuit switch, so as to execute a function associated with individual ones of the commands. The commands may include videocassette recorder-like commands that include commands selected from a group that includes a Load command, an Eject command, a Play command, a Slow command, a Fast Forward command, a Pause command, a Stop command, a Rewind command, and a Mute command. The commands may also include commands selected from a group that includes a Play List command, a Play Length command, and a Batch command. A synchronous application program interface (API) is provided for coupling, via the user interface, a user application program to the at least one control node. The API includes Remote Procedure Call (RPC) procedures.
U.S. Pat. No. 5,550,577 (Verbiest, et al.) illustrates a video on demand network, including a central video server and distributed video servers with random access read/write memories. The video on demand network transmits video signals to user stations pursuant to the receipt of control signals issued by these user stations. In order to optimize the retrieval costs, this video on demand network maintains a large video library in a central video server and stores locally popular video signals in a plurality of local distributed video servers from which the latter video signals are transmitted to the user stations. The video signals provided by the local distributed servers are updated from the central server based upon the changing popularity of the video signals. The video on demand network of Verbiest proposes in particular to store the video signals in the local distributed servers in random access read/write memories, e.g., electronic RAMs, magnetic or optical disks from which the video signals can flexibly be supplied on-line to the user stations and to store the video signals in the central server in sequential access memories, e.g. Digital Audio Tapes (DAT) and CD-ROMs (CDR), providing cheap mass storage.
“Performance Evaluation of QuickVideo OnDemand (QVOD) Server,” InfoValue Computing, Inc. Technical Report IV-TR-QVOD-1999-07-1-1, Jul. 8, 1999, InfoValue Computing, Inc., Elmsford, N.Y. describes a video on-demand system developed for high performance, effective and flexible, network-based, on-demand sharing of videos. QuickVideo on Demand provides streaming throughput for broadband applications. Further, QuickVideo On Demand allows a linearly scalable clustering mechanism, which provides support for higher throughputs, if required. QuickVideo On Demand supports all video formats, codecs, networks and applications, and is compatible with any open application platform.
“Network Video Computing Via QuickVideo Suite,” InfoValue Technical White Paper, InfoValue Computing, Inc., Elmsford, N.Y., 1999, describes Network Video Computing the core of which is video streaming. Video streaming allows the efficient playing of full-motion video content over networks with guaranteed quality. The rigid timing property of full motion video is referred to as the isochronous timing. File servers are designed to minimize transfer latency during conventional network transfers, and are insensitive to video's unique timing requirement. As a result, delivery rates are irregular and produce erratic playback as described above. Video streaming technologies are real-time network transfers that maintain the video's critical timing property throughout the entire delivery period, as depicted in FIG. 2 . This white paper describes an open architecture with a streaming core.
“Web Distribution Systems: Caching and Replication” Chandbok, Ohio State University, 1999, found http://www.cis.ohio-state.edu/˜jain/cis788-99/web 13 caching/index.html, Aug. 15, 2000, provides an overview of the current techniques for caching and replication of digital data on computer systems interconnected through a global or local digital communication network. Refer now to FIG. 3 for a summary of caching in large distributed digital processing networks. Multiple server computing systems 100 a, 100 b, . . . , 100 f are high performance computing systems such as the IBM Corporation RS-6000-SP, The Sun Microsystems, Inc. Enterprise 10000 Server, the Hewlett-Packard Netserver AA-6200, or other server systems. The computer systems 100 a, 100 b, . . . , 100 f are each connected to multiple storage devices 105 a, 105 b, . . . , 105 r. The storage devices 105 a, 105 b, . . . , 105 r are magnetic disk devices, compact disk read only memory (CD-ROM) “juke boxes,” or tapes drives. A group of the server systems 100 a, 100 b, 100 c or 100 d, 100 e, 100 f are respectively interconnected through the digital communications cluster network 110 and 115 to form the server cluster 1 120 and the server cluster 2 125 . The server cluster 1 120 and the server cluster 2 125 may be resident with in the same enterprise data center or placed at different geographical locations either within the enterprises or even in different enterprises.
The cluster networks 110 and 115 are connected respectively to the network routers 130 and 135 . The network routers 130 and 135 are further connected to a public or global digital communications network 155 . The global network 155 may be the public Internet or an enterprise's private Intranet.
The server computer systems 100 a, 100 b, . . . , 100 f contain database information systems, storage for files such as audio or video files, and other data files to be accessed by large numbers of people either publicly or privately within an enterprise through the client systems 150 a, 150 b, 150 c.
Edge servers 140 a, 140 b, 140 c are connected to the global network 155 and thus provide access portals for the client systems 150 a, 150 b, 150 c to the global network 155 to communicate with each other, with other edge servers 140 a, 140 b, 140 c, or with the server computer systems 100 a, 100 b, . . . , 100 f. Each edge servers 140 a, 140 b, 140 c is connected has attached data storage device 145 a, 145 b, . . . , 145 i. The attached data storage device 145 a, 145 b, . . . , 145 i is generally a magnetic disk storage device, but may also include a CD-ROM, magnetic tape, or other storage media.
If a server computer systems 100 a, 100 b, . . . , 100 f has data 160 that is requested by many of the client systems 150 a, 150 b, 150 c, the network traffic to the server computer system 100 a may to great for either the global network 155 or the cluster network 110 to carry and maintain a reasonable quality of service. Quality of service in this context means that the original data 160 is transferred repetitively relatively quickly and if the original data 160 is audio or video files, that the isochronous nature of the transfer of the data is maintained.
If the server clusters 120 and 125 are separated geographically, it may cost less to maintain the quality of service by placing a copy 165 of the original data 160 in a disk 105 I on a second server system 100 d. If the copy 165 of the original data 160 is permanent, it is referred to as being replicated. If the copy 165 of the original data 160 is temporary it is referred to as cached. As the demand for the original data 160 is increased, it may be desirable to either replicate or cache 170 or 175 the data even within the disks 145 b or 145 i of the edge servers 150 a or 150 c.
There are many policies developed regarding which of the original data 160 is replicated or cached 165 , 170 , or 175 . Further, the replacement of cached data 165 , 170 , or 175 by other data that is demanded more often is known and generally follows a least recently used protocol, where the cached data 165 , 170 , or 175 that has not been requested is replaced by data that is more requested.
U.S. Pat. No. 6,088,721 (Lin, et al.) teaches an efficient unified replication and caching protocol. The protocol provides assurance of consistent replication of objects from a central server to caching servers, for example, over data communication networks such as the Internet. It is an application-layer protocol, which guarantees delivery of objects such as files. This protocol insures that objects sent by a source machine such as a server to any number of destination machines such as caching servers actually arrive at the intended caching servers even when the caching servers are temporarily unavailable, for example, due to failure or network partition.
U.S. Pat. No. 6,061,504 (Tzelnic, et al.) illustrates a video file server using an integrated cached disk array and stream server computers. The video file server includes an integrated cached disk array storage subsystem and a multiple stream server computers linking the cached disk storage system to the data network for the transfer of video data streams. The video file server further includes a controller server for applying an admission control policy to client requests and assigning stream servers to service the client requests. The stream servers include a real-time scheduler for scheduling isochronous tasks, and supports at least one industry standard network file access protocol such as Simple Network Management Protocol (SNMP) and one file access protocol Network File System (NFS) for continuous media file access. The cached disk storage subsystem is responsive to video prefetch commands, and the data specified for a prefetch command for a process are retained in an allocated portion of the cache memory from the time that the cached disk storage subsystem has responded to the prefetch command to the time that the cached disk storage subsystem responds to a fetch command specifying the data for the process. The time between prefetching and fetching is selected based on available disk and cache resources. The video file server provides video-on-demand service by maintaining and dynamically allocating sliding windows of video data in the random access memories of the stream server computers.
“Network Caching Guide,” Goulde, Patricia Seybold Group for Inktomi Corp., Boston, Mass., March 1999, describes the various types of caching approaches and the different ways for caches to be implemented. Implementations vary depending on where the cache is placed, who is accessing the cache, and the quantity and type of content that is being cached. Goulde describes the Inktomi Traffic Server from Inktomi Corporation. The Inktomi Traffic Server is capable of delivering fresh content to large numbers of users around the world from a large number of Web servers around the world.
“Inktomi Traffic Server—Media Cache Option”, Inktomi Corporation, San Mateo Calif., 1999, found http://www.inktomi.com, Aug. 15, 2000, describes the caching option for the Inktomi Traffic Server to support streaming of video data files.
“Implementing Multiplexing, Streaming, and Server Interaction for MPEG-4” Kalva et al., IEEE Transactions On Circuits And Systems For Video Technology, Vol. 9, No. 8, December 1999, pp. 1299–1312, describes the implementation of a streaming client-server system for object-based audio-visual presentations in general and MPEG-4 content in particular. The system augments the MPEG-4 demonstration software implementation (IM1) for PC's by adding network-based operation with full support for the Delivery Multimedia Integration Framework (DMIF) specification, a streaming PC-based server with DMIF support, and multiplexing software. The MPEG-4 server is designed for delivering object-based audio-visual presentations. The system also implements an architecture for client-server interaction in object-based audio-visual presentations, using the mechanism of command routes and command descriptors.
“New Solution for Transparent Web Caching: Traffic Server 2.1 Supports WCCP,” Inktomi Corporation, San Mateo Calif., 2000, found http://www.inktomi.com/products/network/traffic/tech/wccp, Aug. 15, 2000 describes the use of the Web Cache Control Protocol (WCCP) from Cisco Systems, Inc. within Inktomi Corporation's Traffic Server.
“API Overview,” Inktomi Corporation, San Mateo Calif., 2000, found http://www.inktomi.com/products/network/traffic/tech/wccp, Aug. 15, 2000, describes the application program interface tools that are available for the Inktomi Corporation's Traffic Server which allow customization or the Traffic Server's event processing thus allowing manipulation of hypertext transaction protocol (HTTP) transactions at any point in their lifetime.
“Web Cache Communication Protocol v2,” Cisco Systems, Inc., San Jose, Calif., found http://www/cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t3/wccp.htm, Aug. 15, 2000, describes the protocol that allows the use a Cisco Cache Engine to handle web traffic, reducing transmission costs and downloading time. This traffic includes user requests to view pages and graphics on World Wide Web servers, whether internal or external to a network, and the replies to those requests. When a user requests a page from a web server (located in the Internet), the router sends the request to a cache engine. If the cache engine has a copy of the requested page in storage, the cache engine sends the user that page. Otherwise, the cache engine retrieves the requested page and the objects on that page from the web server, stores a copy of the page and its objects, and forwards the page and objects to the user. WCCP transparently redirects Hypertext Transfer Protocol (HTTP) requests from the intended server to a cache engine.
“A Practical Methodology For Guaranteeing Quality Of Service For Video-On-Demand,” Zamora et al., IEEE Transactions On Circuits And Systems For Video Technology, Vol. 10, No. 1, February 2000, describes an approach for defining end-to-end quality of service (QoS) in video-on-demand (VoD) services. A schedulable region for a video server, which guarantees end-to-end QoS, where a specific QoS required in the video client, translates into a QoS specification for the video server. The methodology is based on a generic model for VoD services, which is extendible to any VoD system. In this kind of system, both the network and the video server are potential sources of QoS degradation. The effects that impairments in the video server and video client have on the video quality perceived by the end user are examined.
As described above, video files may be very large, on the order of 1.2 GB for a two-hour movie or video presentation. In the digital communication networks 110 , 115 , and 155 of FIG. 3 , the files are generally formed into data packets for transfer. These data packets may not arrive to a designated client system 150 a, 150 b, 150 c in correct order for processing. This requires reception of the complete file before processing may begin. If the file is an audio or video file requiring isochronous presentation of the file, the files must be totally received before processing or the files must be segmented or partitioned into portions to allow smaller units of the files to be processed.
U.S. Pat. No. 5,926,649 (Ma, et al.) teaches a Media server for storage and retrieval of voluminous multimedia data. The Media server provides storage and retrieval of multiple data streams in a multimedia distribution system. A given data stream is separated into a plurality of portions, and the portions are stored in a multi-disk storage system with Y disks each having X zones such that the ith portion of the given stream is stored in zone (i mod X) of disk (i mod Y). The number X of zones per disk and the number Y of disks are selected as relatively prime numbers. The stored data are retrieved using Y independent retrieval schedulers, which are circulated among the Y disks over a number of scheduling intervals. Each retrieval scheduler processes multiple requests separated into X groups, with the requests of each group accessing the same disk zone during a given scheduling interval. The retrieval schedulers are also configured such that the retrieval requests of a given retrieval scheduler access the same disk during a given scheduling interval. The data stream placement techniques in conjunction with the retrieval schedulers provide sequential-like parallel retrieval suitable for supporting real-time multimedia data distribution for large numbers of clients.
U.S. Pat. No. 5,936,659 (Viswanathan, et al.) illustrates a method for broadcasting movies within channels of a wide band network by breaking the communications path into a number of logical channels and breaking each movie up into a number of segments of increasing size. The first segment of each movie is the smallest segment is transmitted in sequence over the first logical channel and repeated. The second segment of each movie, which is proportionately larger than the first segment of each movie, is transmitted in sequence over the second logical channel and repeated. This is repeated for the total number of segments, which equals the total number of logical channels. The segments are broadcast in such a way that, once the first segment is received at a client location, the subsequent segments are also received in time, so that the movie can be viewed continuously.
U.S. Pat. No. 5,973,679 (Abbott, et al.) describes an indexing method for allowing a viewer to control the mode of delivery of program material. By mapping from time to data position, data delivery can begin at any selected time in the program material. The indexing method also provides for controlling data delivery to begin at the beginning of a frame of data. A synchronizing method is provided to minimize a time offset between audio and video data, particularly in environments using groups of pictures.
U.S. Pat. No. 5,996,015 (Day, et al.) describes a method of delivering seamless and continuous presentation of multimedia data files to a target device by assembling and concatenating multimedia segments in memory. The method provides a multimedia server connected in a network configuration with client computer systems. The multimedia server further includes various functional units which are selectively operable for delivering and effecting the presentation of multimedia files to the client such that a plurality of multimedia files are seamlessly concatenated on the fly to enable a continuous and uninterrupted presentation to the client. In one example, client selected video files are seamlessly joined together at the server just prior to file delivery from the server. The methodology includes the analog to digital encoding of multimedia segments followed by a commonization processing to ensure that all of the multimedia segments have common operating characteristics. A seamless sequential playlist or dynamically created playlist is assembled from the selected and commonized segments and the resources needed to deliver and play the playlist are reserved in advance to assure resource availability for continuous transmission and execution of the playlist. At a predetermined point prior to an end point of each selected multimedia segment, the next selected segment is initialized and aligned in memory in preparation for a seamless switch to the next segment at the end of a previous segment, thereby providing a seamless flow of data and a continuous presentation of a plurality of selected multimedia files to a client system.
U.S. Pat. No. 5,608,448 (Smoral, et al.) describes a hybrid architecture for a video on demand server. The processing requirement at each computing element in a video server for a video on demand (VOD) system is reduced to only those needed for VOD, resulting in a less expensive processor with less memory and, hence, lower cost. A hybrid video server architecture combines the features of massive parallel processor (MPP) and workstation designs. Since it is not necessary to run a parallel relational database program in order to accomplish VOD data distribution, a unique type of switch element that is well matched to the VOD server problem is employed. By matching this switch element technology to an appropriate data storage technique, a full featured, responsive VOD server is realized.
U.S. Pat. No. 6,061,732 (Korst, et al.) describes a data streaming system utilizing an asynchronous technique for retrieving data from a stream server. In an audio/video server blocks of data are read from a storage medium by a reader and supplied to users in the form of data streams. The storage medium comprises a plurality of record-carrier based storage units. A reader reads a batch of data units from a storage unit in a single relative movement of a reading head of the storage unit with respect to the record-carrier of the storage unit. A scheduler controls reading of blocks from the storage medium by determining from which storage unit(s) data unit(s) need to be read for the block and placing a corresponding carrier access request in a read queue. The scheduler extracts for each of the storage units a batch of carrier access requests from the queue and issues the batch to the reader in an asynchronous manner, in response to the reader having substantially completed reading data units for a previous batch for the storage unit.
U.S. Pat. No. 5,414,455 (Hooper, et al.) teaches a segmented video on demand system. In the system for distributing videos, multiple videos are stored on a mass storage device. Each video includes a plurality of frames of digitized video data for playback on a viewing device. The system includes a memory buffer for storing a segment of a selected one of the videos. The segment includes a predetermined number of frames representing a predetermined time interval of the selected video. In addition, the memory buffer includes a write pointer and a read pointer. Software controlled servers are provided for writing and reading video data of the selected video to and from the memory buffer, independently, at locations indicated by the write and read pointers to transfer the selected video to the viewing device.
When any of the multiple client systems 150 a, 150 b, and 150 c requests access to the original data 160 present, each request if fulfilled and the original data is routed through the server computing system 100 a, the cluster network 110 , the router 130 , to the global digital communications network 155 , to the edge servers 140 a, 140 b, 140 c to the requesting client systems 150 a, 150 b, and 150 c. Each transfer of the original data 160 consumes a portion of the available transfer rate (Bytes/sec) or bandwidth of the connections from the storage device 105 a to the server computing system 100 a, from the server computing system 100 a to the cluster network 110 , from the cluster network 110 to the router 130 , from the router 130 to the global digital communication network 155 , from the global communications network 155 to the edge servers 140 a, 140 b, 140 c, from the edge servers 140 a, 140 b, 140 c to the requesting client systems 150 a, 150 b, and 150 c. The smallest bandwidth of this chain is generally the determining factor of the loading. In this case the loading determinant will be from the storage device 105 a to the server computing system 100 a. If there are no copies of the original data 160 , as the number of requests for the original data increases, the available bandwidth decrease or loading on the storage device 105 a increases. The loading of the data transfer 160 to and from the data storage device 105 a must be in balance or the requests for the transfer may not be honored. In the case of video-on-demand, this causes interruptions or at least degradation of the quality of service in viewing the demanded video.
“DASD Dancing: A Disk Load Balancing Optimization Scheme for Video-on-Demand Computer,” Wolf, et al., ACM SIGMETRICS 1995, pp. 157–166 proposes a scheme to dynamically perform load-balancing of DASDs: (direct access storage devices), which is referred to as a DASD dancing algorithm. The algorithm consists of two components. The static component assigns movie files to DSGs (disk-striping groups) initially, and it also reassigns movies periodically, for example every day or every week. The dynamic component performs the real-time movie stream scheduling. (A disk-striping group, or DSG, is a group of disks, which contains a number of movies).
“Load Balancing For a Video-On-Demand Server,” DO, Information and Computer Science Dept, University of California, Irvine, 1998, found Oct. 1, 2000, http://www.ics.uci.edu/˜tdo/loadVOD/loadVOD.html, is an overview of the state of the art of load balancing for video-on-demand server systems, the problems that are involved with the server systems, and solutions for those problems.
“Random Duplicated Assignment: An Alternative to Striping in Video Servers,” Korst, Electronic Proceedings ACM Multimedia 97, November 1997, found http://info.acm.org/sigmm/MM97/Papers/korst/RDA.html, Oct. 2, 2000, describes an approach for storing video data in large disk arrays. Video data is stored by assigning a number of copies of each data block to different, randomly chosen disks, where the number of copies may depend on the popularity of the corresponding video data. The use of the approach results in smaller response times and lower disk and RAM costs if many continuous variable-rate data streams have to be sustained simultaneously.
U.S. Pat. No. 5,544,313 (Shachnai, et al.) describes a baton passing optimization scheme for load balancing/configuration planning in a video-on-demand computer system. A video on demand computer system includes multiple storage devises each storing many video data files. The storage devices in this case are disks attached to a computer system. The computer system plays the videos on demand by reading out the videos from the disks as data streams to play selected video data files in response to user requests. The computer system is programmed to monitor the numbers of video data files being performed for each of the disks. Based on the monitoring function performed by the computer system, the computer system performs a load balancing function by transferring the current transfer of a video data file in progress from the disk having the original video data file being transferred to another disk having a copy of the video data file. The computer system periodically performs a reassignment function to transfer videos between the disks to optimize load balancing based on the user performance requests for each of the video data files. There are two phases to the load balancing performed by the computer system; a static phase and a dynamic phase. In the static phase, video data files are assigned to memory and disks, and in the dynamic phase there is provided a scheme for playing video data files with minimal and balanced loads on the disks. The static phase supports the dynamic phase, which insures optimal real-time operation of the system. A process of “baton passing” accomplishes dynamic phase load balancing.
“U.S. Pat. No. 5,333,315 (Saether, et al.) describe a computer system of device independent file directories using a tag between the directories and file descriptors that migrate with the files. The computer file system has a multiple disk storage devices which includes a multiple of file directories, stored on various disks. Each file directory is used to translate file names into corresponding tag values. For each disk there is a file descriptor table with a file descriptor entry for every file stored on the disk. A single tag directory contains one tag entry for every file stored in the system. The tag directory is used by the file system to find a file by translating a tag value into a pointer to the disk on which the file is stored and a pointer to the file's file descriptor entry. To move a file from a first disk to a second disk, the file is copied to the second disk, a new file descriptor entry for the copied file is generated in the file descriptor table for the second disk, the copy of the file on the first disk is de-allocated, and the tag entry for the file is updated to point to the second disk and to the file's new file descriptor entry. Thus, a file can be moved from a first disk to a second without having to locate and update all the corresponding file directory entries. In a preferred embodiment, the file system includes a routine that monitors disk loading and unused disk capacity. It determines when disk usage is imbalanced and automatically moves files among the disks so as to better balance disk usage.
U.S. Pat. No. 5,631,694 (Aggarwal, et al.) describes a maximum factor selection policy for batching VOD requests. A VOD scheduler maintains a queue of pending performance for each video. Using the notion of queue selection factor, a batching policy is devised that schedules the video with the highest selection factor. Selection factors are obtained by applying discriminatory weighting factors to the adjusted queue lengths associated with each video where the weight decreases as the popularity of the respective video increases and the queue length is adjusted to take defection into account.
SUMMARY OF THE INVENTION
An object of this invention is to provide a method and apparatus to dynamically balance the loading of data storage facilities containing video data files.
Further, another object of this invention is to provide a method and apparatus to balance the loading of data storage facilities containing video data files to facilitate the transfer of the video data files or portions of video data files from a file server system to client computing system.
To accomplish these and other objects a method for balancing a loading of a storage device attached to multiple computing systems begins by acquiring a listing of locations of all segments of a requested data object including all copies of the segments of the requested data object. The loading of the storage devices attached to the multiple computing systems containing all copies of all segments of a requested data object is evaluated and those storage devices containing copies of each segment of the data object having a least loading, which is less than a maximum loading for the storage devices, is selected. If the loading of the storage devices is greater than the maximum loading for the storage devices, segment resident on the storage device having loading greater than the maximum loading is designated to be copied to an alternate storage device.
The presence of all segments of the requested data object is determined. If there are missing segments of the requested data object, each of those missing segments is assigned a file identification and file location, such that those missing segments are assigned to data storage devices having the least loading. The missing segments are retrieved from a back-up storage device.
An alternate storage device is selected and the segment is copied to the alternate storage device. The segments of the requested data object are then transferred to a requesting computer system.
To select the storage devices containing copies of the segments of the requested data object and having the least loading, a current segment indicator is first set to indicate which of the segments of the data object is to be transferred next. Then a current storage device indicator is set to specify a primary location of the segment to be transferred next. If the transfer of the segment causes the loading of the storage device containing the segment to be exceeded, the current storage device indicator is incremented to a next location of the segment to be transferred. If the loading for each storage device containing a copy of the segment of the data exceeds the maximum loading, the next copy is examined until one of the storage devices does not have excess loading. If all copies of the segment exceed the loading, a copy of the segment is made to a storage device having light loading.
The transfer of the segments of the data object is defined as reading the segments from the data storage device, writing the segments to the data storage device, and copying the segments from a the data storage device to an alternate data storage device. The loading of the data storage device is allocated between the reading, writing, and copying of the segments to prevent interference with the reading of the segments.
The data objects as described for this invention are video data files to be streamed isochronously to the requesting computer system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of the transfer of files on a digital communications network of the prior art requiring minimal latency.
FIG. 2 is a diagram of the transfer of files on digital communications network of the prior art illustrating isochronous file transfer.
FIG. 3 is a diagram of a distributed computer network system illustrating replication of files in caches of the prior art.
FIG. 4 is a diagram of a distributed computer network system illustrating load balancing of data storage devices of this invention.
FIGS. 5 , 6 , and 7 are flow diagrams illustrating the method of load balancing of data storage devices of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Refer now to FIG. 4 for a description of a video distribution system of this invention. The client computing systems 400 a, 400 b, 400 c are connected through a communications link to an edge server 405 a, 405 b, and 405 c. Each edge server 405 a, 405 b, 405 c acts as an interface for the client computing systems 400 a, 400 b, 400 c to a global communications network 415 . The edge servers 405 a, 405 b, 405 c are at the boundary between the “front-end” and the “backend” of the video distribution system. The front-end being the client computing systems 400 a, 400 b, 400 c that are the terminal points whereby the users can access the video distribution system. Further the edge servers 405 a, 405 b, 405 c are generally Internet service providers to which the client computing systems 400 a, 400 b, 400 c are in communication.
The backend of the video distribution system has server systems 420 a, . . . , 420 f that are grouped together to form server clusters 410 a, . . . , 410 b. The server systems 420 a, 420 b, and 420 c are interconnected together through the cluster network 455 . The server systems 420 d, 420 e, and 420 f are interconnected together through the cluster network 460 . The router 425 provides an interface for the server cluster 1 410 a to the global communication network 415 . Likewise, the router 430 provides an interface for the server cluster n 410 b to the global communication network 415 .
The gateway server 475 is connected through the global communication network 415 to the edge servers 405 a, 405 b, 405 c and thus to the client computing systems 400 a, 400 b, 400 c. The gateway server 475 is the central point of contact for incoming requests to the system from the client computing systems 400 a, 400 b, and 400 c. When a client computing systems 400 a, 400 b, 400 c requests a video data file (on demand) or join a broadcast (multicast) of a video data file, it first contacts the gateway server 475 . The gateway server 475 maintains an updated list of the server systems 420 a, . . . , 420 f in the system. Based on the location of the client computing systems 400 a, 400 b, 400 c and the type of request, it routes the request to the appropriate server systems 420 a, . . . , 420 f.
A large-scale system containing thousands of video data files must offer an efficient and easy to use content management service to the client computing systems 400 a, 400 b, 400 c. Such a content management service includes capabilities to add/delete, categorize, and browse video data files and is provided by the title server 450 . In presence of a dedicated title server 450 , the gateway server 475 redirects the client computing systems 400 a, 400 b, 400 c requests to the title server 450 . In the absence of such a dedicated title server 450 , the gateway server 475 can be configured to provide content management services to client computing systems 400 a, 400 b, and 400 c. Client computing systems 400 a, 400 b, 400 c, then, browse video data file in the gateway server.
In a geographically distributed broadband video distribution system of this invention, there will be multiple title servers 450 , each for a service region. The gateway server 475 will route the client computing systems 400 a, 400 b, 400 c requests to appropriate title servers 450 based on the location of the client computing systems 400 a, 400 b, 400 c.
A distribution server 470 is used to introduce new contents in the video distribution system of this invention. Once a new video data file is available, a media distributor uses this service to propagate the title to different service regions of a geographically distributed system. The distribution server 470 consists of four distinct components. A Distribution Center, which is a remote service, is used by media distributors to push new video data files to regional server systems 420 a, . . . , 420 f. A Distributor Console, a web based remote graphical user interface (GUI), is used to specify locations and contents to be pushed to remote server systems 420 a, . . . , 420 f. A set of Asset Managers, which are local to regional server systems 420 a, . . . , 420 f, is responsible for managing and tracking contents in the regional server systems 420 a, . . . , 420 f. A set of asset databases, one database per regional server system 420 a, . . . , 420 f, which stores the meta data for the available contents (video data files) in that regional server systems 420 a, . . . , 420 f. Asset managers use this database to keep track of local video data files. Multiple asset managers can share one asset database. The title server 450 also uses this database to generate a categorized, browsable list of video data files.
A media distributor uses the distributor console to schedule distribution of new media data objects (video data files) to the a video distribution system of this invention. The new video data files generally reside in a tertiary storage 445 such as a robotic DVD. The media distributor specifies when to push the title, the list of target regional sites, and the textual meta data related to the video. Among other things, the meta data of a title will possibly contain information required to categorize it as well as a set of searchable strings, which can be used to search the content of the video data files. The distributor console connects with the remote distribution center 470 and delivers the schedule. The distributor console contacts the asset managers in the specified target server systems 420 a, . . . , 420 f, and schedules the delivery of the new content. Once a server system 420 a, . . . , 420 f, receives the new video data file, it first stores the content in any available space in a local disk 480 a, . . . , 480 r. Then, it updates the asset database with the information on the new video data file (including the received meta data on the video data file). If it does not have any available space, it replaces an old video data file using a programmed policy.
Based on the client computing systems 400 a, 400 b, 400 c request (browsing by category, or searching using a string), the title server 450 queries the asset database, and creates a list of video data files for the client computing systems 400 a, 400 b, 400 c to browse. The title server 450 uses aggressive caching techniques to improve the performance of the query. When new information is added in the asset database, the cache in the title server 450 is invalidated.
It is sometimes possible for a title server 450 to have information on a video data file, which is not wholly available in the local storage 480 a, . . . , 480 r, for various reasons. Portions of the video data file may have been replaced because the asset manager needed space for a new video data file, or only a portion of a video data file was propagated from the distribution center. Once a client computing systems 400 a, 400 b, 400 c requests such a video data file, server system 420 a, . . . , 420 f, is fetches the video data file to the local storage 480 a, . . . , 480 r. The server system 420 a, . . . , 420 f allocates free space in the local storage 480 a, . . . , 480 r possibly by replacing a portion of a resident video data file. The server system 420 a, . . . , 420 f contacts the distribution server 470 providing the name of the video data file and the remaining portion of the video data file. Once the distribution server 470 is ready, the server system 420 a, . . . , 420 f fetches the remaining portion of the video data file, stores it in the allocated free space, and updates the asset database.
When a user of a client computing systems 400 a, 400 b, 400 c selects a video data file to be viewed, the client computing systems 400 a, 400 b, 400 c contacts the admission server 435 , which based on the bandwidth requirements and the file location of the video data file, assigns a video server system 420 a, . . . , 420 f from the server clusters 410 a, 410 b.
The admission server 435 provides a set of mechanisms, which are used to implement different policies for load balancing. The admission server 435 maintains a cluster topology, a disk usage table, a node usage table, and a cluster map. The cluster topology maintains the connection information of the cluster. It itemizes a list of server systems 420 a, . . . , 420 f of a server cluster 410 a, 410 b, which can access any of the disks 480 a, . . . , 480 r. The cluster topology contains the server system 420 a, . . . , 420 f identification that is the mount point where a disk 480 a, 480 r is mounted, and the access status of the disk 480 a, . . . , 480 r.
The disk usage table maintains the capacity (maximum data rate in Mbps) and the current load (data rate in Mbps) for each disk 480 a, . . . , 480 r in the server cluster 410 a, 410 b. The node usage table maintains the streaming capacity (maximum data rate in Mbps) and the current load for each node in the server cluster 410 a, 410 b. The cluster map maintains an up to date list of network address (internet protocol address), port and the status of the important server system 420 a, . . . , 420 f in the distribution system, and it maintains a list of server systems 420 a, . . . , 420 f in the cluster 410 a, 410 b, their network addresses and their status. A server system 420 a, . . . , 420 f can be in one of two states: Live (L) and Failed (D). Additionally, the admission server 435 maintains a supporting data structure, required to provide fault tolerance and authenticated access to the server cluster 410 a, 410 b. The data structure maintains a table containing the list of active sessions per server system 420 a, . . . , 420 f, and a similar table for active sessions per disk 480 a, . . . , 480 r.
The configuration server 485 allows an administrator to define and to configure server clusters 410 a, 410 b and the distributed server installations. It maintains an up to date information of the distributed installation using a periodic monitoring mechanism and asynchronous update events from the servers 420 a, . . . , 420 f in the system.
As described, the video data files may be several gigabytes in size. In order to facilitate the transfer of the video data files to client computing systems 400 a, 400 b, 400 c for viewing by a user, it is desirable to fragment the video data file into smaller segments. Each segment is assigned a file name and a location within any of the disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x. When a client computing system 400 a, 400 b, 400 c requests a video data file, the admission server 435 retrieves the listing of the segments of the requested data file from the disk usage table. It should be noted, that the requested video data file may in fact be any portion of a larger video data file not just the whole video data file. It should further be noted that the portion of the video data file requested may not encompass whole segments by may also contain fractional segments.
Refer now to FIGS. 5 , 6 , and 7 for a description of the method for balancing of the loading on storage devices of this invention. The video data files or segments of the video data files are copied and distributed to other disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x according to the activity of the disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x and the request patterns for the video data file by the client computing system 400 a, 400 b, 400 c. The client 400 a, 400 b, and 400 c requests (Box 500 ) a video data file (or portion of a video data file) according to an identification (file name) of the requested video data file and a range or indication of the beginning location and size of the requested video data file. The admission server 435 retrieves (Box 510 ) a disk usage table describing the segments contained within the range of the requested video data file. Further, the admission server 435 retrieves (Box 520 ) locations on the disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x of the segments of the video data file. The contents of the disk usage table are interrogated (Box 530 ) to verify the presence of all the requested segments or the total video data file.
If the results of the interrogation (Box 530 ) of the disk indicates the video data file or a segment of the video data file are not present on the disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x, the admission server 435 requests (Box 532 ) the missing video data file or segments of the video data file from the backing store 445 through the distribution server 470 . The admission server 435 assigns (Box 534 ) a disk 480 a, . . . , 480 r, and 495 a, . . . , 495 x that is to receive the video data file or the segments of the video data file based on the available space and disk activity. If the video data file is segmented, the admission server 435 assigns (Box) 536 ) segment file names to the individual segments of the video data file. The video data files are fetched (Box 538 ) from the tertiary or backing store 445 and placed in the assigned locations.
The admission server 435 then requests (Box 510 and Box 520 ) an updated list of the segments of the requested range of the video data file. Once the interrogation (Box 530 ) by the admission server 435 verifies the presence of the complete video data file, a current segment counter in the admission server 435 is set (Box 540 ) to request the first segment of the requested range of the video data file. The current disk pointer in the admission server 435 is assigned (Box 550 ) the location of the first segment of the requested range.
Since the request of the video data is being scheduled at this point, only a portion of the loading P or over all bandwidth for the requested video data file is allocated to the loading (bandwidth) factor L CD of the disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x. There is, for purposes of this embodiment, an equal probability that any of the video data files or segments of the video data files will be transferred at a given time to the requesting edge server 405 a, 405 b, and 405 c and streamed to the client 400 a, 400 b, and 400 c. Therefore, a new loading factor for one of the disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x becomes
{dot over ( L )} CD =L CD +P/n Eq. 1
where:
{dot over (L)} CD is the new loading factor or amount of bandwidth of the disk allocated with the requested segment. L CD is the current loading factor or bandwidth of the disk being consumed by the current disk activities. P is the required bandwidth of the segment being requested. n is the number of copies of the requested video data file.
The new loading factor {dot over (L)} CD is compared (Box 560 ) to a maximum loading factor (MaxL). If the new loading factor {dot over (L)} CD exceeds the maximum bandwidth of loading factor (MaxL), the current disk pointer is set (Box 565 ) to the location of the disk containing the next location of the first segment of the requested video data file. The admission server 435 schedules the transfer and sends the disk location of the first segment of the requested video data file to the edge server 405 a, 405 b, and 405 c requesting the video data file. The edge server 405 a, 405 b, and 405 c contains the player program that streams the requested video data file to a client or clients 400 a, 400 b, and 400 c the video data file. The player state is assigned (Box 570 ) the location of the first segment of the video data file.
Referring to FIG. 6 , the admission server 435 transmits (Box 575 ) an authorization to the edge server 405 a, 405 b, and 405 c granting the edge server 405 a, 405 b, and 405 c permission to admit or request the range (R) with the beginning location (P 1 ) and the ending location (P 2 ) for the segment. The edge server 405 a, 405 b, and 405 c assigns (Box 580 ) the event register the code whether the client 400 a, 400 b, and 400 c is going to start to stream the segment, to continue to stream the segment, or if the current segment has been viewed sufficiently, to start the processing for accessing the next segment (admit forward).
The event register is tested (Box 585 ) and if the segment is to be streamed, the current loading factor L CD of the disk containing the segments to be streamed is assigned (Box 590 ) the loading factor as determined by Eq. 1. The requested segment is transferred from the disk 480 a, . . . , 480 r, and 495 a, . . . , 495 x location to the edge server 405 a, 405 b, and 405 c and then streamed (Box 595 ) to the client or clients 400 a, 400 b, and 400 c for viewing. The event register is then assigned (Box 580 ) the codes for the next event of the process and tested (Box 585 ).
If, in this case, the client 400 a, 400 b, or 400 c has requested that the viewing be stopped, the load factor L CD is assigned a non-active value of Eq. 1. The admission server 435 allocates the load across all copies of the segment in anticipation of the client 400 a, 400 b, and 400 c resuming the request to view the segment of the requested video data file, while recognizing that the request may be rerouted to another copy of the segment of the requested video data file.
The event register is assigned (Box 580 ) the code for the next event and tested (Box 585 ). If the current segment is streamed to a predetermined location (approximately midway through the segment) within the video data file, the next segment is scheduled for transfer. If the event register is assigned a code for the admit forward operation, the current segment register is tested (Box 605 ) to determine if the last segment of the range of the requested data file is being streamed. If it is the last segment, the process ends, (Box 610 ).
Referring now to FIG. 7 , if there are more segments to be streamed, the current segment counter is incremented (Box 615 ) and the current disk register is assigned (Box 620 ) the disk location of the next segment to be processed.
The disk-loading factor L CD with the additional loading of the requested segment is assigned as determined by Eq. 1. The newly allocated disk loading factor L CD is compared (Box 625 ) to the maximum available loading or bandwidth (MaxL). If there is not sufficient allocable bandwidth, the listing of available copies is queried (Box 635 ) to find an available copy of the current requested segment. If all the disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x containing copies of the current segment have their loading factors L CD or bandwidths fully allocated, the admission server 435 assigns (Box 640 ) a new disk location for the segment to a more lightly loaded disk 480 a, . . . , 480 r, and 495 a, . . . , 495 x. The admission server 435 then directs the distribution server 470 to copy (Box 650 ) the requested segment from the tertiary or backing store 445 . If there is a copy of the currently requested segment or the distribution server 470 has copied the segment to a new disk location, the current disk counter is incremented to point to the location of the next copy (newly copied) of the currently requested segment of the video data file.
The loading factor L CD for the current disk containing the copy of the currently requested segment is again compared 625 to the maximum loading factor (MaxL) of the disk. If the allocated current loading factor L CD is less than the maximum loading factor (MaxL) or maximum bandwidth of the disk 480 a, . . . , 480 r, and 495 a, . . . , 495 x containing the currently requested segment, the player state is assigned (Box 630 ) the point to the disk location of the currently requested segment. The currently requested segment is processed as described above for FIG. 5 and the process is repeated until the last segment of the requested range is streamed to the client 400 a, 400 b, and 400 c, where the processing ends (Box 630 ).
It is apparent that there can be not only multiple copies of a video data file within the video distribution system of this invention, but multiple copies of the segments of the video data file that are further divided into sub-segments as the requests video data files or portions of video data files indicate that new segment sizes are required. The copying of the video data files or segments of the video data files are dynamically copied dependent on the bandwidth allocation of the disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x. Thus, various segments of a video data file may have various numbers of copies on multiple disks 480 a, . . . , 480 r, and 495 a, . . . , 495 x to allow the segments to have the appropriate bandwidth to stream the segments to the clients 400 a, 400 b, and 400 c. This allows the viewers to select various segments and the system to adjust the bandwidth accordingly to allow the viewer (client 400 a, 400 b, and 400 c ) demand.
The video distribution system as shown in FIG. 4 illustrates a system having local cluster networks 455 , and 460 , and the global communication network 415 . It is apparent that the server clusters 410 a and 410 b do not require the cluster networks 455 and 460 to virtually construct the server clusters 410 a and 410 b. Further, the disks 480 a, . . . , 480 r may be grouped in such fashion that they can be associated with one or more of the server systems 420 a, . . . , 420 f. The generalized structure allows the configuration server 485 to allocate the functions of the system to any of the server systems 420 a, . . . , 420 f. For instance the admission server 435 and the gateway server 475 may in fact be the same computing system and additionally, may be one of the server systems 420 a, . . . , 420 f. Also, any of the edge servers 405 a, 405 b, or 405 c may physically be on of the server systems 420 a, . . . , 420 f.
The segments of the video data files 490 a are shown as distributed over multiple disks 480 a, 480 b, and 480 c, associated with the server system 420 a. Depending on the file usage factors, and the interactivity factors, various segments or copies of segments 490 a, . . . , 490 h may be placed at other server systems 420 a, . . . , 420 f, on the admission server 435 , the configuration server 485 , or even an edge server 405 a, 405 b, or 405 c. The distribution of the segments 490 a, . . . , 490 h allows the balancing of the loading (the amount of data being transferred) of the disks 480 a, . . . , 480 r and disks 495 a, . . . , 495 w. The admission server 435 controls the placement of the segments and sub-segments and will eliminate segments of video data file based on a policy that will erase those segments that are least recently used, starting at the end of a video data file. Thus certain video data files may have a low number of segments present on the disks 480 a, . . . , 480 r of the server systems 420 a, . . . , 420 f. A request for a video data file having segments missing requires that the distribution server 470 recreate the segments of the video data file requested and transfer them to the server systems 420 a, . . . , 420 f. However, those video data file segments at the beginning of the video data file can be transferred to the client system 400 a, 400 b, 400 c for viewing, while the distribution server 470 is recreating those missing segments.
The load or the amount of data being transferred to or from an individual disks 480 a, . . . , 480 r and 495 a, . . . , 495 w is allocated between a read action (transferring the video data file isochronously to a client system 400 a, 400 b, 400 c for viewing by a user), a write action (transferring the video data file to a disk 480 a, . . . , 480 r and 495 a, . . . , 495 w ), or a copy action (a disk to disk transfer of the video data file). The total bandwidth or transfer rate for a single disk is thus divided in the read action, the write action, or the copy action. The load of the is the amount of the total bandwidth consumed for the transfer of the requested video data files resident on the disk. Therefore, the segment size is determined by the number of disks 480 a, . . . , 480 r and 495 a, . . . , 495 w available to contain the video data file (some maybe off line or too full to accept the video data file) and the loading of the available disks.
It is well known in the art that while the above describes a system to distribute video data files to client systems, the apparatus is implemented as a program code for execution on a computing system. The program code maybe obtained from media such as storage nodes of the cluster network or the global communication network, or stored on storage media such a read only memory (ROM), or a magnetic disk. The program code executed by the computing system executes the method for segmenting video data files to facilitate the transfer of the video data files. The program executed is as described in FIG. 6 .
While this invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention. | A method and apparatus for dynamically balancing the loading of data storage facilities is described. A listing is acquired of locations and loading of all segments of a requested data object including all copies of the segments of the requested data object. Those storage devices containing copies of each segment of the data object having a least loading is selected. If the loading of the storage devices is greater than the maximum loading for the storage devices, the segment is designated to be copied. The presence of all segments of the requested data object is determined. If there are missing segments of the requested data object, each of those missing segments is assigned a file identification and file location, such that those missing segments are assigned to data storage devices having the least loading. The missing segments are retrieved from a back-up storage device. | 7 |
BACKGROUND OF THE INVENTION
The prior art is replete with smog abatement processes using ammonia to react with sulphur dioxide, but recovery of ammonium compounds for sale as byproducts increase power plant costs instead of reducing them. Likewise the resulting ammonium-sulphur compounds and particulates in minute amounts produce a plume and smog from power plant chimneys, which is as objectionable as a sulphur oxide smog.
Currently, the least expensive processes being used for power plant pollution abatement provide for scrubbing the flue gas with a limestone slurry. But, locally mined limestone is rarely available, and capital and operating costs for grinding the limestone, and disposing of precipitated gypsum mixed with fly ash, is expensive. Additional costs for electrostatic precipitators or baghouses are the rule rather than the exception. Typically, the amount of limestone or dolomite required to capture all the sulphur from a high sulphur coal is about equal to the weight of ash in the coal, so massive amounts are needed.
Heretofore, power plant recuperators of heat from flue gas have been so subject to corrosion by sulphur acids condensing out from the gas at temperatures of 300° F. or less that they have not been economical, since downtime for repairs is enormously expensive.
In the prior art, flue gas traveling at high velocities has been explosed to scrubber water to remove SO 2 , wherein film coefficients slow absorption. The physical chemistry at gas speeds of only a foot a second, where fog particles are involved, is quite different from that when speeds of 10 to 40 feet per second existant in conventional practice. The enormous cost of acid resistant metal vessels made large enough to reduce speeds of gas flow through them has prevented them from even being considered.
It is noted in passing that in my previous U.S. Pat. No. 4,054,246, there is disclosed the novel concept of preheating air needed for combustion of power plant fuel by recuperation of the heat in flue gases, using subterranean pits filled with gravel. Further, in my U.S. Pat. No. 4,173,034, the advantages of heat storage in very large beds of pebbles are disclosed in some detail.
Those skilled in the chemical process arts generally appreciate that regenerative and recuperative heaters have been known for centuries. That this is still an active of development is evidenced by three recent U.S. Pat. Nos. 4,383,573; 4,349,069; and 4,361,183, all assigned to Combustion Engineering Inc., which all disclose regenerative heaters, but which are not otherwise pertinent to the present invention.
While the terms "regenerative" and "recuperative" are frequently used in the alternative it is believed that more proper definitions suggest that "regenerative" implies a closed system whereas "recuperative" implies systems where energy may be added (e.g. not a closed system). Insofar as the present invention is of the former type "regenerative" will be used herein.
SUMMARY OF THE INVENTION
A simple and profitable means to prevent air pollution from the particulate and gaseous pollutants from power plants, by recuperating the heat in the flue gases down to atmospheric temperature and pre-heat the air needed from combustion in the boilers. Most fly ash is removed at the face of the regenerators. Condensed moisture from the flue gases dissolves SO 2 and forms a smog, with remaining fly ash particles acting as condensation nuclei, which are caught on the wetted surfaces with the regenerator, washed therefrom to vessles to settle out solids, and the liquid is then treated by vacuum to recover the dissoled SO 2 , which is then compressed to liquid SO 2 and stored in refrigerated tank cars, to be sold as a valuable byproduct.
The regenerators of this invention consist of acid-resistant pebbles in beds or walls of sized pebbles. Usually these are piled loosely, but a novel feature provides the pebbles as a solid block by cementing them together, but only at the points of contact of each pebble and its adjacent ones. When hot flue gases are cooled by entering the precooled walls or beds of the regenerator, their contained moisture condenses to produce a fog or smog similar to that produced by nature in the cold air above power plants without pollution control. That is, fine particles of fly ash act as nuclei to condense moisture in minute droplets which instantaneously absorb SO 2 . The resulting smog is closely confined within the spaces between pebbles, and upon striking their wetted surfaces, is carried downwardly with the flow of condensate. The wetted surface area of the pebble bed must be enormous, because of velocity considerations and the flue gases and smog growing to droplet size are subjected to a tortious path ensuring complete demisting of the flue gas. Shrinkage of gas volume due to cooling and condensation draws gas into the pebble bed.
The bulk of the fly ash, which settles on the face of (45 degree) sloping "snow fences" built across the top of the pebble bed, slides like snow off of a sloping roof and into gutters with perforated false bottoms, up which flows a little gas to fludize the ash and carry it to downspouts and bins. The very fine fly ash travels with the flue gas downwardly to become smog when combining with the water of condensation and absorbed SO 2 . Cold wash water is Periodically used to flood the top of the bed and wash out any accumulations of fly ash.
Additions of ammonia, lime or magnesium oxide are avoided, since they would prevent cheap recovery of SO 2 by vacuum as a valuable byproduct.
Pebbles are preferably quartz or other acid resistant mineral with a low coefficient of expansion, or minerals like slags cast into balls or formulated from fireclay or high alumina cement, combined with heat resistant resins or plastic well known in the chemical industry for resistance to acids. Where walls or blocks of spaced pebbles are needed to enclose baffles to guide coarse fly ash flow to gutters, the pebbles are mixed with a wash or slurry of fireclay or resin or plastic and precast in a form to the shape desired and cured by heat if necessary.
Thus a novel rockbed is disclosed to replace the need for electrostatic precipitators, baghouses, cyclones, gas scrubbers, demisters and their complex ancillary apparatus, and in addition the bed recovers the heat of condensation and sensible heat of flue gas and fly ash. The net effect is to make all coals comparable in heating value, so that pollution control actually becomes profitable, instead of being the large item of expense for power plants it is presently.
OBJECTS OF THE INVENTION
It is a general object of the present invention to provide improved means for pollution control for coal-burning boilers and the like.
A further object of the present invention is to provide improved means of heat and byproduct recovery from flue gases.
A still further object of the present invention is to provide improved means of heat and byproduct recovery for boiler flue gases and the like which are an economic benefit to the overall operation.
Still another object of the present invention is to provide a pair of pebble bed regenerators of very large surface area, whereby flue gas velocities are reduced, fogs/smogs are encouraged to form, and cooling to the ambient range is achieved.
Yet another object of the present invention is to recover heat and byproducts from flue gases heretofore generally wasted.
These and other objects and advantages of the invention will become clear from the following detailed description of embodiments of same, and the novel features will be particularly pointed out in connection with the appended claims.
THE DRAWINGS
Reference will hereinafter be made to the accompanying drawings, in which:
FIG. 1 is a simplified flow sheet or flow diagram illustrating an embodiment of the invention;
FIG. 2 is a simplified diagram illustrating the concepts of condensate recovery and heat storage in accordance with the invention;
FIG. 3 is a partial, cross-sectional elevation view, highly idealized, of a small portion of a pebble wall or block within the pebble bed of the invention;
FIG. 4 is a partial, isometric cross-sectional view of the top or upper portion of a pebble bed illustrating removal of some dry fly ash prior to cooling-condensation carried out within the bed;
FIG. 5 is a transverse, vertical cross-sectional view of a pair of pebble beds in accordance with the invention, and
FIG. 6 is a longitudinal, vertical cross-sectional view of a pebble bed, taken along line B--B of FIG. 5;
DESCRIPTION OF EMBODIMENTS
In essence, the present invention is based, at least in part, on the discovery that current pollution control systems largely waste sensible heat in flue gases below certain temperatures, largely because of their corrosive nature at such temperatures, and that vast sums of money are spent overcoming the corresiveness, when indeed a better approach is to employ acid-resistant materials under conditions controlled so that contained sulphur is never oxidized to sulphuric acid, but is rather recovered as marketable SO 2 . The expense of neutralization is thus avoided, a marketable byproduct is produced and, most important, by utilizing the previously-wasted sensible heat to preheat combustion air going to the boiler, savings of truly surprising dimensions are achieved, as set forth in more detail hereinbelow.
In its important aspects the invention is illustrated in the flow sheet of FIG. 1, and attention is directed thereto. Those skilled in the chemical process industries ("C.P.I.") will immediately appreciate the lack of conventional recovery equipment: precipitators, bag houses and, of course, the input of limestone or dolomite necessary to chemically bind the sulfur. Rather, there are a pair of pebble or rock beds. These beds are truly massive, being as large as 75×150×60 feet, and are formed of sized, acid-resistant aggregate (manufactured or natural stone) providing myriad tortuous paths for cooling gases and condensing fluids.
Before discussing these aspects of the invention in detail, however, it is important to note that FIG. 1 is greatly simplified for purposes of clarity and, for example, does not show steam or power as an output. Rather, it merely shows preheated air as an input and flue gas as an output. Both of these flows are shown as passing through a High Temperature Regenerator, which is a conventional unit forming no part of the present invention. However, it is preferred that those units (two are of course necessary) be Ljunstrom-type rotating wheels with closely-spaced metal vanes forming rings around the vertical axis of rotation. Such units have proven efficient and economic between boiler exit gas temperatures and those lower temperatures at which SO 2 starts to oxidize and become corrosive, normally below about 500° F. As set forth in more detail hereinbelow, however, the physical chemistry is more complex than meets the eye, and specifying a temperature or even temperature range can be a dangerous generalization.
In any pair of regenerative heaters, it is manifest that the sensible heat retained in one is used to preheat incoming, ambient air prior to combustion in the boiler and, at the same time, hot flue gas is cooled in the other, giving up its heat to the walls of same. What distinguishes the present invention is the much greater extent to which this is carried out.
As noted supra, at lower temperatures in the range of 500° to 200° F., this invention makes use of porous gravel or sized pebble beds. These are in the range of about 1.5 to 6 inches diameter, with closely sized 2 inch diameter gravel chosen in the FIGURES and EXAMPLES described hereinbelow. Preferably, the beds are large enough in area and thickness so gas flow need not be reversed by dampers more often than once every eight hours. Such dampers or valves have been common in iron blast furnace stoves for about 100 years.
After cooling in the pebble bed the flue gases may occupy as little as half the volume they do when entering, due both to condensation of contained water, which involves a volume reduction of 950 to 1, and contraction according to the gas laws, e.g. PV=RT. Therefore, fan power to push the clean gas up the power plant chimney is not excessive. Since both particulate and gaseous pollutants that are noxious have been removed in the pebble bed, the need for a stack at all is merely to mix the CO 2 and whatever minor CO is present with atmospheric air.
Of course, in a bed preheating ambient air, more-or-less of the reverse holds true: expansion according to the gas laws and vaporization of any moisture, which will be a variable.
As shown in FIG. 1, the condensate, with its contained SO 2 entrained in the water of condensation together with NO x , chlorides, and other trace elements, is bled out of the bottom of the recuperator into a settling vessel or pond where clear water containing SO 2 is continuously or occassionally removed to a vacuum vessel for evaporation of SO 2 and its compression to a liquid, which is conventionally stored in refrigerated tank cars not under appreciable pressure. After SO 2 removal, the cold water is returned to the recuperators for washing out any fly ash accumulation and to keep the lowest level of the bed cold, to collect smog while the level of the bed immediately above is reaching hot flue gas temperature. This ensures that the smog will have at least a few feet to travel a tortuous path downward through the pebbles, wet with condensate, and be entrapped thereon.
The physical chemistry of this invention may be better understood by consideration of FIG. 2, which is a simplified diagram illustrating smog recovery in condensate water while storing heat in a pebble. In essence, this involves certain physical and thermal interactions between a pebble 10, a covering film of water 12, and smog droplets 14 nucleated on flyash or other particulates 16. As in nature, condensation may start on a particle of flyash 16, since it acts as a nuclei. This condensing fog is distilled water, and, as shown by several scientific papers over the past 24 years, the reaction of SO 2 with H 2 O in this miniscule state is practically instantaneous, even as acidity increases. Reference is made to "SOME ASPECTS OF SO 2 ABSORPTION BY WATER-GENERALIZED TREATMENT" by Gregory R. Carmichael and Leonard K. Peters, published by Pergamon Press Ltd. 1979 in ATMOSPHERIC ENVIRONMENT Vol. 13 pp. 1505-1513. In nature, smog returns to earth when the droplets become large enough to make "heavy" fog or dew. As shown in FIG. 2, droplet 14' has reached film 12 and is attaching as at 18 by surface-tension, but will rapidly become part of film 12. Indeed, in climates where fogs are common, noxious smogs have sometimes produced a rash of fatalities.
FIG. 3 is an idealized cross-section through a porous, pebble wall or pebble block of the invention, wherein evenly-sized crushed rock or pebbles, shown as spheres but actually of more irregular shape, are cemented together at just the points of contact of each pebble with its adjoining pebbles. This is accomplished by mixing the pebbles with a cementing slurry or thick cementing liquid, dumping the mix into a form and jarring or vibrating the form or contained pebble mix sufficiently so that all that remains of the cementing slurry or thick cementing liquid is that which thinly coats the pebble surfaces and which adheres principally around the points of contact of one pebble with its adjoining pebbles. For many purposes in construction of porous walls, floors, ceilings or the like, the slurry may consist of Portland cement with or without fine sand admixed, and water. In the case of the regenerators of this invention, acid resistance is a key element and the cementing slurry should be a fireclay, resin plastic with or without fine quartz sand admixed and water or other liquid. The pebbles are preferably quartz or volcanic rock with lower coefficient of expansion when subjected to repeated heating and cooling. The chemical industry has produced a great many conventional acid-proof cements which may be employed.
A most important aspect of the present invention is the exceptionally large area of the pebble heaters, which means that gas velocity therethrough will be very low. In the case of the incoming flue gas, this means that a substantial portion of the contained fly ash, e.g. the larger particles, will cease to be carried by the gas stream and will "drop out." FIG. 4 is an isometric view of means for coarse fly ash catchment over the pebble beds, with conveyance to downspouts by long prism-shaped pebble masses or blocks 22, having a triangular cross-section, made porous as in FIG. 3, but faced on the upper surface with a very hard and smooth slab 24 of acid resistant concrete, so the fly ash accumulating thereon will slide off into acid proof tile gutters 26 which include a gas permeable bottom, so fly ash falling therein is conveyed to downspouts (not shown) by fluidized flow. The prism shapes 22 are precast in forms and arranged on top of each pebble bed regenerator so they act like snow fences in causing the great bulk of fly ash to fall into the gutters directly or onto the smooth prism faces sloping at about 45 degrees, so any considerable depth of fly ash accumulating slides off into the gutters just as snow slides off a metal roof. The gas fed under the false bottom of the gutters must be very clean, dry and hot so that it will never plug the pores of the false floor of the gutters or cause the fly ash to cake in its route to the downspouts and bins (not shown) below the pebble beds. Alongside the gutters are acid proof tile pipes 27 with perforations on their sides opposite the gutters for flooding the pebble beds occassionally as needed to quickly flush down any accumulation of light fly ash between pebbles, which has not been carried down by the water of condensation from the flue gases. The upper layers of the recuperators are easily accessible for repair or replacement of prism shapes, gutters, flooding conduits or pebbles although little maintenance is contemplated, insofar as with time-proven materials of construction the pebble bed should last the life of the power plant. Some crumbling of pebbles is not serious, unless travel of flue gas becomes impeded.
FIG. 5 is a transverse, vertical section and FIG. 6 is a longitudinal vertical cross-section through a preferred embodiment of the pebble beds 28, 30 of this invention, and featuring low construction and operating costs in comparison with conventional means now employed to carry out the functions of collecting fly ash, cooking the flue gases and removing the noxious and very fine particulates and noxious gases therefrom. This is true despite the very substantial size of these beds.
The beds are in the order of 10 to 80 feet deep or more; this, of course, depends on the size of the power plant. Preferably, the beds are closely sized, spherically-shaped, and are of acid-resistant composition, so as not to be subject to deterioration by repeated heating and cooling, over 20,000 cycles, between 50° F. and 300° F. Any pebble (32) layer may be a single size from about 3/4 inches diameter to 5 inches or more, but smaller pebbles must not be above larger ones. Smaller sizes have more surface to promote SO 2 recovery in the condensate but have a much higher resistance to flue gas flow, and there is greater danger of plugging pore spaces. If mixed sizes were used, of course, gas flow would all but cease.
The horizontal cross-section of the beds is made large enough to slow flue gas speeds downwardly to about 1 foot per second or less at the entering face, which may be only half the velocity at the bottom of the bed due to cooling-contraction. As the hot flue gases reach the enormous area of the precooled pebbles, they are slowed to perhaps one-fifth or one-tenth of their previous speed, and at once start dropping their coarse fly ash on the prism-shaped "show fences," and thence into the gutters. As the partially cleaned flue gases enter the previous cooled bed, the heat capacity of the first foot or two of pebble layers condenses enough moisture to produce a steam-fog and smog out of fly ash, condensed moisture and very fine fly ash. As discussed supra in connection with FIG. 2, the droplet grows in size, its momentum inevitably causes it to collide with the already wetted surface of a pebble, where it is entrapped with further condensate and washed downwardly over colder pebbles so the SO 2 , once absorbed, tends to be retained. As in "Principles of Chemical Engineering" by Walker, Lewis and McAdams explained almost 60 years ago: "Thus, if SO 2 gas, whether or not mixed with inert gas, be brought in contact with water at 20° C., the SO 2 will continue to dissolve in the water until its concentration is sixty times that in the gaseous phase." It should be noted that the cooling of the flue gas is done at the face of a pebble so condensation and simultaneous solution of SO 2 must primarily occur there.
It should be appreciated that the top layers of rocks in the beds will heat up first, while the layers beneath remain cool. The absorbing surface and heat capacity of the rocks is so great that the heating of layers proceeds like a wave. Each successive layer will reach something close to flue gas temperature before the rate of heat transfer slows appreciably and the next layer starts to warm up. But, hot water of condensation, running downwards will speed the process somewhat. The beds must be deep enough so that the lowest layer is cool, and will condense all the water in the flue gases and, furthermore, provide a layer of cool pebbles, so that the smog in twisting and turning around pebbles will be entrapped on the water film covering each pebble.
EXAMPLES
Some specific examples will aid in understanding the invention are set forth hereinbelow. Base-line power plant data has been taken from an E.P.A. study, "Rocky Mountain-Prairie Region VIII: Coal-Fired Power Plant Trace Element Study, A Three-Station Comparison" by Radian Corp., Austin, Texas. Example I below is derived therefrom as denoted (*), and in Example II it is as noted thereunder (**). Thus, data in Table I below is * from Vol. 1, page 11, Table 2-2, and in * Table II it is from Vol. 2, page 27, Table 4-1.
TABLE I______________________________________Station II Flow Rates______________________________________Coal: 2.75 × 10.sup.5 lb/hr = 3300 tons/dayFlue gas: 5.46 × 10.sup.7 scfh______________________________________
TABLE II______________________________________Station II Coal Analysis As Rec'd, Pct. Dry______________________________________Moisture, 29.19Ash, 5.12Volatiles, 30.15Fixed Carbon, 35.54BTU/lb 8290 11,708Ultimate, Pct.Carbon 48.31Hydrogen 6.53Nitrogen 0.67Oxygen 39.02Sulphur 0.35Ash 5.12______________________________________
By estimating the amount of heat which can be recuperated from the flue gases of one pound of coal to preheat the air needed for its combustion, the tons of coal saved by this invention each day can be readily obtained. First, the heat in the steam condensed from the gases is estimated. Second, the sensible heat in cooling the gases down from 300° F. to 50° F. is estimated. The sum of these BTU savings is the increase in the heating value of the coal. Thus, fewer tons will be needed. Heat recovered conventionally (from gases at boiler temperature down to 300° F.) is not included.
Those familiar with heat and material balances will appreciate that total moisture in the boiler flue gases includes all water made from H 2 during combustion, plus moisture in and on the coal, and moisture in the combustion air. In Table III below, data for calculating the latter figure have been taken from "Combustion Engineering" (First Ed.) pp. 25--25 and 25-26, which assume 22% excess air and 34% volatiles, deemed reasonable.
TABLE III______________________________________Heat of Condensation/lb. CoalSource H.sub.2 O per lb.______________________________________Wet coal (as rec'd.) 0.2919Combustion (from H.sub.2) 0.5877(0.0653 × 9)In Comb. Air 0.1007 0.9803______________________________________
So, with a heat of condensation of 950 BTU/lb, there is 0.9803×950=930 BTU recoverable from this water. The sensible heat in these gases is, in essence, that recoverable in cooling from 300° F. to about 50° F.
TABLE IV______________________________________Sensible Heat in Flue Gases(per one pound of coal)______________________________________5.46 × 10.sup.7 scfh/2.75 × 93010.sup.5 = 198.54 scfh (from Table III)per lb. coal198.54 × 0.238 × 0.075 × 886250 =[scfh × (sp. heat) ×lb/cf × F.° temp.change]TOTAL 1816______________________________________
The recuperator efficiency is 95% both in and out, =90.25%×1816= 1639 BTU. Thus, the equivalent heating value of coal, attained by invention by conservation is =8290+1639=9929 BTU. So if -
Y=tons coal/day with invention, then Y×9929=3300×8290. So Y=2755 tons coal per day
3300-2755=545 tons coal saved.
At $40/ton, this equals a: saving of $21,800/day.
The design of FIGS. 4,5, and 6 comprises a pair of pebble beds, which, to be properly effective should each be 75 ft. wide by 150 ft. long and 60 ft. deep. Pebbles are closely sized quartz pebbles or volcanic rocks about two inches in diameter. The heat capacity is calculated below for one of the pair of recuperator beds.
TABLE V__________________________________________________________________________Bed Heat CapacityVolume Rock Density % Solid Specific Temperature HeatOf Bed of Solids Rock Heat Change/cycle Capacitycu. ft. lbs/cu. ft. (voids = 42%) BTU/lb degrees F. BTU__________________________________________________________________________75 × 150 × 165 × 0.58 × 0.21 × 250 = 3.391 ×60 = 6.75 × 10.sup.910.sup.5 ×__________________________________________________________________________
The heat recuperated per day is: 1639/lb×2000×2755 tons=9.03×10 9 . Therefore, the dampers reversing the flow through the beds need to be set to change once every 8 hour shift, although 9 hours allowable.
The flue gas speed downward and combustion gas speed upward are calculated as follows:
5.46×10 7 scfh×(2755/3300÷[60 (min./hr.)×11,250 sq. ft.]=68 ft/min, or about 1 ft. per second. The pressure necessary to force this flow with 2 in. diameter pebbles is about 0.08×60 ft. (depth) or 4.8 inches water. The weight of 4.8 inches of water spread over 150×75 sq. ft. is 281,250 lbs. which, moving at 1 ft./sec., becomes ftlb/sec. Since a kilowatt is equivalent to 737.7 ft.lb/sec., a fan of 281,250/737.7 or about 380 kw is required for each of the recuperators in the pair. Each would add 380×0.948×60×60=12×10 5 BTU/hr friction heat), equivalent to about 1.5 tons coal/day.
The recovery of SO 2 is readily obtained from a calculation of the %SO 2 in the flue gas, compared to the SO 2 recovered in the water of condensation, bearing in mind that equilibrium will be reached and further recovery will cease, when the condensed SO 2 equals 60 times the concentration by weight in the flue gas. In this EXAMPLE I., if all the SO 2 were to remain in the flue gas, it would contain %S=0.35×2=0.70% SO 2 /per lb. of coal.
TABLE VI__________________________________________________________________________SO.sub.2 ExtractionDegree ofExtraction of SO.sub.2 SO.sub.2 in 60 × % SO.sub.2 % SO.sub.2 in CondensateFrom the Flue Gas Flue Gas in Flue Gas by Extraction Process__________________________________________________________________________0 0.047%*** 2.82% 020% 0.0376% 2.256% 0.143%40% 0.0282% 1.692% 0.286%60% 0.0188% 1.128% 0.429%80% 0.00940% 0.564% approx. 0.572% at approximate = equilibrium90% 0.00470% 0.282%* 0.643%100% 0 0 0.715**__________________________________________________________________________ Notes Explaining Derivation of Figures in above Table ***The SO.sub.2 in the flue gas at 0% extraction is calculated as follows % SO.sub.2 in coal is 2 × % S = 0.70% or 0.007 lbs/lb coal. Since scfh flue gas/lb coal = 5.46 × 10.sup.7 /2.75 × 10.sup.5 = 198.54 scfh, then lb flue gas/lb coal = 0.075 lb/cf × 198.54 = 14.9 lb SO.sub.2 /lb flue gas = 0.007/14.89 = 0.00047 = 0.047% **The SO.sub.2 in the condensate at 100% extraction is calculated as follows: % SO.sub.2 in coal is 2 × % S = 0.70% or 0.007 lbs/lb coal The condensate was previously calculated as 0.9796 lbs, so the SO.sub.2 /lb condensate = 0.007/0.9796 = 0.00715 = 0.715% *The 90% extraction is achievable by diluting the condensate with fresh water or condensate from which the SO.sub.2 has been removed by vacuum. This dilution would be done by flooding the lower 10 ft. of pebble bed. That is, by addi ng 1.3 lb fresh water to 1 lb condensate making 2.3 total. The 0.643% SO.sub.2 is reduced to 0.643/2.3 or 0.280%, comparable with 0.282% which is the amount of flue gas SO.sub.2 in water at equilibrium with flue gas containing 0.00470% (see Walker, Le wis and McAdams reference, supra).
EXAMPLE II
A North Dakota Coal is considered in the following example. References to the EPA study (supra) are Table 2-3, p. 12, Vol. 1, and Table 4-1, page 28, Vol. 4.
TABLE VII______________________________________STATION III FLOW RATESSTREAM FLOW RATE______________________________________Coal 2.34 × 10.sup.5 lb/hrFlue Gas 4.11 × 10.sup.7 scfh______________________________________
TABLE VIII______________________________________STATION III COAL ANALYSIS As Received, Pct______________________________________ProximateMoisture 36.84Ash 7.84Volatiles 26.24Fixed Carbon 29.08 100.00Sulphur 0.91BTU/lb 6214Ultimate, Pct.Carbon 41.91Hydrogen 6.77Nitrogen 0.60Oxygen 41.97Sulphur 0.91Ash 7.84 100.00______________________________________
To calculate the coal which can be saved with this North Dakota coal used in a power plant by using the invention, the same procedure applies as used in Example I. Savings by recuperating the heat of the condensate and sensible heat in the flue gases are computed below and added together.
__________________________________________________________________________ ##STR1## POUNDS H.sub.2 O × 950 BTU/lbH.sub.2 O as moisture in coal 0.3684H.sub.2 O from hydrogen (0.0677 × 9) 0.6093H.sub.2 O in air for combustion 0.07550.013 × 935 lb air 0.006214 coal heat value per million BTU Totallb H.sub.2 O per lb coal ##STR2##SENSIBLE HEAT IN FLUE GASES(per one pound of coal)4.11 × 10.sup.7 scfh/2.34 × 10.sup.5 =175.68 × 0.238 × 0.075 × 300° ##STR3##Recuperator efficiency in & out 90.25% × TOTALHeating value of coal obtained by invention = 6214 + 1750 = 7964__________________________________________________________________________BTU/lb
To determine the coal saved per day, again let Y=coal used per day, with the invention, then Y×79.64=2808×6214, so Y=2191.
The tons saved per day =2808-2391=617; so dollars saved per day =617×$40/ton coal =$24,680/day.
Besides the coal saving, the invention greatly reduces SO 2 pollution as the following Table IX illustrates.
TABLE IX______________________________________EXTRACTION OF SO.sub.2Degree of 60 × % SO.sub.2 inExtraction of SO.sub.2 SO.sub.2 in % SO.sub.2 in Condensate byFrom the Flue Gas Flue Gas Flue Gas Extraction Process______________________________________ 0% 0.138%*** 8.28% 020% 0.110% 6.62% 0.34%40% 0.083% 4.98% 0.69%60% 0.055% 3.30% 1.04%80% 0.014% 1.68% 1.38%90% 0.014% 0.83%* 1.56%**100% 0 0 1.728%**______________________________________ Notes explaining this Table ***The SO.sub.2 in the flue gas at 0% extraction is calculated as follows % SO.sub.2 in coal is 2 × % S = 1.85% or 0.0182 lbs/lb coal and since scfh flue gas/lb coal 4.11 × 10.sup.7 /2.34 × 10.sup.5 = 175.64 scfh so lb flue gas/lb coal = 0.075 lb/cf × 175.64 = 13.17 lb SO.sub.2 /flue gas = 0.0182/13.17 = 0.00138 = 0.138% **The SO.sub.2 in the condensate at 100% extraction is calculated as follows: % SO.sub. 2 in coal is 2 × 5 S = 1.82% or 0.0182 lbs/lb coal and since lb condensate was previously calculated as 1.0532 the SO.sub.2 /lb condensate is 0.0182/1.0532 = 0.01728 = 1.728% *The 90% extraction is achievable by diluting the condensate with fresh water or condensate from which the SO.sub.2 has been removed by vacuum. This dilution would be done by flooding the lower 10 ft. of pebble bed. That is, if an amount of fresh water equal to that in the condensate were added, the SO.sub.2 in the condensate would be halved from 1.56% to 0.78% which is lower than 0.83% in equilibrium with flue gas containing 0.014% SO.sub.2. (see Walker, Lewis and McAdams reference previously given) In calculating the heat of condensation used in both examples, a figure od 950 BTU/lb water condensed was used when actually the accepted standard is 1050.3. This makes the above estimates of saving on the conservative side.
As a rough estimate this invention recovers about 90% of the high heating value. The recuperator efficiency of 95% in and 95% out equals 90.25%. Thus, the coal industry as well as the power industry are enormously benefitted both by the coal savings, as well as making high sulphur coal valuable without causing air pollution.
Although these examples show the use of coal, it will be appreciated that savings with oil and natural gas furnaces will be greater to the extent that H 2 O condensate is greater, due to more hydrogen in the oil or gas.
Various other changes in the details, steps, materials, and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in this art within the principle and scope of the invention as defined in the appended claims. For example, it will be appreciated that while this invention has been described with reference to boiler installations for power generation from fossil fuels, it is not so limited and may be employed with any large-scale furnaces burning such fuels; copper smelting, glassmaking or pig iron or scrap melting operations come to mind. | A simple and profitable means to prevent air pollution from the particulate and gaseous pollutants from power plants, by recuperating the heat in the flue gases down to atmospheric temperature and pre-heat the air needed from combustion in the boilers. Most fly ash is removed at the face of the regenerators. Condensed moisture from the flue gases dissolves SO 2 and forms a smog, with remaining fly ash particles acting as condensation nuclei, which are caught on the wetted surfaces within the regenerator, washed therefrom to vessels to settle out solids, and the liquid is then treated by vacuum to recover the dissolved SO 2 , which is compressed to liquid SO 2 and stored in refrigerated tank cars, to be sold as a valuable byproduct. The bulk of the fly ash, which settles on the face of (45 degree) sloping "snow fences" built across the top of the pebble bed, slides like snow off of a sloping roof and into gutters with perforated false bottoms, up which flows a little gas and carry it to downspouts and bins. The very fine fly ash travels with the flue gas downwardly to become smog when combining with the water of condensation and absorbed SO 2 . Cold wash is periodically used to flood to top of the bed and wash out any accumulations of fly ash. | 8 |
FIELD OF THE INVENTION
This invention relates to organic compounds for diagnostic imaging. In particular, it relates to organic compounds which contain at least one aryl group which has been derivatized to contain at least one perfluoro-1H,1H-neopentyl moiety, and methods for their use. In a specific instance, triglyceride or glycerol phospholipid analogs can be prepared to contain benzyl groups which have been derivatized to contain at least one PFNP moiety. These triglyceride or glycerol phospholipid analogs are useful as hepatic imaging agents.
BACKGROUND OF INVENTION
A number of diagnostic and therapeutic medical procedures require the administration of certain organic compounds as contrast enhancing agents in order to enhance the quality of the procedure. These procedures include: contrast-enhancing agents for Magnetic Resonance Imaging (MRI), Computerized Tomography (CT) and X-ray.
The desire for early detection and treatment of metastatic disease has been the motivation for many recent advances in the fields of radiology and nuclear medicine. In particular, significant advances have been made to improve upon noninvasive techniques for visualizing internal organs using radiography and radioisotope scanning. The use of CT instead of conventional X-ray techniques allows for a more sophisticated visualization of the tissues and organs being studied. In addition, many CT agents have now been developed which provide a further advantage over conventional X-ray radiopaques in that they are more site specific.
Weichert et al. of the University of Michigan have studied the use of halogenated triglyceride compounds as liver and hepatocyte site-specific CT agents. In U.S. Pat. No. 4,873,075, this group at the University of Michigan disclosed polyiodinated triglyceride analogs as radiologic agents. The triglyceride compounds are composed of a triglyceride backbone structure that is 1,3-disubstituted or 1,2,3-trisubstituted with, in some embodiments, a 3-amino-substituted-2,4,6-triiodophenyl aliphatic chain wherein the chain has a structure similar to that of naturally occurring fatty acids.
MRI as opposed to CT has the advantage that it exhibits superior soft tissue differentiation. The two most widespread applications of MRI take advantage of the nuclear magnetic resonance of hydrogen ( 1 H) or fluorine ( 19 F). 19 F MRI has the added advantage over 1 H MRI in that while 19 F has an NMR sensitivity nearly equivalent to that of 1 H, it demonstrates negligible biological background.
While 19 F MRI provides significant advantages over other imaging techniques, the success of the imaging agents being used depends on such qualities as ease of synthesis, site-specificity, resistance to hydrolysis in-vivo, a sufficient amount of signal and a high signal-to-noise ratio. In some instances, these desired qualities may actually be mutually exclusive. For example, the signal of a 19 F MRI contrast agent can be increased by adding additional fluorines. However, depending on where the fluorine substituents are attached to the imaging agents being used, the fluorine containing molecules may exhibit different spectral resonance lines. This results in insufficient intensity of the signal of interest relative to noise which leads to a low signal-to-noise (S/N) ratio or band broadening and blurred images due to multiple resonances. As a result, high doses of the imaging agent or long imaging times are required.
The use of 3,5-bis(trifluoromethyl)aryl compounds, such as 1,3-bis[3',5'-di(trifluoromethyl)phenylacetyl] 2-oleoyl glycerol, for site-specific delivery of fluorine MRI agents has been disclosed by Weichert et al. (Abstracts of the Seventh Annual Meeting of the Society of Magnetic Resonance in Medicine (1988) 1; 484). This compound has the advantage that it exhibits only a single resonance frequency. However, it suffers from the problem of having only a limited number of fluorine equivalents per molecule.
The problem of insufficiency of signal was addressed by Rogers et al. with the development of perfluoro-tert-butyl (PFTB) reporter groups with each having 9 magnetically equivalent 19 F nuclei. It was recognized that these compounds provide a mono-resonant fluorine reporter group making these types of compounds practical for MRI measurements. Rogers et al., Synthesis of Reporter Groups for Fluorine-19 NMR; a New Class of Imaging and Spectroscopic Compounds, Abstracts of the Eighth Annual Meeting of the Society of Magnetic Resonance in Medicine (1989) 2, 819; U.S. Pat. No. 5,116,599. However, known methods of introducing PFTB reporter groups are complicated and often involve steps that would destroy the biological activity or geometry of host compounds and thus interfere with their ability to efficiently target specific organs or tissues.
Therefore, there exists a need to provide for a class of 19 F-MRI imaging agents which can overcome the aforementioned disadvantages.
SUMMARY OF THE INVENTION
The present invention provides for PFNP containing contrast agents. These contrast agents include pharmacological and biological compounds rendered active as magnetic resonance imaging agents by being modified to include a phenyl group to which at least one PFNP moiety has been attached. The PFNP groups produce a single magnetic resonance to insure a maximum signal to noise ratio. This reduces the concentration of the agent required for adequate augmentation of the 19 F magnetic resonance signal.
More specifically, the present invention provides a derivatized triglyceride or glycerol phospholipid analog wherein the analog contains at least one PFNP moiety. Glycerol phospholipids are contemplated because of their anticipated low toxicity and desirable amphipathic character.
More specifically, the present invention provides a derivatized triglyceride or glycerol phospholipid analog wherein the analog contains at least one [2,2-di(trifluoromethyl)3,3,3,-trifluoropropyl] moiety. This moiety, which can also be referred to as a perfluoro-1H,1H-neopentyl moiety will hereinafter be referred to as "PFNP".
The novel compounds of the present invention may have the general formula: ##STR1## wherein Q is ##STR2## and A 1 , A 2 and A 3 are each selected from the group consisting of:
saturated and unsaturated aliphatic hydrocarbon chains;
amine substituted saturated and unsaturated aliphatic hydrocarbon chains; and
amide substituted saturated and unsaturated aliphatic hydrocarbon chains;
wherein R 1 , R 2 and R 3 are each selected from the group consisting of: CH 3 ; NH 2 ; CONH 2 ; OH; and ##STR3## wherein R 4 , if present, is selected from the group consisting of: Hydrogen;
Choline;
Ethanolamine;
Serine;
Glycerol;
or myo-Inositol
wherein x 1 , x 2 , x 3 , x 4 and x 5 are each selected from the group consisting of:
Hydrogen;
Iodine;
NH 2 ;
CH 3 ;
(CH 2 ) n CH 3 ;
(CH 2 ) n Z;
CH[(CH 2 ) n Z] 2 ;
and C[(CH 2 ) n Z] 3 ;
wherein n=1 to 3 and wherein Z=C(CF 3 ) 3 ; with the proviso that at least one of x 1 to x 5 is selected from the group consisting of:
(CH 2 ) n Z;
CH[(CH 2 ) n Z] 2 ;
and C[(CH 2 ) n Z] 3 .
In another embodiment the novel compounds of the present invention have the general formula: ##STR4## wherein A 1 , A 2 and A 3 are each selected from the group consisting of:
saturated and unsaturated aliphatic hydrocarbon chains;
amine substituted saturated and unsaturated aliphatic hydrocarbon chains; and
amide substituted saturated and unsaturated aliphatic hydrocarbon chains;
wherein R 1 , R 2 , and R 3 are each selected from the group consisting of: CH 3 ; NH 2 ; CONH 2 ; OH; and ##STR5## wherein x 1 , x 2 , x 3 , x 4 and x 5 are each selected from the group consisting of:
Hydrogen;
Iodine;
NH 2 ;
CH 3 ;
(CH 2 ) n CH 3 ;
(CH 2 ) n Z;
CH[(CH 2 ) n Z] 2 ;
and C[(CH 2 ) n Z] 3 ;
wherein n=1 to 3 and wherein Z=C(CF 3 ) 3 with the proviso that at least one of x 1 to X 5 is selected from the group consisting of:
(CH 2 ) n Z;
CH[(CH 2 ) n Z] 2 ;
and C[(CH 2 ) n Z] 3 .
The novel compounds of the present invention can be more specifically triglyceride analogs having the basic formula: ##STR6## Wherein R is a fatty acyl group with 3-20 carbon atoms, n is 0-18 and m is 0-18. Preferably, n and m are 6. The fatty acid can include saturated or unsaturated aliphatic hydrocarbons of either an even or odd number. Preferably, the triglyceride analog has a low melting point fatty acid such as oleic acid in the 2 position.
In a specific embodiment the PFNP derivatized triglyceride analog is 2-O-oleoylglycerol 1,3-bis(7'-{3",5"-di[PFNP]phenyl}heptanoate). Preferably, the triglyceride analog is delivered to the patient parenterally as an emulsion. As such, long chain fatty acid compounds (i.e., A having a carbon-skeleton of 8-20 carbons in length) are preferred in that these types of compounds are easier to emulsify.
The analogs of the present invention are useful as MRI agents. Also, if iodine is added to the aryl ring, the compound can be used both as an MRI and CT agent at the same time. As contrast agents, the analogs are liver specific and hepatocyte selective. As radiopaque agents, the analogs find particular applicability as a contrast agent for computerized tomography.
Additionally, this invention provides for bifunctional aryl containing contrast agents derivitized with at least one PFNP moiety and a chelating ligand for a paramagnetic metal. These agents would then be useful for both 19 F MRI and 1 H MRI.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the synthesis scheme for 2-O-oleoylglycerol 1,3-bis(7'-{3",5"-di[PFNP]phenyl}heptanoate).
FIG. 2A shows photographs of - 1 H MRI images for the tests discussed in Example 1.
FIG. 2B shows photographs of - 19 F MRI images for the tests discussed in Example 1.
FIG. 3 shows the 19 F spectra of 2-O-oleoylglycerol 1,3-bis(7'-{3",5"-di[PFNP]phenyl}heptanoate).
The 19 F NMR spectra of the compounds were carried out with a Varian, GEMINI-200 MHz NMR instrument model number 958562-14. The spectra were taken in deutero chloroform containing 0.3% freon as internal reference. The chemical shifts of the observed peak were determined with reference to freon. The use of a standard sign convention of (+) signals downfield from (left of freon) and (-) upfield from (right of Freon) was adopted. Vast majority of organic fluorine compounds have signals which are negative. The +50 to -250 ppm range covers most compounds. The triglyceride example shown exhibited one single peak for all the 36 fluorines at -65.16 ppm from freon.
FIG. 4 shows synthesis route to make a gadolinium chelate.
DETAILED DESCRIPTION OF THE INVENTION
This invention is based on the discovery that a large number of magnetically equivalent fluorines can be added to biological or pharmaceutical compounds to render these compounds active as nuclear magnetic resonance spectroscopy or magnetic resonance imaging agents by being modified to include aryl groups to which at least one PFNP group has been attached. When the PFNP group is the only source of fluorine, it provides for a source of nine magnetically equivalent fluorine nuclei and produces a single magnetic resonance with a maximum signal to noise ratio. This in turn reduces the concentration of the agent required for adequate detection, reduces imaging time, and permits the use of lower field strength MR imaging systems.
The PFNP phenyl group may be added to a variety of biological or pharmaceutical compounds. The biological or pharmaceutical compounds contemplated by the present invention include amino acids, amino acid analogs, polypeptides, proteins, lipoproteins, fatty acids, triglycerides, glycerol phospholipids, steroids dendrimers or polysaccharides.
Additionally, multi-functional contrast agents providing for MRI (both 19 F and 1 H) and computerized tomography are contemplated. For example, the biological or pharmaceutical compounds can be iodinated, or the phenyl groups attached thereto can be iodinated. The aryl groups to which at least one PFNP moiety has been added can be incorporated into a chelating ligand such as diethylenetriamine pentaacetic acid. See Greis U.S. Pat. No. 4,647,447, Klaveness WO 89/06979; Cockbain WO 91/05762. This chelating ligand can be used to chelate gadolinium and would be useful for enhancing NMR images. See Greis U.S. Pat. No. 4,957,939. Additionally, dendrimers such as STARBURST (Dow Chemical Co.) polymers can be used to hold multiple chelating ligands incorporating perfluoro-1H1H-neopentyl aryl substituents. See Tomalia U.S. Ser. No. 897,455 (hereby incorporated by reference).
The electronic and steric features of an aromatic system allows easy multiple substitutions. In addition, it permits the introduction of iodines in the presence of PFNP moieties. This enables the synthesis of multifunctional imaging agents, for example for MRI and CT. Adding a PFNP moiety to an aryl group, as opposed to a multiply fluorine-substituted alkyl compound, allows one to take advantage of the electronic and stearic features of aromatic rings. These advantages include the ability to add multiple perfluoro-1H,1H-neopentyl groups per aromatic ring, the ability to create multifunctional imaging agents by also adding iodine to the phenyl group rendering the agent active as both an MRI and CT agent, and the ability to take advantage of the inherent hydrophobicity of the aryl group.
In particular, the method of synthesizing contrast agents which contain a phenyl group having at least one perfluoro-1H,1H-neopentyl moiety has advantages over the method of synthesizing fluorinated contrast agents using aliphatic halides. The benzyl halides used in synthesizing the contrast agents of the present invention react faster with carbanion intermediates such as C 4 F 9 - Cs + and exhibit substantially better yields than aliphatic halides. Additionally, unreacted benzyl halides are more easily removed from the reaction mixture. Also, benzyl halides are readily available, being prepared by using any suitable means of halogenating benzyl-containing compounds, and can be multiply substituted with a variety of functionalities. In particular, the benzyl moiety allows for the addition of multiple perfluoro-1H,1H-neopentyl moieties as well as iodine.
It should be recognized that a suitable carrier is needed if the biological or pharmaceutical compound is not soluble in water. The soluble carriers include lipid emulsions, liposomes, microparticles or microspheres. If the biological or pharmaceutical compound is water soluble a carrier is not required.
In a preferred embodiment of the invention, which will be discussed in greater detail below, the lipophilic nature of the triglyceride analog, in particular 2-O-oleoylglycerol 1,3-bis(7'-{3",5"-di[PFNP]phenyl}heptanoate) (FIGS. 1,9), enables these analogs to be incorporated into a suitable carrier such as a fat emulsion which upon administration to a patient is rapidly sequestered by the hepatocytes in the liver.
The above discussed triglyceride analogs may be administered to mammalian subjects as radiologic agents by a known manner, such as by intraveneous injection. For hepatic imaging, intravenous administration is the preferred route. A transport agent, however, is required for these analogs, such as a lipid emulsion. See U.S. Pat. No. 4,873,075 (hereby incorporated by reference) for a description of emulsions that would be suitable as carriers for the presently disclosed triglyceride analogs.
The following section discloses the synthesis process that provides the following advantages. The intervening methyl group between the fluorine moiety and the aryl compound facilitates coupling of multiple polyfluorinated groups. In the preferred embodiment shown in FIG. 1, 36 magnetically equivalent fluorines are held on an aryl-containing triglyceride analog.
EXAMPLE 1
Synthesis of 2-O-oleoylglycerol 1,3-bis(7'-{3", 5"-di[PFNP]phenyl}heptanoate)
Melting points are uncorrected. Nuclear magnetic resonance spectra were obtained using a 200 MHz instrument tuned for determination of proton ( 1 H) or fluorine ( 19 F) resonances.
1-Bromo-3,5-bis(bromomethyl)benzene (FIG. 1, 1) was prepared by adding bromine (65.2 g, 0.408 mol) dropwise to a solution of 1-bromo-3,5-dimethylbenzene (38.11 g, 0.206 mol) in carbon tetrachloride (350 ml), which was irradiated with a 300 watt General Electric Tungsten lamp. Under these conditions bromine uptake was fast as indicated by the disappearance of the red color. Hydrogen bromide gas evolved and was scrubbed into 10% sodium hydroxide solution. The bromine was completely added in 75 minutes. Irradiation and stirring was continued at ambient temperature for two more hours. The mixture was then diluted with water (100 ml). The carbon tetrachloride layer was separated and washed with water (300 ml). The organic layer was dried (anhydrous sodium sulfate). After filtration, volatile solvents were removed under vacuum. 1-Bromo-3,5-bis(bromomethyl)benzene crystallized on trituration of the residual oil with hexane (150 ml); 27.6 g (0.08 mol, 39% of theoretical) of product was obtained. The melting point of the composition was 90° -93° C.
The 1 H NMR spectrum in CDCl 3 showed the following resonances relative to TMS: 7.48 (s, 1H, aromatic), 7.35 (s, 2H, aromatic), and 4.42 (s, 4H, CH 2 ) ppm.
Next, 1-bromo-3,5-bis[PFNP]benzene (FIG. 1, 2) was prepared. In a flask equipped with a gas inlet, mechanical stirrer and a dry ice condenser was placed a suspension of dry cesium fluoride (31.0 g, 0.20 mol) in monoglyme (200 ml). Perfluoroisobutylene gas (40.0 g, 0.20 mol) was bubbled in. The gas reacted rapidly with cesium fluoride and a yellow solution resulted. The mixture was stirred for one hour, and then a solution of 1-bromo-3,5-bis(bromomethyl)benzene (FIG. 1, 1) (30.0 g, 0.087 mol) in monoglyme (50 ml) was added dropwise. The resulting reaction was slightly exothermic and caused cesium bromide to precipitate from solution. The mixture was stirred overnight and the precipitated salt was removed by filtration. The filtrate was concentrated under vacuum, and the residue was taken up in dichloromethane (120 ml). The organic layer was washed with water (50 ml) and then was dried (anhydrous sodium sulfate). After filtration, the solvent was removed under vacuum. The residue was crystallized from a mixture of hexane and ether (10:90, v/v) to provide 1-bromo-3,5-bis[PFNP]benzene as colorless crystals (45.84 g 0.073 mol, 85%, m.p. 120°-121° C).
Its 1 H NMR spectrum in CDCl 3 solution showed the following resonances relative to TMS: 7.44 (s, 2H, aromatic), 7.20 (s, 1H, aromatic), and 3.37 (s, 4H, CH 2 ) ppm. Its 19 F NMR spectrum in CDCl 3 showed a single resonance at -65.58 (s, 18 F) ppm relative to Freon.
1-Formyl-3,5-bis(PFNP)benzene (FIG. 1, 3) was prepared in a dry flask under argon atmosphere. A solution of 1-bromo-3,5-bis(PFNP)benzene (FIG. 1, 2) (24.3 g, 0.039 mol) in diethyl ether (300 ml) was cooled to -60° C. in a dry ice/acetone bath, and 2.5N n-butyl lithium in hexane (18 ml, 0.045 mol) was added dropwise with stirring. After the addition was completed, the mixture was gradually warmed to 0° C. and then cooled again to -50° C. Dimethylformamide (60 ml) was added dropwise. The resulting reaction was slightly exothermic. The mixture was warmed to room temperature and allowed to stand overnight. After the addition of water (30 ml), organic solvents were removed under vacuum. The residue, which contained small amounts of dimethylformamide, was mixed with water, and the mixture was extracted with dichloromethane (200 ml). The dichloromethane extract was dried (anhydrous sodium sulfate). After filtration, the dichloromethane extracts were allowed to stand and gradually deposited crystalline material which was isolated by filtration. The filtrand was identified as 1-formyl-3,5-bis(PFNP)benzene (FIG. 1, 3). Additional compound was obtained on concentration of the filtrate to give a total of 17.8 g of material (0.023 mol, 77% of theoretical). The melting point of the composition was 128°-130° C. The purified composition was found to be homogeneous on TLC (silica gel, Rf=0.45 after elution with dichloromethane/hexane, 4:6, v/v).
By elemental analysis the compound contained (calculated for C 17 H 8 F 18 O) C, 36.03 (35.78); H, 1.35 (1.40); F, 59.69 (60.0). The 1 H NMR spectrum of its CDCl 3 solution showed the following resonances relative to TMS: 9.98 (s, 1H, CHO), 7.78 (s, 2H, aromatic), 7.51 (s, 1H, aromatic), and 3.47 (s, 4H, CH 2 ) ppm. Its 19 F NMR spectrum in the same solvent showed a single resonance at -65.57 (s, 18F) ppm relative to Freon.
In the next step 7-[3',5'-bis(PFNP)phenyl]hept-6-enoic acid ethyl ester (FIG. 1, 5) was prepared. Using a dry flask and an argon atmosphere, 1.5N lithium diethylamide (LDA) in tetrahydrofuran (19 ml, 0.029 mol) was added dropwise to a stirred solution of 5-(ethoxycarbonyl)pentyltriphenylphosphonium bromide (FIG. 1, 4) (11.4 g, 0.027 mol) in dimethylformamide (35 ml) that had been cooled to -60° C. The reaction mixture turned yellow during the addition of LDA solution. After complete addition, the mixture was warmed to -5° C. and then again cooled to -50° C. A solution of 1-formyl-3,5-bis(PFNP)benzene (15.07 g, 0.025 mol) in warm dimethylformamide (100 ml) was added dropwise with stirring at a rate that kept the reaction temperature below -40° C. The resulting mixture was allowed to warm to room temperature and was stirred overnight, during which time the solution became clear. Dimethylformamide was then removed under reduced pressure. The residue was diluted with water (100 ml) and extracted with dichloromethane (225 ml). The dichloromethane extract was dried (anhydrous sodium sulfate), filtered and concentrated under reduced pressure. The residual, yellow, viscous material was a mixture by thin layer chromatographic (TLC) analysis (silica gel, hexane/dichloromethane, 1:1, v/v). The desired product, 7-[3',5'-bis(PFNP)phenyl]hept-6-enoic acid ethyl ester, was separated from the mixture by column chromatography on silica gel. Elution with a mixture of hexane/dichloromethane (1:1, v/v) initially furnished some starting materials, followed by the pure product, which was isolated as a viscous oil (6.12 g, 0.0087 mol, 34% of theoretical). The oil, 7-[3',5'-bis(PFNP)phenyl]hept-6-enoic acid ethyl ester, was homogeneous by TLC (silica gel, Rf=0.6 following elution with dichloromethane/hexane, 4:6, v/v).
The 1 H NMR spectrum of its CDCl 3 solution showed the following resonances: 7.23 (s, 2H, aromatic), 7.11 (s, 1H, aromatic), 6.38 (d, 1H, ═CH), 5.70 (m, 1H, CH), 4.14 (q, 2H, OCH 2 ), 3.41 (s, 4H, CH 2 ), 2.28 (m, H, CH 2 ), 1.58 (m, 4H, CH 2 ), and 1.27 (t, 3H, CH 3 ) ppm.
The above compound was converted to 7-[3',5'-bis(PFNP)phenyl]heptanoic acid ethyl ester (FIG. 1, 6). 7-[3',5'-bis(PFNP)phenyl]hept-6-enoic acid ethyl ester (FIG. 1, 5) (5.98 g, 0.009 mol) was dissolved in ethanol (125 ml), palladium on charcoal (10%, 0.21 g) was added, and the suspension was hydrogenated at 50 psi until hydrogen uptake ceased. The catalyst was removed by filtration, and the ethanol was evaporated to provide crude 7-[3',5'-bis(PFNP)phenyl]heptanoic acid ethyl ester (FIG. 1, 6) as an oil (5.91 g, 0.0085 mol, 99% of theoretical). The product was homogeneous by TLC (Rf=0.6, silica gel eluted with hexane/dichloromethane, 3:1, v/v).
By elemental analysis the compound contained (calculated for C 17 H 8 F 18 O) C, 36.03 (35.78); H, 1.35 (1.40); F, 59.69 (60.0). The 1 H NMR spectrum of its CDCl 3 solution showed the following resonances relative to TMS: 7.23 (s, 1H, aromatic), 7.11 (s, 1H, aromatic), 4.12 (q, 2H, OCH 2 ), 3.34 (s, 4H, CH 2 ), 2.54 (t, 2H, CH 2 ), 2.25 (t, 2H, CH 2 ), 1.55 (m, 4H, CH 2 ). 1.27 (m, 4H, CH 2 ), and 1.22 (t, 3H, CH 3 ) ppm. The 19 F NMR spectrum of its CDCl 3 solution consisted of a single resonance at -65.51 (s, 18F) ppm relative to Freon.
Next, 7-[3',5'-bis(PFNP)phenyl]heptanoic acid (FIG. 1, 7) was made by dissolving 7-[3',5'-bis(PFNP)phenyl]heptanoic acid ethyl ester (FIG. 1, 6) in trifluoroacetic acid (TFA) solution (50 ml TFA and 5 ml water) and heating under reflux at 105° C. bath temperature for twenty hours. The mixture was cooled, and most of the trifluoroacetic acid was removed under reduced pressure. The residue was diluted with water (50 ml) and then titrated with 10% sodium hydroxide solution to pH 2.3. The aqueous solution was extracted in dichloromethane (200 ml), and the organic extract was washed with water (25 ml). Then the extract was dried (anhydrous sodium sulfate), filtered and concentrated under vacuum to furnish pure 7-[3',5'-bis(PFNP)phenyl]heptanoic acid (FIG. 1, 7) as an oil (5.22 g, 0.0078 mol, 92% of theoretical).
The 1 H NMR spectrum of its CDCl 3 solution showed the following resonances relative to TMS: 7.26 (s, H, aromatic), 7.05 (s, 2H, aromatic), 3.37 (s, 4H, CH 2 ), 2.58 (t, 2H, CH 2 ), 2.34 (t, 2H, CH 2 ), 1.58 (m, 4H, CH 2 ), and 1.34 (m, 4H, CH 2 ) ppm; the COOH proton was observed as a very broad resonance. The 19 F NMR spectrum consisted of a single resonance at -65.54 (s, 18F) relative to Freon.
2-Oleoyl glycerol was prepared by treatment of 1,3-benzylideneglycerol with oleoyl chloride in the presence of an equivalent quantity of pyridine in chloroform solution. The crude product is treated with boric acid in triethyl borate and heated at 100° C. The solvent was removed after 30 minutes and the residue extracted in diethyl ether. Removal of ether furnished the crude oleoyl glycerol which was purified by crystallization from cold petroleum ether kept below -15° C. The compound which was an oil at room temperature, was sufficiently pure to use without further purification. The 1,3-benzylidenglycerol was prepared by refluxing a solution of glycerol, benzaldehyde and p-toluenesulfonic acid (catalyst), in toluene. Concentration of toluene and cooling furnished the benzylideneglycerol as colourless crystals, additional material was obtained from the filtrates on standing, to furnish excellent yields of the product. Martin, The J. of the American Chem. Soc., 75:5482 (1953).
In the final step of the synthesis 1,3-bis{7-[3',5'-di(PFNP)phenyl]heptanoyl} 2-oleoyl glycerol ester (FIG. 1, 9) was prepared by dissolving 2-oleoyl glycerol (1.40 g, 0.004 mol) and 7-[3',5'-bis(PFNP)phenyl]heptanoic acid (FIG. 1, 7) (5.1 g, 0.0076 mol) in dichloromethane (25 ml) in a dry flask under an argon atmosphere and then adding a solution of dicyclohexylcarbodiimide (91.7 g, 0.008 mol) in dichloromethane (25 ml) with stirring. The mixture was initially cooled to 10° C. and then slowly warmed to room temperature. A small amount of dimethylaminopyridine (0.04 g, 0.0003 mol) was added when a solid began to precipitate. The reaction mixture was stirred overnight, and the precipitated dicyclohexylurea was removed by filtration. The filtrate was concentrated under vacuum, and the residue was chromatographed on silica gel. Elution with hexane/dichoromethane (1:1, v/v) furnished initially some impurities followed by 1,3-bis{7'-[3",5"-di(PFNP)phenyl]heptanoyl} 2-oleoyl glycerol ester (FIG. 1, 9). The glycerol ester was eluted completely with dichloromethane and was obtained as a colorless viscous oil (6.17 g, 0.0037 mol, 95% of theoretical). The ester was homogeneous by TLC (silica gel, R f =0.6 after elution with dichloromethane/hexane, 3:7, v/v).
By elemental analysis the ester contained (calculated for C 67 H 76 O 6 F 36 ): C, 48.42% (48.43%); H, 4.56% (4.57%); F, 40.56% (41.20%). Its 1 H NMR spectrum (CDCL 3 solution) consisted of the following resonances relative to TMS: 7.22 (s, 1H, aromatic), 7.03 (s, 2H, aromatic), 5.31 (m, 3H, CH), 4.06-4.03 (m, 4H, OCH 2 ), 3.34 (s, 8H, CH 2 ), 2.54 (t, 6H, CH 2 ), 2.27 (t, 6H, CH 2 ), 1.98 (m, 4H, CH 2 ), 1.47-1.55 (m, 14H, CH 2 ), 1.24-1.26 (m, 28H, CH 2 ), 0.85 (t, 3H, CH 3 ) ppm. Its 19 F NMR spectrum in the same solvent consisted of a single resonance at -65.16 (s, 36F) ppm relative to Freon. Additionally, mass spectral analysis of the final product showed the following: M+=1660, and major peaks at m/e 1379 (M=-281), 991, 653, 569, and 555 (base peak).
In Vivo Imaging
2-oleoyl glycerol -1,3-bis-(7'{3",5"-di[PFNP]phenyl)heptanoate) was prepared as described and emulsified in an oil-in-water emulsion containing a cholesterol:phosphatidyl choline ratio of 0.4 and a final volume of 10% (See also U.S. Pat. No. 4,873,075). An imaging dose of this emulsion was then injected intravenously into a rat.
Proton ( 1 H) and Fluorine ( 19 F) MRI studies were performed at 4.7 tesla using a purpose-built radio-frequency (RF) coil. See FIG. 2A and 2B respectively. The RF coil allows for "whole-body" imaging of rats and is tuneable to both protons and fluorine resonance frequencies so that the subject need not be moved during the MRI study. The proton MRI utilized the following parameters: Repetition time (TR)=1 second, echo time (TE)=18 milliseconds, image data matrix=128×128, number of excitations (NEX)=2, field of view (FOV)=128 nm, and slice thickness=2.5 or 5.0 mm. The fluorine MRI utilized the following parameters: TR=1 second, TE=18 milliseconds, image data matrix =64×64, NEX=32, FOV=128 nm, and slice thickness was not selected.
Proton and fluorine MRI were done before and after administration of the contrast agent emulsion. Proton MRI was used to provide anatomic markers for assessment of the fluorine images. When evaluating the proton MRI imaging results, the pre- and post-contrast images did not change in qualitative appearance. In the fluorine MRI study, there was no detectable signal in the pre-contrast agent images. Forty five minutes after injection of the contrast agent emulsion, a discernable fluorine MR image of the liver and upper intestinal lumen (indicative of biliary excretion) was typically seen. The signal-to-noise ratio for these images for the parameters noted above was generally 2 to 3. See FIG. 2.
EXAMPLE 2
Triglyceride containing both perfluoro-1H,1H-neopentyl phenyl groups and iodine containing aromatic rings can be prepared. In a typical example, glycerol 2-{7'(3",5"-bis [PFNP]phenyl) heptanoyl}-1,3 bis-(7'{3'-amino-2',4',6'-triiodophenyl}heptanoate) can be obtained by acylation of glycerol with 7-(3',5'-bis[PFNP]phenyl) heptanoic acid in the 2 position, followed by 1,3 acylation with two equivalents of the 7-[3'-amino-2',4',6'-triiodo phenyl} heptanoic acid in an inert solvent in the presence of a base such as 4-N,N-dimethylamino pyridine and dicylohexyl carbodiimide at room temperature as previously described. ##STR7##
EXAMPLE 3
The PFNP groups can be incorporated in the synthesis of a polypeptide or protein molecules to afford compounds as potential MRI agents. In a typical example, the 4-bromo benzylbromide can be converted to 4-formyl perfluoro-1H, 1H-neopentyl benzene in two steps by reacting with perfluoro isobutylene gas and cesium fluoride in monoglyme followed by transmetallation with n-butyl lithium in the presence of dimethylformamide. The formyl compound can be converted to 4-[PFNP]phenyl alanine via the Erlenmeyer azlactone intermediate. The derivatized phenylalanine can be incorporated in to polyamino acids and also into peptides and proteins. ##STR8##
Alternatively the water soluble amino group containing macromolecules can be reacted in aqueous solution with an active ester such as a N-hydroxysuccinimide ester of an acid containing the perfluoro1H,1H-neopentyl aryl substituents to furnish stable amides as MRI agents.
EXAMPLE 4
The following example shows the incorporation of the perfluoro-1H,1H-neopentyl aryl substituents into a diethylenetriamine pentaacetic acid derivative. Diethylenetriamine pentaacetic acid anhydride can be reacted with an amino derivative of [PFNP] benzene. This type of compounds can complex with metals such as Gd 3+ which can serve as 19 F MRI and as a paramagnetic contrast agent.
O-Methyl-3,5-bis(PFNP)Benzaldoxime
To a solution of 1-formyl-3,5-bis (PFNP) benzene, (5.25 g, 0.009 mol) in anhydrous ethanol (70 mL), O-methyl hydroxylamine hydrochloride (0.85 g, 0.012 mol) was added followed by dry pyridine (70 mL). The mixture was kept under reflux for 20 hours. The solvents were removed in a rotary evaporator under reduced pressure. Residue was washed with water and filtered. Recrystallisation from ethanol furnished the title compound as colourless crystals (4.81 g, 0.008mol, 91%), m.p. 101°-103° C.
The 1 H NMR spectrum of its CDCl 3 solution showed the following resonances relative to TMS: 8.00 (S, 1H, ═CH), 7.47 (S, 2H, Aromatic), 7.25 (S, 1H, Aromatic), 3.97 (S,3H, OCH 3 ), 3.40(S,4H, 2CH 2 ) ppm. Its 19 F NMR spectrum in the same solvent showed a single resonance at -65.57 (s, 18F) ppm relative to freon.
1-Aminomethyl-3,5-bis (PFNP) benzene
To a suspension of sodium borohydride (1.86 g, 0.05 mol) in anhydrous tetrahydrofuran (20 mL) which was kept in a dry flask under argon, trifluoroacetic acid (5.0 g, 0.043 mol) was added dropwise. The temperature of the mixture was kept at 10° C. during the addition. Subsequently, O-Methyl-3,5-bis (PFNP) benzaldoxime (4.6 g, 0.0076 mol) in anhydrous tetrahydrofuran (50 mL) was added dropwise while stirring. After addition the mixture was refluxed for 3 hours and was finally left stirring overnight at room temperature. After excess sodiumborohydride was decomposed with dilute acetic acid, the solvents were removed under reduced pressure. The residue was extracted with dichloromethane (90 mL) and dried (anhydrous sodium sulfate). Removal of the solvent gave a gummy solid of the title compound which was recrystallized from hot hexane. (1.71 g, 0.003 mol, 39%).
The 1 H NMR spectrum of its CDCl 3 solution showed the following resonances relative to TMS: 7.28 (S, 2H, Aromatic), 7.15 (S, 1H, Aromatic), 3.87 (S, 2H, NCH 2 ), 3.41 (S, 4H, 2CH 2 ). 19 F spectrum in the same solvent showed a single resonance at -65.51 (s, 18F) ppm relative to freon.
Trisodium N 3 ,N 9 -bis[3',5'-bis(PFNP)benzyl aminocarbonylmethyl]-N 6 -(carboxymethyl)-3,6,9-triazaundecanedioic acid
A solution of 1-aminomethyl-3,5-bis(PFNP) benzene (1.1 g, 0.001 mol) in dimethylformamide (5 mL) was added to diethylenetriaminepentaacetic acid anhydride (0.35 g, 0.0009 mol) in dimethylformamide (5 mL) containing triethylamine (0.5 mL) with stirring. The mixture was allowed to stand overnight at room temperature. Dimethylformamide was removed under reduced pressure and the residue was dissolved in pure acetone (30 mL) and the insoluble particles was filtered off. Adding the acetone filtrate to a stirring solution of sodium chloride (1N, 150 mL) resulted in the precipitation of a gummy solid. Addition of dilute hydrochloric acid (1N, 5 mL) to the gummy product, precipitated the pure N 3 ,N 9 -bis[3',5'-bis(PFNP)benzylaminocarbonyl-methyl]-N 6 -(carboxymethyl)-3,6,9-triazaundecanedioic acid as colourless crystals (1.2 g, 0.0008 mol., 87%). The crude acid was dissolved in methanol (10 mL) and titrated with sodiumhydroxide solution (1N) to pH 7.5. Methanol and water removed and the residue was dried in high vacuum to furnish the title trisodium salt (1.31 g, 0.00085 mol., 86%).
The gadolinium complex of trisodium N 3 ,N 9 -bis[3',5'-bis(PFNP)benzylaminocarbonylmethyl]-N 6 -(carboxymethyl)-3,6,9-triazaundecanedioic acid
The N 3 ,N 9 -bis[3',5'-bis(PFNP)benzylaminocarbonylmethyl]-N 6 -(carboxymethyl)-3,6,9-triazaundecanedioic acid trisodium salt (1.31 g, 0.00085 mol) was dissolved in a 1:1 methanol/water mixture (25 mL) and gadolinium(III) chloride hexahydrate (0,326 g, 0.00087 mol) was added. The mixture was gently warmed to 50° C. for 1 hour and the solvent was removed, the residue was dried in vacuum to furnish the gadolinium complex with some sodium chloride. See FIG. 4.
EXAMPLE 5
One way of making 19 F-labeled dendrimers is to use polyamidoamine dendrimers (PAMAM), as described in U.S. Pat. No. 4,558,120 by D. A. Tomalia (hereby incorporated by reference), and react them on their surface with a 19 F-labeled acid such as 4-PFNP-phenylacetic acid: An anhydrous solution of equimolar 4-PFNP-phenyl acetic acid and N-hydroxybenzotriazole in tetrahydrofuran is treated with one equivalent of dicyclohexylcarbodiimide. After stirring for 5 h at room temperature the precipitate of dicyclohexylurea is removed by filtration. A batch of polyamidoamine dendrimers (PAMAM) containing an equimolar amount of free amino groups is added to the anhydrous mixture. After stirring for 24 h, the mixture is quenched with water and worked up by procedures well-known to one skilled in the art.
Although the invention has been described in terms of the specific embodiments many modifications and variations of the present invention are possible in light of the 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. | Organic compounds for diagnostic imaging which contain at least one aryl group which has been derivatized to contain at least one perfluoro-1H,1H-neopentyl moiety are provided. The perfluoro-1H,1H-neopentyl groups produce a single magnetic resonance to insure a maximum signal to noise ratio. One compound disclosed is 2-O-oleoylglycerol 1,3-bis(7'-{3",5"-di[2"',2"'-di(trifluoromethyl)3"', 3"',3"'-trifluoropropyl]phenyl}heptanoate). In the preferred embodiment, a lipid emulsion is provided as a carrier vehicle to deliver the derivitized analog to a mammalian recipient. Methods to use these compounds in MRI and computerized tomography are provided. | 8 |
FIELD OF THE INVENTION
The present invention relates to beam-forming technologies, especially to a beam-forming method for realizing interference suppression, which guarantees direction of a formed beam not deviate.
BACKGROUND
Beam-forming refers to a process of computing an optimal weighting vector according to parameters and specifically refers to the process of realizing an optimal (sub-optimal) combination or an optimal (sub-optimal) allocation of signals after measuring and estimating parameters. The beam-forming technology uses an antenna array to aggregate signal power to a narrow beam so as to improve transmission efficiency of the antenna, reliability of the wireless link and repeat usage ratio of the frequency. Beam-forming algorithm can be designed based on different principles and generally there are two kinds of principles: maximum user power principle and maximum user CIR (Carrier to Interference ratio) principle. The beam-forming algorithm based on the maximum user power principle makes the receive power of the user maximum so that the receive SNR is improved. The beam-forming algorithm based on the maximum user CIR principle makes the receive CIR of the user maximum so that a null is formed in the direction of an interference signal and the directional interference is suppressed. Therefore, in order to suppress the interference signal, the beam-forming algorithm based on the maximum user CIR principle is often adopted.
In the conventional technology, the main idea of the beam-forming algorithm based on the maximum user CIR principle is that obtaining channel impulse responses of an expected user signal and interference signal respectively according to the channel estimation for the expected user signal and the interference signal in the received signals; obtaining array correlation matrix R S (k) of the expected user signal and the array correlation matrix R I (k) of the interference signal; and computing the beam-forming weighting coefficient of the array antenna according to the obtained array correlation matrixes.
Generally, the CIR received by user k can be expressed in formula (1).
γ
(
k
)
=
W
(
k
)
H
R
S
(
k
)
_
W
(
k
)
W
(
k
)
H
R
I
(
k
)
_
W
(
k
)
(
1
)
w (k) is the beam-forming weighting coefficient vector, R S (k) =h (k) *h (k)T is the array correlation matrix of the expected user signal, h (k) is the array channel impulse response vector of user
k , R I ( k ) _ = ∑ ∀ m ∈ I h I ( m ) * h I ( m ) T
is the array correlation matrix of the interference signal and I is a set of interference signals.
For the beam-forming algorithm based on the maximum user CIR principle, since the optimization principle of such kind of beam-forming algorithm leads to maximum CIR and has no limits on the receive power of the user, it may cause that the main lobe of the formed beam may not direct to the direction of the expected user signal. The reason is that according to the formula (1), the interference suppression algorithm is realized by improving the power of the expected user signal and reducing the power of the interference signal. However, for an array antenna with N antenna units, the power of the expected user signal can be improved at most by N times; however, for the interference suppression, the degrees of freedom of the array antenna is N−1, so if the number of the interference signals is not larger than N−1, the interference signal can be set to zero theoretically. In addition, the expected user signal and the interference signal cannot be completely orthogonal. Thus, there is a confliction between making the expected user signal maximum and setting the interference signal to zero and the direction of the formed beam based on the maximum CIR will be deviated.
Therefore, because of the limit of the degrees of freedom and the orthogonality, the beam-forming algorithm based on the maximum CIR principle cannot guarantee the direction of the main lobe of the beam and the power of the expected user signal, which not only reduces the power but also increases the susceptibility to the error of the interference signal estimation.
SUMMARY OF THE INVENTION
A main objective of the present invention is to provide a beam-forming method for realizing interference suppression, which can suppresses strong interference signals and guarantee direction of a formed beam not deviate.
In order to achieve the above objective, the technical solution of the present invention is realized by providing a beam-forming method for realizing interference suppression which includes steps of:
a. performing channel estimation for an expected user signal and an interference signal in signals received by an array antenna and obtaining array channel impulse responses of the expected user signal and the interference signal respectively;
b. obtaining array correlation matrixes of the expected user signal and the interference signal respectively according to the array channel impulse responses obtained in step a;
c. obtaining a new array correlation matrix of the interference signal according to relation between the expected user signal with the interference and noise; and
d. computing a beam-forming weighting coefficient of the array antenna according to the array correlation matrix of the expected user signal obtained in step b and the new array correlation matrix of the interference signal obtained in step c.
In the above solution, the step of obtaining the new array correlation matrix of the interference signal in step c specifically includes:
c1. setting a ratio coefficient according to a desired constraint ability on power of the expected user signal and power of the interference signal;
c2. computing a sum of diagonal elements in the array correlation matrix of the interference signal obtained in step b; and
c3. adding the array correlation matrix of the interference signal obtained in step b to a product of the ratio coefficient, the sum of diagonal elements in the array correlation matrix of the interference signal and an unit array to obtain the new array correlation matrix of the interference signal.
The value of the ratio coefficient ranges between 0 and positive infinity.
The interference in the above solution includes interference in home cell, interference from outside cells and interference between base stations in a non-symmetry service mode in a TDD system.
According to the beam-forming method for realizing interference suppression provided by the present invention, the beam-forming method can suppress the interference and noise at the same time and control power of interference signal become smaller and the expected power become larger by computing the new array correlation matrix of the interference signal according to the relation between the interference and noise with the expected user signal and computing the beam-forming weighting coefficient of the array antenna according to the new array correlation matrix of the interference signal, so that strong interference can be suppressed while the power will not reduce and the direction of the formed beam will not deviate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart of a method according to an embodiment of the present invention;
FIG. 2 is a schematic diagram showing architecture of an eight-unit uniform round array; and
FIG. 3 is a diagram showing comparison between the method of an embodiment of the present invention and the conventional technology.
DETAILED DESCRIPTION OF THE INVENTION
In the beam-forming algorithm based on the maximum CIR (Carrier to Interference ratio) principle, since generally the ratio between the power of a received expected user signal and SINR (Signal-Interference & Noise Ratio) is required to be the maximum, i.e. the array correlation matrix in the denominator in formula (1) should be a sum of interference correlation matrixes and a noise correlation matrix, and the noise doesn't have a space correlation characteristic, the array correlation matrix of the noise is a unit matrix. In receiving the beam-forming, it is applicable that the correlation matrix in the denominator in formula (1) is the sum of interference correlation matrixes and the noise correlation matrix, but in the transmission process since noise sequences received by a user are fixed, there is no noise correlation matrix but only the interference correlation matrix in the transmission process.
For the beam-forming algorithm, only by suppressing the interference and the noise at the same time, i.e. making the power of received interference signal (signals) smallest and the power of expected user signal largest, the received SINR may be made largest. However, if there is no noise item, the beam-forming algorithm may only suppress the power of the interference signal, not constraint the power of the expected user signal, which will make the power of the expected user signal very small.
According to the above principle, the key of the present embodiment is to introduce a constant item and regards it as the received noise correlation matrix. This constant item has no physical meaning but only the function to guarantee the range of the numerator value in mathematics. When considering relation between the value of the unit matrix and the value of the noise correlation matrix, the smaller the constant item is, the stronger the ability of the beam-forming algorithm to suppress the interference is; and the larger the constant item is, the stronger the ability of the beam-forming algorithm to maximize the receiving power of the expected user signal is.
The main idea of the present embodiment is to take a sum of the computed array correlation matrix of the interference signal (signals) with the introduced constant item as new array correlation matrix of the interference signal (signals), and then compute beam-forming weight coefficient of the current array antenna according to the new array correlation matrix of the interference signal so as to guarantee the suppression of the beam-forming algorithm on the interference signal.
As shown in FIG. 1 , the beam-forming method of an embodiment of the present invention includes the following steps.
In step 101 , the channel estimation is performed on the expected user signal and the interference signal (signals) respectively in the signals received by all the antennas in the current array antenna, so as to obtain the array channel impulse response h (k) of the expected user signal and the array channel impulse response h I (m) , m=1, . . . , M of the interference signal according to channel estimation method in the related art, wherein M is the number of the interference signals.
In the present embodiment, the interference includes interference in the home cell, interference from outside cells and interference between base stations in a non-symmetry service mode in a TDD (Time Division Duplex) system.
In step 102 , the array correlation matrix R S (k) of the expected user signal and the array correlation matrix R I (k) of the interference signal are computed respectively based on the array channel impulse response obtained in step 101 and formula (2) and (3), wherein the array correlation matrix R I (k) of the interference signal is simply called interference correlation matrix R I (k) .
R
S
(
k
)
_
=
h
(
k
)
*
h
(
k
)
T
(
2
)
R
I
(
k
)
_
=
∑
∀
m
∈
I
h
I
(
m
)
*
h
I
(
m
)
T
(
3
)
In step 103 , a new interference correlation matrix R I (k) is obtained according to relation between the power of interference signal and power of expected user signal and relation between the unit matrix and the noise correlation matrix. At this time, the interference correlation matrix R I (k) is called the former interference correlation matrix R I (k) . The obtaining process specifically includes the following steps.
Firstly, the trace of the former interference correlation matrix R I (k) is computed according to formula (4), i.e. the sum P of the diagonal elements in the former interference correlation matrix R I (k) is computed;
P = tr R I ( k ) _ = ∑ n N ( R I ( k ) _ ) n , n ( 4 )
n represents a sequence number of an antenna unit, N represents the number of the antenna units and the meaning of formula (4) is the sum of the diagonal elements of R I (k) .
Then, a ratio coefficient λ between the interference correlation matrix and a constant unit array is set, the value of which represents the constraint ability on the power of expected user signal and the power of interference signal and ranges between 0 and positive infinity. If the value of λ is 0, it means that only interference signal is constrained and the expected user signal is not constrained. If the value of λ is positive infinity, it means that only the expected user signal is constrained and the interference signal is not constrained.
Then, the new interference correlation matrix
R I ( k ) _ ′
is obtained according to the relation between the expected user signal and the interference and noise, which is shown in formula (5).
R I ( k ) _ ′ = R I ( k ) _ + λ PI ( N ) ( 5 )
I is a constant unit array.
In step 104 , a beam-forming weighting coefficient w (k) of the array antenna is computed according to the array correlation matrix R S (k) of the expected user signal and the new interference correlation matrix
R I ( k ) _ ′
and based on the formula (6).
w
(
k
)
=
arg
max
w
H
R
S
(
k
)
_
w
w
H
R
I
(
k
)
_
w
(
6
)
In the following description, a specific example will be adopted to illustrate the implementation process of the beam-forming method of an embodiment of the present invention. In the present embodiment, the adopted array antenna is an eight-unit uniform round array antenna, as shown in FIG. 2 . The radius of the array antenna is 0.65λ and there are three interference signals. The direction-of-arrival φ of the expected user signal in the signals received by the array antenna is 50° and the direction-of-arrivals of the three interference signals are 30°, 150° and 250° respectively and they are single path channels.
In step a, a channel estimation is performed on the expected user signal and the interference signal respectively in the signals received by all the antennas in the array antenna, and the array channel impulse response h (1) of the expected user signal and the array channel impulse responses h I (1) , h I (2) , h I (3) of the interference signals are obtained.
h
(
1
)
=
[
-
0.7960
+
0.5002
i
-
0.5975
-
0.7670
i
-
1.0608
-
0.0454
i
0.9353
+
0.3255
i
-
0.9260
-
0.5069
i
-
0.6678
+
0.7391
i
-
1.0130
-
0.0790
i
0.9850
-
0.3019
i
]
h
I
(
1
)
=
[
-
0.8493
-
0.3787
i
-
0.6915
-
0.6868
i
-
0.5149
+
0.8326
i
0.4894
-
0.8939
i
-
0.9793
+
0.3720
i
-
0.7618
+
0.6590
i
-
0.4670
-
0.9570
i
0.5391
+
0.9175
i
]
h
I
(
2
)
=
[
-
0.8493
+
0.3915
i
0.4942
-
0.8381
i
-
0.5149
+
0.8326
i
-
0.6964
-
0.7427
i
-
0.9793
-
0.3982
i
0.4240
+
0.8102
i
-
0.4670
-
0.9570
i
-
0.6467
+
0.7662
i
]
h
I
(
3
)
=
[
0.2467
-
0.9785
i
-
0.8446
+
0.5639
i
-
0.8282
+
0.5829
i
-
0.1566
-
1.0110
i
0.1167
+
0.9718
i
-
0.9148
-
0.5917
i
-
0.7804
-
0.7073
i
-
0.1069
+
1.0345
i
]
In step b, the array correlation matrix R S (k) of the expected user signal and the interference correlation matrix R I (k) are computed respectively according to formula (2) and (3).
In step c, the ratio coefficient λ is set to 0.2 according to the constraint ability on the power of expected user signal and the power of interference signal, and the trace of the interference correlation matrix R I (k) is computed according to formula (4), i.e. the sum P of the diagonal elements is computed.
P = tr R I ( k ) _ = ∑ n N ( R I ( k ) _ ) n , n = 24 .4309
And then, the new interference correlation matrix
R I ( k ) _ ′
is obtained according to formula (5).
R
I
(
k
)
_
′
=
R
I
(
k
)
_
+
λ
PI
(
N
)
=
R
I
(
k
)
_
+
0.2
*
24.4309
I
(
N
)
=
R
I
(
k
)
_
+
4.8862
I
(
N
)
In step d, the beam-forming weighting coefficient of the eight-unit array antenna is computed according to the R S (k) obtained in step b and the
R I ( k ) _ ′
obtained in step c based on the formula (6). In the present embodiment, un-amended beam-forming coefficient w 0 and amended beam-forming coefficient w are shown as below respectively.
w 0 = [ - 0.1906 + 0.6533 i - 0.1058 + 0.1922 i - 0.1837 + 0.2538 i 0.0211 + 0.1399 i 0.2177 - 0.0710 i - 0.2306 - 0.2814 i 0.3196 - 0.2764 i 0.0631 + 0.0573 i ] w = [ - 0.2833 + 0.1018 i - 0.1389 - 0.2474 i - 0.3366 - 0.2494 i 0.1770 + 0.3279 i - 0.0886 - 0.2738 i - 0.2647 + 0.0693 i - 0.4379 - 0.1094 i 0.3820 - 0.0848 i ]
The term “amended” here refers to add (introduce) the weighting of the constant item and the term “un-amended” refers to not add the weighting of the constant item.
FIG. 3 is a diagram showing effect comparison between the beam formed by the method of the present invention and the beam formed by the method of an embodiment of the conventional technology. In FIG. 3 , arrowed solid line 30 represents the direction of the expected user signal, three arrowed broken lines 31 represent the directions of the three interference signals, the solid beam 32 represents the beam formed by the method of the conventional technology and the broken line 33 represents the beam formed by the method of an embodiment of the present invention. FIG. 3 shows that the beam formed by the method of the conventional technology in the expected user signal direction is smaller than that in the interference signal direction and the beam formed by the method of an embodiment of the present invention in the expected user signal direction is obviously larger than that in the interference signal direction, which may suppress interference and guarantee the directivity of the formed beam.
The beam-forming method of the present invention may be used to receive and transmit beam-forming. In the receiving process using the beam-forming method, the interference refers to that on the expected user signal by the signal of the interference signal in the received signals; in the transmission process using the beam-forming method, the interference refers to that on the transmission signal of the interference user by the transmission signal of the expected user.
The above are only preferred embodiments of the present invention, which are not intended to limit the protection scope of the present invention. | The present invention discloses a beam-forming method for realizing interference suppression, comprising steps of: a. performing channel estimation for an expected user signal and interference signal in signals received by an array antenna and obtaining array channel impulse responses of the expected user signal and the interference signal respectively; b. obtaining array correlation matrixes of the expected user signal and the interference signal respectively according to the array channel impulse responses obtained in step a; c. obtaining a new array correlation matrix of the interference signal according to relation between the expected user signal with the interference and noise; and d. computing a beam-forming weighting coefficient of the array antenna according to the array correlation matrix of the expected user signal obtained in step b and the new array correlation matrix of the interference signal obtained in step c. According to this method, strong interference signals can be suppressed and the direction of the formed beam will not deviate. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. provisional application Ser. No. 60/146,142, filed Jul. 30, 1999.
FIELD OF THE INVENTION
The present invention relates generally to the amplification of nucleic acids in a single phase. In a preferred embodiment, the present invention can facilitate the proportional amplification of minute sample amounts of nucleic acids in a manner that may preserve the relative abundance of the individual nucleic acid species, or portions thereof, existing in the original sample.
BACKGROUND OF THE INVENTION
The isolation, characterization and manipulation of nucleic acids has numerous present or potential applications, including those in the basic research, diagnostic and forensic fields. Valuable information about gene expression in in vivo, in situ, and in vitro systems can be obtained by monitoring the abundance of the mRNA encoded by those genes. Methods involving the synthesis of cDNA from mRNA have also enhanced the study of gene expression, for example, by facilitating gene cloning and the production of desired recombinant proteins.
With existing methods for the study or use of mRNA and cDNA, one problematic scenario can arise where the sample size is small, or the relative abundance of an individual mRNA or cDNA species in a sample is low. In such situations, where the availability or accessibility of the desired mRNA or cDNA is compromised (or their amounts are otherwise limited), the lower limits of monitoring or manipulation systems may be exceeded, thus leaving the desired mRNA or cDNA undetected, unrecoverable or unworkable. Therefore, the amplification of such mRNA and cDNA is an important molecular biology methodology, with particular significance in facilitating the detection and study of a broader range of mRNA molecules, and the isolation and manipulation of mRNA available in only minute quantities.
Known nucleic acid amplification methods may typically involve multiple steps and varying reaction conditions such as organic extraction and precipitation. As result, these methodologies can be labor intensive and costly. For example, to amplify RNA in a heterogenous RNA population, known methods can require that a second strand cDNA synthesis is performed in a volume that is more than three times the volume of the first strand cDNA synthesis reaction. Prior to the in vitro transcription (IVT) reaction, in which RNA polymerase may use promoter containing double-stranded cDNA as templates for RNA transcription, the cDNA sample typically must be cleaned by, for example, phenol extraction and ethanol precipitation. When these cleaning and concentration steps are not used, the IVT reaction may be inhibited due to undesirable buffer conditions and enzymatic activities.
In addition, although methods exist for the amplification of nucleic acids, they generally suffer from a phenomenon known as biased amplification. In these cases, the amplified population does not proportionally represent the population of nucleic acid species existing in the original sample. This drawback may preclude meaningful or reliable conclusions regarding the absolute amount or relative abundance of a desired nucleic acid species in the tested sample.
One common problem encountered by past amplification methods is the preference for the amplification of shorter nucleic acid templates. The enzymes responsible for the production of complements or copies of the nucleic acid templates (e.g., DNA and RNA polymerases, or reverse transcriptases) achieve such synthesis through a sequential, oriented process, whether 5′ to 3′ or 3′ to 5′. The probability that such an enzyme will complete a copying event thus may be greater with nucleic acid templates of shorter length. Accordingly, in a sample population containing nucleic acid templates of variable lengths, longer templates may be less likely than shorter templates to be amplified in complete, full-length form. This can result in a bias in the amplified population in favor of nucleotide sequences proximal to the 3′ poly(A) tail of mRNA, for example, a phenomenon known as 3′-sequence bias.
The synthesis of longer templates can also be difficult or less efficient due to interference from secondary and tertiary structure in the template. For example, with respect to nucleic acid amplification based on polymerase chain reaction (PCR) methodologies, longer templates in a sample may be under-represented in the amplified product if respective primers cannot anneal to begin another round of copying because the first round did not proceed to completion. Other potential sources of bias can reflect relative differences between longer and shorter templates. For example, longer templates may (i) not denature sufficiently, or (ii) have a greater likelihood of mismatches, and thus error propagation through amplification, but (iii) have an ability to anneal more easily.
The foregoing shows a need for methods and products involving the amplification of nucleic acids in a simplified manner, and preferably, to facilitate the preservation of the relative abundance of the individual nucleic acid species existing in the original sample.
SUMMARY OF THE INVENTION
An objective of the present invention is therefore the amplification, preferably proportionally, of nucleic acids in a single phase.
In accomplishing these and other objectives, the present invention provides methods for the amplification, preferably proportionally, of nucleic acids that may comprise synthesizing double-stranded DNA from a single-stranded DNA population, and producing multiple copies of RNA from the double-stranded DNA, where the amplification occurs in a single phase. In one preferred embodiment, this process may incorporates the use of an automated machine, preferably a PCR thermocycler.
In a preferred embodiment, the present invention provides methods in which the single-stranded or double-stranded DNA population may be produced from a nucleic acid population selected from the group consisting of one or more of the following: genomic DNA, cDNA, total RNA, poly(A) + RNA, and oligonucleotides. In a preferred embodiment, the poly(A) + RNA may be mRNA.
The present invention also preferably provides methods, which may further comprise contacting the multiple copies of RNA with a solid support comprising nucleic acid probes, and detecting the presence or absence of hybridization of the RNA to the nucleic acid probes on the solid support. In a preferred embodiment, the solid support, which may comprise nucleic acid probes, can be selected from the group consisting of a nucleic acid probe array, a membrane blot, a microwell, a bead, and a sample tube.
The present invention may preferably provide methods wherein the nucleic acid may be isolated from an eukaryotic cell or tissue, mammalian cell or tissue, or human cell or tissue. In a preferred embodiment, the nucleic acid may be isolated from a source selected from the group consisting of dissected tissue, microdissected tissue, a tissue subregion, a tissue biopsy sample, a cell sorted population, a cell culture, and a single cell. In another preferred embodiment, the nucleic acid may be isolated from a cell or tissue source selected from the group consisting of brain, liver, heart, kidney, lung, spleen, retina, bone, lymph node, endocrine gland, reproductive organ, blood, nerve, vascular tissue, and olfactory epithelium. In yet another preferred embodiment, the nucleic acid may be isolated from a cell or tissue source selected from the group consisting of embryonic and tumorigenic.
In a preferred embodiment, the present invention may provide an amplified nucleic acid preparation comprising RNA obtained by the described methods. In another preferred embodiment, the present invention may also provide an amplified nucleic acid preparation comprising DNA obtained by the described methods.
The present invention preferably provides a gene expression monitoring system comprising a solid support, which comprises nucleic acid probes and the amplified nucleic acid preparations. In a preferred embodiment, the present invention may provide a nucleic acid detection system comprising the amplified nucleic acid preparations immobilized to a solid support.
In yet another preferred embodiment, the invention relates to a kit comprising a means for the single-phase amplification. Preferably, the means is a reaction vessel containing one or more reagents in concentrated form, where the reagent may be an enzyme or enzyme mix.
Other objectives, features, and advantages of the present invention will become apparent from the following detailed description. The detailed description and the specific examples, while indicating preferred embodiments of the invention, are provided by way of illustration only. Accordingly, the present invention also includes those various changes and modifications within the spirit and scope of the invention that may become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 depicts an overview of a preferred embodiment of the single-phase amplification methods of the present invention. PolyA+ or total RNA is annealed with the single-stranded oligo dT-tailed promoter primer, T 7 T 20 (ggC Cag TgA ATT gTA ATA CgA CTC ACT ATA ggg Agg Cgg (T) 20 (SEQ ID NO. 1)), creating a primer-template mixture. First strand cDNA synthesis is accomplished by combining the first strand cDNA reagent mix (Superscript II, buffer, DTT, and dNTPs) with the primer-template mixture and incubating at the appropriate time and temperature. Second strand cDNA synthesis is then performed by mixing the first strand cDNA reaction with second strand reagent mix, containing secondary cDNA mix (depc-H 2 O, Tris-HCl (pH7.0), MgCl 2 , (NH 4 )SO 4 , beta-NAD + , and dNTPs) and cDNA enzyme mix (Amplitaq DNA polymerase, E. coli ligase, E. coli RNase H, and E. coli DNA polymerase I)), followed by incubation at the appropriate times and temperatures. The resulting double-stranded (ds) cDNA contains a functional T7 RNA polymerase promoter, which is utilized for transcription. Finally, in vitro transcription is performed by combining the (ds) cDNA with NT reagent (NTP, buffer, T7 RNA polymerase), yielding amplified, antisense RNA.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention can eliminate the need for multiple steps and varying reaction conditions and their associated problems. In preferred embodiments of the present invention, at least three otherwise separate enzymatic reactions can occur consecutively in one phase (i.e., without organic extraction and precipitation), more preferably in the same reaction vessel. Preferably, cDNA synthesis according to the present invention may occur in a modified low salt buffer. In addition, the invention may involve a four-enzyme mix, which may include a thermal stable DNA polymerase and reverse transcriptase for the production of cDNA, terminal transferase, and RNA polymerase for RNA transcription. The enzyme activity may be inactivated at the appropriate step with either heat or chemical treatment (i.e., adjusting the salt concentration) or by the addition of an antibody specific to the enzyme. Furthermore, the single-phase amplification of nucleic acids can take place in the presence of less nucleotides than those which may be required in known methods.
Those skilled in the art will recognize that the products and methods embodied in the present invention may be applied to a variety of systems, including commercially available gene expression monitoring systems involving nucleic acid probe arrays, membrane blots, microwells, beads, and sample tubes, constructed with various materials using various methods known in the art. Accordingly, the present invention is not limited to any particular environment, and the following description of specific embodiments of the present invention are for illustrative purposes only.
In a preferred embodiment, the present invention can involve the amplification of nucleic acids, which may comprise synthesizing double-stranded DNA from a single-stranded DNA population, and producing multiple copies of RNA from the double-stranded DNA, where the synthesizing and producing occur in reaction vessels, preferably in the same reaction vessel.
The reaction vessel according to the present invention may include a membrane, filter, microscope slide, microwell, sample tube, array, or the like. See International Patent applications No. PCT/US95/07377 and PCT/US96/11147, which are expressly incorporated herein by reference. The reaction vessel may be made of various materials, including polystyrene, polycarbonate, plastics, glass, ceramic, stainless steel, or the like. The reaction vessel may preferably have a rigid or semi-rigid surface, and may preferably be conical (e.g., sample tube) or substantially planar (e.g., flat surface) with appropriate wells, raised regions, etched trenches, or the like. The reaction vessel may also include a gel or matrix in which nucleic acids may be embedded. See A. Mirzabekov et al., Anal. Biochem . 259(1):34-41 (1998), which is expressly incorporated herein by reference.
Nucleic acids according to the present invention may include any polymer or oligomer of pyrimidine and purine bases, preferably cytosine, thymine, and uracil, and adenine and guanine, respectively. See Albert L. Lehninger, Principles of Biochemistry , at 793-800 (Worth Pub. 1982). Indeed, the present invention contemplates any deoxyribonucleotide or ribonucleotide component, and any chemical variants thereof, such as methylated, hydroxymethylated or glucosylated forms of these bases, and the like. The polymers or oligomers may be heterogeneous or homogeneous in composition, and may be isolated from naturally-occurring sources or may be artificially or synthetically produced. See U.S. Pat. No. 5,800,992, which is expressly incorporated herein by reference. In addition, the nucleic acids may be DNA or RNA, or a mixture thereof, and may exist permanently or transitionally in single-stranded or double-stranded form, including homoduplex, heteroduplex, and hybrid states.
The single-stranded or double-stranded DNA populations according to the present invention may refer to any mixture of two or more distinct species of single-stranded DNA or double-stranded DNA, which may include DNA representing genomic DNA, genes, gene fragments, oligonucleotides, polynucleotides, nucleic acids, PCR products, expressed sequence tags (ESTs), or nucleotide sequences corresponding to known or suspected single nucleotide polymorphisms (SNPs), having nucleotide sequences that may overlap in part or not at all when compared to one another. The species may be distinct based on any chemical or biological differences, including differences in base composition, order, length, or conformation. The single-stranded DNA population may be isolated or produced according to methods known in the art, and may include single-stranded cDNA produced from a mRNA template, single-stranded DNA isolated from double-stranded DNA, or single-stranded DNA synthesized as an oligonucleotide. The double-stranded DNA population may also be isolated according to methods known in the art, such as PCR, reverse transcription, and the like.
Where the nucleic acid sample contains RNA, the RNA may be total RNA, poly(A) + RNA, mRNA, rRNA, or tRNA, and may be isolated according to methods known in the art. See, e.g, T. Maniatis et al., Molecular Cloning: A Laboratory Manual, 188-209 (Cold Spring Harbor Lab., Cold Spring Harbor, N.Y. 1982, which is expressly incorporated herein by reference. The RNA may be heterogeneous, referring to any mixture of two or more distinct species of RNA. The species may be distinct based on any chemical or biological differences, including differences in base composition, length, or conformation. The RNA may contain full length mRNAs or mRNA fragments (i.e., less than full length) resulting from in vivo, in situ, or in vitro transcriptional events involving corresponding genes, gene fragments, or other DNA templates. In a preferred embodiment, the mRNA population of the present invention may contain single-stranded poly(A)+ RNA, which may be obtained from a RNA mixture (e.g., a whole cell RNA preparation), for example, by affinity chromatography purification through an oligo-dT cellulose column.
Where the single-stranded DNA population of the present invention is cDNA produced from a mRNA population, it may be produced according to methods known in the art. See, e.g, Maniatis et al., supra, at 213-46. In a preferred embodiment, a sample population of single-stranded poly(A)+ RNA may be used to produce corresponding cDNA in the presence of reverse transcriptase, oligo-dT primer(s) and dNTPs. Reverse transcriptase may be any enzyme that is capable of synthesizing a corresponding cDNA from an RNA template in the presence of the appropriate primers and nucleoside triphosphates. In a preferred embodiment, the reverse transcriptase may be from avian myeloblastosis virus (AMV), Moloney murine leukemia virus (MMuLV) or Rous Sarcoma Virus (RSV), for example, and may be thermal stable enzyme (e.g., hTth DNA polymerase).
In a preferred embodiment of the present invention, the single-stranded cDNA produced using a mRNA population as template may be isolated from any resulting RNA:DNA heteroduplexes by heat or enzyme treatment (e.g., RNase H). In a preferred embodiment, terminal transferase may be used to add poly(A) or poly(G) sequences to the 3′-termini of the single-stranded DNA. The double-stranded DNA of the present invention may be synthesized from the heterogeneous single-stranded DNA.
An oligonucleotide primer may be applied to the poly(A), poly(G), poly(C) or poly (T) tailed heterogeneous single-stranded DNA. The oligonucleotide primer preferably includes a poly(T) or poly(C) region complementary to the poly(A) or poly(G) tail attached to the single-stranded DNA. In addition, the oligonucleotide primer preferably includes a promoter consensus sequence capable of facilitating transcription by the RNA polymerase used, for example, the DNA-directed RNA polymerases derived from bacteriophage T7, T3 or SP6. The oligonucleotide primer may be synthesized, for example, using a PCR-MATE Model 391 DNA synthesizer (Applied Biosystems) and purified by high-performance liquid chromatography before use. Second strand DNA synthesis may occur to yield the double-stranded DNA. See, e.g., Examples, infra.
In a preferred embodiment of the present invention, the ends of the double-stranded DNA may be blunted to prevent any concatenation of the double-stranded DNA. T4 DNA polymerase or Escherichia coli DNA polymerase I (Klenow fragment), for example, may be used preferably to produce blunt ends in the presence of the appropriate dNTPs.
In another preferred embodiment, multiple copies of the DNA may be obtained according to PCR methods known in the art in the presence of the appropriate primers. See R. K. Saiki et al., Science 220:1350-1354 (1985), which is expressly incorporated herein by reference. In such circumstances, PCR cycles may preferably be limited to less than twenty to minimize amplification bias.
Multiple copies of RNA according to the present invention may be obtained by in vitro transcription from the DNA preferably using T7 RNA polymerase in the presence of the appropriate nucleoside triphosphates.
In a preferred embodiment of the present invention, the multiple copies of RNA may be labeled by the incorporation of biotinylated, fluorescently labeled or radiolabeled CTP or UTP during the RNA synthesis. See U.S. Pat. No. 8,800,992 and International Patent Application PCT/US96/14839, which is expressly incorporated herein by reference. Alternatively, labeling of the multiple copies of RNA may occur following the RNA synthesis via the attachment of a detectable label in the presence of terminal transferase. In a preferred embodiment of the present invention, the detectable label may be radioactive, fluorometric, enzymatic, or calorimetric, or a substrate for detection (e.g., biotin). Other detection methods, involving characteristics such as scattering, IR, polarization, mass, and charge changes, may also be within the scope of the present invention.
In a preferred embodiment, the amplified DNA or RNA of the present invention may be analyzed with a gene expression monitoring system. Several such systems are known. See, e.g., U.S. Pat. No. 5,677,195; Wodicka et al., Nature Biotechnology 15:1359-1367 (1997); Lockhart et al., Nature Biotechnology 14:1675-1680 (1996), which are expressly incorporated herein by reference. A gene expression monitoring system according to the present invention may be a nucleic acid probe array such as the GeneChip® nucleic acid probe array (Affymetrix, Santa Clara, Calif.). See U.S. Pat. Nos. 5,744,305, 5,445,934, 5,800,992 and International Patent applications PCT/US95/07377, PCT/US96/14839, and PCT/US96/14839, which are expressly incorporated herein by reference. A nucleic acid probe array preferably comprises nucleic acids bound to a substrate in known locations. In other embodiments, the system may include a solid support or substrate, such as a membrane, filter, microscope slide, microwell, sample tube, bead, bead array, or the like. The solid support may be made of various materials, including paper, cellulose, nylon, polystyrene, polycarbonate, plastics, glass, ceramic, stainless steel, or the like. The solid support may preferably have a rigid or semi-rigid surface, and may preferably be spherical (e.g., bead) or substantially planar (e.g. flat surface) with appropriate wells, raised regions, etched trenches, or the like. The solid support may also include a gel or matrix in which nucleic acids may be embedded. See A. Mirzabekov et al., Anal. Biochem . 259(1):34-41 (1998).
The gene expression monitoring system, in a preferred embodiment, may comprise a nucleic acid probe array (including an oligonucleotide array, a cDNA array, a spotted array, and the like), membrane blot (such as used in hybridization analysis such as Northern, Southern, dot, and the like), or microwells, sample tubes, beads or fibers (or any solid support comprising bound nucleic acids). See U.S. Pat. No. 5,770,722, No. 5,744,305, No. 5,677,195 and No. 5,445,934, which are incorporated here in their entirety by reference. See also Examples, infra. The gene expression monitoring system may also comprise nucleic acid probes in solution.
The gene expression monitoring system according to the present invention may be used to facilitate a comparative analysis of expression in different cells or tissues, different subpopulations of the same cells or tissues, different physiological states of the same cells or tissue, different developmental stages of the same cells or tissue, or different cell populations of the same tissue. See U.S. Pat. No. 5,800,922. In a preferred embodiment, the proportional amplification methods of the present invention can provide reproducible results (i.e., within statistically significant margins of error or degrees of confidence) sufficient to facilitate the measurement of quantitative as well as qualitative differences in the tested samples. The proportional amplification methods of the present invention may also facilitate the identification of single nucleotide polymorphisms (SNPs) (i.e., point mutations that can serve, for example, as markers in the study of genetically inherited diseases) and other genotyping methods from limited sources. See, e.g., Collins et al., 282 Science 682 (1998), which is expressly incorporated herein by reference. The mapping of SNPs can occur by any of various methods known in the art, one such method being described in U.S. Pat. No. 5,679,524, which is hereby incorporated by reference.
The RNA, single-stranded DNA, or double-stranded DNA population of the present invention may be obtained or derived from any tissue or cell source. Indeed, the nucleic acid sought to be amplified may be obtained from any biological or environmental source, including plant, viron, bacteria, fungi, or algae, from any sample, including body fluid or soil. In one embodiment, eukaryotic tissue is preferred, and in another, mammalian tissue is preferred, and in yet another, human tissue is preferred. The tissue or cell source may include a tissue biopsy sample, a cell sorted population, cell culture, or a single cell. In a preferred embodiment, the tissue source may include brain, liver, heart, kidney, lung, spleen, retina, bone, lymph node, endocrine gland, reproductive organ, blood, nerve, vascular tissue, and olfactory epithelium. In yet another preferred embodiment, the tissue or cell source may be embryonic or tumorigenic.
Tumorigenic tissue according to the present invention may include tissue associated with malignant and pre-neoplastic conditions, not limited to the following: acute lymphocytic leukemia, acute myelocytic leukemia, myeloblastic leukemia, promyelocytic leukemia, myelomonocytic leukemia, monocytic leukemia, erythroleukemia, chronic myelocytic (granulocytic) leukemia, chronic lymphocytic leukemia, polycythemia vera, lymphoma, Hodgkin's disease, non-Hodgkin's disease, multiple myeloma, Waldenstrom's macroglobulinemia, heavy chain disease, solid tumors, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, testicular tumor, lung carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, menangioma, melanoma, neuroblastoma, and retinoblastoma. See Fishman et al., Medicine , 2 d Ed . (J.B. Lippincott Co., Philadelphia, Pa. 1985), which is expressly incorporated herein by reference.
In yet another preferred embodiment of the present invention, a nucleic acid detection system, the proportionally amplified DNA or RNA, or fragments thereof, may be immobilized directly or indirectly to a solid support or substrate by methods known in the art (e.g., by chemical or photoreactive interaction, or a combination thereof). See U.S. Pat. No. 5,800,992. The resulting immobilized RNA may be used as probes to detect nucleic acids in a sample population that can hybridize under desired stringency conditions. Such nucleic acids may include DNA contained in the clones and vectors of cDNA libraries.
The materials for use in the present invention are ideally suited for the preparation of a kit suitable for the single-phase proportional amplification of nucleic acids. Such a kit may comprise reaction vessels, each with one or more of the various reagents, preferably in concentrated form, utilized in the methods. The reagents may comprise, but are not limited to the following: low modified salt buffer, appropriate nucleotide triphosphates (e.g. dATP, dCTP, dGTP, dTTP; or rATP, rCTP, rGTP, and UTP) reverse transcriptase, RNase H, thermal stable DNA polymerase, RNA polymerase, and the appropriate primer complexes. In addition, the reaction vessels in the kit may comprise 0.2-1.0 ml tubes capable of fitting a standard PCR thermocycler, which may be available singly, in strips of 8, 12, 24, 48, or 96 well plates depending on the quantity of reactions desired. Hence, the single-phase amplification of nucleic acids may be automated, e.g., performed in a PCR thermocycler. The PCR thermocyclers may include, but are not limited to the following: Perkin Elmer 9600, MJ Research PTC 200, Techne Gene E, Erichrom, and Whatman Biometra T1 Thermocycler.
Also, the automated machine of the present invention may include an integrated reaction device and a robotic delivery system. In such cases, part of all of the operation steps may automatically be done in an automated cartridge.
Without further elaboration, one skilled in the art with the preceding description can utilize the present invention to its fullest extent. The following examples are illustrative only, and not intended to limit the remainder of the disclosure in any way.
EXAMPLE ONE
Amplified Sample Preparation
cDNA Synthesis
Step 1: Primer-template annealing. The HPLC purified primer may be obtained from a −20° C. storage stock, prepared in a 100 μM solution with TE (10 mM Tris-HCl (pH 8.0) and 1 mM EDTA (pH 8.0)) and diluted 1:1 with glycerol (for a final concentration of 50 μM in 50% glycerol and 50% TE). Where the desired nucleic acid sample is poly(A)+ RNA, a T 7 T 20 primer (ggc cag tga att gta ata cga ctc act ata ggg agg cgg (T) 20 (SEQ ID NO. 1)) (Operon Technologies, Inc., Alameda, Calif.) for example, may be used. In such case, an RNA sample (10 to 100 ng mRNA or 1-2 ug total RNA suspended in 2.5 μl or less) can be mixed with 0.5 μl primer to give a final volume of 3 μl. The mixture can be incubated at 70° C. for 5-10 minutes, then cooled to 4° C.
Step 2: First Strand cDNA Synthesis. To the 3 μl primer-template mixture, may be added 2 μl of RT reagent, which may contain 0.5 μl Superscript II (200 U/μl, 100 U/reaction (Life Technologies, Inc., Gaithersburg, Md.) and 1.5 μl RT mix (100 μl 5×1° cDNA buffer (shipped with Superscript II); 25 μl DTT (0.1 M); 25 μl dNTP (10 mM)). This 5 μl reaction mixture may then be incubated at 37° C. for 60 minutes, then cooled to 4° C. or on ice.
Step 3: Second Strand cDNA Synthesis. The 5 μl first strand cDNA reaction mixture may be mixed with 5 μl reagent mix (4.5 μl secondary cDNA mix and with 0.5 μl cDNA enzyme mix) at 4° C. or on ice. Ensure that no more than 0.5 μl of enzyme is used. The reaction tube may be placed in a PCR cycler set up with the following program: extension for 2 hours at 16° C., then heat inactivation of enzyme for 20 minutes at 75° C., and an ending temperature of 25° C. The extension step may be within the range of 10-37° C. for many hours and the heat inactivation step may be within the range of 55-85° C. for 1 minute to many hours.
The secondary cDNA mix may be prepared in 4.5 μl aliquots for 100 reactions by combining 245 μl RNase-free H 2 O, 40 μl of 1 M Tris HCl (pH 7.0), 35 μl of 0.1 M MgCl 2 , 100 μl of 0.1 M (NH 4 ) 2 SO 4 , 15 μl of 10 mM beta-NAD + , and 15 μl of dNTP.
The cDNA enzyme mix may be prepared in 0.5 μl aliquots for 100 reactions by combining in a screw-capped tube cooled to −20° C., 5 μl of Amplitaq DNA polymerase (5 U/μl) (PE Biosystems, Foster City, Calif.), 5 μl of E. coli ligase (10 U/μl) (available from, for example, NEB, Inc., Beverly, Mass.), 6 μl of E. coli RNase H (2 U/μl) (available from, for example, Promega, Inc., Madison, Wis.), and 25 μl of E. coli DNA polymerase I (10 U/μl) (available from, for example, NEB, Inc., Beverly, Mass.). This mixture may be total volume adjusted to 50 μl with 9 μl of 50% cold glycerol, followed by a brief and gentle mix and quick spin before storage at −20° C.
cRNA Synthesis
Step 4: In Vitro Transcription. To achieve maximal amplification, the 10 μl total volume of double-stranded cDNA may be combined with 10 μl of IVT reagent, which may contain 7 μl of NTP mix, 1 μl of 10×MEGAscript buffer (Ambion MEGAscript Kit, Ambion, Austin, Tex.), and 2 μl of T 7 enzyme mix (Ambion MEGAscript Kit, Ambion, Austin, Tex.). Alternatively, a dilution may be appropriate, for example, diluting 5 μl of double-stranded cDNA with 5 μl of H20, and combining with 10 μl of IVT reagent.
The NTP mix may be prepared in 7 μl aliquots for 10 reactions, by combining 17.5 μl of 10 mM bCTP, 17.5 μl of 10 mM bUTP, 7.5 μl of 75 mM CTP, 7.5 μl of 75 mM UTP, 10 μl of 75 mM ATP, and 10 μl of 75 mM GTP.
The 20 μl total volume mixture may be incubated at 37° C. for 4-6 hours, but can be 30 minutes to many hours. The resulting samples may be stored at −20° C., or analyzed.
Analysis may occur through the resolution of a 0.5 μl or 1 μl sample on a 1% agarose gel. Purification or quantification of the nucleic acid sample may occur by any one of the methods known in the art.
EXAMPLE TWO
GeneChip® Analysis
GeneChip® nucleic acid probe arrays are manufactured using technology that combines photolithographic methods and combinatorial chemistry. In a preferred embodiment, over 280,000 different oligonucleotide probes are synthesized in a 1.28 cm×1.28 cm area on each array. Each probe type is located in a specific area on the probe array called a probe cell. Measuring approximately 24 μm×24 μm, each probe cell contains more than 10 7 copies of a given oligonucleotide probe.
Probe arrays are manufactured in a series of cycles. A glass substrate is coated with linkers containing photolabile protecting groups. Then, a mask is applied that exposes selected portions of the probe array to ultraviolet light. Illumination removes the photolabile protecting groups enabling selective nucleotide phosphoramidite addition only at the previously exposed sites. Next, a different mask is applied and the cycle of illumination and chemical coupling is performed again. By repeating this cycle, a specific set of oligonucleotide probes is synthesized, with each probe type in a known physical location. The completed probe arrays are packaged into cartridges.
During the laboratory procedure, biotin-labeled RNA fragments referred to as the RNA target are hybridized to the probe array. The hybridized probe array is stained with streptavidin phycoerythrin conjugate and scanned by the Hewlett-Packard (HP) GeneArray™ Scanner at the excitation wavelength of 488 nm. The amount of emitted light at 570 nm and above is proportional to the amount of bound labeled target at each location on the probe array.
Step 1: Target Preparation. A total RNA population may be isolated from tissue or cells and reverse transcribed to produce cDNA. Then, in vitro transcription (IVT) produces biotin-labeled cRNA from the cDNA. The cRNA may be fragmented before hybridization.
Step 2: Target Hybridization.
After the biotin-labeled cRNA is fragmented, a hybridization cocktail is prepared, which includes labeled sample (0.05 μg/μl), probe array controls (1.5, 5, 25 and 100 pM respectively), herring sperm DNA (0.1 mg/ml), and BSA (0.5 mg/ml). A cleanup procedure is performed on the hybridization cocktail after which 200 μis applied to the probe array through one of the septa in the array. It is then hybridized to the probes on the probe array during a 16-hour incubation at 45° C.
The hybridization protocol involves the following: (1) equilibrate probe array to room temperature immediately before use; (2) heat the sample(s) to 95° C. for 5 minutes in a heat block; (3) meanwhile, wet the array by filling it through one of the septa with 1×Hybridization Buffer (1M NaCl, 0.1 M MES pH 6.7, 0.01% Triton X-100) using a micropipettor and appropriate tips; incubate the probe array at the hybridization temperature for 10 minutes with rotation; (5) after incubation at 95° C. (step #2 above), transfer the samples to a 45° C. heat block for 5 minutes; (5) spin samples at maximum speed in a microcentrifuge for 5 minutes to remove any insoluble material from the hybridization mixture; (6) remove the buffer solution from the probe array cartridge and fill with 200 μl of the clarified hybridization cocktail avoiding any insoluble matter in the 20 μl at the bottom of the tube; (7) place probe array in rotisserie box in 45° C. oven; load probe arrays in a balanced configuration around rotisserie axis; rotate at 60 rpm; and (8) hybridize for 16 to 40 hours.
Step 3: Probe Array Washing, Staining, and Fluidics Station Setup
Immediately following the hybridization, the hybridized probe array undergoes manual washing and staining, then washing on the fluidics station. The protocol involves the following: (1) remove the hybridization cocktail from the probe array and set it aside in a microcentrifuge tube; store on ice during the procedure or at −20° C. for long-term storage; (2) rinse the probe array by pipetting 200 μl 1×MES buffer pH 6.7 through one of the probe array septa; (3) fill the probe array septa with 200 μl 6×SSPE-T (300 ml of 20×SSPE and 500 μl of 10% Triton X 100 to 700 ml of water, final pH 7.6) and wash with 6×SSPE-T on the fluidics station with wash A cycle (10 cycles, drain and fill twice each cycle); (4) remove the 6×SSPE-T and rinse the probe array with 0.1×MES buffer pH 6.7 (0.1 M MES, 0.1 M NaCl and 0.01% Triton); (5) fill the probe array with 200 μl 0.1×MES and incubate at 45° C. on the rotisserie at 60 rpm for 30 minutes; and (6) remove the 0.1×MES, rinse the probe array with 1×MES in the probe array while preparing the stain.
Staining the probe array involves preparing Streptavidin Phycoerythrin (SAPE) stain solution. Stain should be stored in the dark and foil wrapped or kept in an amber tube at 4° C. Remove stain from refrigerator and tap the tube to mix well before preparing stain solution. The concentrated stain or diluted SAPE stain solution should not be frozen. The SAPE stain should be prepared immediately before use.
For each probe array to be stained, combine the following components to a total volume of 200 μl (1:100 dilution of SAPE, final concentration of 10 μg/ml): 188 μl 1×MES; 10 μl of 50 mg/ml acetylated BSA (final concentration of 2.5 mg/ml); and 2 μl of 1 mg/ml streptavidin phycoerythrin (SAPE).
Remove the 1×MES and apply the stain solution to the probe array. Incubate for 15 minutes at 60 rpm at room temperature or 40° C.
Remove the stain and fill the probe array with 6×SSPE-T. Wash the probe array with 6×SSPE-T on the fluidics station with wash A cycle.
The experiment parameters are preferably defined using commercially available GeneChip® software (Affymetrix, Santa Clara, Calif.) on a PC-compatible workstation with a Windows NT® operating system. The probe array type, sample description, and comments are entered in the software and saved with a unique experiment name.
The user protocol involves the following: (1) launch the software from the workstation and choose Experiment Info from the Run menu; alternatively, click the New Experiment icon on the GeneChip® software tool bar; the Experiment Information dialog box will appear allowing the experiment name to be defined along with several other parameters such as probe array type, sample description, and comments; (2) type in the experiment name; click on the box to the right of Probe Array type and select the probe array type from the drop-down list; experiment name and probe array type are required; complete as much of the other information as desired; the protocol information at the bottom of the dialog box will be imported to the experiment information dialog box after the hybridization and scan have been completed; (3) save the experiment by choosing Save; the name of the experiment will be used by the software to access the probe array type and data for the sample while it is being processed; data files generated for the sample will be automatically labeled to correspond to the experiment name; the Protocol section of the dialog box will be filled in by the software; and (4) close the Experiment Information dialog box.
The GeneChip® Fluidics Station 400 is preferably used to wash the probe arrays. It is operated using the GeneChip® software as follows: (1) choose Fluidics from the Run menu; alternatively, click the Start Protocol icon on the GeneChip® software tool bar; the Fluidics Station dialog box will appear with a drop-down list for the experiment name; a second list is accessed for the Protocol for each of the four fluidics station modules; (2) prime the fluidics station, by clicking Protocol in the Fluidics Station dialog box; choose Prime for the respective modules in the Protocol drop-down list; change the intake buffer reservoir A and B to 6× SSPE-T; click Run for each module to begin priming; priming should be done whenever the fluidics station is first started up, when wash solutions are changed, after washing if a shutdown has been performed on any module, and if the LCD window instructs the user to prime; priming ensures that the wash lines are filled with the appropriate buffer and the fluidics station is ready for washing; a prime takes approximately 3 to 5 minutes to complete; the fluidics station LCD window and the Fluidics Station dialog box will display the status of the prime and give instructions as it progresses; follow the instructions on the LCD window and dialog box; when priming is complete, the LCD window and dialog box will indicate that the fluidics station is ready to run a wash; (3) wash the probe array on the fluidics station, by customizing the HYBWASH protocol to create a wash of 10 cycles with 2 mixes per cycle with 6×SSPE-T at room temperature; in the Fluidics Station dialog box on the workstation, select the correct experiment name in the drop-down Experiment list; the probe array type will appear automatically; in the Protocol drop-down list, select the modified HYBWASH protocol created in step 1 to control the wash of the probe array; if a customized protocol is run, check the parameters of each of the protocols chosen to be sure they are appropriate for your experiment; this can be done in the Fluidics Protocol dialog box found by choosing Edit Protocol under the Tools menu; choose Run in the Fluidics Station dialog box to begin the wash; follow the instructions on the LCD window on the fluidics station; open the probe array holder by pressing down on the probe array lever to the Eject position; place the appropriate probe array into the probe array holder of the selected module and gently push up on the lever to engage it; the latch should be secure when the probe array holder is fully closed; a light click should be heard; engage the probe array holder lever by firmly pushing up on it to the Engage position; the Fluidics Station dialog box and the LCD window will display the status of the wash as it progresses; when the wash is complete, the LCD window will display EJECT CARTRIDGE; eject the probe array by pushing down firmly on the probe array lever; and (4) perform the cleanout procedure, by returning the probe array to the probe array holder; latch the probe array holder by gently pushing it up until a light click is heard; engage by firmly pushing up on the probe array lever to the Engage position; the fluidics station will drain the probe array and then fill it with a fresh volume of the last wash buffer used; when it is finished, if the LCD window displays EJECT CARTRIDGE again, remove the probe array and inspect it again for bubbles; if no bubbles are present, it is ready to scan; after ejecting the probe array from the probe array bolder, the LCD window will display ENGAGE WASHBLOCK; latch the probe array bolder by gently pushing it up and in until a light click is heard; engage the washblock by firmly pushing up on the probe array lever to the Engage position; the fluidics station will automatically perform a Cleanout procedure; the LCD window will indicate the progress of the Cleanout procedure; when the Cleanout procedure is complete, the LCD window should display Washing done, READY; if no other washes are to be performed, place wash lines into a bottle filled with deionized water; choose Shutdown for all modules from the drop-down Protocol list in the Fluidics Station dialog box; click the Run button for all modules; after Shutdown protocol is complete, flip the ON/OFF switch of the fluidics station to the OFF position; and scan the probe array.
Step 4: Probe Array Scan
Once the probe array has been hybridized, stained, and washed, it is scanned. Each workstation running the software can control one scanner. Each scan takes approximately 5 minutes, and two scans are recommended.
The scanner acquires an image of each of the hybridized 24 μm×24 μm probe cells. Each complete probe array image is stored in a separate data file that corresponds to its experiment name and is saved with a data image file (.dat) extension.
The scanner is also controlled by the GeneChip® software. The probe array is scanned after the wash protocols are complete. The probe array scan proceeds as follows: (1) choose Scanner from the Run menu; alternatively, click the Start Scan icon in the GeneChip® software tool bar; the Scanner dialog box will appear with a drop-down list of experiments that have not been run; a scrollable window will also be displayed showing previous scans; choose the experiment name that corresponds to the probe array to be scanned; a previously run experiment can also be chosen from the Previous Experiments list by double-clicking on the name desired; (2) check for the correct pixel value and wavelength of the laser beam; for a 24 μm×24 μm probe array with a phycoerythrin stain: Pixel value=3 μm, Wavelength=570 nm; (3) once the experiment has been selected, click the Start button; a dialog box will prompt the user to load a sample into the scanner; and (4) load the Probe Array into the HP GeneArray™ Scanner; open the sample door on the scanner and insert the probe array into the holder; do not force the probe array into the holder; close the sample door of the scanner; start the Scan, by clicking OK in the Start Scanner dialog box; the scanner will begin scanning the probe array and acquiring data; when Scan in Progress is chosen from the View menu, the probe array image will appear on the screen as the scan progresses.
Step 5: Data Analysis and Interpretation
Data is analyzed using GeneChip® software. In the Image window, a grid is automatically placed over the image of the scanned probe array to demarcate the probe cells. After grid alignment (the user may adjust the alignment if necessary), the mean intensity at each probe cell is calculated by the software. The intensity patterns are analyzed.
After scanning the probe array, the resulting image data created is stored on the hard drive of the GeneChip® workstation as a .dat file with the name of the scanned experiment. In the first step of the analysis, a grid is automatically placed over the .dat file so that it demarcates each probe cell. One of the probe array library files, the .cif file, indicates to the software what size of grid should be used. Confirm the alignment of the grid by zooming in on each of the four corners and the center of the image.
If the grid is not aligned correctly, adjust its alignment by placing the cursor on an outside edge or corner of the grid. The cursor image will change to a small double-headed arrow. The grid can then be moved using the arrow keys or by clicking and dragging its borders with the mouse.
Sample analysis occurs as follows: (1) choose Defaults from the Tools menu to access the Probe Array Call Settings tab dialog box; in the Defaults dialog box, click on the Probe Array Call Settings tab to display probe array calling algorithm choices; (2) highlight GeneChip® Expression and click the Modify button or double click the algorithm name; (3) in the Probe Array Call Settings dialog box, select the probe array type in the drop down list; for that probe array make sure the Use As Current Algorithm cheek box is selected; (4) click the OK button to apply your choices for the selected probe array type; (5) in the Defaults dialog box, click the OK button to apply your choices regarding parameters set by all of the tab dialog boxes in the window; (6) after confirming that the above parameters are correct, select the appropriate image to be analyzed; and (7) select Analysis from the Run menu or click the Run Analysis icon on the GeneChip® software tool bar; the software calculates the average intensity of each probe cell using the intensities of the pixels contained in the cell; pixels on the edges of each cell are not included, which prevents neighboring cell data from affecting a cells calculated average intensity; the calculated average intensity is assigned an X/Y-coordinate position, which corresponds to the cell's position on the array; this data is stored as a .cel file using the same name as the .exp and .dat files; the .cel file is an intermediate data file; the software then applies the selected probe array algorithm to determine expression levels for each gene; this is done with reference to the information contained in the .cdf file, the second library file for the probe array; the resulting analysis is automatically displayed as a .chp file in the Expression Analysis window of GeneChip® software; the .chp file has the same name as the .exp, .dat, and .cel files.
The specific embodiments described above do not limit the scope of the present invention in any way as they are single illustrations of individual aspects of the invention. Functionally equivalent methods and components are within the scope of the invention. The scope of the appended claims thus includes modifications that will become apparent to those skilled in the art from the foregoing description. | The amplification of nucleic acids in a single phase can reliably provide products at relatively low cost and labor. A single-phase amplification can also increase the amount of nucleic acids while preserving the relative abundance of the individual nucleic acid species, or portions thereof. A single-phase amplified nucleic acid preparation may be analyzed in a gene expression monitoring system, preferably involving a nucleic acid probe array. | 2 |
FIELD OF INVENTION
[0001] The present invention relates to a folding chair that has an improved folding manner for easy transport and with less space of storage in the folded position.
BACKGROUND OF THE INVENTION
[0002] Chairs are widely used in daily activities. A conventional type of chair will not able to provide comfort for user and often not stored after used. It is therefore the foldable chairs have the advantage of being folded and for easy transport and storage.
[0003] The use of folding chairs is known in the prior art. Folding chairs are devised and utilized for the purpose of providing a seat that folds up for easy storage and transport. It is basically consisting of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by most prior art which have been developed for the fulfillment of countless objectives and requirements.
[0004] There are varieties of folded chairs have been made in the market. These folding chairs normally require big volume of space during transportation and storage. This will lead to the increase in the storage space as well as the transportation fee and space.
[0005] It is the general object of the present invention to provide compact folding chair to facilitate transport and storage of the folding chair.
[0006] Still another object of the present invention to provide locking element where the chair will lock automatically once the chair is in an unfolded or opened out position. The opened out position is extremely stable and eliminates the possibility of collapsing when the chair is being placed into such position of use.
[0007] A further object of the present invention is to provide improved multi position chair having an adjustable inclined backrest to enable user to adjust the desirable position of inclination according to their comfortability.
SUMMARY OF INVENTION
[0008] The preferred embodiment of present invention essentially comprises of a sitting base being pivotally connected to the backrest by a plurality of connecting means and supported by a plurality of legs. The said legs consist of a pair of rear legs and a set of front legs, whereby the upper end of the front legs are connected to the said sitting base by connecting means.
[0009] A pivoting bar is provided to connect the said backrest and said rear legs by a plurality of connecting means in order to the said backrest to be rested on the said rear legs. The opening and closing of the chair is governed by a tie bar which link the lower part of the said backrest and said front legs, wherein to prevent the said backrest from expanding to further unstable position. A set of blocks is placed between the said pivoting bar and the said tie bar in order to parallel the connecting of the said backrest to the said front legs.
[0010] The said two pair of legs, sitting base, backrest, tie bars, pivoting bars and blocks can be brought together thereby producing an extremely compact folded position to the chair for less space during transport and storage.
[0011] The said chair is locked automatically when in opened position by a locking mechanism comprises of a locking bar which is mounted on the underside of the said sitting base. The locking must be manually moved into release position in order to unlock and fold the chair.
[0012] The alternative embodiment of the present invention comprises of a backrest, whereby the said backrest is cut into two to form an upper portion and a lower portion, and connected by a bracket having at least two holes in order to provide inclined position for the said upper portion of backrest; and a sitting seat base being pivotally connected to the said lower portion of backrest by a plurality of connecting means and supported by a plurality of legs. The said legs consist of a pair of rear legs and a pair of front legs.
[0013] A pair of armrests is pivotally connected to the said upper portion, wherein each of said armrest has a track with plurality of stop notches at the lower side of the said armrest.
[0014] The said rear legs is pivotally connected to the front end side of the said sitting base by connecting means and to the said lower portion of backrest by a set of pivoting bars with connecting means.
[0015] The said pair of front legs is pivotally connected to the front end side of the said sitting base with connection means. The upper end side of the said front leg is attached with a connector, whereby the said connector is served as a guide element to slide within the said track to enable the user to adjust positions in relation of comfortability to the horizontal plane or the seat of the chair.
[0016] A first set of pivoting bars is pivotally connected at the lower end side of said backrest and to the said rear legs in order to enable the backrest to be rested on the said rear legs when in open out position. A second set of pivoting bars is pivotally connected at the front end side of the said sitting base and to the second set of tie bars.
[0017] A first set of level blocks is mounted at the first set of the said pivoting bars with connecting means. A second set of level blocks is mounted at the said rear legs with connecting means. Both sets of the said level blocks are used to provide parallel level for the connection of two components.
[0018] A first set of tie bars is pivotally connected to the said front legs and to the first set of the said block; so as to keep the said backrest resting on the said rear legs when in open out position. A second set of tie bars is pivotally connected to the second set of the said pivoting bars and to the first set of said block in order to provide stability of the said sitting base in open out position.
BRIEF DESCRIPTION OF THE DRAWING
[0019] FIG. 1 is a side view of the folding chair according to the preferred embodiment of the present invention in its open condition.
[0020] FIG. 2 is a front view of the sitting base.
[0021] FIG. 3 illustrates the locking mechanism with the locking bar in its locking position.
[0022] FIG. 4 illustrates the locking mechanism with the locking bar in its release position.
[0023] FIG. 5 is a side view of the folding chair according to the preferred embodiment of the present invention in its folded condition.
[0024] FIG. 6 is a side view of the folding chair according to the alternative embodiment of the present invention in its open condition.
[0025] FIG. 7 is a side view of the folding chair according to the alternative embodiment of the present invention in its folded condition.
DETAILED DESCRIPTION OF THE INVENTION
[0026] FIG. 1 shows the compact folding chair of the preferred embodiment. A sitting base ( 2 ) being pivotally connected to a backrest ( 1 ) having an inclined surface at the lower end with connection means ( 10 ) which could be nuts and bolt assemblies, fasteners, screws, snaps, clamps, clips or other such equivalents that could be used to secure one surface to another.
[0027] A pair of inclined rear legs ( 3 ) is pivotally connected to the front end of the said sitting base ( 2 ) with pivotal means ( 11 ), whereby the said inclined surface of the said backrest ( 1 ) is rested on the said rear legs ( 3 ) when in open out position. A pair of inclined front legs ( 4 ) is pivotally connected to the front end of the said sitting base ( 2 ) at the same pivotal means ( 11 ) of the rear legs ( 3 ).
[0028] A set of pivoting bars ( 7 ) is pivotally connected to the lower end side of the said backrest ( 1 ) with a first connecting means ( 6 ) and the other end is pivotally connected to the said rear legs ( 3 ) with a second connecting means ( 8 ) to enable the said backrest ( 1 ) to be rested on the said rear legs ( 3 ) when in open out position. A set of level blocks ( 5 ) is mounted at the said pivoting bars ( 7 ) with the first connecting means ( 6 ) at the same position with the said pivoting bars ( 7 ) and the said backrest ( 1 ). A set of tie bars ( 9 ), wherein one end of the said tie bars ( 9 ) is pivotally connected ( 12 ) at the said front legs ( 4 ) and the other end is pivotally connected to the said level blocks ( 5 ) in order to prevent the said backrest ( 1 ) from collapse and retract to folded position.
[0029] FIG. 2 shows the front view of the sitting base ( 2 ). FIGS. 3 and 4 show the cross sectional inner side view of the said sitting base ( 2 ) and a locking bar ( 14 ). The sitting base includes the downwardly extending flange ( 2 a ). The inward faces of the side of the flanges ( 2 a ) adjacent the front edge are provided with a pair of recesses ( 15 ). The locking mechanism comprises the locking bar ( 14 ) extending laterally across the width of the said sitting base ( 2 ) with its ends located loosely in the recesses ( 15 ) preferably a triangular shape recesses on the underside of the said sitting base ( 2 ). A notch ( 25 ) is formed on the top end of the inclined front leg ( 4 ). In the locked condition, the said locking bar ( 14 ) is is caught into the notch ( 25 ) and biased into the locking position as shown in FIG. 3 under the action of gravity, as represented by the arrow ( 13 ). Under this condition, the locking bar ( 14 ) is rests on the inclined edge of the triangular recesses ( 15 ). In order to close the chair, the user must temporarily dislodge the said locking bar ( 14 ) by lifting the said locking bar ( 14 ) into release position, as shown by the arrow ( 16 ) in FIG. 4 .
[0030] In the operation of opening the chair, the front leg ( 4 ) is pivot to the front direction. As the end of the said front leg ( 4 ) approaches the final position wherein the said tie bar ( 9 ) is parallel to the said sitting base ( 2 ) horizontally, the said locking bar ( 14 ) drops down to the locking position in which the lower edge of the said locking bar ( 14 ) is located within the notch ( 25 ) of the front leg ( 4 ). The chair is now on the locked condition shown in FIG. 3 . The said backrest ( 1 ) is prevented from collapse to the folded position and the chair is locked automatically in the course of opening the chair.
[0031] In order to close the chair, the user must temporarily dislodge the locking bar ( 14 ) from the notch ( 25 ) by lifting the said locking bar ( 14 ) into the release position. The said front legs ( 4 ) are then free to move backward to close the chair. Once the said front legs ( 4 ) have disengaged from the locking bar ( 14 ), the latter will drop back under the action of gravity. The chair is now in folded position with the size of the said backrest ( 1 ) and the said rear legs ( 3 ) from the side view as shown in FIG. 5 .
[0032] FIGS. 6 and 7 showed an alternative embodiment of the folding chair of the present invention. A backrest ( 17 ) comprises of upper portion ( 17 a ) and lower portion ( 17 b ) having inclined surface at the lower end whereby the upper portion ( 17 a ) and the lower portion are connected by a bracket ( 24 ) having at least two holes. The said upper portion ( 17 a ) is connected to the upper end of said bracket ( 24 ) by a first connecting means ( 28 ) and the said lower portion ( 17 b ) is connected to the lower end of said bracket ( 24 ) by a second connecting means ( 29 ). A pair of multi position armrest ( 18 ) having a multiple position track ( 22 ) at the bottom surface of the said armrest ( 18 ) is connected to the lower end side of the said upper portion ( 17 a ) by connecting means ( 27 ).
[0033] A pair of inclined rear legs ( 20 ) is pivotally connected to the front end of the said sitting base ( 19 ) with pivotal means ( 33 ), whereby the said inclined surface of the said lower portion ( 17 b ) is rested on the said rear legs ( 20 ) when in open out position. A pair of inclined front legs ( 21 ) is pivotally connected to the front end of the said sitting base ( 19 ) at the same pivotal means ( 33 ). The upper end side of the said front leg ( 21 ) is attached with a guide pin ( 23 ), which serves as a guide element to slide within the said track ( 22 ) so as to enables each armrest ( 18 ) to pull forward and push backward when the chair is in its open out position. The said track ( 22 ) having plurality of stop notches which cooperates with the said guide pin ( 23 ) to enable a user to have various desired inclined positions of the backrest by simply adjusting both armrest ( 18 ).
[0034] Two sets of pivoting bars, two sets of tie bars and two sets of level blocks are used in this alternative embodiment. The first set of pivoting bars ( 26 ) is pivotally connected at the lower end side of the said lower portion ( 17 b ) with an upper first connecting means ( 31 ) and the other end is pivotally connected to the said rear legs ( 20 ) with a lower first connecting means ( 32 ) to enable the said lower portion ( 17 b ) to be rested on the said rear legs ( 20 ) when in open out position. The second set of pivoting bars ( 35 ), wherein one end of the said second set of pivoting bar ( 26 ) is pivotally connected at the front end side of the said sitting base ( 19 ) with an upper second connecting means ( 33 ) and the other end is pivotally connected the first set of tie bars ( 36 ) with lower second connecting means ( 38 ).
[0035] The first set of level blocks ( 39 ) is mounted at the said first set of pivoting bars ( 26 ) at the upper first connecting means ( 31 ) at the same position with the said pivoting bars ( 26 ) and the said lower portion ( 17 b ) to parallel the level between the said first set of pivoting bars ( 26 ) and the second set of tie bars ( 36 a ).
[0036] The said first set of tie bars ( 36 ), wherein one end of the said first set of tie bar ( 36 ) is pivotally connected at the lower end side of the said lower portion ( 17 b ) with the upper first connecting means ( 31 ) and the other end is pivotally connected to the said lower end of the second set of pivoting bars ( 35 ). The second set of the said tie bars ( 25 ) having one end pivotally connected at the said front legs ( 21 ) with connecting means ( 34 ) and the other end is pivotally connected at the said lower portion ( 17 b ) with the upper first connecting means ( 31 ) in order to provide stable condition and avoid collapse of the chair.
[0037] The locking mechanism of the alternative embodiment is the same as the preferred embodiment.
[0038] In the operation of opening the chair, the front leg ( 21 ) is pivot to the front direction. As the end of the said front leg ( 21 ) approaches the final position wherein the said first set of tie bar ( 36 ) and second set of tie bar ( 36 a ) is parallel to the said sitting base horizontally, the said locking bar ( 14 ) drops down to the locking position in which the lower edge of the said locking bar ( 14 ) is located within the notch ( 25 ) of the front leg ( 21 ). The chair is now on the locked condition. The said backrest ( 17 ) is now prevented from collapse to the folded position and the chair is locked automatically in the course of opening the chair.
[0039] In order to close the chair, the user must temporarily dislodge the locking bar ( 14 ) from the notch ( 25 ) by lifting the said locking bar ( 14 ) into the release position. The said front legs ( 21 ) are then free to move backward to close the chair. Once the said second set of tie bars ( 35 ) have disengaged from the locking bar ( 14 ), the latter will drop back under the action of gravity. The chair is now in folded position with the size of the said backrest ( 1 ) and the said front legs from the side view as shown in FIG. 7 .
[0040] It is to be understood that the present invention may be embodied in other specific forms and is not limited to the sole embodiment described above. However modification and equivalents of the disclosed concepts such as those which readily occur to one skilled in the art are intended to be included within the scope of the claims which are appended thereto. | The preferred embodiment of compact folding chair comprises of a sitting base pivotally connected to a backrest, which is supported by two sets of legs and locking mechanism. A set of level blocks, a pair of sliding bars and a pair of tie bars is used so arranged to be move so that the chair could be folded into a compact position for transport and storage purpose. This present invention solves the problems of being taken up space during transportation and storage. The alternative embodiment of the present invention comprises of a sitting base pivotally connected to a backrest, which is supported by two sets of legs and locking mechanism. A pair of armrests, two sets of level blocks, two sets of sliding bars, and two sets of tie bars is used so arranged to be move so that the chair could be folded into compact position and provide comfortability to the user with multi position armrests. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of and priority to U.S. Provisional Application Ser. No. 60/993,973 filed on Sep. 17, 2007, and the entire contents of that application are incorporated herein by reference for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO APPENDIX
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The inventions disclosed and taught herein relate generally to water-tight and heat-dissipating assemblies; and more specifically related to a bulkhead assembly for an engine exhaust pipe.
2. Description of the Related Art
Structural vessels of many different types often times employ stationary energy sources, such as diesel engines. Exhausting the combustion gasses from these energy sources typically requires routing exhaust pipes or conduits through bulkheads, walls, floors, ceilings and other structural elements of the vessels.
The temperature of these exhaust gasses may range between about 500° F. and 1100° F., and some of this heat will be transferred to the exhaust system. To the extent the exhaust system is thermally connected to components of the vessel, those components will likewise be heated by the exhaust gasses.
It is oftentimes undesirable or prohibited to transfer heat from the exhaust system to vessel components. For example, and without limitation, diesel fuel storage tanks may be constructed such that one or more walls of the tank is also a structural component of the vessel. In such situation, it is not desirable, and may be prohibited in certain regions, to transfer exhaust heat to the vessel structure that forms a portion of the fuel tank.
The inventions disclosed and taught herein are directed to an assembly that allows an exhaust system, such as an exhaust conduit, to pass through a structural portion of a vessel, such as a bulkhead, in water-tight fashion and with minimal transfer of heat to the bulkhead.
BRIEF SUMMARY OF THE INVENTION
In general terms, one embodiment of the invention may be described as an assembly, comprising a first structural element having a flange adapted to be rigidly connected to an exhaust conduit, and a wall portion extending from the flange; a second structural element having a flange adapted to be rigidly connected to a bulkhead, and a wall portion extending from the flange; a first annular region defined between the wall portions of the first and second elements; a second annular region defined between the first annular region and the exhaust conduit; a floating ring of predetermined radial width disposed within the first annular region; a first thermal gasket in the first annular region and interposed between the first element and the floating ring; a second thermal gasket in the first annular region and interposed between the second element and the floating ring; thermal insulation in the second annular region and interposed between the exhaust conduit and the first annular region; a first plurality of connectors connecting the first element to the floating ring; a second plurality of connectors connecting the second element to the floating ring; whereby the exhaust conduit is sealed to the bulkhead in fluid tight fashion while minimizing the heat transferred from the exhaust conduit to the bulkhead.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 illustrates an overhead or side view of one of many possible embodiments of the present invention.
FIG. 2 illustrates a cross-sectional view of a portion of the embodiment shown in FIG. 1 .
FIG. 3 is an exploded view of the embodiment shown in FIG. 1 .
FIG. 4 illustrates one of many alternate embodiments of the present invention.
DETAILED DESCRIPTION
The Figures described above and the written description of specific structures and functions below are not presented to limit the scope of what Applicants have invented or the scope of the appended claims. Rather, the Figures and written description are provided to teach any person skilled in the art to make and use the inventions for which patent protection is sought. Those skilled in the art will appreciate that not all features of a commercial embodiment of the inventions are described or shown for the sake of clarity and understanding. Persons of skill in this art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present inventions will require numerous implementation-specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation-specific decisions may include, and likely are not limited to, compliance with system-related, business-related, government-related and other constraints, which may vary by specific implementation, location and from time to time. While a developer's efforts might be complex and time-consuming in an absolute sense, such efforts would be, nevertheless, a routine undertaking for those of skill this art having benefit of this disclosure. It must be understood that the inventions disclosed and taught herein are susceptible to numerous and various modifications and alternative forms. Lastly, the use of a singular term, such as, but not limited to, “a,” is not intended as limiting of the number of items. Also, the use of relational terms, such as, but not limited to, “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and the like are used in the written description for clarity in specific reference to the Figures and are not intended to limit the scope of the invention or the appended claims.
In general terms, we have invented an assembly of components that allows a pipe or conduit conveying heated fluid, such as, but not limited to internal combustion exhaust gasses, to pass through a wall, floor, ceiling, bulkhead or other portion of a vessel or building in water-tight fashion, and with limited transfer of heat from the fluid or pipe.
Generally, embodiments of the invention may comprises a first portion adapted to interface with the exhaust pipe or conduit and a second portion adapted to interface with the wall or such of the vessel or building. The first and second portions are held in water-tight arrangement by a plurality of first connectors that connect the first portion to a floating ring, and a second set of connectors that connect the second portion to the floating ring. Sandwiched between the first and second portions and the floating ring are gaskets adapted to seal against fluid intrusion and to withstand the high temperatures associated with the exhaust pipe. The floating ring is spaced from the outside of the exhaust pipe by a layer of thermal insulation. In this type of embodiment of the present invention, conduction of heat from the exhaust pipe to the vessel or building is limited to a circuitous path through the first and second connectors and floating ring. This type of conduction path substantially reduces the heat transferred to the vessel or building.
Turning now to a more detailed description of one of many possible embodiments of the present invention, FIG. 1 is an illustration of an assembly particularly useful for offshore drilling rigs, offshore production platforms, ships and/or boats in which internal combustion engine exhaust gasses are piped through the exterior wall or bulkhead of the vessel. This embodiment provides a water-tight seal preventing or lessening the intrusion of seawater and other water into the vessel, and lessening the transfer of heat from the exhaust gasses to the vessel.
FIG. 1 shows an assembly 100 fitted about an exhaust pipe 102 . The assembly 100 can be used adjacent the terminal portion of the exhaust pipe 102 or along any portion of the length of the exhaust pipe 102 . The assembly 100 is illustrated to be attached to the exterior of the exhaust pipe 102 by, for example, a circumferential weld 110 . The assembly 100 is also shown to be attached to the vessel, wall or bulkhead 104 , or doubler plate or reinforcing pad 106 by, for example, a circumferential weld 108 . This particular embodiment measures approximately 30 inches in outer diameter 112 for a exhaust pipe 102 of about 22 inches in diameter 114 . The assembly 100 measure about 9 inches in length overall comprising a standoff 116 of about 3 inches, a main section 118 of about 4 inches and an exhaust section 120 of about 2 inches.
FIG. 2 shows a more detailed cross-section of the assembly 100 illustrated in FIG. 1 . The assembly 100 comprises a vessel or bulkhead portion 200 , an exhaust portion 202 , and a floating ring 204 . Bulkhead portion 200 comprises a structural shape having a flange 206 adapted to mount to or connect with the bulkhead 104 , 106 . The flange 206 is connected, integrally or otherwise, to a wall portion 208 . Bulkhead portion 200 is spaced apart from the exhaust pipe 102 a fixed distance to create a portion of an annular region 210 . As will be discussed in more detail below, the wall portion 208 has a plurality of holes formed axially (with respect to the exhaust pipe 102 ) therein.
The exhaust portion 202 comprises a flange portion 214 connected, integrally or otherwise, to a wall portion 216 . It is preferred that exhaust portion 202 also comprise a cover portion 218 . Similarly to the wall portion 208 of the bulkhead assembly 200 , the wall portion 216 of the exhaust assembly 202 has a plurality of holes 220 formed axially therein, but radially offset from (i.e., not axially aligned with) the holes 212 in the bulkhead assembly 200 . The flange 214 is connected to the exhaust pipe 102 , such as by weld 110 , at a predetermined distance along the exhaust pipe 102 from the bulkhead 104 , 106 , thereby forming a second annular region 222 radially displaced from the first annular region 210 .
The floating ring 204 is disposed within the second annular region 222 and is substantially centered therein. The floating ring 204 has a plurality of holes 224 formed therein and in radial and axial alignment with the holes 212 and 220 . It is preferred that that the floating ring holes 224 be threaded to accept threaded fasteners 226 and 228 . Interposed between the walls 208 , 216 and the floating ring 204 are thermal gaskets 232 . While those of skill in the art will appreciate that various types of gaskets or materials may be used, it is preferred that gaskets like those available from Flexatallic Limited, such as the Flexatallic SF 3300 be used. Such gaskets provide fluid sealing as well as thermal isolation.
As can be seen from FIG. 2 , one set of connectors 226 extend from the ring 204 , through the gasket 230 and through the holes 212 in the bulkhead assembly wall 208 . The gasket 230 is compressed between the ring 204 and the wall 208 by nuts 234 . Similarly, the second set of connectors 228 extend from the ring 204 , through the gasket 232 , and through the holes 220 . The gasket 232 is compressed between the ring 204 and the wall 216 by nut 236 . Once the assembly 100 is compressed to the appropriate level to achieve water-tightness, the nuts 234 and 236 may be tack welded or otherwise locked into position. It will also be appreciated that connectors 226 and 228 may be tack welded or otherwise locked to the floating ring 204 as desired or required.
Also shown in FIG. 2 is insulation 238 . Insulation 238 prevents or at least lessens convective or radiative heat transmission from the exhaust pipe 102 to the assembly 100 . While those of skill in the art will appreciate that various types of insulation or thermal material may be used, we have found that Micro-Flex® pipe and tank wrap marketed by Johns Manville is suitable for this purpose.
FIG. 2 also shows engineered heat expansion gaps 240 and 242 . It will be appreciated that because the gaskets are compressed to form a water or fluid-tight seal, these expansion gaps do not affect the water-tight performance of assembly 100 .
FIG. 3 shows an exploded view of the assembly 100 and shows the bulkhead portion 200 with holes 212 , and gasket 230 with holes 300 substantially aligned with the holes 212 in the bulkhead portion 200 . Exhaust portion 202 is shown with holes 220 , and gasket 232 with holes 302 substantially aligned with the holes 220 in the exhaust portion 202 . Floating ring 204 is shown in exploded position and having holes 224 . As described above, floating ring 204 has one set of holes 224 for connectors 226 and another set of holes 224 for connectors 228 .
In one particular embodiment of the present invention substantially similar to the embodiment described in FIGS. 1 , 2 and 3 , engine exhaust gasses at a temperature of about 750° F. passed through a vessel bulkhead and the assembly described herein maintained the bulkhead immediately adjacent the assembly 100 at a temperature of about 10° F. above ambient temperature.
Other and further embodiments utilizing one or more aspects of the inventions described above can be devised without departing from the spirit of our invention. For example, threaded fasteners and nuts can be replaced with bolts, more that one floating ring can be used to further increase the length of the heat path. Further, the embodiment described herein and the methods of using the embodiment can be included in combination with each other to produce variations of the disclosed methods and embodiments. For example, and without limitation, FIG. 4 discloses an alternate embodiment 400 in which the exhaust portion 402 is disposed adjacent the bulkhead 104 , 106 and the bulkhead portion 404 includes a roof or shield portion 406 . This embodiment comprises structures similar to the embodiment of FIGS. 1-3 , including a floating ring 408 , gaskets 410 and 412 , and insulation 414 and 416 . Structural elements that have been described functionally and can be embodied as separate components or can be combined into components having multiple functions.
Thus, our invention has been described in the context of preferred and other embodiments and not every embodiment of the invention has been described. Obvious modifications and alterations to the described embodiments are available to those of ordinary skill in the art. The disclosed and undisclosed embodiments are not intended to limit or restrict the scope or applicability of the invention conceived of by us, but rather, in conformity with the patent laws, we intend to fully protect all such modifications and improvements that come within the scope or range of equivalent of the following claims. | An assembly for establishing a water-tight seal for a conduit passing through a wall or other structure wherein the conduit conveys heated fluid, such as exhaust gasses. The assembly is adapted to minimize the heat transferred to the wall or other structure by creating a circuitous heat transfer path in conjunction with thermally insulating materials. | 5 |
BACKGROUND OF THE INVENTION
Torque responsive clutches of the ball and cam type are used to engage a selectively driveable axle to a wheel hub to render the hub a driven hub when torque is applied to the axle and to render the hub free wheeling with respect to the axle when no torque is applied to the axle. Actuator balls receivable in a plurality of detents or recesses in a pair of opposed working surfaces are forced out of the detents to force the working surfaces axially further apart to force a drive gear drivingly engaged with the axle into driving engagement with a ring gear affixed to the wheel hub. U.S. Pat. No. 4,262,785 which is assigned to the assignee of this application discloses a ball and cam type torque responsive hub clutch.
BRIEF SUMMARY OF THE INVENTION
A ball movement coordinator and cam member for an automatic or torque responsive hub clutch serves to both assure simultaneous and uniform movement of a plurality of actuator balls and cam the balls radially outwardly to actuate the clutch when a rotatable detent ring commences to rotate with respect to a non-rotatable detent ring.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side sectional view of an end portion of a typical vehicle wheel hub having a disengaged automatic hub clutch;
FIG. 2 shows the wheel hub shown in FIG. 1 in which the clutch is engaged;
FIG. 3 is a sectional view of FIG. 1 as indicated by the section lines;
FIG. 4 is a sectional view of FIG. 1 as indicated by the section lines;
FIG. 5 is a sectional view of FIG. 2 as indicated by the section lines; and
FIG. 6 is a sectional view of FIG. 2 as indicated by the section lines.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a full sectional view of an end of a typical wheel assembly 2 such as those used on the selectively driveable wheels of four wheel drive vehicles. Such assemblies are generally comprised of a selectively driveable axle 3 which is journaled in a non-rotatable spindle 4. A wheel hub 5 is coaxially mounted and radially outwardly spaced from the axle and the hub is mounted for rotation about the spindle 4 by anti-friction means such as conventional tapered roller bearings 6. The spindle 4 typically has a radially outwardly facing threaded portion 7 for maintaining the spindle, the bearings and the wheel hub as an assembly by appropriate means 8 such as a threaded nut, a lock washer and a threaded lock or jam nut, as shown.
Spindle 4 has an outboard terminal end 9 and axle 3 extends axially beyond end 9 and terminates at an outboard terminal end 10. The portion 11 of axle 3 which extends beyond the end of the spindle contains a drive means, such as spline 12.
A first detent ring 13 having a central aperture 14 for receiving a portion of spindle 4 adjacent the end 9 of spindle 4 has a radially inwardly extending nib 15 which coacts with a complementary slot in the end of the spindle to non-rotatably affix detent ring 13 to spindle 4.
A drive means sub-assembly mounted for rotation with axle 3 is comprised of a substantially cylindrical base member 16 having axially slideable engagement means, such as radially inwardly projecting teeth 17 for engaging complementary teeth on spline 12 of axle 3. Base member 16 has a drive means such as radially outwardly extending drive gear 18 having a plurality of gear teeth 19. Base member 16 has a shoulder 20 defined by a radially outwardly facing surface 21. Shoulder 20 contains three axially extending, equally spaced slots, such as slot 22.
A second detent ring 23 is mounted coaxial with member 16 and has a central aperture 24 adapted for receiving and sliding axially over surface 21. A plurality of nibs or teeth, such as nib 25, extend radially inwardly from aperture 24. Each of the nibs 25 fits into one of the slots 22 to enable the second detent ring to move axially with respect to shoulder 20 of member 16 and to force the second detent ring 23 to rotate along with member 16 in response to rotation of axle 3. A support washer 26 and a spring type retaining washer 27 are used to limit axial movement of detent ring 23 to maintain each of the nibs 25 in its respective slot 22.
A biasing means, such as helical spring 28, is interposed between an axially inboard facing shoulder of member 16 and an axially outboard facing shoulder of detent ring 23 to resiliently urge the detent ring axially away from the drive gear 18.
A wheel hub engagement member 29 is substantially cylindrical in form and has a plurality of radially outwardly extending teeth 30 for drivingly engaging a number of complementary teeth 31 which extend radially inwardly from wheel hub 5. Engagement member 29 has an axially inboard terminal end 32 and an axially outboard terminal end 33.
Inboard end 32 is engaged with, and rotatable with respect to, detent ring 13. An axially inboard facing shoulder 34 is engageable with at least an axially outboard facing portion of detent ring 13 to limit axial inboard movement of member 29 with respect to detent ring 13. At least a portion, such as portion 35, of member 29 is radially outwardly spaced from a peripheral surface of detent ring 13 and extends axially inward beyond detent ring 13. Retaining means, such as bearing washer 36 and spring type retainer 37 engaged with a slot 38 in member 29, maintain member 29 substantially axially affixed relative to detent ring 13 while enabling rotation of member 29 with respect to non-rotatable detent ring 13.
Adjacent outboard end 33 of member 29 a hub drive means is provided. The hub drive means is comprised of a plurality of radially inwardly extending drive teeth 39. Drive teeth 39 are mutually drivingly engageable with drive teeth 19 on drive gear 18.
A retention means, such as spring type retaining washer 40, is affixed to member 29 adjacent outboard end 33 to maintain the drive and actuating portions of the hub clutch as an assembly to facilitate shipment and installation of the clutch.
Adjacent outboard termianl end 10 of axle 3 a spring retainer means, such as spring retainer cup 41, is provided. Cup 41 is restrained from axial outboard movement with respect to axle 3 by appropriate restraining means, such as spring type retaining washer 42, engaged with groove 43 in axle 3. A biasing means such as helical spring 44, is interposed between drive gear 18 and spring retainer cup 41 to resiliently urge drive gear 18 axially inboard out of engagement with the gear teeth 39 on wheel hub engagement member 29.
Referring now to FIG. 2 it will be seen that detent ring 13 has an axially outboard facing surface 45 and detent ring 23 has an axially inboard facing surface 46.
Additionally, detent ring 13 has a radially outwardly facing shoulder 47. Spaced radially outwardly from shoulder 47 and coaxial with it is an annular bearing means comprised of an annular member 48 and an annular member 49. Annular member 48 is preferably comprised of a sintered metal, such as bronze, impregnated with a lubricant to reduce friction. Member 49 has an axially outboard facing surface 50. Surface 50 of member 49 comprises a portion of the working surface 45 of detent ring 13. However, surface 50 is rotatable with respect to detent ring 13 and, of course, working surface 45 is not rotatable with respect to detent ring 13.
Extending axially outward from surface 50 of bearing member 49 are a plurality of engagement members, such as engagement pin 51.
Detent ring 23 has adjacent its radially outermost axially inboard facing periphery an axially inboard extending cam lip 52. As best seen in FIGS. 3, 4, 5 and 6 cam lip 52 has a plurality of openings or slots 53.
Referring again to FIGS. 1 and 2, a plurality of actuator members, such as actuator ball 54, are interposed between detent rings 13 and 23. As shown, detent ring 13 has a plurality of ball receiving openings or detents 55 on working surface 45 and each ball receiving opening or detent extends axially inboard away from working surface 46 of detent ring 23. Similarly, detent ring 23 has a plurality of ball receiving detents 56 having a ball receiving opening on working surface 46 and extending axially outboard away from working surface 45 of detent ring 13. As best shown in FIGS. 3 and 4 respectively, the detents 55 in detent ring 13 and the detents 56 in detent ring 23 are placed in the detent rings in a radially equal pattern equidistant from each other whereby each detent in detent ring 13 is axially alignable with a corresponding detent in detent ring 23 when the detent rings are rotated to cause the detents to be axially aligned.
Also interposed between detent ring 13 and detent ring 23 is a ball movement coordinator and cam member 57. Member 57 is substantially annular in shape and has a central aperture 58 defined by a radially inward facing surface 59. Aperture 58 is appropriately sized to receive, and be rotatable with respect to, a substantially cylindrical portion 60 of base member 16. A retention means, such as spring-type retainer 61, maintains member 57 mounted on portion 60 of member 16.
As best seen in FIGS. 3 and 5 ball movement coordinator and cam member 57 has three equally spaced ball receiving and camming recesses 62 radially outwardly spaced from aperture 58 and spaced equidistant from each other. Each of the recesses 62 has a radially innermost portion 63 sized to receive an actuator ball 54 and two sides or walls 64 which diverge radially outwardly from portion 63. Sides 64 extend from portion 63 radially outwardly to the periphery of member 57. The sides 64 serve as camming ramps to impel an actuator ball radially outwardly from portion 63 upon rotation of member 57 relative to the rotation of the actuator ball.
Spaced between each of two of the recesses 62 is a cam member movement control slot 65. Each slot 65 is formed of a radially innermost base surface 66 and two ends 67.
A relative rotation control means, such as a plurality of axial inboard extending engagement pins, such as pin 68 shown in FIG. 2, are fixedly secured to detent ring 23 and extend axially inboard from surface 46. The plurality of engagement pins 68 are, as best shown in FIGS. 4 and 6, positioned in a circular pattern concentric with portion 59 of the base member and equally spaced about the circular pattern.
Each engagement pin 68 is positioned to be received within a control slot 65 of member 57. Each pin 68 is radially outwardly spaced from base 66 and positioned to contact an end 67 of one of the control slots to limit rotary movement of detent ring 23 separate from member 57.
In FIG. 1 the clutch is shown in the disengaged position and the wheel hub 5 would be free wheeling with respect to the clutch assembly, axle 3 and spindle 4.
When the driver of the vehicle shifts the transfer case into four wheel drive and operates the vehicle torque is transmitted to axle 3 causing it to be a driving axle. Axle 3 consequently begins to rotate and base member 16 and detent ring 23 are forced to rotate with it. As detent ring 13 is keyed to non-rotatable spindle 4 it does not rotate.
Upon rotation of detent ring 23 each of the actuator balls 54 is forced out of the detent it occupies in each detent ring 23 and 13 and forced into contact with each surface 45 and 46. To accomodate the actuator balls between these surfaces detent ring 23 and base member 16 are forced axially outward or outboard along axle 3 and drive teeth 19 on drive gear 18 are forced into driving engagement with teeth 39 on member 29 to cause the wheel hub 5 to be driven by axle 3.
Continued rotation of detent ring 23 relative to ring 13 causes each of the control pins 68 to travel into contact with an end 67 of the control slot 65 which it occupies in member 57. By virtue of this contact the member 57 is forced to rotate with detent ring 23. Due to the radially outward diverging walls 64 of each ball recess 62 each ball is impelled or cammed radially outward until it occupies a ball receiving slot 53 in lip 52 and is in contact with surface 50 of bearing surface 49, substantially as shown in FIG. 2. In this position each ball engages a contact pin 51 affixed to bearing member 49 and forces bearing member 49 to rotate also.
Each of the balls will remain in this position as long as torque is applied to axle 3 and the teeth 19 will remain drivingly engaged to teeth 39 to drive hub 5.
If the vehicle is stopped, placed in reverse and backed up lip 52 will impel or cam each ball radially inward and each ball will, upon continued reverse rotation, be forced back to the radially innermost portion 63 of the ball recess 62 and occupy a detent in each detent ring 13 and detent ring 23 whereby spring 44 will force base member 16 and detent ring axially inward or inboard to disengage teeth 19 from teeth 39. Continued rotation in the reverse direction will immediately force the balls out of the detents to cause the gear teeth to reengage and the sequence of camming the balls outwardly will be repeated as described, above, except in the opposite direction.
To disengage the teeth 19 from the teeth 39 the vehicle is shifted out of four wheel drive at the transfer case and the vehicle is driven in two wheel drive in the direction opposite to that in which it was last driven in four wheel drive and the balls will be cammed radially inwardly to enable the spring 44 to urge teeth 19 out of engagement with teeth 39 to cause the hub 5 to be free-wheeling about spindle 4.
Due to no torque being applied to axle 3 by the drive train and the disengagement of teeth 19 from teeth 39 axle 3 no longer is caused to rotate. Therefore, the actuator balls will remain in the detents and the clutch will remain in the disengaged position substantially as shown in FIG. 1 until axle 3 is at some future time caused to rotate by application of torque through the vehicle drive train. | An actuator ball movement coordinator and cam member for a torque responsive hub clutch of the ball and cam type serves to assure coordinated movement of a plurality of actuator balls and also cams the balls into positions which cause actuation of the clutch. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to aids for securing a trailer to a towing vehicle and, more particularly, to a trailer hitch coupling kit for aiding in coupling the tow ball of a towing vehicle and the socket of a trailer coupler, by enabling the driver of the towing vehicle to view the tow ball and a guidepost mounted on the trailer drawbar while in the driver's seat.
2. Description of the Related Art
It is well known that connecting a trailer to a towing vehicle is a difficult task when performed by one person. The difficulty arises from the need to position the tow ball of the towing vehicle under the socket of the trailer coupler. Typically, when a lone person backs a towing vehicle toward a trailer, neither the tow ball nor the trailer coupler are visible while he or she is in the driver's seat of the towing vehicle. Therefore, he or she must maneuver the vehicle back and forth numerous times, getting out of the vehicle each time to check on the positioning of the tow ball and trailer coupler socket until he or she has positioned the tow ball just beneath the trailer coupler socket. Although a mirror attached to the rear of the towing vehicle can enable the driver to see the tow ball as he or she backs up, such a mirror cannot enable the driver to also see the trailer coupler until the driver has already aligned the tow ball fairly close to it. Thus, a need exists for a better means of connecting a trailer to a towing vehicle.
Numerous patents teach a mirror assembly that mounts to the rear of a vehicle. These include U.S. Pat. No. 4,905,376 issued Mar. 6, 1990 to R. P. Neeley (apparatus for facilitating trailer hitch element alignment); U.S. Pat. No. 4,925,287 issued May 15, 1990 to B. Lord et al. (mirror assembly for facilitating hitch element alignment); U.S. Pat. No. 5,111,342 issued May 5, 1992 to D. M. Quesada (hitch-viewing mirror assembly); U.S. Pat. No. 5,180,182 issued Jan. 19, 1993 to J. R. Haworth (trailer hitch alignment device); U.S. Pat. No. 5,313,337 issued May 17, 1994 to T. L. Byers (attachable vehicle mirror); U.S. Pat. No. 5,482,310 issued Jan. 9, 1996 to J. L. Staggs (trailer hitch mirror alignment device); U.S. Pat. No. 5,625,500 issued Apr. 29, 1997 to B. Ackerman (hitching mirror); U.S. Pat. No. 5,657,175 issued Aug. 12, 1997 to J. D. Brewington (reflector device for aligning the complementary components of a trailer hitch); U.S. Pat. No. 5,784,213 issued Jul. 21, 1998 to G. Howard (backup mirror for tow vehicle); U.S. Pat. No. 5,825,564 issued Oct. 20, 1998 to K. P. Mazarac (rear-mounted vehicle mirror); U.S. Pat. No. 5,971,555 issued Oct. 26, 1999 to L. M. Wilcox et al. (hitch viewing mirror assembly and method); U.S. Pat. No. 6,102,423 issued Aug. 15, 2000 to H. S. Beck et al. (visual alignment aid for connecting trailers); and U.S. Pat. No. 6,619,685 issued Sep. 16, 2003 to G. Q. Teague (universal trailer hitch mirror system).
Although useful for viewing a tow ball from the driver's seat of a towing vehicle, each of these devices has several drawbacks when used to couple the vehicle and a trailer. First, while each device provides a view of the tow ball, none also provides the driver with a reference to the location of the trailer coupler and, thus, each device is only useful to a driver once he or she has positioned the towing ball fairly close to the trailer coupler. Second, none of the devices easily adjusts into the position presenting the best view of the tow ball and provides a means for recording that position. Third, none of the devices disassembles and stores easily.
Additionally, U.S. Pat. No. 5,269,554 issued Dec. 14, 1993 to B. J. Law (trailer hitch alignment guide); U.S. Pat. No. 5,290,056 issued May 1, 1994 to A. F. Faith, IV (trailer hitch guide); and U.S. Pat. No. 6,612,603 issued Sep. 2, 2003 to M. D. Alger (trailer hitch alignment system) each teaches a guidepost for attachment to the tow ball of a towing vehicle and a guidepost for attachment to a trailer couple. The top of each guidepost is visible from the rear view mirror within a towing vehicle thereby allowing the tow ball to be positioned close to the trailer coupler. However, because none of these devices includes a mirror mountable to the rear of the towing vehicle, it is difficult to align the trailer hitch socket precisely over the tow ball.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a trailer hitch guide solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
The trailer hitch coupling kit includes a mirror assembly with two pivotally connected support legs, a pair of foot members that allow for attachment of the mirror assembly to the rear of a towing vehicle in three distinct manners, a trailer drawbar guidepost with a magnetic base, and a carrying case.
The kit provides the driver of a towing vehicle with both a view of the tow ball and a reference to the location of the trailer coupler and, thus, allows the driver to precisely align the trailer coupler socket over the tow ball without leaving the driver's seat. The components of the kit are easily assembled and disassembled, and conveniently store in a dedicated carrying case. The mirror assembly is configured to easily adjust into the position that presents the best view of the tow ball and provides a means for recording that position. The pair of foot members allows the mirror assembly to be attached to a vehicle in one of three distinct manners.
Accordingly, it is a principal object of the invention to provide the driver of a towing vehicle with both a view of the vehicle's tow ball and a reference to the location of a trailer coupler and, thus, allow the driver to precisely align the trailer coupler socket over the tow ball without leaving the driver's seat.
It is another object of the invention to provide a trailer hitch coupling kit with components that are easily assembled and disassembled, and conveniently store in a dedicated carrying case.
It is a further object of the invention to provide a trailer hitch coupling kit with a mirror assembly that is configured to easily adjust into the position that presents the best view of the tow ball and that provides a means for recording that position.
Still another object of the invention is to provide a trailer hitch coupling kit with a pair of foot members that allows the mirror assembly to be attached to a towing vehicle in one of three distinct manners.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an environmental, perspective view of a trailer hitch coupling kit according to the present invention.
FIG. 2 is a perspective view of a guidepost for a trailer hitch coupling kit according to the present invention.
FIG. 3 is a perspective view of a mirror assembly with a pair of foot members connected thereto for a trailer hitch coupling kit according to the present invention.
FIG. 4 is a side view of a foot member for a trailer hitch coupling kit according to the present invention shown connected to a fragmented mirror assembly support leg.
FIG. 5A is a fragmented view of a foot member shown in relation to a foot bracket for a trailer hitch coupling kit according to the present invention.
FIG. 5B is a top view of a foot bracket for a trailer hitch coupling kit according to the present invention.
FIG. 6 is a fragmented, elevational view of a mirror assembly connected to a foot member of a trailer hitch coupling kit according to the present invention.
FIG. 7 is an elevational view of a mirror assembly for a trailer hitch coupling kit according to the present invention shown with its legs folded.
FIG. 8 is a perspective view of components of a trailer hitch coupling kit according to the present invention shown in relation to the carrying case.
FIG. 9 is a fragmented, elevational view of a mirror assembly for a trailer hitch coupling kit according to the present invention.
FIG. 10A is an environmental side view of a mirror assembly connected to a foot member of a trailer hitch coupling kit according to the present invention shown attached to the tail gait of a fragmented pickup truck.
FIG. 10B is an environmental, perspective view of a mirror assembly connected to a pair of foot members of a trailer hitch coupling kit according to the present invention shown attached to the tail gait of a fragmented pickup truck.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, the present invention is a trailer hitch coupling kit designated generally as 20 in FIG. 8 . The kit includes a mirror assembly 90 , a guidepost 40 , a pair of foot members 60 and 62 with a pair of suction cups 32 for each foot member 30 and a carrying case 22 .
The mirror assembly 90 includes a substantially flat base 92 with a mirror 94 secured to its front side, as shown in FIG. 3 , and a demarcated area 96 for recording hinge setting information on its backside, as shown in FIG. 9 . The base 92 is substantially square with a support leg 98 and 100 extending from each of two opposing corners.
Each of the two support legs 98 and 100 has a square cross section and is connected to the base 92 via a sleeve and spindle hinge 102 , as shown in FIG. 6 . The sleeve and spindle hinge 102 allows the support leg 98 to rotate three hundred and sixty degrees relative to the base 92 . The spindle 104 for each hinge is demarcated with graduated setting indicia 106 to allow a user of the invention to observe the setting that correlates with the angle between the base 92 and the support leg 98 and 100 that provides the best view of the tow ball. Each support leg 98 and 100 has a second hinge 108 that enables the support leg 98 and 100 to fold across opposite sides of the base 92 as shown in FIGS. 7 and 8 . By folding one support leg 98 and 100 across each side of the base 92 , the base 92 is better protected from breakage. Although not shown, the support legs 98 and 100 can also be folded across the same side of the base 92 . As shown in FIG. 6 , each support leg 98 and 100 is extendable by moving an outer sleeve 114 with finger pressure relative to an inner sleeve 116 that extends from the second hinge 108 . The inner 116 and outer 114 sleeves are connected via a push fit engagement. At the distal end 110 of each support leg 98 and 100 , a segment 110 of the support leg 98 and 100 , shown in FIG. 7 , has a square cross section with slightly smaller dimensions than the rest of the support leg 98 and 100 to facilitate push fit engagement with a foot member 60 and 62 .
Referring to FIG. 4 , each of the two foot members 60 and 62 is a clamp with a proximal member 64 and a distal member 66 . The proximal member 64 has a vertical segment 68 with two suction cups 32 and a clip 70 extending from one side and a horizontal segment 72 extending from the opposite side. The distal member 66 has a horizontal segment 74 that mates with the horizontal segment 72 of the proximal member 64 via push fit engagement, a downward extending segment 76 and a support leg connector 78 extending from the top of the horizontal member 74 . The support leg connector is a sleeve and spindle hinge 80 with a receiving leg 82 attached thereto 80 . The spindle is demarcated with graduated setting indicia 112 , as shown in FIG. 6 . The receiving leg 82 is adapted to receive the distal end 110 of a support leg 98 and 100 . A thumb brace 84 , shown in FIG. 4 , extends from the top of the horizontal segment 74 of distal member 66 . Both the proximal 64 and distal members 66 are hollow with square cross sections. The suction cups 32 are attached to the proximal member 64 via an aperture 118 , shown in FIG. 6 , in the vertical segment 68 and can be easily detached and reattached.
The distance between the vertical segment 68 of the proximal member 64 and the downward extending segment 76 of the distal member 66 can be adjusted with finger pressure by adjusting the amount of the horizontal segment 72 of the proximal member 64 that is within the horizontal segment 74 of the distal member 66 . By doing so, the foot member 60 and 62 can be clamped onto the tailgate T of a pickup truck P as shown in FIG. 10A .
In addition to clamping onto a tailgate, the foot member 60 and 62 can be attached to a towing vehicle using its suction cups 32 as shown in FIG. 1 or by inserting its clip 70 into a mating bracket 86 as shown in FIG. 10B . The bracket 86 , shown in FIGS. 5A and 5B , has two apertures 88 for permanent mounting onto a towing vehicle.
Referring to FIG. 2 , the guidepost 40 includes a telescoping rod 42 with a reflective disk 44 attached to one end and a magnet 46 attached to the other end. The reflective disk 44 is a disk with reflective material 48 attached to each of its sides. The magnet 46 is attached to the telescoping rod 42 via a sleeve and spindle hinge 50 and enables the guidepost 40 to be securely attached to the drawbar of a trailer TR as shown in FIG. 1 .
The ideal settings for the two sleeve and spindle hinges 102 that connect the support legs 98 and 100 to the base 92 and the two sleeve and spindle hinges 80 incorporated in the support leg connectors 78 can be recorded in the demarcated area 96 as shown in FIG. 9 .
The carrying case 22 , shown in FIG. 8 , is container adapted to receive and store the mirror assembly 90 , the pair of foot members 60 and 62 , the suction cups 32 and the guidepost 40 . It 22 is constructed of a pliable material, has an open side 24 with a folding flap 26 and has a closing clasp 28 . It can also be constructed of a rigid material.
The kit 20 provides the driver of a towing vehicle with both a view of the tow ball and a reference to the location of the trailer coupler while in the driver's seat. ( FIG. 1 ) Thus, the kit 20 allows the driver to precisely align the trailer coupler socket over the tow ball without leaving the towing vehicle. The components 32 , 40 , 60 , 62 and 90 of the kit 20 are easily assembled and disassembled, conveniently store in the carrying case 22 , and can be constructed primarily of metal, plastic or a combination thereof. The mirror assembly 90 is configured to easily adjust into the position that presents the best view of the tow ball and provides a means for recording that position. The pair of foot members 60 and 62 allows the mirror assembly 90 to be attached to a vehicle with suction cups 32 , with a clip 70 and bracket 86 or with the foot member 60 and 62 clamped to a tailgate.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. | The trailer hitch coupling kit is a kit for aiding a driver in coupling the tow ball of a towing vehicle and the socket of a trailer coupler, by enabling the driver to view the tow ball and a guidepost mounted onto the trailer drawbar while seated in the driver's seat of the towing vehicle. It includes a mirror assembly with two pivotally connected support legs, a pair of foot members that allow for attachment of the mirror assembly to the rear of a towing vehicle in three distinct manners, a trailer drawbar guidepost with a magnetic base and a carrying case. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. National Stage Application of International Application No. PCT/EP2013/066964 filed Aug. 14, 2013, which designates the United States of America, and claims priority to DE Application No. 10 2012 214 565.6 filed Aug. 16, 2012, the contents of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The invention relates to a method and a device for operating an injection valve, which is used, in particular, to meter fluid, to be precise in particular fuel.
BACKGROUND
[0003] Ever stricter legal requirements with respect to the permitted emission of pollutants of internal combustion engines which are arranged in motor vehicles make it necessary to implement various measures which can reduce the emission of pollutants. A starting point in this context is to lower the emission of pollutants which are generated during the combustion process of the air/fuel mixture. In this context, extremely precise metering of fuel is advantageous.
[0004] In addition, in this context it is also advantageous if multiple injections take place during a working cycle at least in certain operating states.
SUMMARY
[0005] One embodiment provides a method for operating an injection valve having a nozzle needle which, in a closed position, stops metering of fluid and otherwise releases the metering of fluid, and having a solid-state actuator which is designed to act on the nozzle needle and to influence its position, wherein, for an injection process, values of a characteristic variable for a state of charge of the solid-state actuator are acquired with a predefined sampling rate, a starting reference time is determined, a final reference time is determined, to be precise chronologically correlated with an operating phase in which the solid-state actuator is discharged to a predefined reference state, by absorbing the energy in a discharge resistor, a correction reference value is determined as a function of a value of the characteristic variable for the state of charge of the solid-state actuator which is acquired correlated with an end of the operating phase, and a predefined reference value, a correction value profile is determined as a function of the final reference time, the starting reference time and the correction reference value, and the acquired values of the characteristic variable for the state of charge are corrected as a function of the correction value profile.
[0006] In a further embodiment, the correction value profile is linear.
[0007] Another embodiment provides a device for operating an injection valve having a nozzle needle which, in a closed position, stops metering of fluid and otherwise releases the metering of fluid, and having a solid-state actuator which is designed to act on the nozzle needle and to influence its position, wherein the device is designed, for an injection process: to acquire values of a characteristic variable for a state of charge of the solid-state actuator with a predefined sampling rate, to determine a starting reference time, to determine a final reference time, to be precise chronologically correlated with an operating phase in which the solid-state actuator is discharged to a predefined reference state by taking up the energy in a discharge resistor, to determine a correction reference value as a function of a value of the characteristic variable for the state of charge of the solid-state actuator which was determined correlated to an end of the operating phase, and a predefined reference value, to determine a correction value profile as a function of the final reference time, the starting reference time and the correction reference value, and to correct the acquired values of the characteristic variable for the state of charge as a function of the correction value profile.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Example embodiments of the invention are explained in more detail below with reference the drawings, in which:
[0009] FIG. 1 shows an injection valve having a control device,
[0010] FIG. 2 shows a hardware integrator circuit arrangement which is embodied in the control device,
[0011] FIG. 3 shows signal profiles during the operation of the injection valve,
[0012] FIG. 4 shows further signal profiles during the operation of the injection valve, and
[0013] FIG. 5 shows a flowchart of a program.
DETAILED DESCRIPTION
[0014] Embodiments of the invention provide a method and a device for operating an injection valve which permit precise metering of fluid by the injection valve.
[0015] More particularly, embodiments of the invention provide a method and a device for operating an injection valve having a nozzle needle which, in a closed position, stops metering of fluid and otherwise releases the metering of fluid. The injection valve also has a solid-state actuator which is designed to act on the nozzle needle and to influence its position. The following steps are carried out for an injection process.
[0016] Values of a characteristic variable for a state of charge of the solid-state actuator are acquired with a predefined sampling rate. A starting reference time is determined which is related to the injection process. In addition, a final reference time is determined, to be precise chronologically correlated with an operating phase in which the solid-state actuator is discharged to a predefined reference state, by absorbing the energy in a discharge resistor. A correction reference value is determined as a function of a value of the characteristic variable which has been acquired correlated with an end of the operating phase in which the solid-state actuator is discharged to the predefined reference state, and as a function of a predefined reference value. A correction value profile is determined as a function of the final reference time, the starting reference time and the correction reference value. The acquired values of the characteristic variable for the state of charge are corrected as a function of the correction value profile.
[0017] In this context, an injection process can be understood as being an individual fluid-metering process. However, an injection process also comprises linking a plurality of partial injections which are carried out by an injection valve during a working cycle of an internal combustion engine, to be precise when the operating phase in which the solid-state actuator is discharged to a predefined reference state by absorbing the energy in the discharge resistor is not assumed between respective partial injections.
[0018] By means of the procedure, in the case of injection processes, in particular in the case of relatively long injection processes, a drift error which occurs there can also be particularly easily and precisely compensated, to be precise, in particular, for the values of the characteristic variable which have been acquired during the respective injection processes. This therefore permits the values to be made available with a high quality level, that is to say a low measuring error. This has the effect that when the values are correspondingly processed further, for example in order to determine characteristic points which are representative of predefined events within the injection valve, particularly precise control of the metering of fluid by the injection valve is made possible.
[0019] According to one embodiment, the correction value profile is linear. In this way, the correction value profile can be determined particularly easily.
[0020] An injection valve has an injector housing 1 ( FIG. 1 ) to which, in addition, an adaptor plate 2 , a nozzle body 4 and a nozzle clamping nut 6 are assigned. The nozzle clamping nut 6 couples the adaptor plate 2 and the nozzle body 4 to the injector housing 1 . Basically, the adaptor plate 2 and/or the nozzle body 4 can also be embodied in one piece with the injector housing 1 .
[0021] The injector housing 1 also has a fluid inlet 8 which is hydraulically coupled to a fluid feed line, which comprises, for example, a fluid high-pressure accumulator.
[0022] A nozzle needle 12 is arranged in a recess 10 in the nozzle body 4 . In addition, at least one injection hole 14 is formed in the nozzle body 4 , said injection hole 14 leading outwards from the recess 10 out of the nozzle body 4 .
[0023] Furthermore, the injection valve comprises a transmission arrangement 16 which comprises a lever and/or a return stroke and via which the nozzle needle 12 can be coupled mechanically to a solid-state actuator 18 .
[0024] The solid-state actuator 18 is embodied, for example, as a piezo-electric actuator. However, it can also be embodied as any other solid-state actuator which is known to a person skilled in the art for such purposes, such as for example a magnetostrictive actuator.
[0025] In addition, an electrical terminal 20 is provided via which the injection valve can be coupled in an electrically conductive fashion to a control device 22 .
[0026] The control device 22 is designed to generate, as a function of at least one operating variable, at least one actuating signal which is provided, for example, for actuating the injection valve. Operating variables comprise in this context any desired measuring variables or variables derived therefrom. The control device 22 can also be referred to as a device for operating the injection valve.
[0027] In a closed position of the nozzle needle 12 , the latter stops metering of fluid through the at least one injection hole 14 . Outside the closed position of the nozzle needle 12 , that is to say when the nozzle needle is located in the axial direction along the longitudinal axis of the injection valve, in a position which is changed in an upward direction in the plane of the drawing with respect to its closed position, it releases the metering of fluid. In order to carry out metering of fluid, electrical energy is firstly fed to the solid-state actuator 18 , to be precise by feeding in a predefined charge.
[0028] This results in the solid-state actuator 18 becoming longer in the axial direction and this lengthening being transmitted to the nozzle needle 12 via the transmission arrangement 16 . In this way, a force is therefore applied to the nozzle needle 12 , which force acts on the nozzle needle 12 in such a way that, without further forces acting on it, the nozzle needle 12 moves out of its closed position. In addition, in particular a spring force of a restoring spring acts on the nozzle needle 12 , as do also hydraulic forces caused by the fluid pressure of the fluid in the recess 10 . As a result, the nozzle needle 12 moves out of its closed position as a function of the force balance of the forces acting on it. However, in order to move the nozzle needle out, its inertial force must also be overcome so that this results in what is referred to as an electrohydraulic delay time period until the nozzle needle 12 actually moves out of its closed position.
[0029] The injection valve can be operated in various operating modes for a closing process of the nozzle needle 12 during which said nozzle needle 12 moves from a position outside the closed position back into its closed position.
[0030] The respective various operating modes are characterized in that a different combination of operating phases is present. FIGS. 3 and 4 illustrate signal profiles, to be precise idealized signal profiles, of an acquired voltage U_AV which drops at the solid-state actuator 18 . In a first operating phase BP 1 , the solid-state actuator 18 is discharged to a predefined partial charge. In a second operating phase BP 2 , the solid-state actuator 18 is operated as a sensor. The operating period of the second operating phase BP 2 is predefined, in particular, in such a way that the closed position of the nozzle needle is reached during the operating period.
[0031] A third operating phase BP 3 is carried out while the solid-state actuator 18 is discharged further to a predefined reference state, to be precise by absorbing the energy in a discharge resistor. In particular, the solid-state actuator 18 is discharged in the third operating phase BP 3 to a predefined reference charge which corresponds, for example, to a solid-state actuator which is completely or virtually completely discharged, and therefore results in a voltage drop at the solid-state actuator 18 of, for example, 0 V. However, owing to the properties of the solid-state actuator 18 it is possible for the reference charge to assume a value which deviates from a neutral value.
[0032] The partial charge is predefined, for example, in such a way that up to approximately 20 V of voltage drops at the solid-state actuator 18 . The operating phase BP 2 can be predefined, for example, at approximately 80 μs, and the operating phase BP 3 is predefined, for example, at approximately 100 μs.
[0033] While the discharge process is being carried out in the first and also in the second operating phases BP 1 , BP 2 , the charge which is conducted away is preferably buffered in a capacitor in order to be able to feed it again to the solid-state actuator 18 in the case of a renewed charging process.
[0034] In a first operating mode, both the first operating phase BP 1 and the second operating phase BP 2 as well as the third operating phase BP 3 are present. What is referred to as a main injection is frequently carried out in the first operating mode.
[0035] In contrast to the first operating mode, in a second operating mode the first operating phase BP 1 and subsequently the second operating phase BP 2 are carried out, while the third operating phase BP 3 is omitted. In this way, the minimum possible metering interval between two successive metering operations of fluid is reduced compared to the first operating mode BM 1 . In the second operating mode BM 2 there is still a small residual charge in the solid-state actuator 18 . In particular the electrohydraulic delay time period is also shortened by the residual charge.
[0036] In the signal profile illustrated in FIG. 4 , the injection valve is operated in the second operating mode BM 2 , for example, during the first two partial injections illustrated there and the subsequent main injection, while it is operated in the first operating mode BM 1 in the last partial injection, which can also be referred to as a post-injection.
[0037] In a third operating mode, the first operating phase BP 1 is carried out, while the second and third operating phases BP 2 , BP 3 are omitted. In this way, the minimum metering interval is reduced further. In the third operating mode, the second operating phase BP 2 is also omitted, and therefore operation of the solid-state actuator 18 as a sensor with corresponding detection of the impacting of the nozzle needle 12 at its closed position is also dispensed with.
[0038] In this context, in the first operating phase BP 1 in the third operating mode it is also possible to discharge the solid-state actuator 18 to a partial charge which is increased compared to the second and/or third operating modes. This also contributes to further shortening of the electrohydraulic delay time period.
[0039] A hardware integrator circuit arrangement (see FIG. 3 ) is preferably embodied in the control device. It is designed, in particular, to detect a current through the solid-state actuator 18 , to be precise by means of a shunt resistor R_S and a difference amplifier 26 . The output signal of the difference amplifier 26 is fed to an integrator 28 which can be reset to a neutral value, for example zero, by means of a resetting signal RES.
[0040] The output signal of the integrator 28 is fed to an A/D converter 30 which is designed to perform analog/digital conversion of the input signal that is present there.
[0041] The output signal of the A/D converter 30 represents values KG_W of a characteristic variable for a state of charge of the solid-state actuator 18 . The conversion in the A/D converter 30 takes place with a predefined sampling rate. The values KG_W of the characteristic variable for the state of charge of the solid-state actuator 18 are fed to a signal processing unit 32 . The latter comprises an offset compensation unit 34 which is designed to determine a correction offset signal as a function of the values KG_W of the characteristic variable and to feed them to a D/A converter 36 , which then generates a correspondingly analog correction offset signal I_OFFS_KOR which is fed to the difference amplifier 26 for offset compensation. The correction offset signal I_OFFS_KOR is respectively newly determined chronologically correlated with the third operating phase BP 3 , to be precise preferably toward the end thereof, and then acts on the output signal of the difference amplifier 26 for a subsequent injection process. The quality of the analog correction offset signal I_OFFS_KOR depends greatly on the accuracy of the D/A converter 36 .
[0042] The resetting signal RES is generated, in particular, chronologically correlated with a start of a respective injection process, to be precise in particular at the start of the injection process. The start of the injection process does not necessarily define the start of the metering of fluid, but instead a chronological correlation with the start of the actuation of the solid-state actuator 18 for feeding in charge for initiating the metering of fluid. The start of the injection process can therefore be the start of the actuation of the solid-state actuator 18 for feeding in charge for initiating the metering of fluid.
[0043] A program for operating the injection valve is stored in a memory of the control device 22 and is processed during the operation of the injection valve in a computing unit of the control device which can comprise, for example, a microprocessor. The program ( FIG. 5 ) is started in a step S 1 in which, if appropriate, variables are initiated.
[0044] In a step S 3 , a starting reference time t_BEG is determined for a respective current injection process. The starting reference time t_BEG corresponds, for example, approximately or, in particular, precisely to the start of the actuation of the injection valve in the case of the starting of the respective injection process. Corresponding examples of this are illustrated in the signal profiles of FIGS. 3 and 4 .
[0045] In addition, a final reference time t_END is determined chronologically correlated with the third operating phase BP 3 , to be precise in particular assigned to that time at which the respective discharge process is currently completed in the third operating phase BP 3 . A time period between the respective starting reference time t_BEG and the respective final reference time t_END therefore extends over the entire injection process, that is to say, for example, as illustrated in FIG. 3 , over what is referred to as a main injection. In the case of the signal profiles according to FIG. 3 , corresponding starting and reference times t_BEG, t_END for the pre-injection or post-injection illustrated there can also be determined.
[0046] The signal profile illustrated in FIG. 4 comprises linking of partial injections, and therefore the time period between the starting reference time t_BEG and the final reference time t_END comprises the entire time period of the partial injections, and the partial injections can be pre-injections or post-injections or also the main injection.
[0047] In a step S 5 , a correction reference value KOR_BW is determined, to be precise as a function of a value KG_W of the characteristic variable which was acquired correlated with the end of the third operating phase BP 3 . The said value KG_W is also acquired, in particular correlated or, in particular, also approximately in a way which coincides with the final reference time t_END.
[0048] Furthermore, the said value KG_W is preferably determined as a function of a reference value REF_W which represents a still remaining quantity of charge. The latter can, for example, be permanently predefined and can be determined, for example, by test or simulation and/can be determined dynamically by means of a charge observer. Said charge quantity basically has a very low value such as, for example, 65 μs.
[0049] The correction reference value KOR_BW is determined, in particular, as a function of a difference between the value KG_W of the characteristic variable, which was acquired correlated with the end of the third operating phase BP 3 , and the reference value REF_W. Said correction reference value KOR_BW can correspond, for example, directly to this difference.
[0050] The correction reference value KOR_BW therefore represents a total offset which arises during a respective injection process.
[0051] In a step S 7 a correction value profile KOR_VERL is determined as a function of the final reference time t_END, the starting reference time t_BEG and the correction reference value KOR_BW. In this context, a predefined function, such as, for example, a linear function or else a function which approximates to the correction reference value KOR_BW exponentially, is assigned to the correction value profile. In the case of the linear function, the gradient corresponds, for example, to the quotient of the correction reference value KOR_BW and the difference between the final reference time t_END and the starting reference time t_BEG.
[0052] In a step S 9 , the acquired values KG_W of the characteristic variable for the state of charge are then corrected as a function of the correction value profile KOR_VERL. This takes place in a corresponding chronological assignment of the respective values KG_W to their position in the respective injection process. Therefore, for example in the case of a linear function, in the case of the correction value profile KOR_VERL half the value of the correction reference value KOR_BW is added, for the purpose of correction, to a value KG_W which is precisely in the center of the time interval between the starting reference time t_BEG and the final reference time t_END.
[0053] The values KG_W_COR, corrected in this way, of the characteristic variable for the state of charge are then made available, in particular, to other programs which are stored in the control device 22 , and are processed during the operation of the injection valve, in order to evaluate further said values KG_W_COR, to be precise, for example, with respect to the detection of specific characteristic points which may be, for example, representative of the impacting of the nozzle needle 12 in its closed position.
[0054] The program is subsequently ended in a step S 11 . The program is preferably called again for each injection process. | An injection valve has a moveable nozzle needle that controls a dosing of fluid and a solid-state actuator that actuates the nozzle needle. To operate the injection valve, values of a characteristic for a load state of the actuator are detected at a predetermined sampling rate. A start reference time and end reference time are determined correlating in chronological terms to an operating phase in which the solid-state actuator is discharged to a predetermined reference state by absorbing the energy in a discharging resistor. A correction reference value is determined based on a detected value of the characteristic correlating to an end of the operating phase, and a predetermined reference value. A correction value pattern is determined based on the end reference time, the start reference time, and the correction reference value. The detected values of the characteristic for the load state are determined based on the correction value pattern. | 7 |
BACKGROUND OF THE INVENTION
A wide variety of single-use type packaging materials are known, the so-called disposable cartons. Many of said packaging materials are in the form of multilayers comprising different materials in order that the composite material may present a desired combination of properties otherwise not available from a single layer of a single composition.
For packaging cartons, known multilayers generally comprise at least one stiffening layer, such as cardboard, which also reliably retains scores and folds therein. The other layers can be variably chosen in function of the protection needed for the contained material. In particular, for dry laundry compounds, which sometimes are moisture sensitive compositions, the disposable cartons consist of a multilayer material comprising generally an aluminum foil coated to cardboard or paper.
The disposable cartons comprising a layer of aluminum foil possess extremely barrier properties. However, this type of multilayers is becoming more and more controversial from the environmental viewpoint.
Consequently, the packaging technology has long been in need of being able to develop an aluminum-free packaging material, that uses materials offering high barrier characteristics, but conferring greater environmental advantages to the multilayer material.
From CH-A5-610 570 it is known that ethylene vinyl alcohol copolymer (abbreviated as EVOH) or mixtures of EVOH with other thermoplastic polymers is a good barrier material for gases in general, oxygen in particular. This material is directly used to preserve liquids or foods in general.
Various multilayer materials comprising EVOH and mixtures thereof have been described in EP-A-245 921, Gibbsons et al., published Nov. 19, 1987; EP-A-423 511, Lofgren et al., published Apr. 24, 1991; WO92/01558, Flom, Atle, published Feb. 6, 1992. The containers formed by these multilayer materials present several layers to achieve different protection of the contained material, from an oxygen barrier to a flavour barrier, always comprising at least a stiffening layer made of cardboard or paper. The EVOH or other thermoplastic polymers are laminated always as one of the outermost layers.
The multilayer materials of this prior art needs special assembling techniques, such as heat sealing or hot melts, to be formed into cartons. In this operation, different parts of said material must be assembled. If the parts, which have to be bonded together, consist of EVOH or mixtures thereof or of other thermoplastic polymers, the carton cannot be simply glued together, but needs, as said before, sophisticated assembling techniques.
It is an object of the present invention to provide a multilayer material, which allows to form packing containers for dry compounds, such as dry laundry compositions, on machines using only glues as adhesives, and nevertheless present a high barrier to moisture permeation and prevent the migration through said material of greasy compounds using an EVOH layer.
It is yet another independent object of the present invention to provide a process allowing for the manufacture of the packaging container from said multilayer material. These and other objectives will become more apparent in the following description of the invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 schematically illustrates the transverse structure of the preferred embodiment of the multilayer material according to the present invention: the ethylene vinyl alcohol copolymer (EVOH) layer is first sandwiched between two tie layers and then sandwiched again between two cardboard or paper layers.
FIG. 2 and 3 show possible modifications of the corresponding transverse structure of the multilayer material. In FIG. 2 only one tie layer is used, whereas in FIG. 3 the EVOH layer is directly attached between two cardboard or paper layers.
FIG. 4 schematically illustrates the preferred embodiment of the packaging container made of one blank composed of said multilayer material.
SUMMARY OF THE INVENTION
The present invention is a multilayer material for making packages adequate for containing dry materials, which exhibits a superior moisture protection and prevents the migration of greasy compounds through an ethylene vinyl alcohol copolymer (EVOH) barrier layer.
The multilayer material of the present invention uses state of the art glues for reforming into a packaging container, and not, as more commonly, heat sealed, since the outermost layers are always made of cardboard or paper.
DETAILED DESCRIPTION OF THE INVENTION
The multilayer of the present invention uses at least two different materials: cardboard or paper and ethylene vinyl alcohol copolymer (EVOH). These materials are available as layers in different thicknesses and density, which determine the weight proportions of the different layers. The ranges described below in the examples for the various materials refer for a container of a dry laundry compound. The ranges that will be mentioned are nevertheless variable for different needs any person skilled in the art can encounter to solve specific problems. These various layers are attached to each other in a variable sequence except that cardboard or paper should always be the outermost layers, described below with the aid of the drawings, and various adhesion techniques.
The thicknesses of the cardboard and paper layers can be chosen freely from any person skilled in the art as mentioned before. The thickness of the cardboard determines the stiffness of the material and compression resistance of the final carton, whereas the thickness of the paper can depend from the printing or pre-printing quality to achieve. For the following examples of the present invention of a multilayer, the proportion amounts preferably between 75% and 80%, for the cardboard layer of the total weight of said multilayer and preferably between 10% and 20%, for the paper layer of the total weight of said multilayer material are representative measures, but not at all unique. The cardboard or paper layer can in addition show a white outer-liner allowing a high quality printing.
The tie layer is principally used to strengthen the adhesion of the ethylene vinyl alcohol copolymer barrier layer onto the cardboard or paper layer. Said layer also provides a protection to the EVOH layer against mechanical or environmental damages. The tie layer can be of many different kinds for example polyethylene. To achieve this tasks, they can be properly used in various thickness and density as selected by any person skilled in the art of packaging.
The EVOH material is needed to substitute the aluminum foil as a moisture barrier. The thickness and the density of this layer is variable to any different needs of a person skilled in the art. For the following examples of the present invention of a multilayer, the thickness should be of 3 μm minimum and the percentage of Ethylene could be varied successfully from 20 to 50% on a weight basis of the EVOH material. The density of the EVOH material used is between from 1.1 to 1.3 g/cm 3 .
Any of the thickness or density ranges mentioned so far do not limit the present invention of a multilayer, because they can be easily varied by any person skilled in the art. All possible coating methods to attach the different layers of the multilayer material of the present invention are all known and common for any person skilled in the art. The present invention is applicable with any coating method the person skilled in the art chooses. The present invention is applicable also to any other non-heat-sealing method capable of achieve a sufficient tight attachment of the layers of the multilayer material.
The production of this multilayer is done on coating machines. The cardboard is unwinded and the inner layers of polymers are applied. Then the paper is unwinded on top and the formed sandwich goes through a series of pressing, and eventually cooling cylinders to allow the adhesion phenomenon to occur.
The EVOH layer can be either extruded, i.e. applied in a molted state (extruded), or laminated, i.e applied in a solid state (film). In the first case, the use of tie layers can strengthen the adhesion, whereas in the second case, the use of tie layers or adhesives is a necessity.
The multilayer material of the present invention represents a barrier board for moisture sensitive compounds or products releasing olefins likely to migrate in the board. Moisture can chemically degrade some compounds or drastically change their physical characteristics, e.g. agglomerating powders in lumps. The migration of grease can stain the pack and considerably decrease its mechanical resistance. It can also jeopardize it shelf appearance. The material here disclosed is particularly suitable to manufacture packages for dry laundry compositions.
Nevertheless, since the outertmost layers of said material are cardboard or paper layers, the different parts of the container formed from said material can be tightly bonded together with state of the art glues, for example vinylic glues. The high commercial importance of this invention resides in the fact that, since the packaging container is glued together, conventional carton erecting machines can be used, i.e. machines for erecting packaging material only made of cardboard.
The packaging container of the invention is made from one blank composed of said multilayer material, as schematically illustrated in FIG. 4. Said blank (40) is reformed into a packaging container by gluing the appropriate edges (42) and (44) together. One of the outermost part of one of the edges (46) of said blank is glued on the opposite outermost part of the other edge (48) of said blank.
The container top and bottom can be closed following the same principle of gluing the internal side of one flap onto the external part of the opposite flat.
The so formed container composed of said multilayer is adequate to contain any dry material, which is sensitive to moisture or likely to release grease. In particular, said container is adequate to contain dry compounds such as Sodium percarbonate, Sodium perborate and olefin. Such compounds are typically present in laundry and household cleaning and bleaching compositions. Its use could be envisaged as well for other products of similar sensitivities e.g food flakes.
EXAMPLE I
The preferred version of the present invention of a multilayer material is illustrated in FIG. 1 through the transverse structure of the multilayer (10) that is reformable into a disposable carton. In this case the ethylene vinyl alcohol copolymer layer (EVOH) (15) is coated, preferably extruded, in between two tie layers (13) and (17), on the board/paper. The thickness of said EVOH layer must be at least 3 μm. Any person skilled in the art of packaging can select the tie layer grade and amount as a function of the desired adherence and economical constraints. For example, the preferred version of the present invention uses a combination of polyethylene and Bynel®, the thickness of each layer ranging from 5 to 10 μm.
Following cardboard-paper combinations of the outermost layers (11) and (19) are possible in the present invention:
a) (11)=cardboard and (19)=cardboard;
b) (11)=cardboard and (19)=paper;
c) (11)=paper and (19)=paper;
All these possible variations of the outermost layer of cardboard or paper, mentioned in the items a) to c), are applicable to all other examples described in the following of the multilayer material of the present invention. These outermost layer of cardboard or paper of the multilayer of the present invention are interchangeably the outer or the inner part of the reformed container in all examples.
EXAMPLE II
In FIG. 2 the EVOH barrier layer (26) is coated preferably extruded together with one tie layer only (24), in between the paper and the cardboard (22) which represents the outer or inner part of the formed packing container. The EVOH barrier layer thickness (26) must be at least 3 μm.
EXAMPLE III
The last possible sequence of the multilayer material of the present invention is illustrated in FIG. 3. The multilayer (30) shows no tie layer, but consists only of an EVOH barrier layer (34) directly coated, preferably extruded, directly onto the two cardboard or paper layers (32) and (36). | The present invention relates to multilayer materials for reforming into package containers with state of the art glues, which adequately protect moisture sensitive compounds and prevent the migration through the wall of greasy compounds. This material is particularly suitable for making containers for dry laundry and household cleaning compositions. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. provisional Pat. application No. 60/042,765, entitled Apparatus and Method for Sensing Dust, filed Mar. 20, 1997.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
None
BACKGROUND OF THE INVENTION
Sensors of small, airborne particles such as dust typically incorporate a mechanical, electrical, or optical sensing mechanism from which a output, or response signal, is measured. The magnitude of this response signal is proportional to the dust quantity. Physical qualities of such dust, such as size, density, and concentration are determined from the effect on this output signal.
Known methods used to effect such a dust sensing system include optical sensors, such as that disclosed in U.S. Pat. No. 5,136,750 in which the flux received is clouded by intervening particulate matter, and mirror based systems, such as that disclosed by U.S. Pat. No. 5,412,221 which receive light reflected from a mirror onto which particles have accumulated. Other methods include mechanical and electronic stimulation of a sensing member, typically an electrostrictive or piezoelectric member, in which particulate accumulation affects the mass of the sensor.
Such devices are disclosed in U.S. Pat. No. 3,653,253, which suggests sampling the mass of an accumulating piezoelectric crystal at two successive points to approximate the particulate mass collected, and U.S. Pat. No. 3,715,911, which discloses coating a sensory member with a tacky substance to accumulate airborne particles.
Often such devices are prone to high maintenance, as cumulative particle accumulation minimizes the sensitivity, therefore mandating frequent cleaning and/or calibration to effect accurate readings. Such devices are also expensive to manufacture, requiring specialized optical or electronic components such as piezoelectric crystals, photoresistors, and photosensors. Additionally, such devices tend to require large amounts of, or precisely metered, electrical power, limiting effectiveness with regard to household AC or common battery power. Further, point based sensors such as piezoelectric crystals have a small sensitivity area, limiting effectiveness and requiring a plurality of sensors when applied to an area. It would be beneficial to utilize a sensor capable of being manufactured from a planar material in which the electronic sensing properties are uniform along the area of the sensor.
SUMMARY OF THE INVENTION
The present invention provides a dust sensing apparatus which operates by oscillating a transducer substrate located in a sensing environment and determining the dust presence from the dampening effect such dust has on the oscillation frequency. By utilizing a conductive polymer such as poly-vinylidene-fluoride, an inexpensive yet effective sensor can be developed.
Such a substrate is treated to provide conductive portions in a particular pattern. Source electrodes are then attached to the non-conductive portions, and ground electrodes connected to the conductive portions. An AC voltage applied to the source electrodes will then create a piezoelectric effect causing substrate to deform. Rapid, alternating deformations caused by the AC voltage produce oscillatory, vibrational movement. This oscillation tends toward an inherent resonant frequency depending on the placement of the electrodes and the substrate material.
As dust presence dampens the oscillation frequency, a feedback circuit increases the voltage to drive the oscillation frequency back towards resonance. An output signal from the transducer is proportional to the amount of dust accumulated on the transducer, and also provides the feedback. The constant vibration serves to shake dust off the sensor and prevents cumulative build up, allowing the transducer to restore resonant frequency when the dust presence subsides.
DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a transducer according to a first embodiment;
FIG. 2 is a transducer according to a second embodiment;
FIG. 3 is a transducer according to a third embodiment; and
FIG. 4 is a schematic of the control and sensor logic circuit for use with the transducer.
DETAILED DESCRIPTION OF THE INVENTION
A dust sensing transducer apparatus according to the present invention applies an AC input signal, or voltage, to a substrate which has certain dielectric properties. This substrate is treated by irradiating or layering to form certain conductive portions, and such that an electrical field is induced within the substrate when such a signal is applied. Input electrodes are positioned on the non-treated surfaces of the substrate, and ground electrodes may be attached to the treated portions, such that the electric field so induced causes oscillatory movement of the substrate. Due to the electrical properties of the substrate, the resistance between the input electrodes varies with the oscillation rate, which is dampened by dust. The level of this resistance is linearly transferable to the quantity of dust on the sensor, and hence indicates the dust present in the sensing environment.
According to a first embodiment, a bi-morph design structure 20 is shown in FIG. 1. The bi-morph design structure 20 comprises a top layer 22 of a polymer sensor type material such as poly-vinylidene-fluoride (PVDF), a middle layer 24 of a conductive polymer, and a bottom layer 26 of a polymer sensor type material such as PVDF. The input signals 64 are applied to an electrode 21 on the top PVDF layer 22 and an electrode 23 on bottom PVDF layer 26. Electrodes 21 and 23 are of sufficient area so as to create an electric field capable of producing oscillatory movement of the substrate 20. The middle conductive layer 24 is grounded.
The bi-morph design structure 20 may also be created by irradiating the inner surfaces of the top PVDF layer 22 and the bottom PVDF layer 26 so that a resulting layer of conductive carbon remains on each inner surface. The inner surfaces may then be mated together to form a conductive carbon layer 24 between the top PVDF layer 22 and the bottom PVDF layer 26. The input signals 64 are then applied to the top PVDF layer 22 and the bottom PVDF layer 26 through electrodes 21 & 23, while the conductive carbon layer 24 is grounded.
The input signals 64 that are applied to the top PVDF layer 22 and the bottom PVDF layer 26 create an electric field which induces a piezoelectric effect in the two layers causing them to repeatedly deform and thereby cause the bi-morph design structure 20 to vibrate at its resonant frequency.
Referring to FIG. 2, a second embodiment comprising a half-morph design structure 30 is shown. The half-morph design structure 30 comprises a single layer 32 of PVDF of which one half of its top surface 34 and the opposing one half of its bottom surface 36 has been irradiated. The irradiated surfaces are grounded. The input signals 64 are applied to the electrodes 31 & 33 on the halves of the top and bottom surfaces of the PVDF slab 32 which have not been irradiated. The input signals 64 induce a piezoelectric effect which cause the PVDF slab 32 to repeatedly deform and thereby cause the half-morph design structure 30 to vibrate at its resonant frequency.
A third embodiment comprises a mono-morph design structure 40 as shown in FIG. 3. The mono-morph design structure 40 comprises a single layer 42 of PVDF which has had two traces 44 on its top surface irradiated. The irradiated traces are grounded. The input signals 64 are applied to the electrodes 41 & 43 on the outer areas on the top surface of the PVDF slab 42 which have not been irradiated. The input signals 64 induce a piezoelectric effect which causes the PVDF slab 42 to repeatedly deform and thereby cause the mono-morph design structure 40 to vibrate at its resonant frequency.
Although poly-vinylidene-fluoride is disclosed in the above embodiments, alternative piezoelectric crystalline materials, such as other polyvinyl compounds, a polymer matrix comprising antimony or bismuth, or other polymer matrix doped or irradiated sufficiently to sustain an electric field, could be used for fabrication of the transducer, thereby allowing for different response characteristics depending on the dielectric and resistive properties of the material chosen.
Referring to FIG. 4, a block diagram of a dust sensor apparatus 10 comprising control circuit 60 and sensor logic circuit 62 connected to the transducer 12 is shown. The transducer 12 within this dust sensor apparatus 10 may be any of the embodiments described above.
An input voltage signal V is generated by control circuit 60 and applied to electrodes 66, 68 of transducer 12, which oscillates in response to the frequency of input voltage signal V at a resonant frequency. An output signal 70 representing the resistance of the oscillating transducer 12 provided between the electrodes 66 & 68 is received by sensor logic circuit 62 which produces an indication of the level of dust presence and concentration. Dampening of the oscillation rate in response to dust causes transducer output signal 70 to vary. An increase in the presence of dust or particles increases the dampening effect, and thus causes a proportional effect on the output signal 70, as resistance of the transducer 12 increases. The output signal 70 is also monitored by control circuit 60 via a feedback 72. In response to the output signal 70 indicating increased resistance due to dampening, control circuit 60 increases the input voltage signal V to drive the oscillation rate back to the resonant frequency. As the dust presence subsides, dust accumulated on the transducer 12 is shaken off, output signal 70 indicates decreasing resistance, and the resonant frequency is again approached. Since output signal 70 indicates decreased resistance as resonance is approached, control circuit reduces input voltage signal V accordingly to maintain resonance.
While the above embodiments describe a response to an AC voltage signal, the input signal and feedback could comprise other waveforms such as a square wave, sawtooth wave, or other extensions of a pure sine wave, and need not be a voltage source but rather any signal that produces a calibratable movement of the substrate in response to particles.
It should be understood that the invention is not limited to the particular embodiments shown and described herein, and that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined by the following claims. | A dust sensing apparatus uses a transducer element oscillating at a resonant frequency to detect changes in dust concentration. The transducer is fabricated from a polymer material which oscillates when a voltage is applied. The presence of dust affects the oscillation frequency. Dampening of the frequency by the dust presence changes the electrical resistance provided by the transducer. Electronic circuitry computes the level of dust by measuring and controlling the level of the AC signal required to maintain the oscillation frequency by monitoring the resistance. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a national stage entry of PCT/MX2013/000032 filed Mar. 15, 2013, under the International Convention, claiming priority over Mexican Patent Application No. MX/a/2012/004494 filed Apr. 17, 2012.
TECHNICAL HELD
[0002] The present invention relates to a surgical system that reduces the bleeding that occurs in the edges region of a classical hysterotomy (cut made in the matrix) during the caesarean practiced because of placenta praevia. The bleeding reduction is due to the compressive of the edges of the hysterotomy. This system comprises essentially a compressive device and its corresponding application clamp.
BACKGROUND OF THE INVENTION
[0003] There is not a specific tool that compresses the edges that are generated by a classical hysterotomy during a cesarean practiced due to placenta praevia. Although there is a clamp called Allis clamp (see FIG. 1 ), the latter has an oppressive part that is very small, which occludes an equally small section of the edges of the hysterotomy, in this place there are blood vessels that have a large diameter, leaving them only partially occluded; also because the hysterotomy edges are too thick, the pressure exerted by the Allis clamp is limited. Also, this clamp is too long and is technically difficult to suture the edges of the hysterotomy and also requires an exaggerated number of clamps in this type of surgery.
[0004] On the contrary, the present invention achieves the hermetic occlusion of a very broad surface of the edges of the hysterotomy, in addition a predetermined compressive is achieved, thus does not require any adjustment by the person applying the device. In addition, its size and design allow easy access for the surgical maneuvers and for performing the suture of the uterine tissue. Therefore, the reduction in bleeding is achieved decreasing the required surgical instruments, compared to traditionally used Allis damp.
[0005] From the use of this device, 80 to 90% of the bleeding has been reduced that occurred at the edges of the hysterotomy.
[0006] Problem to solve:
[0007] Reduce the maternal death by bleeding.
[0008] The World Health Organization blames maternal bleeding as the leading cause of maternal mortality in Latin America, which is a tragedy.
[0009] The World Health Organization's fifth objective literally states, “maternal death should be reduced”; objective that must be attained.
[0010] How to solve the problem:
[0011] The bleeding problem from the area of the hysterotomy, of which we refer to, has been solved by using the aforementioned compressive system for reducing the bleeding of the classical hysterotomy; instrument that is designed for use in placenta praevia. This system blocks 80 to 90% of the blood flow in the edges of the hysterotomy.
[0012] The experience with performing 75 surgeries, in which were applied the compressive system of the present invention to reduce the bleeding of the classical hysterotomy for use in placenta praevia, demonstrates the utility of this device.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention provides a compressive system for reducing the bleeding originated on the edges to the classical hysterotomy for the placenta praevia cases. The elements of the compressive system are:
[0014] 1. Compressive device. See FIG. 2 .
[0015] 2. Application clamp for the compressive device. See FIG. 3 .
[0016] 1. Compressive device, FIG. 2 . Comprises two sections: a) the compressive bars ( 2 . 1 ) and b) the brackets ( 2 . 2 ).
[0017] A) The compressive bars ( 2 . 1 ) are two solid bars that are placed against one another by one of its longitudinal faces ( 2 . 1 . 1 ). On each of the longitudinal faces ( 2 . 1 . 1 ) is a series of teeth ( 2 . 1 . 2 ) with pointed ends whose function is partly to penetrate the tissue of the edges of the hysterotomy. This series of teeth ( 2 . 1 . 2 ) prevent the sliding of the compressive bars ( 2 . 1 ). The central part of the compressive bars ( 2 . 1 ) includes a machined bridge ( 2 . 1 . 3 ) located on the opposite sides of both longitudinal faces ( 2 . 1 . 1 ). The bridge has two holes, a first hole ( 2 . 1 . 4 ) and the second hole ( 2 . 1 . 5 ) which is perpendicular to the first hole ( 2 . 1 . 4 ).
[0018] Each of the ends of the compressive bars ( 2 . 1 ), includes a threaded hole ( 2 . 1 . 6 ), located on the same side where the bridge is machined ( 2 . 1 . 3 ). In each threaded hole ( 2 . 1 . 6 ) a screw stud ( 2 . 1 . 7 ) is screwed.
[0019] 6) The brackets ( 2 . 2 ). The brackets ( 2 . 2 ) are two. Each one comprises two bars ( 2 . 2 . 1 ). Each bar has one end of its ends a machined hole ( 2 . 2 . 2 ) that is used to join to the other bar by a bolt ( 2 . 2 . 3 ) which functions as an axis of rotation, and at the two opposite ends of both bars ( 2 . 2 . 1 ), there is a drilled base ( 2 . 2 . 4 ), both bars are designed to permit the placement of a spring ( 2 . 2 . 5 ) which is fixed in the holes ( 2 . 2 . 6 ) of the two bars. The spring ( 2 . 2 . 5 ) is placed at close distance to the pin ( 2 . 2 . 3 ), The magnitude of the compressive force is in accordance with the mechanical properties of the material of the spring ( 2 . 2 . 5 ).
[0020] Both brackets ( 2 . 2 ) are connected to the compressive bars ( 2 . 1 ), through the section of the element called the drilled base ( 2 . 2 . 4 ), through this drilled base ( 2 . 2 . 4 ) the screw-bolt ( 2 . 1 . 7 ) is passed, which is screwed into the threaded hole ( 2 , 1 . 6 ) of the compressive bars ( 2 . 1 ).
[0021] Likewise, allows the spring ( 2 . 2 . 5 ) to be replaced by any other element that provides the compressive force, such as screws, arcs, polymers, etc.
[0022] Moreover, is allowed a varying number of brackets ( 2 . 2 ) used to obtain the desired compressive.
[0023] 2 —. Application clamp for the compressive device, FIG. 3 . The clamp has two sections: A) the handle ( 3 . 1 ), and B) the jaw ( 3 . 2 ). Both sections are connected by a rotation pin ( 3 . 3 ). On the outside part of the tips of the jaw, a protrusion ( 3 . 4 ) is machined which is adapted to the bridge ( 2 . 1 . 3 ) located on the opposite side of the longitudinal face ( 2 . 1 . 1 ) of the compressive bars ( 2 . 1 ). The application clamp for the compressive devices, FIG. 3 , allows the opening of the compressive bars ( 2 . 1 ). This way allows to place the compressive device, FIG. 2 , to the hysterotomy to reduce bleeding as was previously indicated.
[0024] A threaded adjustment bolt ( 3 . 5 ) which is close to the rotation pin ( 3 . 3 ) allows to adjust the initial opening of the application clamp for the compressive device, FIG. 3 , to facilitate the entrapment of the bridges ( 2 . 1 . 3 ) of both bars compressive ( 2 . 1 ) when the compressive device, FIG. 2 , has not yet been applied to the hysterotomy.
[0025] Also, allows a thickness reduction of the bridge ( 2 . 1 . 3 ), or any other configuration that allows the entrapment of the protrusion ( 3 . 4 ) with the bridge ( 2 . 1 . 3 ).
[0026] Integral mechanism of operation of the compressive system to reduce the bleeding in the edges of the classical hysterotomy for cases of placenta praevia:
[0027] The compressive system comprises: A. a compressive device, FIG. 2 , and B. application clamp for the compressive device, FIG. 3 . The compressive system works as follows:
[0028] a) Before use, the compressive device, FIG. 2 , has the compressive bars ( 2 . 1 ) strongly linked through the springs ( 2 . 2 . 5 ). Furthermore, before using the compressive device normally has the brackets longitudinally oriented to the compressive bars, as shown in FIG. 4 .
[0029] b) To apply the compressive device, FIG. 2 , both brackets must be at right angles with respect to the compressive bars ( 2 . 1 ) and both brackets must also be on the same side, relative to the compressive bars, FIG. 5 .
[0030] c) Application of compressive device, FIG. 2 , is made by adapting the protrusions ( 3 . 4 ) of the application clamp for the compressive device, FIG. 3 , to the bridges ( 2 . 1 . 3 ) of both compressive bars ( 2 . 1 ). Then, the two arms of the handle ( 3 . 1 ) are approximated to thereby separate the compressive bars ( 2 . 1 ) and are applied to the edges of the hysterotomy, see FIG. 6 .
[0031] d) Once the compressive device, FIG. 2 , is applied to the edges of the hysterotomy, the application clamp of the compressive device is removed, FIG. 3 , which allows the compression of the edges of the hysterotomy, to stop the bleeding,
[0032] e) Upon completion of the surgical procedures the compressive devices, FIG. 2 , are removed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 shows an Allis clamp. Including:
[0034] Element ( 1 ): Clamp tip, characterized by having small slits in each of the arms,
[0035] Element ( 2 ): rotation axis, which allows the opening or closing of the arms of he clamps.
[0036] Element ( 3 ) clamping rings and control of the opening and closing of the arms of the clamps.
[0037] Element ( 4 ) clamping and adjusting pressure slits of the clamp tip.
[0038] FIG. 2 , shows the compressive device according to the present invention. The compressive device comprises:
[0039] A) The compressive bars ( 2 . 1 ), these have a longitudinal face ( 2 . 1 . 1 ) with a series of teeth ( 2 . 1 . 2 ) and also a bridge ( 2 . 1 . 3 ) that has a first hole ( 2 . 1 . 4 ) and a second hole ( 2 . 1 . 5 ), also has threaded holes ( 2 . 1 . 6 ) and screw-studs ( 2 . 1 . 7 ).
[0040] B) Brackets ( 2 . 2 ) which have bars ( 2 . 2 . 1 ), holes ( 2 . 2 . 2 ), pins ( 2 . 2 . 3 ), drilled bases ( 2 . 2 . 4 ), springs ( 2 . 2 . 5 ) and the holes ( 2 . 2 . 6 ).
[0041] FIG. 3 , shows an application clamp for the compressive device, according to the present invention The clamp comprises:
[0042] The handles ( 3 . 1 ), the jaws ( 3 . 2 ), the rotation pin ( 3 . 3 ), protrusions ( 3 . 4 ) and the threaded adjustment bolt ( 3 . 5 ).
[0043] FIG. 4 , shows the compressive device with the brackets ( 2 . 2 ) longitudinally oriented to the compressive bars ( 2 . 1 ).
[0044] FIG. 5 , shows the compressive device with both brackets ( 2 . 2 ) at right angles with respect to the compressive bars ( 2 . 1 ) on the same side, in relation to compressive bars.
[0045] FIG. 6 , shows the application clamp ( FIG. 3 ) and the compressive device ( FIG. 2 ), both devices are shown on how to be coupled prior to their placement on the edge of the hysterotomy (cut made in the matrix).
[0046] The claims are based on the fundamental problem of bleeding in placenta praevia, which is a serious complication that occurs during a caesarean section, to which the present device offers an alternative solution to reduce the bleeding of the hysterotomy for a classic cesarean section; for which an extensive experience in Fray Antonio Alcalde Civil Hospital of Guadalajara, Jalisco.
[0047] Having described my invention, as above, I consider it as a novelty and claim my property in the following claims. | The invention relates to a compressive system for reducing edge bleeding in classical hysterotomy in cases of placenta praevia, said system comprising: a compressive device formed by two compressive bars and bracketing members; and a clamp for applying the compressive device, said clamp comprising two handles, two jaws, a rotation nut, two protuberances and a threaded adjustment nut. The clamp allows the opening of the compressive bars. The device is applied to the edges of the hysterotomy and, subsequently, the clamp is withdrawn. | 0 |
PRIORITY CLAIM
[0001] This application claims the benefit of U.S. Provisional Application No. 60/477,893, filed 12 Jun. 2003. The entire contents of this priority application is hereby incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to an email processing system capable of routing incoming email based on sender registration status and addressee defined preferences.
BACKGROUND OF THE INVENTION
[0003] Marketers often send vast amounts of commercial electronic mail (“email”), usually in an effort to reach potential customers. Such commercial bulk email (“CBE”), which can be solicited or unsolicited by the addressee, is commonly referred to as “spam email”. Because of its unsolicited nature, the content of CBE is often, although not always, of little interest to the recipient. Given the high volume of CBE and the low relevancy to many users, the task of reviewing and filtering CBE can be time-consuming, frustrating, and even deleterious at times. For example, a CBE will occasionally deceive the recipient as to the origin or purpose of the email, thereby attracting sustained attention from the user, and will perhaps even succeed in defrauding the recipient at times. In other instances, an actual important email will be overlooked in the high volume of CBE. Additionally, the high volume of CBE often causes computer users and network administrators, especially Internet service providers, to invest significant computing resources in handling CBE.
[0004] Consequently, many computer users have attempted to forego the task of reviewing CBE by installing CBE filters configured to route CBE to a “junk folder” that is periodically emptied, often on an automated basis. Network administrators have implemented similar techniques at the Internet service provider level in an effort to prevent CBE from reaching individual users. These approaches often reduce or eliminate the hassle of reading and filtering large volumes of CBE on a regular basis. Other proposals for reducing the volume of CBE involve implementing an email postage system wherein all senders or all senders of unsolicited email are required to pay a postage fee to have an email message delivered. Postage based CBE reduction systems operate on the principle that the cost of paying postage may discourage the sending of CBE.
SUMMARY OF THE INVENTION
[0005] In accordance with the foregoing, in one embodiment of the present invention, an email processing system comprises a first database configured to store a user's email routing preferences. The system further comprises a second database configured to store registration information on paying email senders. The system further comprises email identification analysis code configured to determine whether an incoming email is commercial bulk email. The system further comprises email routing code configured to selectively deliver the incoming email to a folder or to delete the incoming email. The email routing code routes email based at least partially on the user's email routing preferences, the determination of the email identification analysis code, and the email sender registration information. The email routing code is configured to deliver the incoming email to a junk folder if the email identification analysis code determines that the incoming email is commercial bulk email, the email sender is a paying sender, and the user's email routing preferences indicate that commercial bulk email from a paying sender is to be delivered to the junk mail folder. The folder is an inbox folder or the junk mail folder.
[0006] In another embodiment of the present invention, a method for processing email comprises receiving an incoming email addressed to a recipient. The method further comprises identifying a sender of the incoming email and determining if the sender is a paying sender. The method further comprises determining if the recipient has elected to receive nonpaying email from the sender. The method further comprises determining if the recipient has elected to receive commercial bulk email from paying senders. The method further comprises determining if the incoming email is commercial bulk email. If the incoming email is not determined to be commercial bulk email, the method further comprises delivering the incoming email to an inbox folder. If the incoming email is determined to be commercial bulk email, the method further comprises (a) delivering the incoming email to a junk mail folder if the sender is not a paying sender and if the recipient has not elected to receive nonpaying email from the sender, (b) delivering the incoming email to an inbox folder if the sender is not a paying sender and if the recipient has elected to receive nonpaying email from the sender, (c) delivering the incoming email to a junk mail folder if the sender is a paying sender and if the recipient has not elected to receive paying email from the sender, or (d) delivering the incoming email to an inbox folder if the sender is a paying sender and if the recipient has elected to receive paying email from paying senders.
[0007] In another embodiment of the present invention, an apparatus comprises code. When executed, the code is configured to deliver an incoming email to an inbox folder or a junk mail folder. The determination is based on first and second user preference settings. The first user preference setting controls whether an email recipient receives nonpaying emails from a particular sender. The second user preference setting controls whether an email recipient receives commercial bulk email from paying senders. The apparatus further comprises an accounting module configured to authenticate a sender of commercial bulk email as a paying sender. The accounting module causes a charge to be applied to an account associated with the paying sender upon receipt of commercial bulk email from the paying sender.
[0008] In another embodiment of the present invention, an apparatus comprises a first instruction configured to identify a sender of an email and determine if the sender is a paying sender. The apparatus further comprises a second instruction configured to determine if a recipient of the email has elected to receive nonpaying email from the sender. The apparatus further comprises a third instruction configured to determine if a recipient of the email has elected to receive commercial bulk email from a paying sender. The apparatus further comprises a fourth instruction configured to determine if the email is commercial bulk email. The apparatus further comprises a fifth instruction configured to deliver the email to an inbox folder or a junk mail folder based on the determinations made in the first and fourth instructions, and at least one of the second and third instructions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a flowchart illustrating the operation of an exemplary embodiment of a postage-based email processing system wherein the user is provided with the option of opting out of receiving paid CBE.
[0010] FIG. 2 is a schematic diagram illustrating the postage-based email processing system of FIG. 1 .
[0011] FIG. 3 is a flowchart illustrating the operation of an exemplary embodiment of a postage-based email processing system wherein the user is not provided with the option of opting out of receiving paid CBE.
[0012] FIG. 4 is a flowchart illustrating the operation of an exemplary embodiment of a postage-based email processing system wherein incoming email without postage is not delivered to the addressee's inbox.
[0013] FIG. 5 is a schematic diagram illustrating an exemplary email processing system using secure tokens to authenticate CBE senders.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] In some conventional email processing systems, incoming email is distributed directly into users' inboxes according to addressee information contained within the email. As described above, CBE filters are often used with conventional email processing systems. CBE filters are usually configured to route email identified as CBE to a user's “junk folder” that is distinct from the user's inbox folder. For example, the junk folder can be separate folder from the inbox folder, or can be a subfolder of the inbox folder. The junk folder is typically the designated location for email such as CBE or other unwanted email, such as email having undesirable characteristics, including email soliciting unwanted products or email containing offensive subject matter. The junk folder can have other names, such as “trash,” “deleted items,” and the like. Often, the junk folder is configured to be automatically emptied on a periodic basis.
[0015] As used herein, the terms “junk folder” and “inbox folder” refer, in addition to file folders, and in addition to their ordinary meanings, to other methods for organizing email for a user's convenience. CBE filters represent an attempt to mitigate the burden of reviewing and filtering the CBE that would otherwise be routed directly into a user's inbox. CBE filters can be installed at the Internet service provider level such that intercepted CBE never reaches users, or at the user level thereby providing individual users with greater ability to control and monitor the operation of the filter.
[0016] Few, if any, CBE filters are absolutely effective in accurately identifying all incoming email as CBE or not CBE. Even if a CBE filter allows only a small percentage of CBE to pass through the filter undetected, such as 0.1% or less, this amount of CBE can still cause great inconvenience to individual users. In particular, because senders of CBE can easily send large quantities of CBE without incurring significant costs, filters can often be neutralized by simply increasing the volume of incoming CBE. The effectiveness of CBE filters is further limited by CBE senders' rapidly advancing ability to send CBE that is effectively disguised as genuine solicited email, thereby circumventing the filter's ability to detect CBE.
[0017] These difficulties are addressed in an exemplary embodiment of the postage-based email processing system disclosed herein and illustrated in FIGS. 1 and 2 . By way of example, this system can be implemented using instructions, modules, and/or the like that are executed on or by one or more computer systems. As illustrated in FIGS. 1 and 2 , an incoming email processor 210 is capable of receiving email from the Internet 200 in an operational block 100 . The incoming email processor 210 then routes the email according to a series of tests, as illustrated in FIG. 1 , and as described in greater detail below.
[0018] The incoming email processor 210 first determines whether the incoming email can be identified as CBE in decisional block 110 . This determination can be performed at an organizational level, at the Internet service provider level, at the user level or at another level. However, by testing incoming email for CBE status closer to the point of receipt from the Internet or other public network, fewer network resources can be spent routing the CBE.
[0019] Regardless of when the email is tested for CBE status, the CBE determination can be accomplished using a wide variety of techniques. For example, in one embodiment, the identity of the sender is checked against a list of known senders of CBE, such as can be stored in a database or other data store. An exemplary database is the sender registration database 225 illustrated in FIG. 2 . Such a database can be compiled by the incoming email processor 210 , by other software applications, by the collective efforts of individual users, or by some combination of the above. In another embodiment, email sending patterns from a particular sender are analyzed for indicia of CBE, such as a large number of emails (for example, a number greater than a preset threshold) sent from a single sender to multiple recipients in a short time period. In still other embodiments, other CBE detection algorithms can be used in decisional block 110 , including other algorithms that are developed in the future. In addition, the content of the incoming emails can be analyzed for certain keywords prevalent in CBE, such as “free”, “Viagra” and the like. Furthermore, several of the algorithms listed here can be used in combination to enhance the CBE identification decisional block 110 . If the incoming mail processor 210 determines that the incoming email is not CBE, the incoming email is delivered to the user's inbox folder 230 in operational block 115 .
[0020] However, if the incoming mail processor 210 determines that the incoming email is CBE, the incoming mail processor 210 then identifies the sender of the CBE as a paying sender or a nonpaying sender in decisional block 120 . As used herein, a “paying sender” is a sender of CBE that has paid a postage fee in exchange for a prioritized handling of its CBE. The postage fee can be paid to the addressee, the Internet service provider, a governmental agency, or another entity, or any combination thereof. The postage fee can be paid in advance, or can be charged to an account for which the CBE sender is billed on a recurring basis. In a modified embodiment, the postage fee can be a flat fee paid on a recurring basis, such as a pre-established monthly fee. As used herein, a “nonpaying sender” is a sender of CBE that has not paid the postage fee.
[0021] A CBE sender's payment of the postage fee can be used to advantageously subsidize the recipient's email service. For example, in one embodiment the email recipient will be directly paid to receive a CBE. In such an embodiment, the recipient will be more likely to review the contents of the CBE, thus benefiting the sender. In addition, if the Internet service provider receives all or a portion of the postage fee, the Internet service provider can recapture the cost of administering CBE manipulation software.
[0022] In the exemplary embodiment illustrated in FIG. 2 , a list of paying senders is maintained in a sender registration database 225 , also known as a “white list”. Thus, when the incoming email processor 210 detects incoming CBE, the incoming email processor 210 queries the sender registration database 225 to determine whether the sender of the CBE is a paying sender in decisional block 120 . If the sender is registered in the sender registration database 225 as a paying sender, then operation proceeds to decisional block 130 . Conversely, if the sender is not registered in the sender registration database 225 as a paying sender, then operation proceeds to decisional block 125 .
[0023] In a modified embodiment, illustrated in FIG. 5 , the CBE sender authenticates itself as a paying sender by including a secure token or other identifier in its emails. The secure token can be obtained from a third party digital signature processor, which can also be configured to authenticate the secure token for the receiving mail server. In certain embodiments, the third party digital signature processor can also be configured to administer the distribution of revenues received from secure token sales to CBE stakeholders, such as user recipients, Internet service provider recipients, and third parties. The CBE sender can acquire the secure token by paying a postage fee as described above. In such embodiments, the incoming mail processor 210 is configured to screen incoming mail for the secure token; if the secure token is identified in incoming CBE, then the incoming CBE is authenticated as paid CBE.
[0024] In decisional block 125 , the incoming mail processor 210 determines whether the CBE addressee has elected to receive email from the nonpaying CBE sender. This determination can be based on individual preferences set by the addressee and stored in the user preferences database 220 . For example, if a user wishes to receive CBE from a particular nonpaying CBE sender, such as a preferred vendor or a company that the user is considering patronizing, the user can register that CBE sender as “allowed” by the user. If the CBE sender is identified as allowed by the user, then the CBE is delivered to the user's inbox folder 230 in operational block 140 . In contrast, if the CBE sender is identified as not allowed by the user, then the CBE is delivered to the user's junk folder 240 in an operational block 135 . This configuration advantageously allows the user to “opt-in” to receive CBE from selected CBE senders.
[0025] In decisional block 130 , the incoming mail processor 210 determines whether the CBE addressee has elected to receive CBE from a paying sender. This determination can be based on individual preferences set by the addressee and stored in the user preferences database 220 . Specifically, if a user wishes to receive CBE from paying senders, the user can register these preferences with the user preferences database 220 . For example, a user may register to receive CBE from a paying sender if the user thinks that such messages will have higher relevancy or will contain commercial offers with enhanced value. The user can register to receive CBE from a paying sender for any number of other reasons as well, such as a desire to have the cost of email service subsidized by the CBE sender. If the CBE addressee has elected to receive CBE from a paying sender, then the CBE is delivered to the user's inbox folder 230 in operational block 140 . In contrast, if the CBE addressee has not elected to receive CBE from a paying sender, then the CBE is delivered to the user's junk folder 240 in operational block 135 . This configuration advantageously allows the user to “opt-in” to receive CBE from paying senders.
[0026] In a modified embodiment, illustrated in FIG. 3 , the addressee is not provided with the option of opting out of receiving paid CBE. As illustrated in FIG. 3 , if incoming email is identified as CBE, and if the sender is identified as a paying sender, then the email is delivered to the addressee's inbox folder without consideration of the addressee's preferences with respect to receiving paid CBE. For paid CBE senders, such an embodiment provides an increased inbox delivery rate for paid CBE.
[0027] In another modified embodiment, illustrated in FIG. 4 , the incoming mail processor 210 is configured to route all incoming email without postage to the addressee's junk folder. In other embodiments, the nonpaying incoming mail can be deleted or otherwise be prevented from reaching the user. In either of such embodiments, the incoming mail processor can be further configured to send a standardized response to the nonpaying sender advising of the requirement to pay a postage fee, and providing instructions for doing so.
[0028] The various embodiments of the postage-based email processing system described herein offer several advantages over conventional systems. For example, requiring senders of CBE to pay a postage fee in exchange for prioritized handling of CBE provides a disincentive for senders of CBE to increase yield rates by simply increasing the volume of mail sent. Moreover, requiring senders of CBE to pay a postage fee to reach an addressee will provide an incentive for senders of CBE to deliver more modest quantities of CBE. In embodiments wherein the postage fees are paid to Internet service providers and/or mail recipients, the activities of CBE senders can serve as a payment to those entities and users that bear the burden of unchecked CBE in conventional email processing systems. In addition, by storing user preferences with respect to receiving CBE from particular senders and receiving nonpaying CBE, the CBE that is delivered into a user's inbox folder will generally have increased relevancy as compared to conventional email filtering systems.
Scope of the Invention
[0029] While the foregoing detailed description has described several embodiments of the present invention, it should be understood that the above description is illustrative only and is not limiting of the disclosed invention. It will be appreciated that the specific configurations and operations disclosed can differ from those described above, and that the methods described herein can be used in contexts other than electronic mail processing. | In accordance with the foregoing, in one embodiment of the present invention, an email processing system comprises a first database configured to store a user's email routing preferences. The system further comprises a second database configured to store registration information on paying email senders. The system further comprises email identification analysis code configured to determine whether an incoming email is commercial bulk email. The system further comprises email routing code configured to selectively deliver the incoming email to a folder or to delete the incoming email. The email routing code routes email based at least partially on the user's email routing preferences, the determination of the email identification analysis code, and the email sender registration information. | 7 |
CROSS-REFERENCE TO RELATED ACTIONS
[0001] This application claims the benefit of and priority to Italian Patent Application No. MI2010A001293, filed Jul. 14, 2010, which is incorporated by reference herein in its entirety.
BACKGROUND
[0002] It is known in the technical sector of packaging that there exists the need to apply onto each product container a corresponding identification label. Also known are apparatus which are able to transfer onto the container individual self-adhesive labels which are mounted on a backing strip and wound on a reel, by means of programmed and controlled unwinding of the said reel and transfer of a label onto the corresponding container which is moving on an associated labeling machine. In this technical sector also well known are so-called “linerless” labels or labels that are not mounted on a backing strip that must be separated from the label when the latter is applied and recovered separately for disposal thereof. These “linerless” labels essentially consist of a single sheet of suitable material, one of the opposite surfaces of which is provided with an adhesive layer for gluing to the container, while the opposite surface is lined with a transparent and non-adhesive varnish designed to prevent adhesion of the continuous strip when wound onto itself. The continuous strip can also be provided with (pre-cut) perforations forming preferential cutting lines suitable for separation of each label from the ones adjacent thereto.
[0003] Reference WO 2009/030893 discusses a method and an apparatus for transferring linerless labels to a container moving on a labeling machine along a given path associated with the machine. The apparatus is based on the use of a silicone-lined transfer belt which rotates in a closed loop around two rollers and which conveys the continuous strip of labels in a direction inclined at a suitable angle relative to the plane of displacement of the product onto which the label must be applied. This relative angle essentially allows the label, which advances together with the transfer belt, to come into contact tangentially with the container and, when it adheres by means of contact to the container, to be cut along pre-cut lines by a fixed blade arranged upstream and perpendicular to the belt itself. Although fulfilling its function, this apparatus nevertheless has a number of drawbacks associated mainly with the fact that the labels made of soft and/or thin material tend not to separate from the transfer belt in a reliable and highly repeatable manner, said separation being determined by the radius of curvature of the transfer belt which cannot be reduced beyond a certain limit value.
[0004] In addition, it has been found that the surface of the belt, to which the label is attached, tends to become soiled over time, resulting in an unstable relative contact between belt and label. This can cause, at the moment of separation, an incorrect angle with respect to the belt, with the result being that the label is positioned crookedly on the finished product. Moreover, this solution requires that the labels be made of materials that are so rigid that they are unable to follow the small angle of curvature of the drive belt and therefore become separated from it.
[0005] The fixed position of the cutting blade moreover has the effect that it is not possible to cut labels with a certain margin of tolerance in terms of their longitudinal dimension. These drawbacks also mean that with the known apparatus it is not possible to reach the high speeds at which the containers travel on most recent labeling machines, said apparatus thus being essentially unsuitable for the present-day production/packaging cycles.
SUMMARY
[0006] In general, in an aspect, embodiments of the invention can provide a drum for cutting linerless labels from a continuous strip and transferring the labels to a container movable with a given trajectory and speed on a machine, the drum including a side surface suitable for guiding the strip by contacting a non-adhesive surface of the labels, the side surface defining a vertical slit, a coaxial and concentric sleeve for centering the drum on a corresponding support spindle, a cutting blade parallel to a vertical direction of the drum, the cutting blade being displaceable in a radial direction from a position retracted inside the drum to a position at least partially extended through the vertical slit outside the side surface of the drum, a fixed cam relative to which the drum rotates and that is configured to press against the cutting blade so as to cause the cutting blade to extend out in a predefined angular position, and a seat that extends in the vertical direction (Z-Z) and is connected to the cam and which is suitable for engagement with a corresponding fixed reference pin in order to determine a predefined angular position of the cam, wherein the drum is configured to retain the strip against the side surface of the drum.
[0007] Implementations of the invention can provide one or more of the following features. The side surface of the drum defines a plurality of holes, and the drum further includes a plurality of channels that connect the plurality of holes to a suction device such that air is sucked in towards the inside of the drum thereby retaining the strip. The cam is mounted inside the drum. The cam is of the double track type suitable for pushing/recalling the blade. The drum further includes a spring configured to recall the blade into the retracted position. The drum further includes a plurality of cutting blades arranged at a predefined constant angular distance. The side surface has at least one buffer element made of resilient material and arranged downstream of each blade and is able to come into contact with the surface of the container substantially at the moment of impact with the label. The drum further includes at least one reference notch suitable for being detected by a fixed sensor for determination of a start-of-cycle position of the drum.
[0008] In general, in another aspect, embodiments of the invention can provide an apparatus for applying linerless labels from a continuous strip onto a container movable with a given trajectory and speed on a machine comprising at least one drum, as described herein, for cutting and transferring the labels.
[0009] Implementations of the invention can provide one or more of the following features. The apparatus according further includes a first unit for unwinding the continuous strip of labels and a second unit for driving the strip, the first and second units are arranged in series with each other and upstream of the drum. The first unit for unwinding the strip includes a vertical-axis reel on which the strip is wound, a plurality of transmission rollers, at least one jockey roller for tensioning the strip, and a motor for rotationally actuating the reel. The second unit driving the strip includes a vertical-axis cylinder associated with a roller to which it is connected via belts angularly arranged so as to produce a tangential orientation of the strip leaving the drive unit relative to the transfer drum, a motor for rotationally actuating the cylinder, and a sensor arranged tangentially with respect to the drive cylinder for detecting reference marks printed on the strip. The drive cylinder is associated with jets of air supplied to the annular grooves of the drive cylinder and designed to press the strip against the drum. The drive cylinder is rotationally actuated in a discontinuous start/stop sequence. The drive cylinder is rotationally actuated in a continuous manner at a variable speed. The strip moves in synchronism with the drum and the product. The side surface of the drum has at least one buffer element made of resilient material and arranged downstream of each blade and able to come into contact with the surface of the container at the moment of impact with the label. The drum rotates synchronized in terms of its position and with a tangential speed, in the angular position of impact of the label with the container, equal to the tangential speed of the container itself. The drum rotates synchronized in terms of its position and with a speed equal to the speed of the machine. The drum rotates synchronized in terms of its position and with a speed which is different from the speed of the machine, wherein the speed is variable with acceleration/deceleration ramps. The drum rotates synchronized in terms of its position and with a speed which is different from the speed of the machine, namely in start/stop manner with acceleration/deceleration ramps. The drum rotates with a speed of rotation equal to the sum of the speed of the machine and a predefined speed of rotation of the container about its vertical axis. The drum has a plurality of cutting blades arranged in an angular position defined by the geometrical configuration of the labeling machine. The apparatus according further includes an air suction device in communication with a plurality of holes defined in the side surface. The apparatus is mounted on a support base.
[0010] In general, in yet another aspect, embodiments of the invention can provide a method for cutting linerless labels from a continuous strip and transferring the labels to a container movable with a given trajectory and speed on a container-conveying machine, the method including providing a drum, as described herein, rotating synchronized in terms of its position and with a tangential speed equal to the tangential speed of the container itself at the angular position of impact of the label with the container, feeding a strip of linerless labels to the drum with start/stop mode advancing of the strip, retaining the strip of labels with relative contact between the side surface of the drum and the non-adhesive side of the labels, sending, by the container-conveying machine, a consent signal indicating the presence of a container at a predefined distance from the angular position of impact with the label, synchronizing the advancing of the strip so as to position the first label at the point of impact with the container, impacting the label and the container, extending the cutting blade from the drum, tensioning of the strip by the container, separating the label from the strip, and completing adhesion of the label on the container.
[0011] Various aspects of the invention may provide one or more of the following capabilities. An apparatus for the application of linerless labels onto moving containers, which is able to solve the technical problems mentioned above can be provided. A device having small dimensions can be provided. A device that is easy and inexpensive to produce and assemble and is able to be installed easily on pre-existing machines, without the need for excessive special adaptation, can be provided. A drum for cutting linerless labels from a continuous strip and transferring them onto a container movable with a given path and speed on a labeling machine can be provided.
[0012] These and other capabilities of the invention, along with the invention itself, will be more fully understood after a review of the following figures, detailed description, and claims.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 shows a partially exploded perspective view of an apparatus with the cutting and transfer drum partly sectioned.
[0014] FIG. 2 shows a perspective view of the apparatus of FIG. 1 with the cutting and transfer drum mounted.
[0015] FIG. 3 shows a perspective view of the apparatus shown in FIG. 2 .
[0016] FIG. 4 shows a top plan view of the apparatus according to FIG. 2 .
[0017] FIGS. 5-7 show partial views, from above, of the apparatus during various operating stages.
[0018] FIG. 8 , shows a front view of a further example of a label that can be applied by means of the apparatus.
DETAILED DESCRIPTION
[0019] Embodiments of the invention provide techniques for providing a drum for cutting and transferring linerless labels from a continuous strip to a moving container and an apparatus for applying linerless labels to moving containers, provided with said drum. Other embodiments are within the scope of the invention.
[0020] As shown in FIG. 1 and FIG. 4 , and assuming solely for the sake of convenience of description and without any limitation of meaning a set of three reference axes in a longitudinal direction X-X, corresponding to the direction of extension of a continuous strip of linerless labels, transverse direction Y-Y, and vertical direction Z-Z, respectively, as well as a front side corresponding to the side where the label leaves the apparatus and a rear side opposite to the front side.
[0021] The apparatus preferably includes a unit 100 for unwinding a continuous strip 1 of labels 2 of the linerless type with a rear adhesive surface 2 a and a front non-adhesive surface 2 b . The strip also preferably has perforations (pre-cuts) 1 c extending parallel to the vertical direction Z-Z and arranged at constant intervals along the longitudinal extension of the strip 1 so as to separate the individual labels 2 and form pre-weakened cutting lines. The strip 1 can also be provided with printed reference marks 1 d as shown in the example of FIG. 1 , on either side of the pre-weakened cutting line. The reference marks can be, for example, suitable for being detected by a sensor as will be descried more clearly in the description below.
[0022] The apparatus preferably also includes a unit 200 for driving the strip 1 , a drum 300 for cutting and transferring the individual labels 2 onto the respective container 3 (e.g., as shown in FIG. 5 ) which travels along a given path on a machine 4 , which may be equally well of the rotating type (e.g., as shown) or linear type, and on which a surface 3 a for application of a label is provided.
[0023] In greater detail, the unit 100 for unwinding the strip 1 preferably comprises a vertical-axis reel 110 onto which the strip 1 is wound, a plurality of transmission rollers 111 , and at least one jockey roller 112 for tensioning the strip during unwinding thereof. The unit 100 also preferably includes a motor 113 for driving the reel, via which it is possible to maintain the correct tension of the strip 1 during unwinding thereof.
[0024] The unit 200 for driving the strip 1 preferably comprises a vertical-axis cylinder 210 associated with a roller 211 to which it is connected by means of belts 212 which are housed inside associated annular grooves 210 a and 211 a on the cylinder 210 and the roller 211 , respectively. The belts 212 preferably assume an angular position such as to determine a tangential orientation of the strip 1 leaving the drive unit relative to the label transfer drum 300 described below. The unit 200 also preferably includes a motor 213 for rotationally actuating the cylinder 210 with start/stop operation, and a photocell 215 arranged tangentially with respect to the drive cylinder 210 for detecting reference marks 1 d printed on the strip.
[0025] The label transfer and cutting drum 300 preferably comprises an outer side surface 301 provided with through-holes 301 a and a first coaxial and concentric sleeve 310 for centering the drum on an associated spindle 311 supporting the said drum. Both the sleeve 310 and the spindle 311 can have a cylindrical or grooved engaging surface. In its bottom part, according to the layout shown in FIG. 1 , the first sleeve 310 can have at least one seat 312 extending in the vertical direction Z-Z and suitable for engagement with a corresponding fixed reference pin 313 so that the pin/seat connection determines predefined angular positioning of a cam 320 which is fixed with respect to the drum 310 which rotates coaxially relative thereto.
[0026] In the example shown in FIG. 1 the cam 320 can be arranged on the top front surface 312 a of the first sleeve 310 and have a pressing surface 320 a able to act by means of special connection elements 321 (conventional per se and therefore not described in detail) on at least one cutting blade 330 parallel to the vertical direction Z-Z and housed inside corresponding vertical slits 302 on the side surface 301 of the drum. Owing to the interaction with the cam 320 , the blade 330 can be displaceable, in a radial direction, from a position retracted inside the drum into an extracted position outside the side surface of the drum. The angular position of the cam can therefore define the angular position for cutting the label in relation to the length, in the longitudinal direction X-X, of the label to be applied.
[0027] Springs 334 can be fastened at their first ends to the same cam/blade connection elements 321 and can be fixed at their other end (e.g., as shown in the example) to a second sleeve 333 for centering the drum, which can be coaxial with the first sleeve 310 . The springs 334 preferably being able to recall the blade 330 into its retracted position.
[0028] Downstream of each blade 330 , the side surface 301 of the drum 310 preferably has buffer elements 303 that are made of resilient material and are able to come into contact with the surface of the container in order to take up any excess play in the transverse dimensions of the container. The inside of the drum can also be provided with channels 350 which can be connected to corresponding suction means (not shown) for creating the vacuum on the surface 301 of the drum. The drum can have associated with it, via the spindle 311 , a corresponding motor 336 that is able to keep the drum itself rotating constantly about the cam 320 .
[0029] In a preferred embodiment, it is envisaged that the apparatus is associated with a device 500 for programming and controlling the motors, the various detection sensors and the corresponding operating sequences. For example, the device 500 can be a conventional computer.
[0030] It is also envisaged that the device 500 can be connected to a fixed sensor (not shown) for detecting a reference notch on the drum 300 in order to determine the angular position of the latter and be able to bring it into the correct position for synchronization with the product to be labeled. During application of the label, feeding of the strip 1 will preferably also be synchronized with the product to be labeled so that extraction of the blade, which preferably always occurs in the same angular position upon operation of the fixed cam, corresponds to the passing movement of the pre-cut line 1 c in front of the said angular position where extraction of the blade occurs.
[0031] All the parts described above are preferably mounted on a single support 10 .
[0032] With this structure the operating principle of the apparatus can be as follows. The drum 300 can be prepared so as to correspond to the height of the label 2 in the direction Z-Z and its length in the direction X-X. The apparatus can be installed opposite the machine 4 for moving the container 3 so that, at the point of application of the label 2 , the side surface 301 of the drum is tangential to the surface 3 a of the moving container (shown rotating in the illustrative example) along a predefined path on a labeling machine 4 . The strip 1 can be manually prepared by unwinding it from the reel 110 until the first label is situated opposite the sensor 215 of the drive cylinder 210 . The control unit 500 can be used to set, as main parameters, the length of the label 2 in the longitudinal direction X-X and the speed of rotation of the drum 300 so as to correspond to the speed of the machine 4 . In this case, the blade interval of the drum can be equivalent to the product interval on the machine. The drive motor 213 can be operated manually so that the strip 1 advances along its path around the drive cylinder 210 , causing reversal of the opposite surfaces 2 a , 2 b of the label 2 which reaches the drum 300 with its non-adhesive surface 2 a directed towards the side surface 301 of the drum and adhesive surface 2 b directed outwards. In this way, continuing its feeding movement, the strip 1 can be removed from the drum 300 retaining it by means of suction via the holes 301 a.
[0033] Then, when the labeling machine 4 starts to rotate about its axis, the control unit 500 can cause rotation of the drum 300 , synchronizing the movement of the latter with the speed and the position of the product 3 to be labeled. In this way the contact surfaces of the drum and the product 3 to be labeled can have the same tangential speed and arrive correctly and synchronized at the impact point. Preferably, when the container 3 is close to the labeling position, the labeling machine 4 can send a consent signal to the control unit 500 of the apparatus that can operate the drive 200 so as to feed the strip 1 until it reaches the speed of the product to be labeled. During synchronized feeding of the strip 1 the first front label 2 can be situated at the point of impact with the container 3 to which it starts to adhere and from which it starts to be removed in synchronism. In this instant, the container 3 , the drum 300 , and the strip 1 preferably have the same speed.
[0034] Simultaneously, the cam 320 preferably causes extraction/extension of the blade 330 , which in that moment passes the angular position opposite that the pre-weakened perforated line 1 c of the strip 1 also passes. Consequently, the container, which continues its movement along its path, draws along with it the label 2 and the latter is cut and separated easily and in a reliable manner from the strip 1 opposite the blade 330 only after adhering to the product. In this way, the label can adhere completely to the container, optionally being assisted by a smoothing device (not shown).
[0035] Subsequently, the sensor 215 of the drive cylinder can detect the reference notch 1 d on the strip 1 , causing stoppage of the drive unit 220 , which also stops the strip, preparing it so that it is ready to start for the next application, while the drum 300 continues its rotational movement with a speed and position synchronized with that of the machine 4 . Continuing its rotation, the drum can cause rotation of the element 321 which, continuing to adhere to the cam 320 , allows the blade 330 to be recalled inside the drum by the action of the springs 334 , being prepared for the next cut.
[0036] One exemplary method is therefore described how the drum for cutting and transferring linerless labels and an associated apparatus provided with the drum are able to provide a solution to the technical problems of the prior art, allowing flexible and thin labels to be applied at a high speed since the labels are held on the drum by means of their non-adhesive surface, ensuring precise and square positioning and safe and repeatable separation at the moment of impact with the container.
[0037] In addition to the above, with the apparatus described herein, it is possible to apply in a fast, safe and repeatable manner also shaped linerless labels 102 of the type shown in FIG. 8 , in strip form 101 , application of which is at present considered to be extremely problematic.
[0038] With the drum 300 as described changing of the format may also be performed in an extremely quick and easy manner since it is possible to provide a cutting and transfer drum for each series of homogeneous labels. The drum being replaced when there is a variation in the type of label, thereby reducing the downtime of the apparatus and therefore of the labeling machine.
[0039] A number of variations of embodiments of the apparatus are also envisaged. For example, the drum 300 can rotate at a speed different from that of the machine, namely continuously with a variable speed comprising acceleration/deceleration ramps for recovering any difference between the angular distance of the blades and the interval of the products to be labeled. The drum 300 can rotate at a speed different from that of the machine and in a discontinuous start/stop manner with acceleration/deceleration ramps. The speed of rotation of the drum 300 can be equal to the speed of rotation of the machine plus the speed of rotation of the container about its vertical axis, allowing the application of labels that are longer in the longitudinal direction onto containers that are larger without any variation in the advancing speed of the machine 4 . The drum can have a plurality of cutting blades 330 which are arranged in an angular position defined by the geometrical configuration of the labeling machine (e.g., pitch diameter and number of container-support discs 3 ) so that cutting occurs several times during each complete rotation of the drum. The blade extraction cam 320 can be provided with a double track so that it is possible to perform both extraction and retraction of the blade 330 . Air jets can be supplied to the annular grooves 212 a of the drive cylinder 210 so as to push the strip 1 against the drum 30 for equivalent transfer of the strip 1 from the drive cylinder 210 onto the drum 300 . The drive cylinder 210 can be rotationally driven continuously at a variable speed so as to reduce downtime.
[0040] Other embodiments are within the scope and spirit of the invention. For example, due to the nature of software, functions described above can be implemented using software, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.
[0041] Further, while the description above refers to the invention, the description may include more than one invention. | A drum for cutting linerless labels from a continuous strip and transferring the labels to a container movable with a given trajectory and speed on a machine, the drum including a side surface suitable for guiding the strip by contacting a non-adhesive surface of the labels, the side surface defining a vertical slit, a coaxial and concentric sleeve for centering the drum on a corresponding support spindle, a cutting blade parallel to a vertical direction of the drum, the cutting blade being displaceable in a radial direction from a position retracted inside the drum to a position at least partially extended through the vertical slit outside the side surface of the drum, a fixed cam relative to which the drum rotates and that is configured to press against the cutting blade so as to cause the cutting blade to extend out in a predefined angular position, and a seat that extends in the vertical direction (Z-Z) and is connected to the cam and which is suitable for engagement with a corresponding fixed reference pin in order to determine a predefined angular position of the cam, wherein the drum is configured to retain the strip against the side surface of the drum. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a substrate heater and a heating element.
A substrate may undergo a series of processing steps, one or more of which may include heating, in the course of forming a processed substrate. Typically, the substrate is moved from station to station within a deposition chamber where the successive processing steps are performed. The conditions which exist at each station may vary greatly from, e.g., atmospheric pressure to high vacuum, room temperature to high temperature, and air environment to a pure gas environment.
SUMMARY OF THE INVENTION
In general, in one aspect, the invention features a method for providing heat to substrates at a step of a process by providing separate movable heating devices, one for each substrate, placing each substrate onto one of the heating devices, sequentially moving each device into a position where the step of the process can be performed on the substrate, and causing each device to provide heat to the substrate at the step of the process.
In preferred embodiments, the method may include moving the devices sequentially into another position; a step of the process may be performed in a vacuum environment or at atmospheric pressure; preferably, the vacuum is held at any chosen level below atmospheric pressure down to 10 -11 Torr, or in an oxygen environment, preferably held at a chosen partial pressure within the range of 10 -3 to 760 Torr, into which the devices can be moved. Movement of each heating device may be accomplished by insertion of a support into a portion of the device or by engaging a support on an external wall of the device, and then transferring the device to another position where another step of the process can be performed. The method may include causing each of the devices to heat the substrate to a temperature of at least 1000° C. and which does not vary by more than ±50° C. uniformly across the substrate.
In another aspect, the invention features resistive heating a substrate using an apparatus that includes a heating alloy which has an oxidation resistant outer surface and is stable at a temperature of at least 1000° C. in a vacuum.
In preferred embodiments, the alloy is stable in a vacuum environment up to 10 -11 Torr. Preferably, the alloy contains iron, chromium, and aluminum and is, most preferably, Kanthal-AF; or it contains nickel, chromium, iron, aluminum, and barium, and is, most preferably, Haynes alloy; either alloy may be in wire or sheet form. Most preferably the outer layer is aluminum oxide. The apparatus may further include a nonconductive material, such as a ceramic, most preferably, alumina or boron nitride, and the wire alloy is wrapped around the nonconductive material.
In another aspect, the invention features resistive heating a substrate using a movable apparatus that includes both holes for receiving a fork support and sides which a second alternative support may embrace; the holes and sides enable movement of the apparatus from a first position to a second position
In another aspect, the apparatus includes pins capable of resting within holes of a support, and the holes for receiving a fork support and the pins enable movement of the apparatus from a first position to a second position.
Preferred embodiments include the following features. The fork holes have electrically conductive walls, and either the pins or the sides are also electrically conductive. Nonconductive means separate the alloy from the substrate and the wire alloy. The wire alloy has a first end and a second end and is wrapped around the nonconductive material that serves to electrically separate the alloy from the substrate. A first conductive screw holds the first end of the wire alloy and a second conductive screw holds the second end of the wire alloy. An external power source is electrically coupled to the apparatus and the first screw is in electrical contact with either the fork holes, the sides, or the pins of the apparatus and is thus able to conduct current supplied by the external power source to the first screw and through the wire to the second screw.
In another aspect, the invention features a method of forming an oxidation resistant heating element from an alloy, in which the alloy is attached to a nonconducting heat resistant material to form an assembly, the assembly is placed in an oxygen environment, the oxygen environment is subjected to a chosen temperature within the range of 800° C. to 1000° C. for a period of time, and the assembled alloy is then slowly cooled.
Preferred embodiments include the following features. The alloy is wound around the nonconducting material, and the assembly alloy is subjected to 1000° C. for a chosen time within the range of 10 min. to 1 hour; preferably for a time of 30 minutes. Alternatively, the heating element may be assembled as part of a movable apparatus for resistive heating a substrate and the entire apparatus is placed in the oxygen environment, subjected to the chosen temperature, and cooled.
In another aspect, the invention features an oxidation-resistant heating element made of an iron, chromium and aluminum alloy and having an aluminum oxide outer surface. Preferably, the heating element also contains nickel and barium.
Because the movable heating device is oxidation- resistant in a vacuum environment, the invention allows fabrication and surface analysis steps to be performed on a series of substrates, e.g., forming high temperature superconducting circuits on substrates, by attaching the substrates to the movable heaters and moving the assemblies through all of the chosen processing steps requiring a variety of processing environments. The heater can be cleaned, reused, and discarded as appropriate and are relatively inexpensive to fabricate. Dedicated heaters need not be provided at the processing station. Furthermore, during movement of the substrate/heating device, electrical contact between the heating device and the supports may be maintained using an electrically conductive portion of the device, e.g, holes, pins or sides, that corresponds to an electrically conductive portion of the support. Therefore, electrically produced heat may be supplied to the substrate at any chosen time during processing.
Other features and advantages of the invention will be apparent from the description of the preferred embodiments, and from the claims.
DESCRIPTION OF PREFERRED EMBODIMENTS
We first briefly describe the drawings.
FIG. 1 is a schematic view of a substrate-treatment process using a reactor.
FIGS. 2a, 2b are front views of a movable heater alone and with associated grabbers, respectively.
FIG. 3 is a bottom view of the movable heater of FIG. 2b.
FIG. 4 is a side view of the movable heater.
FIGS. 5a, 5b are front views of a movable heater alone and with associated pin hole sleeves.
FIG. 6 is a bottom view of the movable heater of FIG. 5b.
FIG. 7 is a side view of the movable heater.
FIGS. 8a, 8b are a top view of a conductive fork partially in section, and a front view of the fork, respectively.
FIG. 9 is a schematic diagram of movement of the heater using the grabber approach.
FIG. 10 is a schematic diagram of movement of the heater using the pin approach.
FIG. 11 is a schematic top view of the wire alloy wrapped around a ceramic piece.
FIG. 12 is a schematic top view of an etched sheet form of alloy.
MOVEMENT OF HEATER DURING PROCESSING
Referring to FIG. 1, a series of identical substrates 7, 9, 11, 17 are each attached to a separate movable substrate heater 10, 12, 14, 15 at the first step of a process that includes steps to be performed within a reactor 13. Each heater and its substrate are transferred between and within different environments for processing. Each heater performs two functions: it holds the substrate and it supplies heat to the substrate in selected processing steps. Reactor 13 has a load lock 20, a central processing or deposition chamber 30, and an analytical lock 40, each of which has a central axis 19, 32, 41, respectively, around which the heater may be positioned during processing. Radiating out from each central axis are electrically conductive forks or platforms, e.g., 70, 80, 71, for supporting the movable heaters and for supplying electricity to the heaters. Movement of the forks or platforms may occur 360° around a X-axis (which is perpendicular to the surface of the page) and also around the X-axes. The processing chamber 30 may contain more than one central axis.
Each lock or chamber has windows, or ports, e.g., load lock ports 37, 39, 33, through which, for example, oxygen can be introduced from oxygen tank 35, electricity can be conducted using leads 21, 23 connected to a power source 29, or air can be removed from the lock or chamber to reduce the internal pressure using a vacuum pump 31. The processing chamber 30 and analytic lock 40 also have one or more ports, e.g., 34 and 42, respectively, which may be used for any one of these purposes. Between the locks and the processing chamber are ports 24 and 24' for movement of the substrate/heater between either lock and the chamber. In addition, the locks are loaded or unloaded through entry/exit ports 22, 43.
For processing a substrate in sequential steps of the process, each substrate/heater is moved into the load lock 20 through entry/exit port 22 to a position 16. The load lock is maintained at atmospheric pressure during loading and may be evacuated using vacuum pump 31 after the port 22 is closed. A pure gas, e.g., oxygen, may then be bled into the load lock through port 37 from oxygen tank 35. The substrate heater may then be moved to position 17, where a step of the process may be performed using heat. When heat is required at a step of the process, power source 29 is turned on and current is conducted through leads 21, 23 which connect the power supply to the heater 17 in a manner to be described.
The substrate/heater may then be transferred into the processing chamber 30 through port 24 to position 18, then to positions 36 and 38, each position corresponds to a step of the process at which heat may be supplied from power source 29 using leads 21, 23. During transfer of the substrate/heater between chambers, the processing chamber 30 is maintained under vacuum, e.g., 10 -11 Torr, by bringing the lock to an equivalent vacuum before transfer. Conditions within the processing chamber, e.g., the vacuum or gas content within the chamber, or the temperature of the heater, may be altered to conform to the desired processing step using ports, e.g., 34, as described above for the load lock.
If analysis of the substrate is desired, the processed substrate may be transferred into the analytic chamber 40 through port 41; analysis may occur at position 43 or other positions (not shown) within the analytic chamber and, if heat or a vacuum or gas environment is required during analysis of the processed substrate, then a change in the environment may be effected using an analytic chamber port 42, as described above for ports leading into either the load lock or processing chambers. After analysis, the processed substrate may be removed directly from the analytic reactor 13 after transfer back through the processing chamber along positions 38, 49, 18, through port 24, into the load lock 20, and out of the load lock through port 22. After processing in the reactor, the processed substrate 48 can be lifted off the heater 46 (arrow 45), and the heater may be discarded (arrow 51) or cleaned (arrow 53) for re use.
Each heater is designed to resist sublimation and oxidation in a high temperature/high vacuum environment of the kind that may be required for substrates such as high temperature superconducting materials (HTSC), e.g. the Y Ba--Cu O Bi Sr Ca--Cu O and Ti--Ba Ca--Cu 0 HTSC groups. These materials are metal oxides with low resistance at room temperature, and may be fabricated from precursors which are subjected to processing in a deposition chamber, e.g., at 1000° C. at 10 -6 Torr.
In one example, the dimensions of the heater and the mounted substrate are limited by the size of reactor chamber ports 22, 24, 41, 43; for example, for a 100 mm diameter port, the heater may hold a substrate wafer of size between 25.4 mm by 50.8 mm. Although the maximum length of the heater can be 25.4 mm and the maximum width of the heater can be 95.0 mm in order to fit through a 100 mm port, it is preferred that only 70% of this size be used. This safety margin will allow the heater to be transferred between load lock, deposition, and analytic chambers 20, 30, 40 through ports 24 and 41, should there be misalignment between them. The heater may have a thickness of approximately 30 mm.
THE HEATER
Among the alternative ways for the heater to perform both functions of heating and moving the substrate are through conductive forks that contact conductive holes in the heater; conductive "E pieces", which are sleeves that grip conductive sides of the heater; or conductive pin-hole pieces that fit around conductive pins of the heater.
Referring to FIGS. 2a, 2b, 5a, and 5b, in either the grabber embodiment or the pin embodiment, the heater 10, 11 includes a nonconductive central ceramic portion 52 around which a conductive alloy wire 79 is wrapped, and two nonconductive ceramic plates 50, 54 which sit on the bottom and top, respectively, of the central ceramic portion 52. The ceramic is 99% aluminum oxide, Al 2 O 3 .
Referring to FIGS. 2a, 2b and 3, in the grabber embodiment, adjoining each side of the central ceramic portion, including 50, 52, 54 of heater 10, are side arms 55a, 56b made of conductive stainless steel 304. Each arm 55a, 56b contains a hole 58 into which a prong 90a, 90b of a fork 70 (FIG. 8) can be inserted, and a recessed portion 59 to receive, respectively, protrusion 61a, 61b of an "E" piece 60a, 60b. E pieces 60a, 60b are permanently attached to a grabber platform 80 (FIG. 3); they are not permanently attached to heater 10, but grab onto it (FIG. 2b) during the grabber movement discussed below with respect to FIG. 9. Arms 55a, 56b are joined to central ceramic portion 50, 52, 54 using screws 62a, 62b; each screw extends from each arm at the screw plate portions 64a, 64b of the arms 55a, 56b through screw plates 68a and 68b, and through ceramic portions 50, 52, 54, to nut plates 65a, 66b. The screws are made of stainless steel 304 and are thus able to conduct current from arms 55a, 56b to the conductive alloy 79 that is wrapped around ceramic portion 52. The screw plates 68a, 68b are made of ceramic so as to prevent heat loss from the heating element through arms 55a, 56b. The nut plates are made of alloys. In addition to screw plates 68a, 68b and nut plates 65a, 66b, there are centrally positioned screw plates 63 and nut plates 65 that hold the substrate in place, depending on whether it is affixed to the top or bottom of the heater. (The orientations "top" and "bottom" are relative to the figures and do not have functional significance.) The substrate 7 may be fixed to the middle of ceramic plate 50 or, alternatively, to ceramic plate 54 of heater 10 using screws 67; these screws extend through screw plates 63 and ceramic portions 50, 52, 54 to nut plates 65. The substrate itself is not screwed to the ceramic, but is held down at either end by screw plates 63 (FIG. 3). A hole 69 through the middle of ceramic portion 52 is for insertion of a thermometer to measure temperature within the ceramic portion 52.
E pieces 60am, 60b are also made of stainless steel 304 and make good contact with their respective arms 55a, 56b (FIG. 2b). The leads 21, 23 are attached respectively to the E pieces 60a, 60b.
In operation, the substrate and heater become hot when power source 29 is turned on and current is conducted, e.g., by lead 21 to conductive "E" piece 60a and then conductive heater side 56a. which touches conductive screw 62a which pass through side 56a (FIG. 3). Screw 62a is in electrical contact with one end of wire heat resistant alloy 79 that is wrapped around ceramic portion 52. Thus, the current may be conducted from the screw 62a through the wire 79 to its other end, which is in electrical contact with screw 62b (FIG. 3), and then through the corresponding parts of the heater to lead 23 and power source 29. Electrical current passing through the alloy wire 79 causes it to become hot and heat is conducted through ceramic plates 50, 54 to the substrate 7 (FIG. 3).
Each E piece 60a, 60b is attached indirectly to the body of the grabber platform 80 through a ceramic adaptor or standoff 83 so that the E piece is fully insulated from grabber platform 80.
Referring to FIG. 4, holes 86 on E piece 60b receive screws for attachment of the ceramic standoff (83 in FIG. 2b); the standoff joins E piece 60a or 60b to the grabber platform 80. Because E piece 60b is electrically insulated from grabber platform 80 due to ceramic standoff 83, current will not pass to the grabber platform.
Referring to FIGS. 5a, 5b, 6, 7 in the pin embodiment, heater 11 contains (stainless steel 304) pins 72a, 72b, which extend down from arms 55a, 56b and fit snugly into pin holes (not shown) of conductive pin hole sleeves 76. Pin hole sleeves 76, made of stainless steel 304, are permanently attached to pin platform 82, but are not permanently attached to heater 11. Each pin-hole sleeve 76 is fully insulated from pin-hole platform 82 through a ceramic standoff 83. As in the grabber approach, the heater 11 becomes hot when current passes from power source 29 along lead 21 to pin hole sleeve 76 and to conductive pin 72, due to the contact between these two conductive pieces, and then to the wire alloy 79, and the circuit is completed through the corresponding pin and pin-hole sleeve.
ASSEMBLY OF THE FORK
Referring to FIG. 8a, fork prongs 90a, 90b of fork 70 slide into holes 58 of heater 10 or 11 and thus provide mechanical support to enable movement of the heater and also provide an electrically conductive path between the conductive leads and the heater. The current travels through fork prongs 90a, 90b, which are made of stainless steel 304, from conductive leads 21, 23 via the ends 92a, 92b of the fork prongs, also made of stainless steel 304; the fork ends 92 may be threaded for the purpose of attaching the leads using nuts. Fork prongs 90, shown in partial section in the figure, are mounted perpendicular to and on opposite ends of a stainless steel 304 center piece 94a. Fork ends 92a, 92b are mounted to center piece 94a through center piece holes 95a, 96b, but the fork prongs do not directly contact center piece 94a due to ceramic standoffs 98a, 98b. The standoffs 98a, 98b serve to electrically isolate the conductive fork prongs from the center piece. Center pieces 94a and fork arm 94b move as one piece during operation of the fork. If desired, a thermocouple (not shown) may be attached to center piece 94a by spot-welding the thermocouple to the middle of the center piece between the fork prongs; the thermocouple senses the temperature within the heater cartridge by sliding into hole 69 of the heater (FIGS. 2a and 5a).
Referring to FIGS. 9 and 10, positions A, B, and C respectively represent load lock chamber 20 with central Y axis 19, processing chamber 30 with central Y axis 32, and analytical chamber 40 with central Y axis 41, respectively.
In line 1 of FIG. 9, fork 70 holds heater 10 and is moving from position A in the load lock chamber to position B in the processing chamber; movement of the fork and heater is both along the X-axis direction and around the Y axis until the heater sides are aligned in the same plane as the E pieces (60a, 60b in Figs. 2b-4) of the grabber platform 80; in line 2, fork 70 moves along the X axis towards grabber platform 80 until the heater sides are inserted within the E pieces of the grabber platform 80 (this configuration is shown from the front in FIG. 2b; note that in FIG. 9 the E pieces are shown only schematically by reference number 60); in line 3, fork 70 then moves away from grabber platform 80 along the X axis; in line 4, the grabber platform containing the heater turns, e.g., 180° , around the X-axis through the deposition chamber, thereby delivering heater 10 to a second fork 71, identical to fork 70; in line 5, fork 71 moves along the X-axis toward the heater, and fork prongs 90 insert into the heater in line 6. In line 7, fork 71 moves along the X axis away from the grabber, thus withdrawing the heater from the grabber platform 80, and, in line 8, fork 71 continues movement of the heater away from the grabber platform along the X axis and into position C, the analytical chamber, where it can be rotated about the X-axis.
Referring to FIG. 10, in the pin approach, in line 1, fork 70 holds heater 11 and moves along the X axis until it is aligned with pin-hole platform 82 (the pin hole platform is also shown from above, 99, with pin holes 74); in line 2, pin hole platform 82 then moves upward along the Y axis until pin holes 74 receive heater pins 72a, 72b (line 3); in line 4, fork 70 then slides out of heater 11; in lines 4 and 5, pin hole platform 82 containing heater 11 turns 180° around the Y axis to deliver the heater to fork 71; in line 6, fork 71 then moves along the X-axis until fork prongs 90 insert into heater 11; in line 7, pin hole platform 82 then moves downward along the Y axis, thus disengaging the pin holes 74 from the heater pins 72; and in line 8, fork 71 moves away from the pin platform along the X-axis.
For both the grabber and pin embodiments, if desired, forks 70, 71 may rotate 180° around the X-axis, as shown in line 8, thus turning the heater upside-down relative to its initial upright position. This rotational movement may be desired if deposition occurs from both the top and bottom of processing chamber 30. In addition, as mentioned above in describing FIG. 1, more than one central axis may be present in the processing chamber, thus allowing for transfer of the heater about each axis and between the axes to cover a larger spatial area. Note that, for each step of either grabber or pin embodiments, the heater is always in electrical contact with either the grabber arms or the pin-hole sleeves and the fork. Therefore, heat may be supplied to a substrate in any of the positions described during movement or while the heater is being held stationary.
ASSEMBLY OF MOVABLE HEATER
The heater is made of a heating alloy, an insulating material, and stainless steel 304, all of which are stable at high temperature, for example, 1000° C., in ultra high vacuum, for example, 10 -11 Torr, are inert to oxidation and metallic ion corrosion, and have high emissivities. Referring to FIG. 11, the heater is constructed by wrapping a wire alloy 79 around and into grooves 73 etched into the surface and edges of the ceramic insulating material 52. When electric current is applied to one end of the wrapped wire at
d wire pattern to 62a 1 , it will pass along the wrapped the other end of the wire at 62b 2 , thus generating heat which is absorbed by the emissive insulating material and transferred to the ceramic plates 50, 54 and the substrate 7.
The alloy must be oxidation resistant upon heating; for example, Kanthal AF or Haynes alloys may be used. Kanthal AF (Kanthal, Hallstahammar, Sweden) is a FeCrAl alloy for element temperatures up to 1400° C. Haynes Alloy No. 214 (Haynes International, Inc., Kokomo, ID) is a nickel based alloy containing Cr, Fe, Al, and Y. Kanthal AF and Haynes alloys are available in a variety of forms, for example, wire, strip, bar, or ready made forms. By itself, neither alloy is stable, i.e., resistant to sublimation in vacuum during heating. However, if treated by a process of this invention that causes the aluminum to leach to the surface of the alloy, the aluminum will form a densely packed and inert aluminum (III) oxide when it contacts oxygen. This hard oxide coating prevents further oxidation and corrosion of the alloy, prevents further leaching of aluminum to the surface, and, during heating in vacuum, prevents sublimation of metals from the alloy.
The insulating material is a nonconducting emissive material, such as ceramic, and is used as a base for the conductive alloy. Aluminum oxide (Al 2 O 3 ) and boron nitride are preferred ceramics because they can withstand oxidation, corrosion, and high temperature thermal treatment. In addition, their emissivities are very high, approximately 0.9; thus, heat absorbed from the heating element is radiated to the substrate as infra red heat. 99.9% pure alumina should be used for ultra high-vacuum and high temperature environments, because it has minimal outgassing during high thermal treatment; extra pure boron nitride is also preferred because it delivers uniform heat distribution from heater to substrate.
The treatment process for preparing the heating alloy consists of first assembling the alloy on a nonconducting heat-resistant material, such as a ceramic plate which has circular cross section grooves etched on its surface, by winding the wire around the ceramic plate. Then the wire-wound ceramic plate (referred to herein as the heating element) is placed in a pure oxygen environment and subjected to a temperature of 800° C. to 1000° C. for a period of time, which may be 30 min. Then the heating element is cooled slowly. Alternatively, the heating element may be assembled into the movable heater before subjecting the alloy to heat. The thus treated alloy is well-suited for heating in pure oxygen and/or ultra-high vacuum environments.
WINDING PATTERN OF ALLOY
The heater provides very high temperature and uniform thermal contact with the substrate. As used herein, "high temperature" means approximately 1000° C., or in the general range of 800° C. to 1200° C. "Uniform" thermal contact means the temperature across ceramic plates 50, 54 does not vary by more than ±50° C. In order to achieve high temperature and uniform thermal contact, the alloy must conduct enough current and be patterned around the space limitation of ceramic piece 52 so as to generate the required temperature, e.g., 1000° C., uniformly across the substrate. As shown in FIG. 11, the wire alloy 71, which in this example has a diameter 0.032-0.035 inches, must be wound a pre-determined number of times around grooves 73 etched into ceramic portion 52 and must not cross over itself in winding. The following example describes factors that relate to determining how many times the wire alloy must be wound around the ceramic piece to deliver a high, uniform temperature to the substrate when electric current is passed through it.
Factors that affect the design of the heating element of the heater are: the surface area of the heater, the resistance of the heating element, the size of the wire, the surface load of the wire, and the radiant heat loss at 1000° C. In table I, formulae for calculating the surface area of the heating element are shown; in table II, the following relationships for Haynes alloy are given: temperature in ° C., power dissipation (W)/cm 2 , total power dissipation (W), resistance (R) in ohms, current (I) in Amps, and surface power load (S.L.)/cm 2 .
TABLE I______________________________________Resistance per unit length (R) R/L = P/Awhere L = length in cm .sup. P = resistivity .sup. A = cross-sectional area;Power dissipation from a resistive load: W = I.sup.2 × R,where W = power per unit area, .sup. I = resistance .sup. R = current in Amp;Surface power load (W.sub.s): W.sub.s =W/A.sub.s,where A.sub.s = surface area of the .sup. heating element.______________________________________
TABLE II______________________________________Haynes alloy°C. W/cm.sub.2 total W R I S.L./cm.sup.2______________________________________ 0 0.03 0.57 1.949 0.54 0.02100 0.11 1.98 1.949 0.54 0.02500 2.02 36.44 1.949 4.32 1.30800 7.52 135.29 1.949 8.33 4.841000 14.89 268.02 1.949 11.73 9.60______________________________________
A 0-30 Amp power source may be used to generate current and a voltage regulator controls the exact voltage and current outputs. A voltage regulator may be used that both removes radio frequency interference (K-type) and withstands high voltage. The voltage is fixed at 110 VAC; therefore, the minimum resistance value is 3.67 ohms, the maximum current is 30 Amps, and the maximum power is 3300 Watt. Since the emissivities of both oxidized heating alloy and ceramic is approximately 0.9, the energy loss in radiation is approximately 241 Watts. At 1000° C., the power density is 14.89 Watt cm 2 and the total output power of the heater required to compensate the energy loss in radiation is 268.1 Watts. For example, if the diameter of the wire is 1 mm and the overall length of the wire is 0.8 m, then the current required to bring the heater temperature to 1000° C. is 13.7 Amps.
For a heater that must fit through a 100 mm port, the heat zone has a maximum size of 30 mm 2 . If the minimum insulating space between the wires is 1 mm, then the maximum number of turns the wire can make around the ceramic portion will be 30/(1+1)=15; similarly, if the insulating space is 2 mm, then the maximum number of turns of the wire is 10. Variations of this design may be calculated using the formulae given in Table I and example calculations presented in Table II.
OTHER EMBODIMENTS
Other embodiments are within the following claims; for example, the pattern that the current follows during conduction through the alloy may be designed differently; for example, square or circular spirals may be used, or any other pattern that avoids localized heating and cooling and cross over of the alloy on itself. Alternatively, instead of alloy wire, a pure alloy plate (e.g., 1 mm thick), as shown in FIG. 12, may be etched in a design which carries the current from an electronegative source applied to screw 62a 1 at one end of the plate along the raised alloy pattern 75 defined by the etched space 77 to an electropositive source applied to screw 62d 2 at the opposite end of the plate. The formula given for the wound-wire embodiment described above may also be used to determine how to etch the alloy plate to allow current to be conducted to produce in a high temperature and uniform heating.
Any ceramic may be used as insulating material in the heater, as long as it has the following properties; it is nonconductive, resistant to sublimation or cracking at high temperatures, for example, 1000° C., in ultra-high vacuum, for example, 10 -11 Torr, and is highly emissive. Other environments in which both the ceramic insulating material and the alloy will be stable are, e.g., pure gas environments such as argon, nitrogen, and silane; corrosive gas environments, such as sulfer dioxide, should be avoided.
The movable heater of the invention may also be used solely for heating the substrate or solely for carrying the substrate. For example, a substrate less heater may be used to supply radiant heat to a substrate that is carried by another heater. In addition, the heater may be used to carry more than one sample.
The movable heater may also be used to promote nucleation of any kind of thin film substrate, e.g., substrates having other electrical or mechanical properties; e.g., for the deposition of dielectric or metal coatings. | Heat is provided to substrates at a step of a process by providing identical movable heating devices, one for each substrate, placing each substrate onto one of the heating devices, sequentially moving each device into a position where the step of the process can be performed on the substrate, and causing each of the devices to provide heat to the substrate at each step of the process. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part application of and claims the priority benefit of U.S. application Ser. No. 13/284,974, filed on Oct. 30, 2011, now pending, which claims the priority benefit of China application serial no. 201110100828.0, filed on Apr. 21, 2011. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a DC to DC buck converting controller, and more particularly a DC to DC buck converting controller with programmable output voltage.
[0004] 2. Description of Related Art
[0005] FIG. 1 is a schematic diagram of a conventional DC to DC buck converting circuit. The DC to DC buck converting circuit comprises a controller 10 , two switches M 1 and M 2 , an inductance L, a capacitance C, a bootstrap circuit BS and a voltage divider VD. The voltage divider VD detects an output voltage of the buck converting circuit and accordingly generates a feedback signal FB. The controller 10 turns the switches M 1 and M 2 on/off according to the feedback signal FB, so as to make the DC to DC buck converting circuit to convert an input signal Vin into an output voltage Vout which is stabilized at a preset output voltage, as well as provide an output current Iload.
[0006] The controller 10 is packaged in a package, and comprises a comparator 12 , a on-time period circuit 14 , and a logic circuit, which has a logic control circuit 16 and two gate driving units 18 , 20 . The comparator 12 generates a feedback control signal according to the feedback signal FB and a reference voltage Vref, which is generated inside the controller 10 . An on-time period of the on-time period circuit 14 is determined by the input voltage Vin and the output voltage Vout, and the on-time period circuit 14 generates a constant on-time signal according to the feedback control signal. The logic control circuit 16 determines conduction timing and cut-off timing of the switches M 1 and M 2 , and generates two control signals Sl and Su respectively via the gate driving units 18 and 20 to turn on and off the switches M 1 and M 2 . The switch M 2 is a N-type MOSFET. For avoiding that the gate driving unit 20 in the controller 10 cannot generate a signal which is high enough to turn on the switch M 2 . The bootstrap circuit BS is used to supply a sufficiently high voltage to the gate driving unit 20 .
[0007] The constant on-time period circuit 14 adjusts the constant on-time period according to the input voltage Vin and the output voltage Vout to make the DC to DC buck converting circuit operate in a quasi-constant frequency. Therefore, an electromagnetic interference (EMI) generated by the switches M 1 and M 2 can be easily filtered out, regardless of the levels of the input voltage Vin and the output voltage Vout in different applications.
[0008] Compared with a conventional converting controller with error amplifier structure, the DC to DC buck converting controller with on-time structure has a better transient response. FIG. 2 shows waveform diagrams when a loading driven by the conventional converting circuit with on-time structure is changed. At a tome point t 1 , the output current Iload is raised while the loading increases. During the interval from the time point t 1 to a time point t 2 , the output voltage Vout is temporarily decreased due to that an increased output power provided by the converting circuit is not enough. After the time point t 2 , the output voltage Vout starts to be elevated and then reaches the original voltage level at a time point t 3 . The constant on-time period circuit 14 determines the on-time period in response to the input voltage Vin and the output voltage Vout. However, the output voltage Vout is lower than the original voltage level during an interval from the time point t 1 to the time point t 3 , and so the on-time periods of cycles within the interval are shorter, which is a great disadvantage for transient response.
SUMMARY OF THE INVENTION
[0009] The invention adjusts the programmable on-time period of a DC to DC buck converting controller according to a reference signal, so as to be suitable for any applications with different requests of output voltages or different operating mode, and enhance the transient response. Furthermore, the converting controller can omits a pin for obtaining the information of output voltage to lower the cost of the converting controller and a PCB board therefore.
[0010] To accomplish the aforementioned and other objects, an exemplary embodiment of the invention provides a DC to DC buck converting controller, which is packaged in a package and adapted to control a DC to DC buck converting circuit which converts an input voltage into an output voltage. The DC to DC buck converting controller comprises a feedback circuit and a driving circuit. The feedback circuit receives a reference signal through a pin of the package and generates a feedback control signal according to a reference signal representative of a reference voltage and a feedback signal representative of the output voltage. The driving circuit generates at least one control signal to control the DC to DC buck converting circuit according to the feedback control signal. The driving circuit comprises an on-time period circuit. The on-time period circuit sets an on-time period of the DC to DC buck converting circuit according to the level of the reference voltage.
[0011] It needs 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 as claimed. In order to make the features and the advantages of the invention comprehensible, exemplary embodiments accompanied with figures are described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention will now be specified with reference to its preferred embodiment illustrated in the drawings, in which:
[0013] FIG. 1 is a schematic diagram of a conventional DC to DC buck converting circuit.
[0014] FIG. 2 shows waveform diagrams when a loading driven by the conventional converting circuit with on-time structure is changed.
[0015] FIG. 3 is a schematic diagram of a DC to DC buck converting circuit according to a first embodiment of the invention.
[0016] FIG. 4 is a schematic diagram of an on-time period circuit according to an embodiment of the invention.
[0017] FIG. 5 shows waveform diagrams when a loading, driven by the DC to DC buck converting circuit shown in FIG. 3 , is changed.
[0018] FIG. 6 is a schematic diagram of a DC to DC buck converting circuit according to a second embodiment of the invention.
[0019] FIG. 7 is a schematic diagram of an anti-noise circuit according to an embodiment of the invention.
[0020] FIGS. 8 ( a ) and ( b ) show waveform diagrams for difference reference voltages.
[0021] FIG. 9 shows waveform diagrams of control signals generated by the conventional converting controller and the converting controller of the invention.
DESCRIPTION OF EMBODIMENTS
[0022] In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawings.
[0023] FIG. 3 is a schematic diagram of a DC to DC buck converting circuit according to a first embodiment of the invention. The DC to DC buck converting circuit comprises a controller 100 , two switches M 1 and M 2 , an inductance L, a capacitance C, a bootstrap circuit BS and a voltage divider VD. The voltage divider VD detects an output voltage Vout of the DC to DC buck converting circuit and accordingly generates a feedback signal FB. The controller 100 turns the switches M 1 and M 2 on/off according to the feedback signal FB, so as to make the DC to DC buck converting circuit convert an input voltage Vin into an output voltage Vout which is stabilized at a preset output voltage and provide an output current Iload to a load (not shown).
[0024] The controller 100 comprises a feedback circuit 112 , a driving circuit which comprises an on-time period circuit 114 , a logic control circuit 116 and two gate driving units 118 , 120 , which is packaged in a package with a plurality of pins. The feedback circuit 112 comprises a comparator. An inverting input terminal of the comparator receives the feedback signal FB and a non-inverting input terminal thereof receives a reference voltage Vr and accordingly outputs a feedback control signal Sfb. The on-time period circuit 114 receives the feedback control signal Sfb and the reference voltage Vr and accordingly generates an on-time signal Sto. Therefore, the on-time period circuit 114 does not need the information of the output voltage Vout and can omit one pin for coupling to the output voltage Vout, which is used to get the information of the output voltage Vout in the conventional arts. A pulse width (time period) of the on-time signal Sto is determined by a voltage level of the reference voltage Vr. A starting timing of the on-time signal Sto, i.e., rising/falling edge, is determined according to the feedback control signal Sfb. The logic control circuit 116 is coupled with a connection node of the two switches M 1 and M 2 to detect a current of the inductance L and determine turned-on timings and turned-off timings of the two switches M 1 and M 2 according to the feedback control signal Sfb and the current of the inductance L. The logic control circuit 116 generates two control signals Slg and Sug respectively via the gate driving units 18 and 20 to turn the two switches M 1 and M 2 on/off. In the present embodiment, a duty cycle of the DC to DC buck converting circuit, i.e., a time ratio of a period time to transmit the power from the input voltage Vin into the DC to DC buck converting circuit via the switch M 1 and a cycle time thereof, is determined by turned-on period of the switch M 1 . That is, when a beginning of each cycle (when the level of the feedback signal FB is lower than the level of the reference voltage Vr), the feedback circuit 112 generates a feedback control signal Sfb to make the on-time period circuit 114 to generate the on-time signal Sto with a pulse width (time period). The logic control circuit 116 turns on the switch M 1 according to the on-time signal Sto. After the pulse width (time period), the logic control circuit 116 turns the switch M 1 off and turns the switch M 2 on to make the current of the inductance L freewheel through the switch M 2 .
[0025] When the current of the inductance L is decreased to zero, the switch M 2 is turned off.
[0026] The reference voltage Vr may be an external reference signal, input to the controller 100 through a pin of the package. The reference signal may be an analog signal having a reference voltage, or a digital signal indicative of the reference voltage. Therefore, a level of the reference voltage Vr is determined by an external circuit or set by users according to a preset output voltage. In the present embodiment, the controller 100 further comprises a reference voltage generating circuit 115 . The reference voltage generating circuit 115 generates a reference base voltage Vr 0 . The user makes the reference base voltage Vr 0 divided into a demand reference voltage Vr by a voltage divider and transmits the reference voltage Vr into the feedback circuit 112 and the on-time period circuit 114 through the pin. The voltage divider comprises the resistances RV 1 , RV 2 and a voltage division ratio thereof is set by the input voltage Vin and the preset output voltage. In addition, the voltage division ratio of the voltage divider VD may affect the ratio of the feedback signal FB and the output voltage Vout. Therefore, the ratio of the resistances RV 1 , RV 2 is set according to the voltage division ratio of the voltage divider VD.
[0027] FIG. 4 is a schematic diagram of an on-time period circuit according to an embodiment of the invention. The on-time period circuit 114 comprises a current source I, a period capacitance Cton and a comparator 1141 . The current of the current source I is set by a current minor MI and an on-time period resistance Rton. The on-time period resistance Rton is coupled with the input voltage Vin and so a current flowing through the on-time period resistance depends on the input voltage Vin. The current flowing through the on-time period resistance is mirrored to the current source I by the current minor MI. On the beginning of each cycle, the period capacitance Cton is charging from zero by the current source I. The comparator 1141 compares the voltage of the period capacitance Cton with one of the original voltage Vset and the reference voltage Vr to generate the on-time signal Sto, and the original voltage Vset is higher than the reference voltage Vr. On the beginning of enabling the circuit, the comparator 1141 compares the voltage of the period capacitance Cton with the original voltage Vset to make the on-time period longer and so the output voltage Vout could be increased faster. Just before or when the output voltage Vout reaches the preset voltage, the comparator 1141 compares the voltage of the period capacitance Cton with the reference voltage Vr to make the output voltage Vout to be stabilized on the preset output voltage. The on-time period circuit 114 further comprises a SR flip-flop 1142 and an inverter 1143 . A set terminal S of the SR flip-flop 1142 is coupled with the output terminal of the comparator 1141 through the inverter 1143 , a reset terminal R thereof is coupled with the feedback circuit 112 and an output terminal is coupled with the discharging unit SWd. The discharging unit SWd is coupled with two ends of the period capacitance Cton to discharge the period capacitance Cton according to the controlling of the SR flip-flop 1142 . When the voltage of the period capacitance Cton is higher than the reference voltage Vr, the on-time signal Sto is changed into low level to trigger the SR flip-flop 1142 through the inverter 1143 . Then, the discharging unit SWd discharges the period capacitance Cton. When the output voltage Vout is lower than the preset voltage, the feedback control signal Sfb is at high level and input to the reset terminal R of the SR flip-flop 1142 to make the SR flip-flop 1142 reset to stop the discharging unit SWD discharging. Therefore, on the beginning of each cycle, the output voltage Vout is lower than the preset output voltage and the period capacitance Cton is charged by the current sources I. When the voltage of period capacitance C is higher than the reference voltage Vr, the period capacitance Cton is discharged to zero voltage to wait for the next cycle.
[0028] FIG. 5 shows waveform diagrams when a loading, driven by the DC to DC buck converting circuit shown in FIG. 3 , is changed. At a tome point t 4 , the output current Iload is raised while the loading of the load increases. During the interval from the time point t 4 to a time point t 5 , the output voltage Vout is temporarily decreased due to that an increased output power provided by the converting circuit is not enough. After the time point t 5 , the output voltage Vout starts to be elevated and then reaches the original voltage level at a time point t 6 . The on-time period circuit 114 determines the on-time period in response to the input voltage Vin and the reference voltage Vr regardless of the output voltage Vout. Due to that the reference voltage Vr is fixed regardless of the variation of the loading, the pulse width of the control signal Sug is fixed while the duty cycle thereof is increased. Therefore, the interval from the time point t 4 to the time point t 6 is shorter than that from time point tl to the time point t 3 shown in FIG. 2 , i.e.: the controller 100 has a better transient response than that of the conventional constant on-time converting controller.
[0029] FIG. 6 is a schematic diagram of a DC to DC buck converting circuit according to a second embodiment of the invention. Compared with the embodiment shown in FIG. 3 , the controller 200 omits the reference voltage generating circuit 115 and the voltage divider, and adds anti-noise circuit 125 . The feedback circuit 112 directly receives the reference voltage Vr through a pin of the package and compares the reference voltage Vr with the feedback signal FB to generate the feedback control signal Sfb. If a digital reference signal indicative of the reference voltage is input through the pin, the controller 200 may adds a digital to analog converter to convert the digital signal into the reference voltage Vr. The anti-noise circuit 125 is coupled between the feedback circuit 112 and the on-time period circuit 114 for avoiding noise interferences in generation of the feedback control signal Sfb. The anti-noise circuit 125 generates a trigger signal Sd to the on-time period circuit 114 when the feedback control signal Sfb is generated for an anti-noise time. The anti-noise circuit 125 also receives the reference voltage Vr and modulates the anti-noise time in response to the reference voltage. FIG. 7 is a schematic diagram of an anti-noise circuit according to an embodiment of the invention. The anti-noise circuit comprises a bias current source Ib, a current mirror 1252 , a delay capacitance 1254 , a switch 1256 , and a comparator 1258 . A control terminal of the switch 1258 is coupled to an output end of the feedback circuit 112 , and the switch 1256 is turned on and off according to the feedback control signal Sfb. The current mirror 1252 mirrors a current provided by the bias current source Ib to discharge the capacitance 1254 . When the feedback signal FB is higher than the reference voltage Vr, the feedback control signal Sfb is at a low level. At this time, the switch 1256 is turned on to keep a voltage of the delay capacitance 1254 close to a supply voltage VDD higher than the reference voltage Vr, and so the comparator 1258 stops to generate the trigger signal Sd. When the feedback signal FB is lower than the reference voltage Vr, the feedback control signal Sfb is at a high level. At this time, the switch 1256 is turned off and so the current mirror 1252 starts to discharge the capacitance 1254 . When the voltage of the capacitance 1254 is discharged to be lower than the reference voltage Vr, the comparator 1258 outputs the trigger signal Sd to the reset terminal R of the SR flip-flop 1142 . At this moment, the on-time period circuit 114 starts to generate the on-time signal Sto. An anti-noise time is the time interval from the timing of generating the feedback control signal Sfb to the timing of generating the trigger signal Sd.
[0030] FIGS. 8 ( a ) and ( b ) show waveform diagrams for difference reference voltages. A level of the reference voltage Vr represents the loading of the load as well as the preset output voltage. A reference voltage Vr 1 of FIG. 8( a ) is lower than a reference voltage Vr 2 of FIG. 8( b ). The anti-noise time is shortened when the reference voltage is increased, and alternatively the anti-noise time is lengthened when the reference voltage is lowered. Therefore, an anti-noise time d 1 of FIG. 8( a ) is longer than an anti-noise time d 2 of FIG. 8( b ). A ripple of the output voltage is increased with the increasing of the output voltage, and so an angle between the reference voltage Vr 2 and the feedback signal FB 2 is larger than that between the reference voltage Vr 1 and the feedback signal FB 1 . Hence, when the preset output voltage is higher, the ripple of the output voltage is larger and a stability of the converting circuit is better but a transient response is poor. At this time, the anti-noise time of the anti-noise circuit of the invention is shortened to enhance the transient response. On the other hand, when the preset output voltage is lower, the ripple of the output voltage is smaller and the transient response of the converting circuit is better but the stability is poor. At this time, the anti-noise time of the anti-noise circuit of the invention is lengthened to enhance the stability.
[0031] FIG. 9 shows waveform diagrams of control signals generated by the conventional converting controller and the converting controller of the invention. The on-time period of the control signal Sug is determined according to the reference voltage Vr in the present invention. In contrast, the on-time period of the control signal Su is determined according to the output voltage Vout in the conventional arts. At a time point t 7 , the loading is increased and so the output current Iload and the reference voltage Vr are synchronously increased. The on-time period of the control signal Sug is increased with the increasing of the reference voltage Vr. However, the Vout is increased after, even temporarily reduced. The on-time period of the control signal Su is still retained. Moreover, the anti-noise time of the invention is shortened. The beginning of the control signal Sug is early than that of the control signal Su. Both the longer on-time period and the shorter anti-noise time, the invention significantly improves the transient response while the loading is increasing.
[0032] At a time point t 8 , the loading is reduced and so the output current Iload and the reference voltage Vr are synchronously decreased. The on-time period of the control signal Sug is reduced with the reducing of the reference voltage Vr. However, the Vout is decreased after, even temporarily increased. The on-time period of the control signal Su is still retained. Moreover, the anti-noise time of the invention is lengthened. The beginning of the control signal Sug is later than that of the control signal Su. Both the shorter on-time period and the longer anti-noise time, the invention simultaneously improves the transient response and the stability while the loading is reducing.
[0033] All the features disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. | A programmable on-time period of a DC to DC buck converting controller is adjusted according to a level of a preset output voltage or a reference signal. Therefore, the DC to DC buck converting controller of the present invention is suitable for any applications with different requests of output voltages or different operating mode. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to an adjustable lens securing system for rimless eyewear, and more particularly to an adjustable tensioning system that allows easy assembly and adjustment of a wire used to secure at least one eye lens.
[0003] 2. Description of the Related Art
[0004] Recently, developments in the eyewear industry have resulted in the creation of eyewear in which the lenses appear to be unattached to any frame. Such eyewear is being called “rimless.” Temples and a bridge can be secured to the lenses with fasteners that extend through the lenses or with clamps that clamp over a portion of the lenses. Such arrangements result in a visible overlap of the mechanical structures used to support the lenses and the lenses themselves. Furthermore, while a goal of rimless eyewear is to minimize the visual impact created by the rim structures, many of these structures result in an emphasis on the components. Moreover, when preparing the lenses or when mounting the mechanical structures to the frames, the lenses are prone to chipping and cracking, which results in the lenses having to be discarded and increase the ultimate cost to the consumer of the eyewear. In addition, these mounting systems require highly precise drilling of holes, notches, etc., such that costly and time consuming outside lens preparation services are often required.
SUMMARY OF THE INVENTION
[0005] Even more recently, a rimless style of eyewear has been proposed in which the lenses are substantially encircled by a thin, multiple filament wire. Examples of such eyewear are described in co-pending U.S. patent application Ser. No. 10/678964, filed on Oct. 2, 2003, which is hereby incorporated by reference in its entirety, as well as the following applications from which that application claims priority: U.S. patent application Ser. No. 10/610862, filed on Jun. 30, 2003, U.S. patent application Ser. No. 10/269811, filed on Oct. 11, 200, and U.S. Provisional Patent Application No. 60/394837, filed on Jul. 10, 2002, each of which also are hereby incorporated by reference in their entirety.
[0006] The constructions described in the co-pending application generally require the wire to be sufficiently taut such that undesired movement of the components can be minimized or eliminated. The correct tautness or tension is achieved in many of these constructions only when the lenses are cut to the proper shape and size within very small tolerances. Given variations in the calibration and measuring systems of individual lens cutting equipment, and allowances for variations by the optical technicians using the equipment, this style of rimless eyewear admits to some improvements such that secure and practical rimless eyewear can be manufactured.
[0007] While various systems for adjustment and tensioning of the wire can be envisioned, it is preferred that the adjustment system have an exterior configuration that closely resembles a standard endpiece. Such a construction would minimize the visual prominence of the adjustment system. Moreover, such a construction would minimize any overlap of the lens by the system such that the prominence of the mounting structure can be reduced and the eyewear can become even more transparent to observers of the user of the eyewear.
[0008] Accordingly, certain aspects of the present invention are directed to an adjustment and tensioning system for rimless eyewear that comprise any of a number of embodiments of a flexible wire adjustment and tensioning mechanism. Various ones of the disclosed flexible wire adjustment and tensioning embodiments ensure ease of assembly as well as a system for adjusting the tension of the flexible wire that secures the lens in the rimless eyewear. In addition, it should be noted that the present invention may be used for many types of eyewear, including ophthalmic frames, sunglasses, magnetic eyewear and protective eyewear.
[0009] In most preferred embodiments, the system is sized and configured to fit within a housing or to define a housing that resembles endpieces in present eyewear systems. In other words, when assembled, the housing would have a height, a width and a depth, with at least one of the width and the depth being substantially greater than the height. In other words, most present eyewear feature endpieces (e.g., where the temples attach to the lens supporting structures) that do not have a height as the longest dimension.
[0010] An aspect of the present invention involves eyewear comprising a lens. The lens comprises a peripheral side surface with a groove being formed in the side surface. A wire generally encircles the lens with at least a portion of the wire being positioned within the groove. The wire comprises a first end and a second end. A first tensioning block is connected to the first end and a second tensioning block is connected to the second end. The second tensioning block has an abutment surface that generally abuts a portion of the first tensioning block. An anchor is positioned on the second end of the wire. The second tensioning block comprises a passage. The wire extends through the passage and the anchor is positioned proximate the abutment surface of the second tensioning block.
[0011] Another aspect of the present invention involves eyewear comprising a lens. The lens comprises a peripheral side surface with a groove being formed in the side surface. A wire generally encircles the lens. At least a portion of the wire is positioned within the groove. The wire comprises a first end and a second end. A first block is connected to the first end of the wire and a second block is connected to the second end of the wire. At least one of the first block and the second block comprises a plurality of slots. At least one of the first end of the wire and the second end of the wire comprises an anchor bar. The anchor bar is sized and configured to be secured within one of the plurality of slots.
[0012] A further aspect of the present invention involves eyewear comprising a lens. The lens comprises a peripheral side surface. A groove is formed in the side surface. A wire generally encircles the lens. At least a portion of the wire is positioned within the groove. The wire comprises a first end and a second end. A first block is connected to the first end of the wire. A second block is connected to the second end of the wire. The second block comprises an adjustment passage. The adjustment passage comprises a channel. An adjustment block is secured to the second end of the wire. The adjustment block comprises a tooth. The adjustment block is moveably positioned within the adjustment passage with the tooth being positioned within the channel. The adjustment block comprises a threaded portion. A threaded member extends through a portion of the second block and engages the threaded portion such that rotation of the threaded member results in movement of the adjustment block.
[0013] An additional aspect of the present invention involves eyewear comprising a lens. The lens comprises a peripheral side surface with a groove being formed in the side surface. A wire generally encircles the lens with at least a portion of the wire being positioned within the groove. The wire comprises a first end and a second end. A first block is connected to the first end of the wire and a second block is connected to the second end of the wire. An anchor is secured to the second end of the wire. The anchor is rotatably secured within an adjustment screw. The adjustment screw is positioned within a threaded opening in the second block.
[0014] Yet another aspect of the present invention involves eyewear comprising a lens. The lens comprises a peripheral side surface with a groove being formed in the side surface. A wire generally encircles the lens with at least a portion of the wire being positioned within the groove. The wire comprises a first end and a second end. A first block connected to the first end of the wire. A mounting plate is secured to the second end of the wire. The mounting plate being securable to the first block with at least one shim being positioned between the mounting plate and the first block.
[0015] A further aspect of the present invention involves eyewear comprising a lens. The lens comprises a peripheral side surface with a groove being formed in the side surface. A wire generally encircles the lens with at least a portion of the wire being positioned within the groove. The wire comprises a first end and a second end. The first and second ends of the wire being connected to a first block and a second block. A tensioning recess formed in at least one of the first block and the second block and the first and second ends of the wire being positioned within the recess. The recess comprises a portion that is substantially the same width as one diameter of the wire. The recess also comprises a portion that is substantially larger that the one diameter of the wire. A threaded opening extends through at least one of the first block and the second block and intersects the substantially larger portion of the recess. A threaded member is positioned within the threaded opening.
[0016] Since there are many well-known methods of attaching temples to a projection extending from the outside perimeter edge of a lens, it should be understood in reading any descriptions of the embodiments of the present invention that any suitable method can be used to attach the temples to the various closing mechanisms described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Other features, aspects and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, some of the basic principles of the invention. Certain preferred embodiments are shown in the drawings, which are intended to illustrate and not to limit the invention.
[0018] FIG. 1 is an example of eyewear arranged and configured in accordance with certain features aspects and advantages of the present invention.
[0019] FIG. 2 is a front exploded perspective view of a wire tensioning system for pseudo rimless eyewear, which system is arranged and configured in accordance certain features, aspects and advantages of the present invention.
[0020] FIG. 3 is a sectioned view of the system of FIG. 2 .
[0021] FIG. 4 is a sectioned view of the system of FIG. 2 taken along the line A-A of FIG. 3 , the view shows the system prior to assembly.
[0022] FIG. 5 is a sectioned view of the system of FIG. 2 taken along the line A-A of FIG. 3 , the view shows the system following assembly and adjustment of tension.
[0023] FIG. 6 is a sectioned view of the system of FIG. 2 taken along the line B-B of FIG. 5 .
[0024] FIG. 7 is an exploded view of another wire tensioning system arranged and configured in accordance with certain features, aspects and advantages of the present invention.
[0025] FIG. 8 is top plan view of a lower tensioning block of the system of FIG. 7 with different tab slots allowing a positioning tab to adjust tension applied to a wire used to generally circumscribe a lens.
[0026] FIG. 9 is a sectioned view of the lower tensioning block taken along the line C-C of FIG. 8 .
[0027] FIG. 10 is an exploded view of another wire tensioning system arranged and configured in accordance with certain features, aspects and advantages of the present invention and illustrating a tensioning screw and a corresponding threaded tensioning anchor.
[0028] FIG. 11 is a sectioned view of the system of FIG. 10 and showing an upper tensioning block and the lower tensioning block.
[0029] FIG. 12 is a sectioned view taken along the line D-D of FIG. 11 .
[0030] FIG. 13 is a sectioned view of another wire tensioning system arranged and configured in accordance with certain features, aspects and advantages of the present invention and illustrating a two piece threaded tensioning anchor.
[0031] FIG. 14 is an exploded perspective view of the system of FIG. 13 .
[0032] FIG. 15 is an exploded perspective view of another wire tensioning system arranged and configured in accordance with certain features, aspects and advantages of the present invention and illustrating multiple tension adjustment shims.
[0033] FIG. 16 is an elevation view of the system of FIG. 15 illustrating a screw and two of the multiple tension adjustment shims installed.
[0034] FIG. 17 is a sectioned view of the system of FIG. 15 taken along the line E-E in FIG. 16 .
[0035] FIG. 18 is an exploded perspective view of another wire tensioning system arranged and configured in accordance with certain features, aspects and advantages of the present invention and illustrating upper and lower tensioning blocks and a tensioning plate used to adjust the tension of the wire.
[0036] FIG. 19 is an elevation view of the system of FIG. 18 illustrating an adjustment screw that contacts a portion of the tensioning plate, which is shown in phantom.
[0037] FIG. 20 is a sectioned view taken along the line F-F of FIG. 19 .
[0038] FIG. 21 is a sectioned view taken along the line G-G of FIG. 20 .
[0039] FIG. 22 is a simplified, partial top view of eyewear arranged and configured in accordance with certain features, aspects and advantages of the present invention and illustrating an interface between tension blocks and a lens.
[0040] FIG. 23 is another simplified, partial top view of eyewear arranged and configured in accordance with certain features, aspects and advantages of the present invention and illustrating another interface between tension blocks and a lens.
[0041] FIG. 24 is an illustration of a bridge construction for eyewear arranged and configured in accordance with some embodiments of the present invention.
[0042] FIG. 25 is a view along the line H-H of the bridge construction shown in FIG. 24 .
[0043] FIG. 26 is an illustration of another bridge construction for eyewear arranged and configured in accordance with some embodiments of the present invention.
[0044] FIG. 27 is an illustration of a further bridge construction for eyewear arranged and configured in accordance with some embodiments of the present invention.
[0045] FIG. 28 is a view along line I-I of the bridge construction shown in FIG. 27 .
[0046] FIG. 29 is a sectioned view of a bridge construction for eyewear arranged and configured in accordance with some embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] The present invention generally relates to eyewear frame assemblies featuring a flexible wire that forms at least a major portion of a lens securing frame. In some arrangements, the flexible wire generally circumscribes the associated lens. To provide a generic frame assembly that is capable of providing customizable lens shapes and sizes, the wire can have a length sufficient to extend around a lens and can be tightened about the lens such that lenses of varied sizes and shapes can be secured within a single frame assembly. In all of the embodiments described herein, each lens can comprise a tinted lens, a corrective lens or any other desired type of lens, including but not limited to a protective lens.
[0048] Preferably, the wire extends around at least about 90% of the circumference of the associated lens. In some embodiments, the wire extends around at least about 95% of the circumference of the associated lens. In other embodiments, the wire extends almost entirely or entirely around the circumference of the associated lens. By extending the wire around substantially the entire circumference of the associated lens within a groove, a rimless look is provided to eyewear while creating a flexible and durable lens mounting system as compared to other rimless or semi-rimless eyewear (e.g., eyewear with the lens secured in an upper or lower metal frame with a nylon cord). In addition, such a construction is easy to assemble by opticians and the like without the use of costly and time consuming outside services often employed to assemble other types of fully rimless eyewear. The wire also can comprise two or more portions that generally encircle the lens. For instance, two wire portions can each extend about halfway around a lens such that the two portions together generally encircle the lens. The wire portions can have one end suitably secured to another eyewear component, such as, for example but without limitation, a bridge, closing member or temple hinge, while the other ends of the two wires can be secured together in any manner disclosed herein. Other numbers of wire portions also can be used but exceeding more than two wire portions can undesirably complicate assembly of the eyewear.
[0049] In some embodiments, rigid components, such as, for example but without limitation, a bridge, a brow bar, or closing members can be positioned along the circumference of the associated lens. Preferably, these rigid components together span less than about 10% of the total circumferential length of the lens. In some embodiments, the rigid components span less than about 5% of the total circumferential length. In some preferred embodiments, the closing members have a vertical dimension that is smaller than at least one of a lateral dimension and a rearward (i.e., toward the ear) dimension. Such embodiments reduce the aesthetic presence of the closing members and improve the rimless appearance of the eyewear.
[0050] Each wire desirably comprises a multiple filament construction. In other words, the wire preferably comprises more than one filament, fiber or strand. In some embodiments, the filaments are made from a metal, a metal alloy, a nylon, a polymer, a resin, a natural fiber or another naturally occurring or man-made material that is suitably strong in tension while maintaining sufficient flexibility to secure a lens in a manner described herein. In some embodiments, the wire may be manufactured of a type of fiber-optic material. While a single filament can be used and is practicable, it is currently believed that the multiple filament construction provides greater flexibility while maintaining sufficient strength for use in the manners described herein and, therefore, multiple filament constructions are preferred. Furthermore, multiple filament constructions increase the friction interface between the lenses and the wire, which friction helps secure the lens orientations relative to the other eyewear components.
[0051] The multiple filaments preferably are intertwined, braided or wrapped together to define the wire. The wire can be encased within a sheath, cover, jacket or casing, if desired. By enclosing the multiple filaments in a casing or the like, the filaments can be better protected against normal wear and tear that might otherwise occur. In one embodiment, the wire is constructed similarly to a braided fishing leader wire.
[0052] To provide a rimless appearance, the diameter of the wire should be sufficiently narrow. In some embodiments, the wire has an average diameter of between about 0.1 mm and about 3.0 mm. Preferably, the wire has an average diameter of between about 0.4 mm and about 1.6 mm, and more preferably has an average diameter of between about 0.4 mm and about 0.6 mm. In one embodiment, the wire has an average diameter of about 0.5 mm.
[0053] With reference to FIG. 1 , eyewear 2 is shown featuring a wire tensioning system 10 that is arranged and configured in accordance with certain features, aspects and advantages of the present invention is shown. The tensioning system 10 can be used with any rimless eyewear, including those disclosed in copending U.S. patent application Ser. No. 10/678964, filed on Oct. 2, 2003, U.S. patent application Ser. No. 10/610862, filed on Jun. 30, 2003, U.S. patent application Ser. No. 10/269811, filed on Oct. 11, 200, and U.S. Provisional Patent Application No. 60/394837, filed on Jul. 10, 2002, which references are hereby incorporated by reference in their entirety. Copending U.S. patent application Ser. No. ______, filed concurrently herewith, entitled Eyeglass Frame Assembly and having Attorney Docket No. IMMAST.013CP3, copending U.S. patent application Ser. No. ______, filed concurrently herewith, entitled Adjustable Tensioning System for Rimless Eyewear and having Attorney Docket No. IMMAST.021A also are hereby incorporated by reference in their entirety. In general, the rimless eyewear 2 features a wire 12 that is positioned within a groove 14 in a lens 18 to secure the lens 18 in position. Closing members 4 , which are described in detail below, can be used to close the wire 12 into a loop form. In some arrangements, the closing members 4 can be used to attach temples 6 or a bridge 8 to the lenses 18 .
[0054] With reference now to FIG. 2 , a first end 20 of the wire 12 can be secured to an upper tensioning block 22 . The first end 20 of the wire 12 can be secured to the upper tensioning block 22 in any suitable manner, including but not limited to, bonding, welding, brazing, soldering, adhering, cohering, and other forms of mechanical connection using interlocking structures or the like.
[0055] A second end 26 of the wire 12 in the illustrated arrangement is connected to an anchor 28 . The anchor 28 is adapted to be received within in a lower tensioning block 30 in a manner that will be described. The second end 26 of the wire 12 also can be connected to the lower tensioning block 30 in other suitable manners. Preferably, however, the second end 26 of the wire 12 is connected in a manner that allows the tension in the wire 12 to be adjusted. It also should be mentioned that the wire 12 can be split into separate pieces such that the first end and the second end are not necessary directly connected along a single piece of wire (e.g., the two wires can extend about the perimeter of the lens and be connected together in any suitable manner).
[0056] With reference now to FIG. 2 , a portion of each of the upper tensioning block 22 and a lower tensioning block 30 that lies generally adjacent the lens 18 preferably comprises a raised lip or tooth 34 that advantageously fits inside the groove 14 in the lens 18 . The tooth 34 reduces the likelihood that the tensioning blocks 22 , 30 will slide off of the peripheral side of the lens 18 . Thus, the tooth advantageously enhances the stability of the mounting of the upper tensioning block 22 and the lower tensioning block 30 to the lens 18 . In some arrangements, only the upper or the lower block 22 , 30 will include the tooth 34 . In other arrangements, such as those shown in FIGS. 22 and 23 , neither block includes any teeth and generally flush connections are provided between the tensioning blocks 22 , 30 and the periphery of the lenses 18 . As also shown in FIGS. 22 and 23 , the periphery of the lenses 18 can be generally square or more rounded (compare FIG. 22 to FIG. 23 ). Preferably, the contour of the abutting surface of at least one, and more preferably both, of the tensioning blocks 22 , 20 is shaped to complement the peripheral surface of the associated lens 18 .
[0057] With reference now to FIG. 4 , the lower block 30 preferably comprises a passage 36 and a receptacle 38 . The passage 36 and the receptacle 38 preferably are connected such that the wire 12 can be inserted into the passage 36 and the anchor 28 can be placed into the receptacle 38 . It should be noted that throughout the disclosure, unless otherwise specified or apparent, diameters of any passages, bores, or other channels or formations that accept the wire preferably are sufficiently greater than the diameter of the associated wire to facilitate movement of the movement therein. In the illustrated arrangement, the passage 36 comprises a generally cylindrical tunnel. In some arrangements, the passage 36 can be a slot that extends through a surface of the lower block 30 . In other arrangements, the receptacle 38 can be positioned on the upper block 22 and the passage can extend through at least a portion of both blocks. In further arrangements, the receptacle 38 can be positioned in the upper block 30 and the passage 36 can be a slot that extends through at least the upper block 22 and, in some arrangements, both the upper block 22 and the lower block 30 . While arrangements with slots may have less strength in the blocks, assembly is more easily accomplished. Further, while arrangements with the receptacle 38 in the upper block 22 may have an advantage in that tensioning the wire 12 draws the blocks 22 , 30 together, placing the receptacle 38 in the lower block 30 conceals the anchor 28 .
[0058] The upper tensioning block 22 and the lower tensioning block 30 can be connected together in any suitable manner. For instance, in the illustrated arrangement, the two blocks 22 , 30 can be securely assembled with one or more threaded fasteners 42 (see FIG. 2 ). It should be noted that throughout the application, any threaded fastener can be replaced by a suitable fastening arrangement, including but not limited to, snap-fit assemblies or components or press-fit components. Other suitable fastening arrangements also can be used. For instance, if the anchor 28 is positioned in a receptacle 38 in the upper block 22 and the wire passes through both blocks 22 , 30 , wraps around the lens 18 and is connected to the upper block 22 , then tightening the wire 12 would tend to draw the two blocks 22 , 30 together.
[0059] With reference to FIG. 3 , the illustrated threaded fastener 42 is received within a countersunk bore 44 , which bore 44 has a countersunk portion 46 and extends through the upper block 22 . A bore 50 in the lower block 30 is generally aligned with the bore 44 in the upper block 22 . The bore 50 in the lower block 30 preferably is threaded while the bore 44 in the upper block 22 is not.
[0060] With reference to FIGS. 5 and 6 , the wire 12 can be adjusted by an adjustment screw 52 to a predetermined tension once the upper tensioning block 22 and the lower tensioning block 30 are securely assembled. In the illustrated arrangement, a threaded hole 54 is positioned in the lower block 30 . The adjustment screw 52 is inserted into the hole 54 . Preferably, the hole 54 intersects the passage 36 in a region in which the passage 36 has a wall opposite to the hole 54 but more than at least one diameter of the wire 12 from the intersection of the hole 54 and the passage 36 such that the adjustment screw can offset the wire.
[0061] When the adjustment screw 52 is threaded into the hole 54 , the wire 12 is offset laterally within the passage 36 . By offsetting the wire 12 , the wire 12 is tightened around the lens 18 . If the adjustment screw 52 is retracted from the hole 54 , the wire 12 moves in a manner that allows the tension on the wire 12 to be reduced.
[0062] With reference to FIGS. 7-9 , another preferred embodiment of a wire tensioning system 10 is shown. In this arrangement, an anchor bar 60 is attached to the second end 26 ′ of the wire 12 ′. The lower tension block 30 ′, in turn, comprises a number of slots 62 . The slots 62 preferably are connected with a connecting slot 63 . The connecting slot 63 accommodates a portion of the wire 12 ′ as desired.
[0063] The slots 62 , 63 preferably have a depth of at least the diameter of the wire 12 ′. In some arrangements, the slots 62 , 63 can have depths that differ from each other. Moreover, in some arrangements, the slots 62 , 63 can be formed such that the lower block 30 ′ has a portion of the depth of the slots 62 , 63 while the upper block 22 ′ also has a portion of the depth of the slots 62 , 63 . Such a configuration, however, is less desirable from a manufacturing and assembly standpoint.
[0064] The anchor bar 60 advantageously can be positioned in one of the many possible slots 62 incorporated into the lower tensioning block 30 ′. Depending upon into which slot 62 the anchor bar 60 is placed, the tension on the wire 12 ′ will increase or decrease. For example, if the anchor bar 60 is positioned in a slot 64 the length of the wire 12 ′ will be a predetermined length corresponding to a wire tension. If, however, the anchor bar 60 is placed in a different slot 68 , the length of the wire 12 ′ will be another length corresponding to another wire tension. By positioning the anchor bar 60 in the different possible slots 62 , the tension of the wire 12 ′ can be adjusted to a proper wire tension.
[0065] While the illustrated arrangement shows a generally T-shaped anchor bar 60 , other shapes also can be used. In addition, the slots 62 , 63 can have different configurations, if desired. The various shapes of the anchor bar 60 and corresponding slots 62 can include, but are not limited to a ball shape, a square shape, or any shape that allows the filament wire 12 to be securely held in the corresponding slots 62 within the lower tensioning block 30 .
[0066] In one arrangement, the slot 63 extends through the end of the combined blocks 22 ′, 30 ′ and the anchor bar 60 is angled rearward such that a point is defined toward the end of the combined blocks. In this arrangement, the anchor bar 60 preferably is slightly nonyieldably bendable such that the end of the wire 12 ′ can be positioned to extend out of the combined blocks 22 ′, 30 ′ and pulled to increase the tension with the anchor bar 60 designed to reduce the likelihood that the wire 12 ′ retracts out of the housing and reduces the tension once locked in position by the anchor bar 60 .
[0067] While not shown, the blocks 22 ′, 30 ′ can be secured together in any suitable manner. For instance, the blocks 22 ′, 30 ′ can be connected with threaded fasteners, mechanical clips, clasps, interlocking structures, welding, soldering, brazing, adhesives, cohesion, or the like.
[0068] With reference now to FIGS. 10-12 , another wire tensioning system 10 ″ is shown therein. Incorporated into the lower tensioning block 30 ″ is an adjustment passage 70 (see FIG. 11 ) with at least one channel 72 that allows an anchor or adjustment block 76 to move up and down within the adjustment area 70 . The adjustment block 76 preferably comprises a predetermined number of guide teeth 78 corresponding to the number of channels 72 in the adjustment area 70 . The guide teeth 78 generally maintain the adjustment block 76 in a desired orientation. Other sizes, shapes and configurations of adjustments blocks 76 and passages 70 also can be used.
[0069] A threaded member 80 extends through at least a portion of the block 30 ″. The illustrated threaded member 80 is positioned inside a through hole 86 in the lower tensioning block 30 ″ and against a shoulder 88 . The threaded member 80 preferably engages with a threaded portion of the adjustment block 76 such that rotating the threaded member 80 drives the adjustment block 76 along the length of the screw. In the illustrated arrangement, the adjustment block 76 is suitably connected to the wire 12 ″ such that movement of the adjustment block 76 increases and decreases the tension of the wire 12 ″.
[0070] With reference now to FIGS. 13 and 14 , another wire tensioning system 10 ′″ is illustrated therein. In the illustrated arrangement, an anchor 92 is attached to the second end 26 ′″ of the filament wire 12 ′″. In the illustrated arrangement, the anchor 92 is generally spherical; however, other sizes, shapes and configurations of an anchor 92 also can be used, including but not limited to expanded wire diameters, knots, and separate components that are attached to the wire in any suitable manner.
[0071] With reference to FIG. 14 , an externally threaded socket ring 94 allows the wire 12 ′″ to pass through a through hole 96 that forms an integrated socket 100 where the ball anchor 92 can rest and rotate within the socket 100 . It is advantageous that the socket 100 can rotate relative to the anchor 92 . Other suitable socket configurations also can be used.
[0072] An adjustment screw 102 preferably has an outer threaded surface 104 as well as an inner threaded bore 108 . The threaded socket ring 94 advantageously is received within the threaded bore 108 such that the anchor 92 can be captured within the adjustment screw 102 . The adjustment screw assembly 103 , which comprises the anchor 92 , the second end 26 of the wire 12 , and the socket ring 94 , then can be threaded into either of the tensioning blocks. Preferably, however, the adjustment screw assembly 103 is positioned within the lower tensioning block 30 ′″.
[0073] When assembled, the wire tensioning system 10 ′″ illustrated in FIGS. 13 and 14 allows the wire tension to be adjusted as the adjusting screw 102 is rotated. For example, if the adjusting screw 102 is rotated in one direction, the captured anchor 92 pulls on the wire 12 ′″ to increase the tension of the wire 12 ′″. If the adjustment screw 102 is rotated in the opposite direction, the tension of the wire 12 is decreased.
[0074] With reference now to FIGS. 15-17 , a further wire tensioning system 10 ″″ is shown. In this arrangement, the second end 26 ″″ of the filament wire 12 ″″ is advantageously attached to a mounting plate 112 . The mounting plate 112 and numerous similarly shaped shims 116 each comprise a hole 118 through which a fastening screw 120 can pass. The upper tensioning block 22 ″″ has a threaded hole 124 that receives the fastening screw 120 and allows the fastening screw 124 to secure the mounting plate 112 as well as at least any desired shims 116 .
[0075] Adding shims 116 between the mounting plate 112 and the upper tensioning block 22 ″″ reduces the tension around the lens 18 ″″ ( FIG. 16 ). For example, if one shim 116 is placed between the mounting plate 112 and the upper tensioning block 22 ″″, then the tension in the wire 12 ″″ will be higher than if two or more shims 116 are placed between the mounting plate 112 and the upper tensioning block 22 ″″. Shims 116 that are not used to determine the tension in the wire 12 ″″ can be placed between the mounting plate 112 and the screw 120 , if desired. Therefore, all the shims 116 can be assembled together between the screw 120 and the upper tensioning block 22 ″″, however only the shims that are placed between the mounting plate 112 and the upper tensioning block 22 ″″ will determine the tension in the wire 12 ″″.
[0076] With reference to FIGS. 18-21 , a further wire tensioning system 10 ′″″ will be described. The upper tensioning block 22 ′″″ has a tensioning recess 126 . The lower tensioning block 30 ′″″ has a tensioning recess 128 that is similar in shape to and is positioned relatively opposite the upper tensioning block recess 126 . In some arrangements, the entire recess can be formed in a single tensioning block. The recesses have a portion that is substantially width as one diameter of the wire and another larger portion that allows a length of the cable to be offset within the recess. Offsetting the cable, as will be described below, allows the tension to be adjusted within the system 10 ′″″.
[0077] The two tension blocks 22 ′″″, 30 ′″″ can be connected in any suitable manner. For instance, in the illustrated arrangement, an upper threaded portion 132 of a threaded hole 134 is positioned in the upper tensioning block 22 ′″″ and a lower threaded portion 136 of the threaded hole 134 is positioned in the lower tensioning block 30 ′″″. It is envisioned that one block may have a threaded hole in its entirety.
[0078] In the illustrated arrangement, the lower tensioning block 30 ′″″ includes a through hole 138 that allows a screw 140 to pass through and enter a threaded hole 141 located in the upper tensioning block 22 ′″″. When the upper tensioning block and the lower tensioning block are assembled and held together by the screw 140 (see FIG. 20 ), the upper threaded portion 132 and the lower threaded portion 136 form the threaded hole 134 described above. The threaded hole 134 receives an adjustment screw 142 and allows the adjustment screw 142 to change the tension in the filament wire 12 ′″″.
[0079] The first end 20 ′″″ of the wire 12 ′″″ is advantageously attached to the upper tensioning block 22 ′″″ at point 144 . The second end 26 of the wire 12 ′″″ is advantageously attached to the lower tensioning block 30 ′″″ at a point 148 . The first end 20 ′″″ and second end 26 ′″″ of the wire 12 ′″″ can be secured to the upper tensioning block 22 ′″″ and to the lower tensioning block 30 ′″″, respectively, in any suitable manner, including but not limited to, bonding, welding, or secured by any suitable fastener.
[0080] In the illustrated arrangement, a tension plate 150 is placed between the adjustment screw 142 and the wires 12 ′″″ (see FIGS. 19-21 ) within the tensioning recesses 126 and 128 . Because the wire ends 20 ′″″, 26 ′″″ are attached to the upper and lower tensioning blocks 22 ′″″, 30 ′″″ respectively, when the adjusting screw 142 is rotated against the tension plate 150 , the tension plate 150 changes the tension of the wires 12 ′″″. This change in tension allows the wire to tighten or loosen around the lens. When the adjustment screw 142 is rotated in one direction the tensioning plate 150 can increase the tension of the attached wires. If, however, the adjustment screw 142 is rotated in the opposite direction, the tensioning plate 150 can decrease the tension of the attached wires 12 ′″″.
[0081] With reference now to FIGS. 24-29 , any of the eyewear described above can receive any of a number of bridge constructions. The bridge constructions facilitate the joining of both lenses 18 . FIGS. 24-29 illustrate four variations of bridge constructions. Other bridge designs also can be used if desired.
[0082] With reference now to FIGS. 24 and 25 , a bridge 200 is illustrated therein. The bridge 200 can comprise a central portion 202 and a pair of legs 204 . The legs extend generally downward from the central portion 202 and, together with the central portion 202 , define a generally inverted U-shaped bridge 200 . While other dimension can be practicable, for a robust design, the legs 204 preferably have a thickness (see FIG. 24 ) that is at least one wire diameter while the legs 204 preferably have a width (see FIG. 25 ) that is at least two wire diameters. Moreover, the bridge 200 can have any suitable cross-sectional shape, including portions having differing cross-sections. For instance, the central portion 202 can be cylindrical, tubular, rectangular, square, oval or the like. In addition, the legs 204 can be generally flat but other cross-sectional shapes also can be used.
[0083] At least one hole 206 preferably is formed in each of the pair of legs 204 . In the illustrated arrangement, two holes 206 are positioned in each of the legs 204 . In some embodiments three or more holes can be used. Having two holes 206 is believed to improve the ability of the bridge to remain in position once the associated eyewear is fully assembled and in use. Moreover, in frame assembles that featuring fully adjustable lengths (e.g., lenses of substantially different perimeter dimensions can be accommodated), the position of the bridge 200 along the wire can be fully adjusted into a desired position. Similarly, in frame assemblies featuring the ability to accommodate differing shapes but not necessarily different perimeter dimensions, the bridge 200 can be repositioned relative to the lens shape until a desired positioning is achieved.
[0084] The holes 206 preferably are greater than one diameter of the wire and less than two diameters of the wire. In some constructions, the holes 206 can be greater than two diameters of the wire, but such sizing may result in an increased width of the legs 204 , which may be less desirable in some eyewear configurations.
[0085] The holes 206 preferably are formed with a recessed or inset region 210 of the legs 204 extending between the holes 206 . The inset region 210 preferably is sized and configured to be accepted within the groove of the associated lens. Such a construction allows at least a portion of the width legs 204 , not necessarily including the inset region 210 , to abut a surface of the perimeter of the associated lens. Moreover, in the illustrated arrangement, the wire advantageously does not protrude beyond the legs 204 . Such a construction aids in the appearance of a rimless look. In some embodiments, however, the wire can extend slightly beyond the surface of leg 204 such that the wire slightly protrudes from the leg 204 . In such constructions, the recess 210 can have a decreased dimension or the legs 204 can have a smaller overall dimension.
[0086] In use, the wire can be threaded through the holes 206 prior to assembly of the associated wire and lens components. The bridge 200 can be positioned along the lenses as desired and can be secured in position when the wire is closed in a loop. The wire tension can be adjusted in any manner set forth above and with any suitable construction, including those discussed above.
[0087] With reference now to FIG. 26 , a bridge 230 is illustrated therein. The bridge 230 comprises a central portion 232 with a short extension 234 positioned at each end of the central portion. In some arrangements, the extensions 234 can be omitted. Moreover, any suitable cross-sectional shapes can be used for the central portion 232 and the extensions 234 . In the illustrated arrangement, a pair of wires (or wire portions) are fixed to the extensions 234 . The wires (or wire portions) can be fixed in any suitable manner, including but not limited to soldering, welding, adhering, or mechanically interlocking structures. Furthermore, the ends of the wires (or wire portions) can be directly fixed to the central portion 232 , if desired. This construction allows the placement of the bridge to be securely fixed relative to the lens when the eyewear is fully assembled. Moreover, this construction facilitates correct alignment of the lens axis because the bridge position is not likely to shift along the length of the wire during or after assembly.
[0088] With reference now to FIGS. 27 and 28 , a further bridge 240 is illustrated therein. In this arrangement, the bridge 240 generally comprises a central portion 242 and a short extension 244 positioned at each end of the central portion. In some arrangements, legs similar to those shown in FIGS. 24 and 25 can be used in place of the extensions 244 . Similar to each of the constructions described above, the bridge and its component(s) can have any suitable cross-sectional configuration. Moreover, the cross-sectional configuration can be varied along any portion of the bridge.
[0089] A passage 246 preferably extends through at least a portion of each extension 244 . In the illustrated arrangement, the passage 246 extends through the full length of the extension 244 but other constructions can feature passages that extend through a limited portion of the extension. Moreover, in some variations, the passage 246 can extend through an end of the central portion and the extensions 244 can be omitted. The passage can have any suitable cross-sectional configuration. In some arrangements, the passage 246 is cylindrical or has an elliptical or oval cross-section. Preferably, at least one lateral dimension of the passage 246 is greater than one diameter of the associated wire. Similarly, the extension 244 preferably is larger than at least two diameters of the associated wire such that a robust construction results. The dimensions of the components can be varied as desired.
[0090] With respect to the arrangement of FIGS. 27 and 28 , the bridge 240 can be used with eyewear having a fixed wire length or a fully adjustable wire length. The bridge 240 can be moved along the length of the wire to achieve a desired bridge placement. Moreover, the bridge can be easily removed from the wire and be replaced on a different wire, which allows the wire to be replaced as needed or desired. The bridge 240 also advantageously allows the connection to the wire to be substantially hidden when the eyewear is fully assembled, which can be desired in some eyewear constructions. The obscured attachment location further enhances the rimless appearance of the eyewear with which the bridge 240 is used.
[0091] With reference to FIG. 29 a further bridge 260 is illustrated therein. In this arrangement, as with those described above, the bridge 260 generally comprises a central portion 262 and a short extension 264 positioned at each end of the central portion 262 . In some arrangements, legs similar to those shown in FIGS. 24 and 25 can be used in place of the extensions 264 . Similar to each of the constructions described above, the bridge and its component(s) can have any suitable cross-sectional configuration. Moreover, the cross-sectional configuration can be varied along any portion of the bridge.
[0092] A passage 266 preferably extends through at least a portion of each extension 264 . In the illustrated arrangement, the passage 246 extends through the full length of the extension 264 but other constructions can feature passages that extend through a limited portion of the extension. Moreover, in some variations, the passage 266 can extend through an end of the central portion and the extensions 264 can be omitted. The passage 266 can have any suitable cross-sectional configuration. In some arrangements, the passage 266 is cylindrical or has an elliptical or oval cross-section. Preferably, at least one lateral dimension of the passage 266 is greater than one diameter of the associated wire. Similarly, the extension 264 preferably is larger than at least two diameters of the associated wire such that a robust construction results. The dimensions of the components can be varied as desired.
[0093] While the bridge 260 of FIG. 29 is similar to the bridge 240 of FIG. 28 , the bridge 260 of FIG. 29 further includes a wire locking mechanism 270 . The locking mechanism 270 comprises a projection 272 that extends through an opening 274 . The projection 272 has a length sufficient to contact a portion of the wire that passes through the passage 266 . In some arrangements, the projection is formed on a leaf 276 . In further arrangements, another projection 278 can be positioned on an opposite side of the leaf 276 . This opposing projection 278 preferably is sized and configured to fit within the groove formed in the peripheral surface of the lens. If the portion of the leaf 276 carrying the projections 272 , 278 is slightly offset, as in the illustrated arrangement, the opposing projection can be smaller than the diameter of the wire or the depth of the groove in the lens.
[0094] The leaf 276 can be secured to the extension 264 with the projection 272 positioned in the opening 274 and the opposing projection 278 extending toward the ultimate position of the lens. Thus, as the lens is positioned and tightened in its location adjacent to the extension 264 , the lens contacts the opposing projection 278 , which urges the projection 272 through the opening 274 and into engagement with the wire.
[0095] Preferably a recess 280 is formed in the passage 266 to allow the wire to be offset into the recess 280 . In some arrangements, the recess 280 is formed when the opening 274 is formed through the extension 264 . The wire preferably is sufficiently flexible to allow the wire to be offset into the recess when the eyewear is being assembled and the tension is being adjusted on the wire.
[0096] In assembling eyewear comprising any of the above-described tensioning systems, the lens is first prepared and a groove is formed in an outer peripheral edge of the lens. The cable is secured to the tensioning block or blocks, as set forth above. The cable then is closed about the lens with the cable being positioned within the groove. The cable can be slightly tightened about the lens to allow the cable to securely mount at least one a pair of temples or a bridge. In some situations, the cable can be slightly loosened to allow the tension blocks or the cable to be securely closed about the lens. Tightening and loosening the cable is cable in the manners set forth above.
[0097] Although the present invention has been disclosed in the context of certain preferred embodiments, examples and variations, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, while a number of variations of the invention have been shown and described in detail, other modifications, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. For instance, the exterior shape and dimensions of the closing members, housings or projections can be any suitable shape or configuration, including the use of curved or straight surfaces in the place of straight or curved surfaces so long as the wire and/or any tensioning components can be properly attached thereto, positioned there within or associated therewith. Moreover, any of the closing members, housings or projections described herein can have legs or projections that extend along a portion of the lens surface, for aesthetic reasons and/or to add additional desired support to the assembly by increasing the contact area between the component and the respective lens.
[0098] It is also contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the invention. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed invention. Moreover, some variations that have been described with respect to one embodiment and not another embodiment can be used with such other embodiments. Moreover, while most of the embodiments above are shown with symmetrical constructions, it is practicable to use constructions that vary from the left lens to the right lens and such constructions would not necessarily avoid the scope of protection afforded to the disclosed embodiments. Many other variations also have been described herein and cross-application is intended where physically possible. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow. | Rimless eyewear features a wire that encircles a lens. Systems are provided for selectively increasing or decreasing a tensile load on the wire to facilitate assembly and maintenance of the eyewear. An adjusting screw, different wire securement positions, and/or adjustment shims provide easy tension adjustment of the wire and secure the eye lens in a predetermined position and orientation. | 6 |
This invention relates to a method for treating the surfaces of particulate olefin polymer particles so as to stabilize the polymers against detrimental effects of environmental conditions (particularly oxidative degradation). An aspect of this invention relates to the surface treatment of olefin polymers in nonextruded particle form wherein the particles have a regular, essentially symmetrical, usually substantially spheroidal geometrical shape. Still another aspect of this invention relates to the resulting treated polymer particles. A further aspect of this invention relates to treated polymer particles useful in injection molding and extrusion processes where melt stability is not necessary.
DESCRIPTION OF THE PRIOR ART
In recent years, it has been discovered that certain olefin polymerization processes utilizing a Ziegler-Natta catalyst inherently produce particulate olefin polymers in which the polymer particles have a strong tendency to be regular in geometrical shape and fairly narrowly distributed in particle size range (e.g. where the majority of the particles are 0.5 to 4.5 mm in their longest dimension). The size and shape (and relatively good consistency of size and shape) of these particles is advantageous, as is their high flowability, high bulk density, and absence of fines, hence masses of these particles lend themselves to a wide variety of uses, including the formation of polymeric articles that come into contact with substances (such as food, drugs, etc.) that are subject to human or animal consumption or ingestion. These polymeric articles must meet high standards of safety and purity, e.g. low or negligible toxicity.
Although the inherently well-controlled size and shape of these polymeric particulate masses may be ideal for certain uses, the particles themselves are not necessarily suited for storage, handling, processing and end-use unless they are modified in terms of stability, a major stability problem being the tendency of the particles to be oxidatively degraded. The particles can be blended with antioxidants, light stabilizers, slip agents, antistatic agents, etc. in a mixer and then re-pelletized, but this approach to stabilization fails to capitalize on the inherent advantages of the particulate olefin polymers discharged from the polymerization reactor. Another approach involves treating the particles in a solvent or suspending medium, but this approach involves inconvenient or complicated solvent-removal steps, and the resulting coating may not survive prolonged periods of storage or handling.
A highly effective, relatively simple, and convenient process for surface treatment (stabilization) of these polymer particles is disclosed in European laid-open application 0,411,628 (Caselli et al), laid-open on Feb. 6, 1991. The process of EP '628 takes advantage of the fact that certain antioxidants, melt-stabilizers, and other treatment or additive agents are liquid (e.g. molten) in the temperature range at which the freshly-polymerized polymer particles emerge from the polymerization reactor. Accordingly, the additive composition is in a liquid state when it is applied to the polymer particles, and it tends to form an adherent coating on the surfaces of the polymer particles. Moreover, the additive composition can be formulated so that it will utilize only those ingredients which are generally recognized as safe (under pure food and drug laws), whereby the treated or coated polymer particles can be used to make a wide variety of shaped polymeric articles, including polymeric articles which come into contact with food, drugs, etc.
The additive compositions of EP '628 are sufficiently tacky at the temperature of application so as to form a highly adherent coatings on the surfaces of the polymer particles. This adherent effect is provided by the melt-stabilizer component of the additive composition, i.e. the organic phosphites and/or phosphonites disclosed in EP '628. So long as this melt-stabilizer component is present, sufficient adherent properties are not a problem for the additive composition.
Not all polymers need to be melt-stabilized, however. Indeed, with respect to particulate olefin polymers utilized in certain shaping processes, such as some injection molding processes, melt stability is a disadvantage, not an advantage.
Accordingly, a problem yet to be satisfactorily addressed in this particular art is the formulation of an essentially phosphite- and phosphonite-free additive composition for additive treatment of the olefin polymer particles, which additive composition will have adequate adherent properties, at least in the temperature range at which it is applied to the polymer particles and preferably also at room temperature.
The formulation of additive or coating compositions containing antioxidants is a vast art in itself, extending far beyond the treatment of polymer particles. The following references are considered to be illustrative of this vast art: U.S. Pat. Nos.4,289,670 (Creekmore et al.), issued Sep. 15, 1981, 4,708,979 (Pedrazzetti et al.) issued Nov. 24, 1987, 4,837,259 (Chucta), issued Jun. 6, 1989, 4,879,141 (Chatterjee), issued Nov. 7, 1989, and Canadian patent 1,267,244 (Sandrmohaghegh), issued Mar. 27, 1990.
SUMMARY OF THE INVENTION
It has now been found that certain combinations of antioxidants with a viscosity-reducing agent in certain specific ratios provide an essentially phosphite- and phosphonite-free additive composition (to which antistatic agents, slip agents, etc. can be added) with strongly adherent properties at the temperature of application to the polymer particles and also at room temperature. Depositing this additive composition on the surfaces of the olefin polymer particles results in an adherent coating which is not significantly damaged and remains substantially intact despite prolonged storage and handling.
Although the essentially phosphite- and phosphonite-free additive compositions utilized in this invention are mixtures that can contain as many as 10 or more ingredients, control over the key physical properties of the additive compositions is achieved by selecting particular ratios for only three of the ingredients. (The most important physical property to be controlled here is the tendency of the additive composition to be sticky--preferably even to the point of being almost aggressively tacky--at the temperature of application to the polymer particles, e.g. at temperatures above 45° C., but typically below about 130° C., and preferably also at room temperature.) Two of these ingredients are antioxidants, and the third is a viscosity-reducing agent or relatively low viscosity carrier material (e.g. an aliphatic oil or wax or a polymerized dimer and/or trimer acid e.g., PRIPOL 1013 or 1014).
More specifically, the three ingredients which control adherent properties are:
a. a polyhydric alcohol ester (preferably a tetrol ester) of 3-(3',5'-di-t-butyl-4'-hydroxyphenyl) propionic acid which has a melting point or melting range below about 130° C.,
b. a mono-ester of 3-(3',5'-di-t-butyl-4'-hydroxyphenyl) propionic acid which also has a melting point or melting range below about 130° C., and
c. the viscosity-reducing agent or relatively low-viscosity carrier material, i.e. an oily liquid or low-melting wax having a viscosity, measured in Saybolt Universal Seconds or "SUS" units (ASTM D88), ranging from about 180 SUS at 100° F. (about 35 or 40 Centistokes [cSt] at about 38° C.) to about 55,000 SUS at 100° F. (roughly 12,000 cSt at 38° C.). The preferred viscosity reducing agent is an aliphatic oil or wax, e.g. an oil (which is liquid at room temperature) or an aliphatic hydrocarbon wax having a melting point low enough to be molten at temperatures well below 130° C., e.g. at about 30° to 80° C.
The preferred viscosity range for the viscosity-reducing agent is 250 to 405 SUS at 100° F. (about 50 or 55 cSt to about 85 or 90 cSt at 38° C.), more preferably at least about 280 SUS at 100° F. (≧60 cSt at 38° C.).
It is convenient to express the ratios of these three ingredients in terms of parts per hundred by weight (pph), based on the weight of component "a". Expressed in this manner, the amounts of components "b" and "c" are about 20 to 35 pph (preferably 20-30 pph) and about 20 to 75 pph (preferably 25 to 65 pph), respectively.
The fully-formulated additive composition can be applied to the surfaces of the polymer particles generally in accordance with the method described in EP '628, but the resulting olefin polymer particles are coated with an additive composition which is essentially free of phosphites and phosphonites. These polymer particles are useful in a wide variety of shaping processes and the like and are particularly useful in injection molding processes.
DETAILED DESCRIPTION
As explained above, a key aspect of this invention was the discovery of a three-component composition which, by itself or in combination with antistatic agents, slip agents, and other useful additives (other than phosphites and phosphonites) would be inherently sticky at least at the temperature of application, e.g. temperatures of about 130° C. and below, particularly at temperatures in the range of about 50° to 130° C. This three-component composition, by itself or in combination with other additives, other than phosphites and phosphonites, can be deposited on the polymer particles as an almost continuous coating or at least a surface impregnation (depending on the ingredients in the composition and the porosity of the polymer particles being treated). The thus-treated polymers have good resistance to degradation (due to, for example, exposure to air) which degradation can take place during prolonged periods of storage, handling processing and end-use. These treated polymers can also exhibit good resistance to color and physical property changes caused by environmental exposure.
The amount of additive composition deposited on the polymer particles is not large--generally 0.02 to 2% by weight and preferably at least about 0.1% by weight, based on the weight of the olefin polymer.
The three-component composition which appears to provide the necessary control over adherent properties is described in detail below, subsequent to the following definitions of terms used in this application.
Definitions
The term "copolymer", as used in this application, refers to polymers derived from more than one monomer and therefore includes terpolymers, etc. The monomers used to form the "copolymer" can be polymerized at the same time (as in random co-polymers), sequentially (as in block co-polymers, heterophasic co-polymers, etc.), and in other non-random sequences or orientations.
The term "flowable", as used in this application, refers to a material which is in a liquid or molten state, either because at least one of the components of the "flowable" material is a liquid at room temperature, or because at least one of the components is in a molten state.
The Three-Component, Adherent Composition
Achieving a sufficiently adherent additive composition was difficult, since key ratios of the three components had to be determined empirically, and equipment is available which makes it possible to add the three ingredients to the polymer simultaneously or seriatim. The antioxidants and viscosity-reducing agents have markedly different effects upon cloud point (ASTM D 2500), viscosity in the liquid state, and solidification characteristics (e.g. pour point - ASTM D 97), and in some ratios the ingredients appear to be influencing these properties in opposite or inconsistent ways. Actually, opposite effects upon physical properties may be desirable, since the goal of this invention is a carefully crafted balance of physical properties.
It appears to be desirable that the three-component composition be coatable at the temperature of application to the polymer particles, but pasty and sticky at room temperature. Apparently, relatively higher amounts of mono-ester of 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionic acid (particularly the higher aliphatic alcohol mono-esters) can have a thickening effect which provides some pastiness, while large amounts of viscosity-reducing agent such as an aliphatic oil or molten aliphatic wax can have a viscosity-reducing effect. On the other hand, there are certain specific ranges of aliphatic hydrocarbon oil content which have the greatest effect upon the pour point, and there appears to be no directly proportional relationship between pour point and oil content.
Both of the antioxidants employed in the three-component composition belong to the class of compounds known as hindered phenols. Commercially available hindered phenols typically contain one or more o,o-di-tert.-butyl phenol substituents and can be linked to a carboxylic acid residue (typically propionic acid) via the para-position of the phenolic ring, thereby providing a 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionic acid structure, which, of course, can be esterified. When the carboxylic group of the propionic residue is esterified with a monohydric alcohol, the result is a mono-ester, but polyhydric alcohols having 2 to 6 OH groups can also be esterified with the propionic acid-bearing hindered phenol group, thereby providing two or more ester groups, preferably one ester group for each hydroxyl group of the polyhydric alcohol (i.e. full esterification).
The fully esterified polyhydric alcohol esters of 3-(3', 5'-di-t-butyl-4'-hydroxyphenyl)propionic acid have significantly different physical properties as compared to the mono-esters. The mono-esters have been used to stabilize polyolefins for many years, due to their excellent compatibility with polymers such as polyethylene. The melting points or melting ranges of these mono-esters tend to be lower than those of the fully esterified polyhydric alcohol esters.
The preferred antioxidants used in this invention are (a) tetrol esters (tetra-esters) of 3-(3',5'-di-butyl-4'-hydroxyphenyl)propionic acid having a melting point or melting range below about 130° C., preferably pentaerythrityl tetrakis 3-(3,5-di-t-butyl-4-hydroxyphenyl)propanoate, also known as tetrakis [methylene (3, 5-di-tert-butyl-4-hydroxyhydrocinnamate) methane or as 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl 3, 5- bis(1, 1-dimethylethyl)-4-hydroxybenzenepropanoate, a white, crystalline powder which has a melting range of 110°-125° C. and is commercially available as IRGANOX 1010 (trademark of Ciba-Geigy Corporation). This hindered phenol-propionic acid/pentaerythritol tetra-ester has been approved for use in certain types of polymeric food packaging materials. (b) The mono-esters of the hindered phenol-substituted propionic acid are preferably esters of higher aliphatic alcohols (e.g. C 12 -C 24 -alkyl alcohols), and these mono-esters have melting points or melting ranges which are also below about 130° C., more typically below 100° C., but above about 45° C. The preferred mono-ester is octadecyl 3-(3',5'-di-t-butyl-4'-hydroxyphenyl) propionate, also known as octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, a white, crystalline powder having a melting range of 50° to 55° C., and is commercially available as IRGANOX 1076 (trademark of Ciba-Geigy Corporation). This antioxidant has also been approved for use in certain types of polymeric food packaging materials.
The ratio of the hindered phenol/propionic acid polyol ester (component "a") to the hindered phenol/propionic acid mono-ester (component "b") is of great importance in this invention. It has been discovered that the b:a ratio cannot be as high as 0.5:1 or even as high as 0.4:1, and 0.35:1 is only marginally operative but within the broadest ambit of this invention. In the b:a=0.4-0.5:1 range, phase separation is typically observed in the three-component composition; that is, viscosity-reducing agents (particularly the aliphatic oils) tend to phase-out to some degree. As a result, the homogeneity of the composition can be poor; the composition, though viscous, is oily rather than pasty, and the much-needed adherent properties are missing.
Homogeneity problems are also observed when the b:a ratio (i.e. the mono-ester:polyol ester ratio) is too low, e.g. 0.12:1. At 0.12:1, oiliness is also observed, due to lack of complete homogeneity. Stickiness is therefore insufficient with this composition also.
As the b:a ratio approaches 0.2:1 (e.g. 0.18:1), homogeneity improves dramatically, both in the long term and in the short term. However, the overall balance of physical properties still does not sufficiently favor stickiness or tackiness at room temperature until the b:a ratio at least equals and preferably exceeds 0.2:. This stickiness at room temperature is still observed even after a period of two months.
When the b:a ratio reaches about 0.34 or 0.35:1, homogeneity is still good, at least initially, and stickiness is initially good at room temperature, but stickiness is seen to be poor after about two months.
All of the foregoing observations are particularly valid when the amount of viscosity-reducing agent (e.g. aliphatic hydrocarbon oil) in the three-component system is fixed at 33% by weight of the total (three-component) formulation.
Having determined that the optimum b:a ratio is about 0.25:1, various levels of viscosity-reducing agent content (e.g. aliphatic hydrocarbon oil or wax), from 0% to 45% of the three-component composition, were investigated while fixing the b:a ratio at 0.25:1. By selecting these levels of the oily aliphatic viscosity-reducing agent, a series of c:a ratios was obtained, ranging from 0:1 to 1:1. At c:a=0:1, homogeneity was not affected and was excellent. At c:a=1:1, homogeneity was poor. Accordingly, selection of the optimum c:a ratio is a matter of striking a good balance between homogeneity (which may be sacrificed to a slight degree) and stickiness at room temperature, which is maximized within the c:a range of 0.25-0.75:1, the optimum c:a ratio being less than 0.65:1 but well above 0.25:1, e.g. at or near 0.5:1.
Accordingly, the preferred c:b:a ratios appear to be in the range of (1-3):(0.8-1.2):4, and the optimum ratios appear to be 2:1:4 and 2.5:1:4, although good results are also obtained with c:b:a=1:1:4.
As noted above the viscosity-reducing agent can be an oily material or a low-melting wax. Preferred oils and waxes are aliphatic, e.g. mineral oils, paraffin waxes or oils, etc. The oils can be liquid at room temperature. The waxes preferably melt at relatively low temperatures (well below 130° C.), e.g. 30° or 40° C. Suitable oils include "OB-55" (available from Raffineria Olii Lubrificanti of Milan, Italy), "Witco A-300" and "Kaydol" oils (available from Witco Corp./U.S.A.), and "Primol 355" oil (available from Exxon). These particularly suitable oils have Saybolt viscosities at 38° C. within the range of 290 to 380 SUS.
Other Ingredients of the Additive Composition
It is a goal of this invention to provide an additive composition which coats and adheres strongly to the polymer particles and remains adhered to these particles for long periods of storage and handling. Slip agents and antistatic agents can be applied at a suitable point in the process, and such agents when present, can enhance additive adhesion on the surfaces of the polymer particles. Typically they are present in significant amounts; e.g., for each such ingredient, amounts of 30 to 1000 pph, based on the weight of component "a" (the hindered phenol/propionic acid polyhydric alcohol ester) when used.
The preferred slip agents are primary, secondary, or tertiary, preferably primary or secondary amides of long-chain (e.g. C 12 -C 24 ) aliphatic carboxylic acids having a low or modest degree of unsaturation (typically 1 to 3, preferably only one, carbon--carbon double bond), e.g oleamide or erucamide or stearyl erucamide.
The preferred antistatic agents are non-water soluble fatty acid esters, such as ATMER glycerol stearates and ATMER polyoxyethylene sorbitan monolaurate or monostearate, fatty acid amines, such as ATMER ethoxylated synthetic amines, fatty acid amides, and ATMER quaternary ammonium compounds (ATMER is a trademark of ICI).
Other useful ingredients (typically added in amounts of 20 to 1000 pph, based on the weight of component "c") include light stabilizers, acid scavengers or neutralizers, such as metal stearates; nucleating agents; etc. and mixtures thereof, but not phosphite or phosphonite compounds which could provide an undesirably high level of melt stability. Moreover, oily liquids and diluents other than paraffin oils are kept to a minimum or avoided altogether, since they may alter the delicate balance provide by the preferred c:b:a ratios. Typical light stabilizers are described in EP 0,411,628, which description is incorporated herein by reference.
The Polymer Particles
Suitable polymer particles which can be used in this invention are described in EP 0,411,628. These polymers are prepared with the aid of catalysts and processes which can produce regular shape polymer particles (e.g. spheroids) having a controlled particle size distribution. Masses of such polymer particles have high flowability and high bulk density values and a low concentration of fines. Since the polymerization process itself inherently produces the olefin polymer in this particularly desirable form, extrusion or the like plays no role in the formation of the particles. (Masses of these polymer particles, after they have been obtained, can of course be subjected to a variety of forming processes, including extrusion.)
Preferred catalysts for formation of the olefin polymer particles are of the Ziegler-Natta type and can contain, for example, titanium compounds and aluminum compounds or magnesium compounds. If stereospecific or stereoregular polymers are desired, highly active stereospecific catalysts are well known and are described extensively in the patent and scientific literature.
A preferred type of olefin polymer particle is generally symmetrical in shape and has a longest dimension of 0.5 to 4.5 mm; spherical or spheroidal particles having diameters in this range are particularly preferred. These particles exhibit a controlled particle size distribution, e.g. with at least 90% (numerically or by weight) of the particles having a diameter between 0.5 and 4.0 mm.
The polymerization which produces these particles can be carried out in liquid phase, e.g. in the presence or absence of an inert hydrocarbon solvent, or in gas phase, or even in combinations of such polymerizations. The polymerization temperature is generally between 40° and 160° C., and the process is carried out at atmospheric pressure or higher.
Thus, the polymer particles--which are already in useful sizes, size distributions, and shapes--are discharged from the polymerization reactor at moderately elevated temperatures. The surfaces of the polymer particles which later come into contact with additive compositions of this invention will be at temperatures generally within the 40°-160° C. range, typically not lower than 50° C., more typically not lower than 60° C.
A typical particle size distribution for substantially spherical olefin polymer particles is set forth below, where the symbol φ is used to represent the diameter of the particles:
______________________________________ .0. > 3.5 mm = 1 to 5% 2 < .0. < 3.5 mm = 45 to 55% 1 < .0. < 2 mm = 40 to 50% 0.5 < .0. < 1 mm about 2%______________________________________
The monomers used to prepare these olefin polymers are essentially mono-olefins, but dienes such as butadiene, ethylidene-norbornene, and 1,4-hexadiene or the like can be co-polymerized with the mono-olefin or mono-olefins; typically, when a diene is used the amount of diene is in the range of from 1 to 10 weight-%. The mono-olefins can be straight or branched and can contain from 2 to 8 carbon atoms, the most commercially interesting monomers being ethylene (ethene), propylene (propene), 1-butene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-butene, and the like. Polymers of ethylene can be high density or low density homopolymers. Polypropylene homopolymers can be isotactic or substantially isotactic. Ethylene/propylene copolymers are contemplated, as are copolymers (including terpolymers, etc.) of polypropylene with higher alpha-olefins such as 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene.
Copolymers can be random or non-random (e.g. heterophasic polymers obtained through sequential polymerization). Heterophasic copolymers are of particular interest in this invention, e.g. those containing 1 to 50% by weight of ethylene units.
After being treated according to this invention, the polymer particles can have pourability values from 9 to 16 seconds, measured according to ASTM norm D1895-69, method A, and bulk densities from 0.3 to 0.6 g/cm 3 , measured according to ASTM norm D1895-69, method A. Polymer particles having the higher pourability values are of particular importance in this invention. Polymer particles with extremely high melt flow values benefit greatly from treatments with phosphite-free and phosphonite-free additive compositions of this invention.
Method of Addition
The additive compositions of this invention are preferably deposited on the surfaces of the polymer particles shortly after discharge of the polymer particles from the polymerization reactor, separation of the polymer, and deactivation of the catalyst and purification stages. Such stages include the removal, e.g. through "flashdrying" of the excess liquid monomer or solvent that may be present in the polymerization reactor discharge (separation), and the deactivation or "killing" of the catalyst. Volatile substances, such as solvents, unreacted monomers and oligomers, if any, can be removed during the deactivation stage by treating the polymer particles with inert gases (e.g. N 2 ) at elevated temperatures (up to a few degrees below the polymer melting point) and/or steam. If steam is used, residual moisture is preferably eliminated from the polymer particles.
Upon exiting the separation and deactivation systems, the polymer particles are still fairly hot (e.g. >50° C., more typically >60° C. but <160° C.), and it is preferred to deposit the flowable additive composition on the particles while they are at these moderately elevated temperatures, using known methods of surface additivation, e.g. by using continuous or discontinuous mixers (particularly horizontal mixers) optionally equipped with a spraying mechanism. Typical residence times of the polymer particles in the mixer are at least 5 minutes in order to obtain a good distribution on the surface of the particles. The ingredients of the additive composition can be introduced into the mixer from heated storage vessels in a sequence, if desired. It is especially desirable to introduce certain optional ingredients downstream from the point at which the three essential components are added, preferred examples of a downstream additives being the light stabilizers, acid scavengers or neutralizers, and particularly the slip agent or agents (e.g long-chain aliphatic carboxylic acid amides).
The principle and practice of this invention is illustrated in the following Examples.
EXAMPLES
In these Examples, the following materials were used.
IRGANOX 1076 octadecyl 3-(3',5'-di-t-butyl-4'-hydroxy-phenyl)propionate antioxidant.
IRGANOX 1010 pentaerythrityl tetrakis 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propanoate antioxidant.
PRIMOL 355 paraffin oil reported to have a viscosity of 356 SUS at 100° C.
ERUCAMID ER erucamide slip agent.
ATMER 122 antistatic agent.
EXAMPLES 1 to 5
The ingredients listed below in Table 1A were heated to 100° to 120° C. under agitation in an N 2 atmosphere until a clear, homogeneous liquid was obtained. This procedure was repeated until a set of five additive formulations (formulations 1 to 5) were obtained. This set of five formulations was prepared to investigate the behavior of different IRGANOX 1076/1010 ratios in paraffin oil. The five formulations and some of their properties are set forth in Table 1, below.
TABLE 1__________________________________________________________________________Formulations With Varying Antioxidant Ratios - (Ingredient Amounts in %By Weight)Ingredient 1 2 3 4 5__________________________________________________________________________Paraffin Oil 33 33 33 33 33(PRIMOL 355)IRGANOX 1076 7 10 13.5 17 22.5IRGANOX 1010 60 57 53.5 50 44.5IRGANOX RATIO 0.12 0.18 0.25 0.34 0.5(1076/1010)CLOUD POINT 73° C. 64° C. 46° C. 37° C. 10° C.(ASTM D 2500)APPEARANCE ATROOMTEMPERATURE(a) after 1 solid, white waxy, thick pasty, thick, pasty, waxy, viscous,week white thick, white oily(b) after 2 granular, hard, solid, thick, slightly granular, evidentmonths oily, yellow- brittle, slight granular, slightly brittle, waxy, phase ish oil spewing white yellowish, oily, solid sep'n., oil pasty and solidHOMOGENEITY(a) after 1 fair excellent excellent good poorweek, rm. temp.(b) after 2 poor good fair fair poormonths, rm. t.STICKINESS(a) after 1 fair fair excellent fair poorweek, rm. tmp.(b) after 2 poor poor fair poor poormonths, rm. t.__________________________________________________________________________ Formulations 1 and 2 tended to form crystals faster than the other formulations and became hard, brittle, and granular after two months. Formulations 4 and 5 remained liquid and viscous, but were nonhomogeneous Crystals appear in the mixture after 1 to 2 weeks, showing a phase separation.
Thus, formulation 3 exhibited the optimum balance of properties. The melt viscosity at 100° C. is suitable for pumping, mixture homogeniety is optimum, and the formulation remains pasty and sticky for a relatively long time at room temperature.
Formulation 3 showed approximately the same homogeneity and stickiness as the phosphonite-containing stabilizing liquid mixture of Example 2 of EP 0,411,628.
The solidification characteristics at the freezing points of the formulations are summarized below.
______________________________________Formulation Characteristics______________________________________1 No crystals or filaments observed.2 Filaments observed.3 Filaments observed.4 Small crystals observed.5 No crystals or filaments observed.______________________________________
EXAMPLES 6 to 10
The additive formulations of these Examples were prepared in the same manner as Examples 1 to 5, but the oil concentration was varied instead of the antioxidant (IRGANOX 1076/1010) ratio. (In all five of these Examples, the IRGANOX 1076/1010 ratio was set at or near 0.25:1, as in Example 3). The five formulations and some of their properties are set forth in Table 2A.
TABLE 2A__________________________________________________________________________Formulations With Optimum Antioxidant Ratio ButVarying Oil Concentrations FORMULATIONS (Ingredient Amounts in % By Weight)INGREDIENT 6 7 8 9 10__________________________________________________________________________Paraffin 0 16 29 38 45Oil (PRIMOL335)IRGANOX 20 16 14 13 101076IRGANOX 80 68 57 49 451010CLOUD POINT none none 46° C. 52° C. 60° C.(ASTM D observed observed2500) at at <-10° C. <-10° C. 46° C. 52° C. 60° C.APPEARANCE hard, pasty, pasty, pasty, granularat room solid, viscous, thick, slightly oilytemp. after trans- thick, white* granular,1 wk. lucent trans- oily yellow, lucent, brittle yellowHOMOGENEITY excellent excellent excel- poor poorat room lent**temperatureafter 1weekSTICKINESS poor excellent excel- fair poorat room lent**temp. after1 week__________________________________________________________________________ *Pasty, thick, and slightly granular after 2 months. **Still good after 2 months.
Formulation 8 was found to be softer than formulations 6 and 7, and more liquid-viscous than formulations 9 and 10. Formulation 8 was found to have a viscosity slightly below 100 cSt at 100° C., which means that the formulation is suitable for pumping and melt-spraying.
In a laboratory mixer, 2 kg of PRO-FAX 6501S polypropylene in spherical form having a nomimal melt flow rate of 4 dg/min (ASTM D1238-79) were heated to 65°-70° C., and enough additive formulation of Example 8 (in a flowable, i.e. molten and/or liquid state) was fed onto the hot polymer particles to provide 1000 parts per million (ppm) by weight of loading on the polymer, based on the weight of the polymer.
The spheroids treated with the formulation of Example 8 were discharged from the mixer and screened. The +18 U.S. mesh fraction (1.0-2.0 mm diameters) was retained for testing.
TABLE 2B______________________________________LOADING OF EXAMPLE 8FORMULATION ON POLYMEREX. 8 INGREDIENT ppm______________________________________Paraffin Oil 500(PRIMOL 335)IRGANOX 1076 250IRGANOX 1010 1000______________________________________
The spherical polymer particles surface-treated with formulation 8 were oven-aged for 5 hours, and a visual evaluation was done every hour. Samples of the surface-treated particles were also compression-molded, and the plaques were oven-aged for 7 days at 150° C. Every day, a visual evaluation was performed. The results were compared with oven-aging tests done the same way on spherical polymer particles surface treated with the phosphonite-containing formulation of Example 2 of EP 0 411 628 and on plaques molded from these surface-treated spherical particles. The spheroids treated with formulation 8 and the plaques obtained from them were found to exhibit discoloration effects and thermal stability, respectively, similar to the discoloration effects of the EP '628-treated spherical polymer particles and similar to the thermal stability of the plaques made from EP '628-treated spheroids.
EXAMPLES 11-13
The Example 8 formulation was modified by adding ERUCAMID ER slip agent and ATMER 122 antistatic agent or just Atmer 122 antistatic agent. In Examples 11 and 12, 3000 lbs. of PRO-FAX SV951 heterophasic propylene polymer in spherical particle form having an ethylene content of 3.5 wt.-% and, in Example 13, 12,000 lbs. of PTO-FAX 6101S polypropylene in spherical particle form having a nominal melt flow rate of 35 dg/min were treated with the loadings set forth in Table 3 according to the procedure of Example 8.
TABLE 3______________________________________LOADINGS OF EXAMPLE 11-13 FORMULATIONSON POLYMER IN PARTS PER MILLION EXAMPLE EXAMPLE EXAMPLEINGREDIENTS 11 12 13______________________________________Paraffin oil 500 500 500(PRIMOL 355)IRGANOX 1076 250 250 250IRGANOX 1010 1000 1000 1000ERUCAMID ER 2500 7000ATMER 122 7000 5000 6000______________________________________
Surface-treated spherical particles (or other geometrically regular particles) of this invention are particularly well suited to injection molding and extruding processes where melt stabilization of the polymer is not necessary. Such injection molding and extrusion processes are conventional and are well known to those skilled in the art of making shaped polymeric articles. In the extrusion processes, a mass of polymeric particles in typically heated or softened or plasticized in some manner in the extruder and forced through an extrusion die to form an extrudate. In the injection molding processes, the mass of polymeric particles is typically melted and then injected into the mold, where the molten mass solidifies to form a shaped article. | Disclosed is a process for treating olefin polymer particles with phosphite- and phosphonite-free compositions consisting essentially of:
A. a polyhydric alcohol ester of a hindered phenol derivative of propionic acid having a melting point or melting range below about 130° C.,
B. about 20 to 35 parts based on 100 parts by weight of component A of a mono-ester of a hindered phenol derivative of propionic acid having a melting point or melting range below about 130° C.,
C. about 20-75 pph of a viscosity-reducing agent having a viscosity of about 180 to 55,000 Saybolt Universal Seconds at 100° F. (38° C.),
D. up to 1000 pph each of an antistatic agent, a slip agent or mixture thereof and
E. up to 1000 pph each of a light stabilizer, a thioether, an organic polysulfide, an acid scavenger or neutralizer, a nucleating agent, or a mixture thereof. The resulting surface-treated polymer particles and end uses therefor are also disclosed. | 2 |
BACKGROUND TO THE INVENTION
This invention relates to apparatus for monitoring the working stroke of a hydraulic ram, and in particular to monitoring apparatus for a hydraulic ram used for adjusting the cutting horizon of a mineral winning machine such as a coal plough.
In order to adjust the cutting horizon of a mineral winning machine such as a coal plough, control means of various types are known. With these known types of contorl means, the position of the plough guide, that is to say the longwall conveyor carrying the plough guide, can be tilted by means of hydraulic control rams in such a manner that the plough dips towards, or rises away from, the floor of the longwall working. In a known installation of this type, the control rams are arranged between a goaf-side conveyor attachment and the head pieces which attach the conveyor to the advance mechanisms of hydraulic roof support units positioned on the goaf side of the conveyor. In use, the control rams tilt the plough guide in the plane at right-angles to the floor of the working, there being a direct relationship between the working strokes of the rams and the angle of tilt. Where the conveyor is a scraper-chain conveyor, control rams are usually associated only with alternate channel sections (pans) of the conveyor. During the tilting movement, the plough guide pivots with the conveyor about the pivot joints of the head pieces. (Control means of this type is described in the specification of U.S. Pat. No. 4,045,089).
Difficulties are encountered with these known arrangements in controlling the extension of the individual control rams. This is particularly the case when the rams are arranged in groups of, for example, three rams, each groups being associated with a respective control valve arranged on the goaf side of the conveyor. From the position at which the control valves are operated, it is not possible to monitor, in a reliable manner, the working stroke of the individually connected control systems. In practice, this can lead to inaccurate tilting of the conveyor, and hence poor control of the cutting horizon of the plough. In particular, the entire installation may be tilted in the same direction, when differential tilting is required for different portions thereof.
In order to obviate these difficulties, it has been proposed (see British Patent Specification No. 2 113 305) to provide a common indicator for each group of hydraulic rams. Each ram has a cylinder and a piston movable relative thereto. The monitoring apparatus comprises an indicator which is connected to each of the rams by a respective transmission element. The apparatus is such that the indicator provides an indication of the position of each of the pistons relative to its cylinder. The transmission elements are constituted by Bowden cables which are positioned within, and protected by, the hydraulic hoses which are used to supply the rams with pressurised hydraulic fluid.
A particular disadvantage that has been observed with this monitoring apparatus, apart from the relatively short service life of the Bowden cables, is the poor elasticity of the hydraulic hoses. These hoses become reduced in length when subjected to pressure, and this leads to nonuniform monitoring at the indicator.
In order to eliminate the difficulties inherent in the use of Bowden cables, it has been proposed (see the specification of U.S. patent application Ser. No. 610,641--which is assigned to the assignee of the present application) to connect the indicator of a monitoring apparatus to the associated hydraulic ram(s) by a respective hydraulic line. Each hydraulic ram includes a metering cylinder having a metering chamber connected to the associated hydraulic line. The indicator comprises a cylinder housing a piston which is displaced against the pressure of a return spring in dependence upon the outward movement of the metering cylinder. The metering chamber(s) of the metering cylinder(s) and the cylinder chamber of the indicator form a closed system, i.e. sealed from atmospheric pressure, so that the movement of the indicator piston over a scale gives a visible indication of the extent to which the associated hydraulic ram(s) is (or are) extended.
The aim of the invention is to provide an improved form of monitoring apparatus of this type.
SUMMARY OF THE INVENTION
The present invention provides apparatus for monitoring the working stroke of a hydraulic ram, the monitoring apparatus including an indicator having a housing containing a tubular measuring chamber connectible to the hydraulic ram by a hydraulic line, wherein the tubular measuring chamber is transparent on at least one side for the observation of the level of hydraulic fluid contained therein, the lower end of the tubular measuring chamber being connected to the hydraulic line leading to the hydraulic ram, the upper end of the tubular measuring chamber being closed by an air=permeable but dustimpermeable member.
Accordingly, this indicator does not need a special indicator piston, so that the problems and difficulties attributable to the indicator piston, such as piston sealing or piston jamming, are avoided. Instead, the stroke monitoring is effected by observation of the level of hydraulic fluid in the tubular measuring chamber, the fluid level being measured against a scale, and being dependent upon the degree of extension of the associated hydraulic ram. Moreover, by avoiding the use of an indicator piston (with piston seal and associated piston spring), this indicator is of simpler construction, and has an increased operational reliability. The indicator can, therefore, be small, compact and robust.
In a preferred embodiment, the tubular measuring chamber is constituted by a transparent tube which is seated in a reception bore formed in the housing. In this case, at least that part of the housing adjacent to said one side of the tubular measuring chamber is made of transparent material. Alternatively, the housing may be provided with an inspection opening extending in the longitudinal direction of the tube.
In another preferred embodiment, the tubular measuring chamber is constituted by a cylindrical bore formed in the housing, at least that part of the housing adjacent to said one side of the tubular measuring chamber being made of transparent material. In either case, the housing may be made of synthetic plastics material.
The space in the tubular measuring chamber above the fluid level must be constantly vented, that is to say this space must be in constant communication with the atmosphere. However, this space must be closed against access of dust. It is, therefore, advisable for a plug to constitute the air-permeable dust-impermeable member. Preferably, the plug is a sintered body.
Advantageously, the lower end of the tubular measuring chamber is connected to the hydraulic line by a port member. Preferably, the port member is a plug-like member which is screwed into the reception bore (or into said bore).
Preferably, the housing is held in a mounting which is provided with an attachment for pivotally connecting the indicator to a carrier. This enables the indicator to be attached to, for example, a longwall conveyor or an attachment thereof. The pivotal attachment enables the indicator to be orientated in such a manner that the measuring chamber is at least approximately vertical.
Advantageously, the housing is provided with a socket for housing a calibration bar. The calibration bar can be used to displace excess fluid out of the measuring chamber.
The invention also provides apparatus for controlling the position of a mineral mining machine movable along guide means, the apparatus comprising a plurality of hydraulic rams which are pivotally arranged between the guide means and a support structure for tilting the guide means, each hydraulic control ram having a cylinder and a piston movable relative thereto, each hydraulic ram being associated with a respective indicator, each of the indicators being connected to its hydraulic ram via a respective hydraulic line, the indicators being mounted in a housing, each indicator having a tubular measuring chamber the lower end of which is connected to the associated hydraulic line, wherein each tubular measuring chamber is transparent on at least one side for the observation of the level of hydraulic fluid contained therein, the upper end of each tubular measuring chamber being closed by a respective air-permeable but dust-impermeable member.
BRIEF DESCRIPTION OF THE DRAWINGS
Monitoring apparatus constructed in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a part-sectional side elevation of the monitoring apparatus and an associated hydraulic ram; and
FIG. 2 shows the indicator of the apparatus of FIG. 1 looking in the direction of the arrow II shown in FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to the drawings, FIG. 1 shows a hydraulic ram 1 which is connected, via a hydraulic line 2, to an indicator 3. The hydraulic ram 1 is a hydraulic control ram of an apparatus for controlling the cutting horizon of a mineral winning machine such as a coal plough.
The hydraulic ram 1 has a cylinder 4 having a spherical head 5 whereby it can be pivotally mounted in a joint socket (not shown) which is arranged, for example, on the goaf side of a longwall conveyor. The spherical head 5 of the cylinder 4 has a stepped radius; being constituted by a hemispherical cap 6, and a shoulder 7 disposed between the hemispherical cap and the cylinder 4. Radially-projecting lugs 8 are arranged in the zone where the cap 6 merges with the shoulder 7. The radially-projecting lugs 8 prevent rotation of the ram 1, about its axis, in its joint socket.
The cylinder 4 has a port 9, to which is connected the hydraulic line 2. The open end of the cylinder 4 is closed off by a cylindrical cover 10. A piston 12 slides in the cylinder 4, the piston having a piston rod 13 which slides in a guide bush constituted by the cylindrical cover 10. The piston rod 13 is sealed with respect to the cover by a seal 11. The piston rod 13 has a spherical head 14 which is pivotally mounted in a joint socket (not shown) which is provided for example, on the rod head of the guide linkage of the advance mechanism of an associated roof support unit.
A bore 16 is formed centrally in the top 15 of the cylinder 4. The bore 16 communicates with the port 9 (and therefore with the hydraulic line 2) by way of a duct 18 which is formed in the wall of the cylinder 4, that is to say in the spherical cap 6 and the shoulder 7. A metering cylinder 17 is fixed to the bore 16, the metering cylinder being slidable in a bore 19 formed in the piston rod 13. The metering cylinder 17 is sealed with respect to the cylindrical working chamber 21 of the ram 1 by an O-ring 20. A metering chamber is formed within the metering cylinder 17 by a metering piston 22. When the ram 1 is retracted, pressurised hydraulic fluid is displaced from the metering chamber, this fluid passing through the duct 18 and the hydraulic line 2 to the indicator 3. The metering piston 22 is secured to the piston rod 13, that is to the base of the bore 19, the metering piston being sealed off, by means of a gasket 23, with respect to the inner wall of the metering cylinder 17.
The indicator 3 has a housing 24 which contains a transparent indicator tube 25 defining a measuring chamber, the tube being seated in a vertical reception bore 26 provided in the housing. A port member 27 is provided at the lower end of the indicator tube 25, the port member being connected to the hydraulic line 2. The port member 27 is in the form of a plug, and is screwed, from beneath, into the bore 26 of the housing 24, the hydraulic line 2 being connectible to the port by means of, for example, a push-in coupling 40.
The upper end of the indicator tube 25 is closed by a closure body 28 which is air-permeable but prevents the penetration of dust into the indicator tube. Thus, the interior of the indicator tube 25 is in constant communication with the external atmosphere via the closure body 28. The closure body 28 is in the form of a plug which is screwed, from above, into the bore 26. The plug-like closure body 28 may include an internal filter insert 41 secured in place by a push-in coupling 42 and which is air-permeable but prevents the entry of dust into the tube, and such closure body 28 (or the filter insert arranged therein) preferably consists of an air-permeable sintered body.
The two ends of the transparent indicator tube 25 are held by the screwed-in plugs 27 and 28. The housing 24 is also made of a transparent material, such as a synthetic plastics material, whereby the level of the fluid in the indicator tube 25 can be ascertained from the exterior of the housing. Alternatively, the housing 24 may be opaque and be provided with an inspection window on the visible (or reading) side of the indicator. A scale 29 is formed on the housing 24, so that the degree to which the ram 1 is extended can be read. It will be understood that the level of the fluid in the indicator tube 25 is dependent upon the degree of extension of the hydraulic ram 1, and has its maximum value when the hydraulic ram is fully retracted, and its minimum value when the hydraulic ram is fully extended.
In general, the housing 24 contains three small indicator tubes 25, to which three hydraulic rams 1 of a group are connected by separate hydraulic lines 2, the indicator tubes being expediently arranged parallel to one another. Thus, with the aid of the indicator 3, the degree of extension of three hydraulic rams 1 can be indicated at any time. In FIG. 1, the components of a second indicator tube corresponding to the parts 27 and 28 are indicated by 27' and 28'. Alternatively, the indicator may contain any other number of indicator tubes 25, whereby the indicator is suitable for the indication of the degree of extension of the hydraulic rams 1 of a group of rams having any desired number.
The housing 24 is seated in a stable mounting frame 30, the housing being made fast in the mounting by means of a locking screw 34. The frame 30 has an open box-shaped construction, into which the housing 24 can be inserted or pushed. The box-shaped frame 30 is open on the inspection (reading) side of the housing 24. Alternatively, the frame 30 may have an aperture through which the indicator tubes 25 are visible. The frame 30 has a rear wall 31 which is provided with a pivot journal 32 which engages in the bore of a socket 33. The pivot journal 32 and socket 33 constitute a pivot joint for connecting the indicator 3 to a support 43 in any desired position. For example, the pivot joint can be used to connect the indicator 3 to a longwall conveyor or an attachment thereof.
On one vertical narrow side 35, the frame 30 has a socket 36 for a calibration radar bar 37 which is provided with a head piece 38. In order to calibrate the indicator 3, the calibration bar 37 is drawn upwards out of its socket 36. Then, with a given plug 28 unscrewed, the calibration bar 37 is introduced, from above, into the associated indicator guide 25. Alternatively, the calibration bar 37 may be introduced into the indicator tube 25 through the plug 28 by first removing the filter insert 41. Any excess fluid is then displaced upwards out of the indicator tube 25. When not in use, the calibration bar 37 is re-inserted into the socket 36.
Obviously, the indicator 3 described above could be modified in a number of ways. For example, it may be possible to dispense with the transparent indicator tube(s). In that case, each indicating device 25 can be formed by a bore in the housing 24, to which bore the port member or plug 27 is attached from beneath, and the plug 28 is attached from above. If the housing 24 is made of transparent synthetic plastics material, the liquid level in the bore(s) forming the indicating device(s) can be read off without difficulty. If, on the other hand, the housing 24 is made of opaque material, each bore forming an indicating device can be closed, on the reading side of the indicator 3, by a transparent inspection window. | Apparatus for monitoring the working stroke of a hydraulic ram 1 includes an indicator 3 having a housing 24 containing a tubular measuring chamber 25 connected to the hydraulic ram by a hydraulic line 2. The tubular measuring chamber is transparent on at least one side for the observation of the level of hydraulic fluid contained therein. The lower end of the tubular measuring chamber is connected to the hydraulic line leading to the hydraulic ram. The upper end of the tubular measuring chamber is closed by an air-permeable but dust-impermeable member 28. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates generally to antenna systems for use in wireless communication systems. More particularly, the present invention relates to dual and multi-band antenna systems for use in wireless communication systems.
The expansion of mobile and personal cellular telephone systems has been rapid and widespread during the last few years. originally, cellular telephone systems were designed to provide communications services primarily to vehicles and thus replace mobile radio telecommunication systems. Advancements in technology and production have sufficiently decreased the costs of cellular service to the point at which cellular telephone service has now become affordable to a majority of the general population. Therefore, a "cellular telephone system" no longer strictly refers exclusively to cellular telephones, which originally were physically attached to and made a part of a vehicle. A cellular telephone system now includes portable, personal telephones which may be carried in a pocket or purse and which may be easily used inside or outside a vehicle or building.
Traditionally, wireless communication systems have included antenna systems which transmit and receive radio frequency ("RF") signals within the AMPS bands of frequencies in the United States or the GSM bands of frequencies in Europe. Wireless communication systems which operate in the AMPS or GSM frequency bands generally operate in a low frequency band. In the United States, the AMPS bandwidth used for cellular communication extends from about 824 Mhz to about 894 MHz. In Europe, the GSM bandwidth extends from about 890 MHz to about 960 MHz.
The wireless communications industry has recently broadened the scope of communications services by providing small, inexpensive, hand-held transceivers that transmit and receive voice and/or data communications, notwithstanding the geographic location of the user. This newer communications system operates at a higher frequency band than the AMPS/GSM frequency bands and has generally been referred to as a personal communication network/personal communication system ("PCN/PCS"). The PCN/PCS-type systems are envisioned to be wireless communication systems which should, for all intents and purposes, eliminate the need for separate telephone numbers for the home, office, pager, facsimile or car.
With the recent surge in the use of wireless communication devices, a need has grown to extend the capacity and to improve the communication quality and security of the applicable wireless communication system has also grown. As such, several countries and communication providers have agreed upon international communication standards and set aside a portion of the ultra-high frequency microwave radio spectrum as frequency bands which are dedicated exclusively for PCN/PCS communication systems.
On a worldwide basis, the PCN/PCS frequency band is expected to extend from about 1.5 GHz (1500 MHz) to about 2.4 GHz (2400 MHz). Within that band, individual countries have set aside particular portions of it for their respective PCN/PCS wireless communication systems. For example, Japan has set aside from about 1.49 GHz (1490 MHz) to about 1.521 GHz (1521 MHz), Europe has set aside from about 1.710 GHz (1710 MHz) to about 1.880 GHz (1880 MHz) and the United States has set aside from about 1.850 GHz (1850 MHz) to about 1.990 GHz (1990 MHz) for their PCN/PCS systems.
The bandwidths of the above different frequency bands represent approximately 11%, or only about 200 MHz, of the total possible bandwidth set aside for PCN/PCS-type wireless communication systems. The lowest frequency included within this PCN/PCS bandwidth is almost two times higher than the standard frequency of around 800 MHz at which cellular telephone communication systems operate within the United States. As a general rule, one can consider the conventional wireless communication frequency bands and the intended PCN/PCS frequency bands to be separated by just about 1000 MHz.
While operating within the PCN/PCS frequency bands, wireless communication systems typically employ principles of digital communication that have improved the communication quality and strengthened their security of the PCN/PCS over the conventional cellular telephone systems which utilize the lower frequency bands.
An ever increasing number of regions within the United States now utilize the PCS frequency bands for wireless communications, while in Europe, the use of PCN frequency bands is growing. In most of these regions, wireless telephone units must be able to operate in both the higher and lower bands of frequency (i.e., in both the AMPS and PCS frequency bands in the United States; in both the GSM and PCN frequency bands in Europe) so that a user of such units may selectively choose the frequency band of operation for the unit. Additionally, the units themselves may selectively choose their frequency band of operation so that the chosen band matches the frequency band of the electromagnetic signals received from a wireless telephone unit placing an incoming call to that particular unit.
Under these circumstances, it is desirable to develop antenna systems that are tuned to resonate within both of the above-identified bands of frequency (i.e., the AMPS and PCS bands for United States-based wireless communication systems and the GSM and PCN bands for European-based wireless communication systems). One approach would be to use a dual port antenna system utilizing two radiators with each radiator being tuned to resonate within a different frequency band. Although theoretically feasible, as a practical matter, this type of antenna systems is undesirable because it would be larger than a single radiator system. Furthermore, such an antenna system would require two RF signal feed lines resulting in a system more expensive to manufacture, thereby increasing the ultimate cost to the consuming public.
In light of these disadvantages, there is a present need for a single port, dual band antenna that is tuned to resonate within both bands of frequency in the user's region, i.e., in both the AMPS and PCS frequency bands in the United States and in both the GSM and PCN frequency bands in Europe.
One dual band antenna system generally available in the prior art uses the structure of a monopole antenna modified for dual band operation. Broadband monopole antennas are widely used in the mobile antenna design industry because of their simple embedding characteristics, their solid mechanical features and their inherent advantages over a ground plane environment. However, it is believed that some dual band antenna systems utilizing monopole radiators would be unable to maintain the simple structure of a standard broadband monopole antenna and/or obtain the minimum level of efficiency within both of the resonant bands of frequency necessary for commercially marketable quality of the product. Design modifications that would be necessary to allow those antenna systems to operate have raised the complexity of the systems as well as their cost.
Further, dual band antenna systems utilizing monopole radiators are typically mounted externally on the vehicle so that the monopole radiator is exposed to the external environment, which may lead to a shorter life and less efficient performance due to the environment. Finally, dual band, monopole radiator antenna systems are undesirable because they are not low profile. Accordingly, as a practical matter, dual band, monopole radiator antenna systems are not a feasible solution to the above-identified dilemma.
The second type of prior art dual band antenna systems are antenna systems that utilize two microstrip antennas. These are not typically single port, dual band antennas, but are rather dual port, dual band antenna systems. These systems have a major disadvantage in that they need an additional RF signal feed line. Furthermore, the operation of microstrip antenna dual band antenna systems depends upon the use of a ground plane. If a ground plane is not included or cannot be used in the system, the antenna will not operate.
The standard microstrip antenna configuration comprises two conductive layers of material separated by a passive substrate such as a printed circuit board. One conductive layer serves as the radiator portion of the antenna while the other conductive layer serves as a ground plane. This inherent need for a ground plane by all microstrip antennas makes them less desirable than the ground plane independent antenna of the present invention.
Still, dual band antenna systems that utilize microstrip antennas are classified as directional antennas since the electromagnetic signals are transmitted from and received by the antenna in a single direction, usually from the radiator portion of the antenna away from its associated ground plane.
A third prior art dual band antenna system utilizes a monopole type radiator connected to an external coupling element that is capacitively coupled with an internal coupling element. The internal coupling element is, in turn, connected to the transceiver by an RF signal feed line. These antenna systems may be glass mounted but their use has revealed a considerable number of disadvantages. In particular, such glass mount antennas utilize two modules mounted on respective outside and inside surfaces of a window in order to transmit signals between the opposing modules through the window glass. In these capacitively coupled antenna systems, two metal plates are used in the modules which cooperatively act as a capacitor to transmit RF energy through the intervening dielectric window glass.
These glass mount capacitive coupling-type antenna systems are also disadvantageous because they require a ground plane. Most glass mount surroundings cannot provide an ideal ground plane for the monopole radiator section of the antenna system, thereby degrading its performance. Furthermore, the physical characteristics of the dielectric to which the antenna is mounted, i.e., the window, generally inhibit sufficient capacitive coupling between the two coupling elements in both of the desired frequency bands. As such, loss occurs in the prior art glass mount antennas because they must propagate RF signals through the dielectric material and must further match the impedance of the external monopole type radiator.
Finally, the monopole type radiator used in these coupled dual band antenna systems is also mounted externally on a vehicle so that these systems are susceptible to the previously described disadvantages which result from exposure of portions of an antenna system to the outside environment.
In light of the aforementioned shortcomings of the available dual band antenna systems, it is desirable to provide a dual band antenna system comprising a low profile, ground independent, omni-directional, dual band antenna which may be mounted to the surface of a dielectric. Accordingly, the present invention is directed to an antenna system that overcomes the aforementioned shortcomings of the prior art and which utilizes novel radiating elements to provide a ground plane independent, dual band antenna suitable for transmission and reception of signals in two separate, selected frequency bands in either of the AMPS/GSM and either of the PCN/PCS frequency bands.
It is therefore a general object of the present invention to provide a new dual band antenna system that is ground plane independent.
It is another object of the present invention to provide an inexpensive dual band antenna system that includes a low-profile, omni-directional antenna.
It is yet another object of the present invention to provide an improved antenna system having a dual band, ground plane independent concealed antenna that is adapted for mounting on a glass surface of a vehicle or building, the antenna assembly having a flexible housing that adapts to its mounting surface.
It is still yet another object of the present invention to provide a dual band antenna system which includes a planar radiating structure formed on a circuit board that utilizes both broadband and microwave technology to transmit and receive RF signals at two separate, selected frequency bands in either of the AMPS/GSM frequency bands and either of the PCS/PCN frequency bands.
It is yet another object of the present invention to provide a flexible outer housing for an antenna assembly having a discontinuous outer configuration that permits the housing to conform to the shape of different dielectric surfaces, to thereby facilitate the installation of the antenna assembly.
It is yet a further object of the present invention to provide a ground-plane independent, dual band antenna system that utilizes a radiating structure having a tuning bridge that capacitively and inductively loads a portion of the radiating structure to thereby permit selection of two different resonant frequency bands for the antenna system.
It is still another object of the present invention to provide a dual band antenna system having a tuning bridge which permits selection of the two resonant frequency bands of the antenna system by setting the electrical length and/or width of the elements of the tuning bridge to specific values.
It is yet another object of the present invention to provide a dual band antenna system comprising a tuning bridge formed with transmission line-like conductive strips.
SUMMARY OF THE INVENTION
In accomplishing these objects and as exemplified in the preferred embodiment of the present invention, an antenna system having a dual band radiating structure is provided in which the radiating structure includes a tuning element in the form of a tuning bridge.
The radiating structure of the antennas of the present invention as exemplified by the preferred embodiment thereof is defined by a conductive layer disposed on a circuit board held within an outer housing. The conductive layer includes two conductive portions that cooperatively define a cone-angle section on the circuit board. The two conductive portions are interconnected by a tuning network in the form of a tuning bridge. The conductive portions and the tuning network are arranged in the preferred embodiment in a mirror image-like manner around a line of symmetry on the circuit board.
In another principal aspect, the radiating structure of the antenna of the present invention does not use a ground plane in association therewith and is therefore ground plane independent, thereby eliminating the need for placing the antenna in a specific location on a vehicle window. The configuration of the radiating structure further renders the antenna omni-directional rather than unidirectional.
In still another principal aspect of the present invention, a flexible housing for an antenna is provided having a discontinuous outer surface that includes a plurality of indentations formed therein which impact a degree of flexibility to the housing, thereby adapting it for mounting on curved glass or other dielectric surfaces and thereby eliminates the need to modify the mounting surface or to use a magnetic mounting assembly.
These and other features, objects and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference numerals identify like elements throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
In the course of the following detailed description, reference will be made to the attached drawings in which:
FIG. 1 is a partial perspective view of an antenna system constructed in accordance with the principles of the present invention mounted in plane on an automobile;
FIG. 2 is an elevational view of the antenna system of FIG. 1 as seen from the interior of the automobile looking rearwardly;
FIG. 3 is an exploded perspective view of the dual band antenna shown in FIG. 1;
FIG. 4 is a top plan view of the interior circuit board of the dual band antenna of FIG. 3;
FIG. 4A is a plan view of a circuit board illustrating an alternate radiating structure suitable for use in the antenna of FIG. 1;
FIG. 5 is a bottom plan view of the circuit board of FIG. 4 illustrating the connection between the system feed line and the antenna radiating structure;
FIG. 6 is a cross-sectional view of the antenna of FIG. 2 taken along lines 6--6 thereof;
FIG. 7 is a schematic diagram of the antenna of FIG. 3;
FIG. 8 is a sectional view taken through the antenna housing along lines 8--8 in FIG. 3;
FIG. 9 is an enlarged detail view of the radiating structure of FIG. 4 highlighting the tuning bridge portion thereof;
FIG. 10 is a plan view of an alternate embodiment of the present invention, illustrating the radiating structure of FIG. 4 used in association with a ground plane; and,
FIG. 11 is a plan view of another embodiment of an antenna constructed in accordance with the principles of the present invention that is ground plane dependent and is equivalent to the antenna system shown and described in FIGS. 1-9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a dual band antenna system constructed in accordance with the principles of the present invention is generally designated as 10. The antenna system 10 is a low-profile system that permits wireless transmission and reception of RF signals in two bands of frequency.
The antenna system 10 includes an antenna 11 held within an antenna module 13 that is mounted within the passenger compartment 12 of a vehicle 14. Although the antenna module 13 is illustrated and described hereinafter in the context of being mounted to the interior surface 15 of the vehicle window 16, it will be understood that the antenna module of the present invention finds equal utility when mounted to a building window.
The antenna module 13 includes a housing 22, an interior circuit board 32 with an antenna radiating structure 35 formed thereon, an adhesive attachment member 18 and a feed line 20 which connects the antenna module 13 to a transceiver unit (not shown) in the vehicle 14. The feed line 20 may be run to the transceiver unit within the interior surface 28 with the passenger compartment 12 as illustrated in FIG. 2.
Turning now to FIGS. 3 and 6, it can be seen that the antenna housing 22 has a plurality of walls 21 that cooperatively form a hollow interior defined in essence by an interior lip, or shoulder 23, that engages the perimeter 33 of the antenna circuit board 32. A series of additional circuit board supports are provided in the interior of the housing 22 and are illustrated as ribs 34 which extend between opposing edges of the housing 22. Those support ribs 34 preferably abuttingly contact the circuit board 32 and generally reach the level of the housing shoulder 23.
In an important aspect of the present invention, the housing 22 of the antenna module 13 has a structure that permits it to be attached to curved mounting surfaces such as the window 16 shown. In this regard, the housing 22, that is preferably made out of a flexible material, such as a plastic that is sound enough to maintain its structural integrity, yet pliable enough to permit it to bend to match the contour of the window 16. The housing 22 further includes, in its top wall 29, a series of indentations 24 formed therein that are separated by intervening ridges 25 to form, as illustrated in FIG. 8, an accordion-like structure, when viewed in cross-section. In the interior of the housing 22, each of the indentations 24 may be further provided with secondary support ribs 26 that supplement the function of the main support ribs 34. In order to accommodate passage of the antenna feed line 20 out of the housing 22, a port 27 may be provided in one of the housing walls. The combination of indentations 24 and ridges 25 in the housing 22 permit the outer wall 29 thereof to flex to a greater degree than a solid housing wall, and thereby enhances the capability of the housing 22 to match the contour of the window 16.
In order to complement the flexibility aspect that the indentations 24 and ridges 25 provide, it is desirable that the interior support ribs 34 are discontinuous in their extent between the opposing ends of the housing 22. As illustrated best in FIG. 3, the housing support ribs 34 include a plurality of interruptions, shown illustrated as slots 36. These discontinuities permit the support ribs 34 to flex along with the housing 22 and enhance the ability of the housing 22 to attach to various window contours.
As mentioned above, the antenna module 13 is preferably adhesively attached to the window 16 by way of an adhesive member 18 that is interposed between the antenna module 13, particularly the circuit board 32 thereof and the window mounting surface 15. In this regard, the adhesive member 18 has a substrate 17 with adhesive layers or coatings 19 disposed on its opposite sides. (FIG. 6.) The adhesive member 18 preferably extends to the perimeter of the housing 22 (and circuit board 32) to provide a seal between the antenna circuit board 32 and the window 16. The adhesive member 18 material has a thickness which has an effect on the electrical characteristics of antenna system 10 in that it will increase the load of the radiating structure 35. To tune the antenna system 10, the thickness of the adhesive member 18 is maintained at a predetermined value and is then taken into account along with the dimensions of the other elements of the antenna system.
Turning now to FIGS. 3 and 4, the details of the antenna radiating structure 35 shall now be described in detail. The circuit board 32 has a conductive layer 37 disposed on the outer surface 38 of the circuit board substrate 39. The conductive layer 37 defines the radiating structure 35 of the antenna 10 on the circuit board 32 and may be formed thereon of conventional means, such as photo-resist etching. The conductive layer 37 is preferably a highly conductive metallic material, such as copper, while the circuit board 32 may be formed from a conventional circuit board material, such as a fiberglass-reinforced epoxy material. The circuit board 32 preferably is of a thickness that imparts a flexible nature thereto so that the circuit board 32 will flex with the antenna module housing 22 when mounted to a curved surface.
The radiating structure 35 of the antenna system 10 of the present invention uniquely takes advantage of broadband and microwave technology to act as a dual band antenna to transmit and receive RF signals at two separate, selected frequency bands separated by about 1000 MHz. The radiating structure 35 of the antenna 11 is further tunable, as explained in greater detail below, to transmit and receive signals in the AMPS frequency band (about 824 MHZ to about 894 MHz) and the PCS frequency band (about 1850 MHz to about 1990 MHz), or in the GSM frequency band (about 890 MHz to about 960 MHz) and the PCN frequency band (about 1710 MHz to about 1880 MHz). The separation between these frequency bands ranges from about 750 MHz to about 1096 MHz and may be considered to average about 1000 MHz.
The radiating structure 35 first takes advantage of broadband technology by way of a special angled section 42 in the form of a cone. This cone-angle section 42 is defined largely by two conductive portions 44 that are mirror images of each other and positioned on opposite sides of a line of symmetry 8 that coincides with a centerline of the circuit board 32 in the preferred embodiment. As illustrated, the two conductive portions 44 are substantially right triangular portions. (FIGS. 4 & 9.) In effect, cone-angle section 42 of radiating structure 35 would operate much like a steel broadband dipole if it constituted the entire radiator of the antenna, and if the tuning network described below was not present to interconnect the conductive portions 44 together.
The antennas of the present invention also take advantage of the principles of microwave technology by interconnecting the conductive portions 44 with a tuning network, illustrated as a tuning bridge 48. As will be appreciated, the tuning bridge 48 permits the radiating structure 35 of the antenna system 10 to resonate within two separate, selectable frequency bands. The tuning bridge 48 is part of the conductive layer 37 of the circuit board 32 and may be formed at the same time the two conductive portions 44 are formed.
The tuning bridge 48 interconnects the two conductive portions 44 as shown in the throat 49 of the cone-angle section 42. In the preferred embodiment, the tuning bridge is substantially symmetrical and is aligned with the line of symmetry 8 of the radiating structure 35. As shown best in FIG. 9, which highlights the tuning bridge 48, it can be seen that the tuning bridge 48 includes first and second triangular portions 50, 52 which are mirror images of each other and are positioned on opposite sides of the line of symmetry 8 of the radiating structure 35 and are positioned along the angled surfaces of the conductive portions 44. The tuning bridge further includes a series of transmission line-like strips 48 that are arranged in a unique pattern to define, as illustrated in FIG. 4, a pulse-like or square wave-like section, generally 54. This pulse-like shaped section 54 preferably includes a pair of first conductive strips 56, 58 that are substantially identical in configuration and are disposed on opposite sides of the line of symmetry S and extend from their respective associated triangular portions 50, 52 toward the line of symmetry S. Preferably, these first conductive strips 56, 58 extend generally perpendicular to the line of symmetry S.
A pair of second conductive strips 60, 62 are also provided as part of the tuning bridge 48. These second conductive strips 60, 62 angularly extend from the first strips 56, 58 in a different direction and preferably perpendicular to the first strips 56, 58. In the embodiment shown, the second strips 60, 62 extend generally parallel to the line of symmetry S on opposite sides thereof.
A third conductive strip 64 is provided that extends between the ends of conductive strips 60, 62 and bridges the free ends thereof. Conductive bridge strip 64 extends in a third direction across the line of symmetry S that is generally parallel to that of the first conductive strips 56, 58. The line of symmetry S acts as a perpendicular bisector of the radiating structure 35. The structure of the tuning bridge 48 defines three dielectric gaps 66, 68, 70. Two such dielectric gaps 66, 68 are disposed between the triangular portions 50, 52 and the first conductive strips 60, 62 of the tuning bridge 48 while the third dielectric gap 70 is positioned between the second conductive strips 60, 62.
It will be appreciated by those skilled in the art that the tuning bridge 48 forms a structure that contributes to the capacitive and inductive loading for the antenna radiating structure 35 as illustrated in FIG. 7. A change in the electrical characteristics of tuning bridge 48 will in a change in the resonant frequencies for radiating structure 35. Thus, by changing the electrical length and/or width of the tuning bridge 48, it is possible to tune the radiating structure 35 so that it resonates within two separate and distinct, selectable frequency bands. For instance, each of the dielectric gaps 66, 68, 70 may be shorted by placing a suitable conductor such as foil or wire across the gaps. By doing so, the electrical length and/or width of the elements of tuning bridge 48 are altered which, in turn, changes the inductive and/or capacitive loading for radiating structure 35. As a result, the two resonant frequency bands for radiating structure 35 may be selected and changed so that the radiating structure comprises a tunable dual band antenna. Although the conductive strips 56, 58, 60, 62 and 64 that make up part of the tuning bridge 48 illustrated in FIG. 4 are shown arranged in a linear fashion, it is contemplated that the conductive strips 56', 58', 60', 62' and 64' may be arranged in a curvilinear fashion to form a serpentine section 48' as illustrated in FIG. 4A. The tuning bridge 48 may also be moved out of the throat 49 toward the far edge 46 of the circuit board 32 to change the tuning features of the antenna 11.
Referring now to FIGS. 5 and 6, the connection between the feed line assembly 20 and the radiating structure 35 for antenna system 10 is shown in greater detail. In particular, two terminals or contact pads 72, 74 are disposed on the bottom surface 75 of the circuit board 32. The inner conductor 76 of the feed line 20 is connected to terminal 72, preferably by soldering. Likewise, the outer conductor 78 of the feed line 20 is connected to terminal 74. In a manner well known in the art, the two terminals 72, 74 are connected to corresponding terminals 80, 82 (FIG. 4) of the radiating structure 35 through the substrate 39 of the circuit board 32 such as by soldering. One or more holes 77 may be drilled through the circuit board 32 to provide a passage for molten solder to flow between the terminals on the opposite surfaces of the circuit board 32.
Those skilled in the art will appreciate that radiating structure 35 is shorted when fed with a direct current or relatively low frequency signal, but it is loaded when fed with relatively high frequencies such as the RF signals contemplated during operation of dual band antenna system 10.
Based on the foregoing description, it will be appreciated that the dual band antenna system 10 of the invention provides a low profile, omni-directional dual band antenna which enables selection of its two resonant frequency bands by changing the electrical length and/or width of the elements of tuning bridge 48. Further, the preferred embodiment described above comprises a ground plane independent antenna system. As such, the operation of dual band antenna systems of the present invention is not dependent upon situating the radiating structure 35 in close proximity with a ground plane. The dual band antenna system 10 may therefore be mounted to the surface of a dielectric in a position far removed from a ground plane such as the window of an ungrounded office building.
Although the dual band antennas of the present invention are generally ground plane independent, the use of a ground plane with such antenna systems may provide certain benefits. As shown in the alternate embodiment of FIG. 10, those skilled in the art will recognize that implementation of a ground plane 84 with the radiating structure 35 will provide certain benefits. By extending the ground plane 84 generally perpendicular to the plane of the circuit board 32, but not through the circuit board 32, the radiating structure 35 along with its corresponding image resulting from use of the ground plane, will provide twice as much gain to the antenna as without a ground plane. For vertically polarized radiation, the ground plane should extend in the direction shown in FIG. 10, namely parallel with the line of symmetry 8 for the radiating structure 35 and perpendicular to the plane of the radiating structure. On the other hand, for horizontally polarized radiation, the ground plane 84 should extend in a different direction, namely in a direction transverse to that shown in FIG. 10.
Furthermore, although the preferred embodiment of the above-described dual band antenna system 10 is referred to as a ground plane independent antenna system, another alternate embodiment of an antenna 11' is shown in FIG. 11 that uses a ground plane 84' with only half of the radiating structure 35 which results in an antenna that is equivalent to the antenna system 10 of FIGS. 1-9 is shown. To achieve this result, the ground plane 84 is preferably positioned at the line of symmetry S for the radiating structure 35" of FIG. 4 so that it perpendicularly bisects the plane of circuit board 32 at the line of symmetry S and so that the third strip 64' contacts the ground plane 84'. In effect, only one half of the radiating structure 35a is physically present in this antenna system, i.e., that shown in solid in FIG. 11. The other half is provided by the image 35b resulting from use of the ground plane. Accordingly, the equivalent of the entire above-described radiating structure of the preferred embodiment (FIGS. 1-9) would exist. As such, those skilled in the art will appreciate that, although it is not identical to the preferred embodiment shown and described above, this ground plane dependent embodiment falls within the literal scope of the appended claims.
The antenna system 10 illustrated in the preferred embodiment is arranged to transmit and receive vertically polarized RF signals such as those typically used for wireless communication systems. Those skilled in the art will appreciate that the antenna system 10 may likewise be arranged to permit transmission and reception of horizontally polarized RF signals.
Accordingly, while the preferred embodiment of the invention has been shown and described in detail, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the appended claims. | The present invention is directed to a dual band, omni-directional antenna having a symmetrical radiating structure defined by a pair of conductive portions interconnected by a tuning bridge formed on a printed circuit board. An outer housing holds the circuit board in place. An adhesive layer is used to secure the antenna to a dielectric, such as the rear window of an automobile. The antenna housing incudes an outer surface includes a plurality of surface interruptions in the form of ridges and valleys that render the housing flexible so that it may conform to the shape of different mounting surfaces. The tuning bridge of the antenna permits tuning of the resonant frequency bands for the radiating structure to define two separate and distinct, selectable frequency bands. | 7 |
BACKGROUND OF THE INVENTION
The invention relates to a pusher for scraper chain conveyors, especially of the kind used in underground mining. In particular, the present invention relates to a pusher with a bridge element that wraps over a lower portion of a scraper chain conveyor.
Pushers of this type used in underground mining usually comprise two parts, an upper and a lower part which are bolted together. The two parts secured firmly in place, anchor chain strands located within the jointing plane between the upper and lower parts of the pusher. For this purpose, each pusher is provided with chain beds for the chain links.
Pushers of this kind are known, for example, from the German patent application DE-A-27 17 449. The jointing plane between the upper and lower parts is configured such that the two ends of the lower part act as guide members. These two ends also engage the lateral guide profiles of the trough conveyor, while coupled to the upper part. This pusher design has become standard over the course of time because it offers enhanced wear resistance.
Although these pushers have by all means proved worthwhile in practice, the introduction of high forces—for example as a consequence of strain introduced within the guide profiles—can cause them to bulge and distort, and, in particular, can cause the bolts to shear off and the upper part of the pusher to be severed off. This problem occurs most frequently after the chain exits large-diameter sprocket wheels of a kind commonly used. In this configuration, the chain strands with the scrapers mounted on them are diverted along a curved path by guide beads arranged in the conveyor frame. The curved path is used to permit the chain to bridge the difference between sprocket wheel and conveyor trough. The chains are guided downwards at a steep angle until they slide into the trough profile, with the scrapers taking up the necessary pressing force through end elements.
SUMMARY OF THE INVENTION
The object of the present invention is to overcome the drawbacks of the prior art, in particular by designing a pusher that is stable even when there is operating constraints. It is a further object that the pusher assembly be easily installed and maintained.
This object is established according to the invention by the features contained in the characterising part of claim 1, useful developments being characterised by the features contained in the subclaims.
According to the invention, the upper part of the pusher is designed as a bow-like bridge element, the ends of which wrap over the two ends of the lower part from above and confine the lower part in a clasp-like manner. In cases of strain on the pushers within the lateral guide profiles of the trough conveyor, which occurs especially during the transition from sprocket wheel to conveyor trough, the forces generated are introduced predominantly in the region of the wrap-over ends. However, because the ends of the upper part embrace the lower part in a clasp-like manner, distortion of the upper and lower parts is prevented. This arrangement provides an advantage over the prior art because it avoids severing a pusher part. This design also considerably facilitates assembly, because the lower part, being of smaller width (transverse to the direction of transport) than the upper part, can very easily be pushed under the two chain strands when the pusher is being fitted. The bridge-like upper part is then simply mounted on top and bolted. If, in addition, as is expedient, the upper and lower parts are symmetric with respect to the transverse center line, i.e. the line perpendicular to the longitudinal direction of transport and axis/axes of the chain strand or strands, assembly becomes even easier because the pushers can also be fitted laterally transposed. When fitting the pushers, it is no longer necessary to differentiate between the front and rear ends of the pusher in terms of the direction of transport.
The lower part is preferably confined in clasp-like manner within the space delimited by the bridge-like upper part. This structure results in a stable joint between the upper and lower parts. In this connection, it is expedient to have a small space between the upper and lower parts in the area of the central jointing plane, because this permits desirable pretensioning between the upper and lower parts by means of the bolts. It is especially beneficial if this space is effected by way of the distal cuneiform contact surfaces—which run obliquely outwards from top to bottom—between the wrap-over ends of the upper part and the ends of the lower part.
It is furthermore of advantage to design the guide surfaces of the upper part so that the preferably cuneiform ends of the bridge-like upper part are guided within the lateral guide profiles of the trough conveyor. Most of the wear on the parts then occurs in the upper part, which is very easily removed for repair purposes and can be replaced by a repaired upper part.
By means of appropriate recesses in the area of the upper port guide surfaces, raised wear surfaces are obtained that can be repaired very easily by build-up welding or by welding on shells. A check for the occurrence of wear can be provided by wear marks—grooves, flutes or steps—in these upper wear surfaces. If the grooves, flutes or steps are no longer visible, the pusher can be considered worn to the extent that the need for maintenance to replace or repair the scraper is easily observed.
Again in the context of wear markings, the invention provides that each chain bed—formed by two axial chain conduits—features a peripheral, groove-like depression. These depressions serve simultaneously as wear marks and to accommodate the weld of the chain links. As a result, the chain links are accommodated with very little friction, in particular, both positively and non-positively in the pushers.
Another useful feature of the invention is that to reduce friction, the ends of the lower part are recessed, creating a free space which bridges the welds formed by welding the base plate to the lateral guide profiles of the trough conveyor. It is to advantage if the recessed surfaces are flush with the lower surface of the wrap-over ends of the upper part.
It is additionally expedient to provide a groove-like recess in the top surface of the upper part, the recess running transversely with respect to the direction of transport and preferably extending from the bridge centre to the proximity of the holes for the bolts. This measure not only saves material, but also gives the upper part an essentially T-shaped cross-section, as a result of which the moment of resistance in the direction of transport is increased.
Another feature permitting high stresses to be taken up in the direction of transport is the provision of centring noses or centring projections in the region of the ends of the lower part and the lands between chain conduits. These projections prevent conveying forces from causing displacement of the upper and lower parts.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects of the present invention are achieved in the preferred embodiments of the invention, described below with reference to the drawings in which:
FIG. 1 shows a partly sectional view of a pusher in a trough of a continuous conveyor for underground mining, comprising an upper and a lower run;
FIGS. 2 a, b, and c respectively show side cross-section, top and bottom views of the upper part which has the form of a bridge;
FIGS. 3 a, b, c respectively show side cross-section, top and bottom views of the lower part of a pusher.
FIG. 4 shows a partly sectional lateral view of a pusher, with cutting planes indicated;
FIG. 5 shows several sections cut along the planes shown in FIG. 4; and
FIG. 6 shows a detailed view of the end of a pusher, and, in the upper part of the Figure, the sectional view E—E to show the contact surface between the upper and lower parts.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A shown in FIG. 1, the stationary part 1 of a scraper chain conveyor for underground mining has an upper run 2 and a lower run 3 . The two runs are separated by a base plate which is welded at each end to the upper and lower lateral guide profiles 5 and 6 of the trough conveyor to form welds 7 . The lower run 3 is closed at the bottom by a covering plate 8 which, as again shown in the Figure, is welded on.
It can be seen that on the inside, the guide profiles 5 and 6 form a profile which encloses the ends 9 of the pushers, which are all identical and have the general reference numeral 10 . To secure them in place, the pushers 10 are provided with two centrally located chains. Accordingly, each pusher has two chain beds 11 , 12 to accommodate the two parallel chains. The chain beds, each of which serves to secure one horizontal chain link of a round link chain in position, are identical to each other. For this purpose, parallel chain conduits 13 and 14 are provided for each chain bed 11 , 12 . The rounded inner surface of the chain conduits have a slightly larger radius than do the round, horizontal steel chain links.
Each of the pushers, referred to generally by the reference numeral 10 , is made up of an upper part 15 and a lower part 16 . To this end, each pusher is divided along a horizontal plane, the ends of which, however, are angled downwards and outwards due to the special design of the upper part. At the contact surfaces, nose-like projections 17 , 18 at the ends of the lower part positively engage complementary recesses in the opposing surface of the upper part, thus having a centring effect. This ensures optimum transmission of forces, and the larger contact surface area also reduces wear. An added advantage is that any displacement of the upper and lower parts of the pusher due to forces acting in the direction of transport is safely ruled out.
To secure the horizontal chain links in the chain beds 11 and 12 in position, and also the upper and lower parts 15 and 16 , each pusher is provided with bolts 19 , 20 . The bolts are in each case located to the outside of the chain bed; in the embodiment shown they are located in particular between the chain bed and the corresponding end of the pusher. The bolts, which engage corresponding nuts, are of identical design in all the pushers 10 .
The upper part 15 of each pusher 10 is designed as a bow-like bridge element and has a bar-like central part 21 extending transversely to the direction of transport. The extremities of central part 21 adjoin downwardly projecting, cuneiform ends 22 , which wrap over the lower part 16 . The lower part 16 is likewise designed as a linear, bar-like part with projections 17 , 18 at end portions. The ends 22 of the upper part 15 wrap over the projections 17 , 18 of the lower part from above and confine the projections 17 , 18 between the ends 22 in a clasp-like manner. The contact surface between the upper and lower parts is an oblique surface 23 which extends outwardly from top to bottom.
If there is strain introduced within the lateral guide profiles, which occurs most frequently after the chain has been passed over a large-diameter sprocket wheel and is then guided steeply downwards before it enters into the guide profile of the trough conveyor, considerable forces are generated in the region of the pusher ends. These forces are introduced via the ends 22 of upper part 15 , and are transmitted via the oblique contact surfaces 23 into the lower part 16 . This causes the pusher to bulge outwards, which in conventional pushers causes the bolts to shear off, resulting in severing off of the upper part of the pusher. The damaged pushers must then be replaced by new ones. However, if the upper part 15 is of bridge-like design, and its two ends 22 embrace the two ends of lower part 16 from above, the pusher is prevented from bulging in this way. As a result, shearing off of the bolts and severing of the two parts of the pusher is effectively prevented. The accompanying stabilisation of the pushers in the critical areas also means that wear at the wear surfaces is significantly reduced. Thus increasing the pusher's service life.
The two ends 22 of the bridge-like upper part 15 are designed as pusher guide members. In consequence of their cuneiform shape, they have an upper guide surface 24 and a lower guide surface 25 , which approach each other obliquely. As best seen from FIG. 2, which shows three different views of the upper part, namely a lateral view, a top view and a view from below, the guide surface 24 is raised at 26 as a wear surface. This is effected by providing recesses 27 at both ends. In the area of the wear surface 26 , it is useful to provide an optical wear indicator in the form of a groove, a flute or a recessed surface 38 , with which the wear at wear surface 26 and the material attrition between opposing end elements can be indicated. If this wear mark is no longer visible, the wear has progressed to a stage which could pose a danger, and the pusher must be exchanged and repaired.
As best seen from FIG. 2 (bottom view) and FIG. 3 (middle view), which shows various aspects of the lower part 16 , each chain bed or longitudinal chain conduit 13 and 14 features a transverse flute or groove 28 , which again serves as a wear mark but also accommodates the weld of an O-shaped chain link in each case. This prevents vibrations and increases the service life of chain and pusher. The land 29 of each chain bed 11 and 12 in the lower part 16 has at the top a nose-like projection 30 , which engages with a matching recess 31 in the corresponding land 29 of the upper part and acts as centring projection. This enhances the anchorage of the upper and lower parts, and together with the centring noses at the ends rules out any displacement of upper or lower part in the direction of transport. The interaction of the centring projection 30 and the recess 31 is also depicted clearly in FIG. 1 .
As best seen from FIG. 3 the ends of the lower part 16 feature a recess 33 , creating a free space between each end of the lower part 16 and the base plate 4 shown in FIG. 1 . This means that the weld at 7 between the base plate 4 and the trough conveyor's lateral guide profiles 5 , 6 is effectively bridged, which again leads to a reduction in possible wear. As best seen in FIG. 1, the recessed surface 33 is flush with the ends 22 of the upper part 15 .
FIGS. 2 and 3 also show that both the upper and the lower part are symmetric with respect to the transverse centre line, i.e. the line which runs perpendicular to the longitudinal direction of transport. This results in the formation of scraper edges 34 and 35 on each side, one of which acts in the transport direction and one in the reverse direction, and which, especially in the area of the lower run, scrape off material to be conveyed.
As shown at the top right of FIG. 3, an arched area 37 is provided towards the outside of the upper and lower parts at the level of each land 29 . It serves as bearing surface for the vertical chain links, and prevents the chains from kinking after they pass over the sprocket wheel and are either slack or tensioned only very slightly.
With the design of the invention, distortions in the upper and lower parts are prevented even when there is pronounced strain with correspondingly high forces. With conventional pushers, distortions can lead to severing of the upper part from the lower part. The vertical bolted connection ensures that the chain is securely clamped in the pusher. As explained before, the holes for the bolts are located as far out from the centre as possible so as to avoid critical bending stresses in the middle of the chain bed. Because the upper and lower parts are designed with a space between them in the area of the bolted connections, there is an intended pretensioning reserve which prevents the nuts from loosening and considerably facilitates maintenance performed after the pusher has been used the first time. Scraper edges are ensured on both sides, so that the lower run is cleaned continuously by each pusher. Another useful feature of the invention is that the chains in the chain conduits are sufficiently long to prevent slippage of chain links—especially in closed trough profiles—behind the pusher, even in the case of narrow chains. Kinking of the chain behind the pusher is prevented thanks to the arched surfaces on the two outer sides of the upper and lower parts. It is beneficial to manufacture the pushers from high-grade steel, preferably 42 CrMo 4 , because this will guarantee that the construction in question has a high degree of ductility, excellent bending strength, low susceptibility to cracking and optimum wear properties. The pusher design facilities build-up welding or the welding on of repair shells during corrective maintenance. The symmetrical design also facilitates fitting of the pushers, because it is no longer necessary to differentiate between the front and the rear of the part. On the contrary, the pushers can be fitted in either direction. Fitting of the pushers is facilitated still further by the fact that during fitting, the lower part can easily be pushed under the chain strands, and the bridge-like upper part then simply mounted on top. This makes it much easier to thread the pushers into the chain strands.
FIG. 5 shows various views illustrating the arched surface 37 in the upper and lower parts (section C—C of FIG. 4 ), which are shaped to conform with the rounded surfaces of the chain links and prevent the vertical chain links from kinking when the chain is not fully tensioned. The sectional view C—C also shows the centering connection between the upper and lower parts in the area of the central transverse axis. Section D—D shows how recess 36 imparts a T-profile to the bridge-like upper part, enhancing its strength and also the stability of the jointed pusher, so that severing of the two parts is prevented.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims. | A scraper chain conveyor has pushing members with an upper and lower part shaped to prevent relative lateral movement in the direction of travel. The members are complementary shaped, with recesses and cooperating protrusions on either part, respectively. The parts have grooves to avoid conveyor protrusions that contribute to part wear and cooperating chain beds that retain a chain link when coupled together. Spaces between the coupled parts permit a pretensioning force applied to the coupled parts. The upper part bridges the lower part to improve the stability of the part coupling. The parts include wear indicators and can relieve strain introduced on the chain conveyor from larger drive sprockets. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the invention.
[0002] The present invention relates to a device for deaerating a fiber stock suspension.
[0003] 2. Description of the related art.
[0004] Devices for the deaeration of fiber stock suspensions are well known to the experts in the industry. As the name indicates, these devices deaerate fiber stock suspensions. During deaeration minor contaminates which would otherwise interfere with paper or cardboard production are removed. The devices are large tanks into which the fiber stock suspension, that is to be supplied to the paper or cardboard machine, is fed in the form of a thin mixture. The functional principle of the device is that the fiber stock suspension is boiled in a vacuum, the gas is removed to a so-called gas chamber, and the other minor impurities present on the liquid surface in the tank are discharged. The fiber stock suspension which is to be supplied to the paper or cardboard machine is removed through an opening in the tank floor, located there for the purpose of removing fiber stock suspension from the tank that is as gas free as possible. In order to maximize the deaerating capabilities of the device, a vacuum is generated in the tank by a pump, whereby the gas is forced through a line from the tank. The deaerating capability is improved when the supplied gas-containing fiber stock suspension is fed into the tank through steel pipes located above the liquid level in the tank whereby the gas which is present in the added fiber stock suspension, possibly in the form of bubbles is discharged prior to coming into contact with the already present fiber stock suspension. In addition to stabilizing the liquid level, the single overflow is used to remove minor contaminations from the liquid surface in the tank, so they do not reach the paper or cardboard machine. The minor contaminates flow over the single overflow to the discharge and then on to further treatment.
[0005] German Disclosure Document DE 42 34 522 A1 describes a deaeration chamber in accordance with the aforementioned generic term of the present invention, as used in the paper and pulp industry. The separation wall which forms the overflow for the separated, excess fiber stock suspension is essentially level with the rear edge of the outlet for the gas-free suspension and the overflow for the separated, excess suspension itself slopes toward the overflow in the tank, in opposite direction to the flow direction.
[0006] Further disclosures regarding the position and shape of the separation wall forming the overflow for the separated, excess fiber stock suspension may be found in the German prior art documents DE 32 19 740 A1, in the PCT application WO 97/15717 and in U.S. Pat. No. 5,868,905 (PK10542 US).
[0007] All aforementioned documents share the disadvantages with regard to the overflow for the separated, excess fiber stock suspension in that the separation wall is located transversely and symmetrically to the tank axis (longitudinal axis), that it's location is a given due to it's shape, meaning that it is located on one of the two end areas of the tank and it's overflow length is fixed.
SUMMARY OF THE INVENTION
[0008] The present invention provides a device for deaerating of fiber stock suspension where the overflow for the separated, excess fiber stock suspension can be located independently from both the inlet for the fiber stock suspension and the outlet for the deaerated fiber stock suspension. An overflow in the shape of an overflow pipe having an overflow height and an overflow length located prior to the outlet opening for the separated, excess fiber stock suspension, viewed in the flow direction.
[0009] In one embodiment of the invention a dwell chamber in the form of a hydraulic stabilizer is located after the outlet opening for the gas-free fiber stock suspension. The dwell chamber consisting of preferably a long horizontally cylindrical tank, with at least one inlet opening to accept the fiber stock suspension coming from a prior tank. The tank having outlet openings for the separate discharge of the gas-free fiber stock suspension, the separated gas, the excess fiber stock suspension and the separated, excess fiber stock suspension. The opening for the discharge of the separated excess fiber stock suspension being an overflow tube having an overflow height and an overflow length.
[0010] By designing the overflow for the separated, excess fiber stock suspension as an overflow tube having an overflow height and an overflow length, a design advantage as well as a fluidic advantage is achieved in that the overflow for the separated, excess fiber stock suspension may be positioned at any desired location in the tank; rather than being positioned transversely and symmetrically to the tank axis in one of the two end areas of the tank. Further, the design of the overflow length may be freely selected within a certain range.
[0011] In one embodiment of the invention the overflow pipe has a funnel shaped opening with an aperture angle of between 30° and 80°, preferably between 40° and 50°. This type of initial opening has an advantage in that the opening orifice area of the overflow tube is independent from the continuing diameter of the overflow tube. In addition, the flow geometry can be positively influenced by the selection of the aperture angle.
[0012] One embodiment of the invention provides that the overflow tube be a telescopic structure, thereby offering a changeable overflow height. Changeability of the overflow height provides the option to control the liquid level in the tank, or to regulate it, if a drive unit including a control system are present, whereby the liquid level will influence the dwell duration and the dwell volume of the fiber stock suspension in the tank. The telescopic construction of the overflow tube may be a sliding device.
[0013] A further embodiment of the invention provides, that the overflow tube including the discharge pipe be movable, thereby providing for an adjustable overflow height. The discharge pipe of the overflow tube also may have a transition piece whose length and shape are adjustable so that, even if the overflow tube is moved, no local shifting occurs in the subsequent system. The transitional piece would preferably be in the form of folded tubing.
[0014] In yet a further embodiment of the invention the overflow tube is a telescopic and divergent structure, providing for an adjustable overflow length. An increased overflow length provides the advantage of additional abatement due to reduced flow in the separated, excess fiber stock suspension.
[0015] In a preferred embodiment of the invention, the overflow tube can be coupled with at least one tube segment, thereby providing adjustability for the overflow height and/or the overflow length. Depending upon the shape of the pipe segment, the configuration may influence the overflow height and/or overflow length without having to fall back upon expensive and operationally critical mechanisms.
[0016] In a further embodiment of the current invention the outlet opening for the separated, excess fiber stock suspension is located between the inlet opening for the fiber stock suspension and the outlet opening for the gas-free fiber stock suspension. Thereby the contaminated fiber stock suspension can be brought directly, without having to pass the outlet for deaerated fiber stock suspension, to the outlet opening and be removed.
[0017] In another embodiment of the invention the tank includes at least two outlet openings for separated, excess fiber stock suspension, whereby at least one outlet opening is designed as an outlet in the form of an outlet pipe with an overflow height and an overflow length and the additional outlet openings are equipped with covers. The presence of multiple outlet openings offers the technological advantage that the overflow which is designed as an overflow pipe may be located at various positions in the tank and therefore, it's specific location can be selected to best suit the fiber stock suspension characteristics.
[0018] In a further embodiment of the invention an overflow, designed as an overflow pipe with an overflow height and an overflow length is located prior to the outlet opening for the gas-free fiber stock suspension, as viewed in the direction of flow. The advantage is that the overflow for the gas-free fiber stock suspension can be placed at any desired location in the tank. It further provides the advantage that different volumes can be discharged in a fluidically optimum manner, by means of different size openings.
[0019] In a further embodiment of the invention a device is provided for producing vacuum in the tank including a vacuum connection, a vacuum line and at least one vacuum pump. Several vacuum connections can, at any given time, be operated individually with a separate vacuum line and a separate vacuum pump, or with individual vacuum lines and a common vacuum pump.
[0020] A further embodiment of the invention provides that in the upper interior tank area several nozzles are located for moistening the interior surface of the tank which does not come into contact with the fiber stock suspension, whereby the speed and efficiency of the fiber stock deaeration process taking place in the tank is positively influenced. Moisturizing also prevents fiber stock or ash deposits.
[0021] It is also advantageous if the distributer pipe is parallel or approximately parallel to the tank axis. The distributer pipe can be outside or inside the tank. This arrangement results in spacial (space requirement) and technological (distribution uniformity) advantages.
[0022] In a further embodiment of the invention the hydraulic stabilizer for the preferably gas-free fiber stock suspension is a dwell tank having a certain dwell duration and a certain dwell volume having fluidically optimum interior contours. The fluidically optimum interior contour is that of a horizontal cylinder, or that of a conical tube, aligned in the direction of flow of the fiber stock suspension. This hydraulic stabilizer is particularly suitable for new line installations for deaerating of fiber stock suspensions whose design principles for the tank construction in each case is disclosed in the aforementioned U.S. Pat. No. 5,868,905 (PK10542 US).
[0023] A further embodiment of the invention provides that, the dwell duration of the preferably gas-free fiber stock suspension in the hydraulic stabilizer is between 2 and 80 seconds, preferably between 5 and 40 seconds; and the dwell volume of the preferably gas-free fiber stock suspension in the hydraulic stabilizer is between 0.8 and 100 m 3 , preferably between 4 and 70 m 3 . These parameters have the advantage that they ensure optimum design of the above constant section and optimum operation as far as runability, etc. of the paper or cardboard machine. The hydraulic stabilizer is located immediately or indirectly following the outlet opening for the preferably gas-free fiber stock suspension.
[0024] According to the preferred embodiment of the invention there is located between the outlet opening for the preferably gas-free fiber stock suspension and the hydraulic stabilizer, at least one tube or pipeline.
[0025] It is also understood that the aforementioned and subsequently further explained characteristics of the invention may be utilized not only in the cited combinations, but also in other combinations, or self-contained, without relinquishing the scope of the invention.
[0026] Additional characteristics and advantages of the invention result from the subclaims and the following description of preferred design examples, whereby reference is made to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
[0028] [0028]FIG. 1 is a schematic and sectional side view of a device for deaerating a fiber stock suspension embodying the present invention;
[0029] [0029]FIG. 2 is another schematic and sectional side view of a device for deaerating a fiber stock suspension also embodying the present invention;
[0030] [0030]FIG. 3 is yet another schematic and sectional side view of a device for deaerating a fiber stock suspension also embodying the present invention; and
[0031] [0031]FIG. 4 is yet still another schematic and sectional side view of a device for deaerating a fiber stock suspension also embodying the present invention.
[0032] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Referring now to the drawings, and more particularly to FIG. 1, there is shown device 1 for deaerating fiber stock suspension 2 including horizontal tank 3 with a tank axis 3 a into which fiber stock suspension 2 , is supplied to a paper or cardboard machine, and is fed in the form of a thin mixture through at least one distributer pipe 4 which is parallel to tank axis 3 a and from which a plurality of successive jet tubes 5 originate for feeding fiber stock suspension 2 into tank 3 . The flow direction of fiber stock suspension 2 is shown by directional arrows ‘S’. In an effort to improve the deaerating capabilities of device 1 introduced fiber stock suspension 2 which, at this point still contains gas, is fed through jet tubes 5 above liquid level 6 in tank 3 , whereby gas 7 which may be present in the form of bubbles in fiber stock suspension 3 is separated before introduced fiber stock suspension 2 comes into contact with fiber stock suspension 2 already present in tank 3 . Jet tubes 5 terminate in slightly below tank ceiling 8 , reinforcing the deaeration process of fiber stock suspension 2 , since fiber stock suspension 2 impacts with tank ceiling 8 .
[0034] Referring additionally now to FIG. 2, a supply of fiber stock suspension 2 can also occur through a chamber system. Further, the addition of fiber stock suspension 2 may also occur in at least one of the ways described in unpublished German patent application DE 199 47 905.4 (PK10987 DE); its contents is herewith made the object of this description. In the upper area of tank ceiling 8 vacuum connection 9 with vacuum line 10 is connected to vacuum pump 11 . Vacuum connection 9 may alternatively be located in a side area of tank ceiling 8 . By connecting tank 3 to vacuum pump 11 the deaerating capability of device 1 is maximized, whereby gas 7 is pumped from tank 3 by vacuum pump 11 .
[0035] Further, in the area of tank ceiling 8 facing away from jet tubes 7 , several nozzles 13 are provided for the purpose of moistening tank surface 14 which is not in contact with fiber stock suspension 2 . This positively influences the speed and efficiency of the fiber stock suspension deaeration process taking place in tank 3 . Outlet opening 15 which flows into pipe system 16 for the purpose of discharging gas-free fiber stock suspension 2 . 1 is provided in the area of tank 3 which is facing away from distributor pipe 4 . Between distributor pipe 4 and outlet opening 5 for gas-free fiber stock suspension 2 . 1 , outlet opening 17 is provided for the separated, excess fiber stock suspension 2 . 2 which runs into pipe system 18 for the purpose of returning excess fiber stock suspension 2 . 2 into the circulation loop which is not illustrated here, which however, is well known in the art.
[0036] In one embodiment of the invention device 1 includes overflow 20 with overflow tube 19 having an overflow height H Ü and an overflow length L Ü located prior to outlet opening 17 to accommodate the flow of the separated, excess fiber stock suspension. Overflow tube 19 may be cylindrical or it may have a funnel like initial opening 21 having an aperture angle α, as illustrated in FIG. 1. The overflow length L Ü is calculated from the initial circumference of initial opening 21 . The aperture angle α generally assumes a value of between 30° and 80°, preferably between 40° and 50°. Overflow pipe 19 including discharge pipe 18 may be designed movably in accordance with the sliding mechanism indicated by double arrow 22 ; allowing for adjustment in overflow height H Ü . Weir 38 attached to the interior of tank 3 is located to deflect flow of the fiber stock suspension. In a preferred embodiment, pipe system 18 is adjustable in its length and form, such as a folded tube or similar. Overflow pipe 19 may be telescopic and divergent in nature providing adjustability of overflow height H Ü . Overflow pipe 19 may be coupled with at least one pipe segment which will alter overflow height H Ü and/or overflow length L Ü . Tank 3 may also include at least two outlet openings 17 , for separated excess fiber stock suspension 2 . 2 . At least one outlet opening 17 is designed as outlet 20 in the form of an outlet pipe 19 with an overflow height H Ü and an overflow length L Ü and whereby the at least one additional outlet opening is equipped with cover 36 .
[0037] A schematic sectional side view of a second preferred embodiment of device 1 for deaerating fiber stock suspension 2 , is illustrated in FIG. 2. Tank 3 inclusive of component parts and component groups of device 1 is described in the US-patent documentation U.S. Pat. No. 3,538,680 (≈DE-A 17 61 496). The content of this aforementioned patent document is herewith made the object of this description. The supply of fiber stock suspension 2 into tank 3 occurs via a plurality of communicating chambers 23 , whereby only two chambers 23 are indicated schematically. Communicating chambers 23 are located above liquid level 6 of fiber stock suspension 2 in tank 3 . Please refer to FIGS. 1 and 2 regarding possible arrangement of outlet opening 17 , including overflow pipe 19 for separated, excess fiber stock suspension 2 . 2 . Overflow 25 in the form of overflow pipe 24 having overflow height H Ü1 and overflow length L Ü1 is located prior to outlet opening 15 for directing the flow of the gas free fiber stock suspension 2 . 1 .
[0038] Concerning the arrangement of overflow pipe 24 we refer you to the details in FIG. 1 pertaining to overflow pipe 19 and overflow 20 for the flow of separated, excess fiber stock suspension 2 . 2 .
[0039] Additionally referring to FIG. 3 there is shown device 1 designed for deaerating of fiber stock suspension 2 . Device 1 includes horizontal cylindrical tank 3 with a tank axis 3 a into which fiber stock suspension 2 , that is to be supplied to the paper or cardboard machine, is fed in the form of a thin mixture through at least one distributer pipe 4 from which a multitude of successive jet tubes 5 originate for feeding fiber stock suspension 2 into tank 3 . Regarding additional design characteristics please refer to tank 3 illustrated in FIG. 1. Outlet opening 26 for the flow of gas free fiber stock suspension 2 . 1 is located in floor 27 of tank 3 . A vacuum in tank 3 is provided by way of vacuum connection 9 , vacuum line 10 , at least one vacuum pump 11 , optional condensers 37 and continuing line 12 near tank ceiling 8 . Further, in the area of tank ceiling 8 facing away from jet tubes 5 , nozzles 13 are provided for the purpose of moistening interior tank surface 14 which is not in contact with fiber stock suspension 2 .
[0040] Dwell chamber 28 in the form of hydraulic stabilizer 28 . 1 is located after at least one outlet opening 26 for the preferably gas-free fiber stock suspension 2 , viewed in direction S. Dwell chamber 28 including preferably a long horizontally cylindrical tank, at least one inlet opening 29 to accept fiber stock suspension 2 coming from tank 3 , at least one each outlet opening 30 , 31 , 32 located in tank 28 . Outlet opening 30 provided for the flow of gas-free fiber stock suspension 2 . 1 . Outlet opening 31 provided for the flow of gas 9 , outlet 32 being provided for the flow of excess fiber stock suspension 2 . 2 . Weir 38 may be attached to the interior of tank 3 and dwell chamber 28 being located to deflect flow of the fiber stock suspension. Overflow 33 in the embodiment of overflow tube 34 having overflow height H Ü and overflow length L Ü . Regarding the arrangement of overflow tube 34 we refer you to the details in FIG. 1 of overflow pipe 19 of overflow 20 for separated, excess fiber stock suspension 2 . 2 .
[0041] Hydraulic stabilizer 28 . 1 for preferably gas free fiber stock suspension 2 offers a dwell volume V V of between 0.8 and 100 m 3 , preferably between 4 and 70 m 3 , and dwell duration V D of preferably gas-free fiber stock suspension 2 in hydraulic stabilizer 28 . 1 is between 2 and 80 seconds, preferably between 5 and 40 seconds. Hydraulic stabilizer 28 . 1 is connected indirectly by tubing or piping with outlet opening 26 for the passage of preferably gas-free fiber stock suspension 2 and is located downstream from it.
[0042] Now further referring to FIG. 4 there is shown device 1 for deaerating fiber stock suspension 2 , similar to FIG. 3. Tank 3 is consistent with tank 3 shown in FIG. 2 in a different view; we therefore refer you to FIG. 2 for the further description. Tank 28 is consistent with tank 28 illustrated in FIG. 3; therefore we refer you to FIG. 3 for further details.
[0043] While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
Component identification index
[0044] [0044] 1 Device (for deaerating fiber stock suspension)
[0045] [0045] 2 Fiber stock suspension
[0046] [0046] 2 . 1 Gas free fiber stock suspension
[0047] [0047] 2 . 2 Separated, excessive fiber stock suspension
[0048] [0048] 3 Tank
[0049] [0049] 3 a Tank axis
[0050] [0050] 4 Distributer pipe
[0051] [0051] 5 Jet tube
[0052] [0052] 6 Liquid level
[0053] [0053] 7 Gas
[0054] [0054] 8 Tank ceiling
[0055] [0055] 9 Vacuum connection
[0056] [0056] 10 Vacuum line
[0057] [0057] 11 Vacuum pump
[0058] [0058] 12 Line
[0059] [0059] 13 Nozzle
[0060] [0060] 14 Tank interior surface
[0061] [0061] 15 , 17 , 17 . 1
[0062] [0062] 26 , 30 , 31 , 32 Outlet opening
[0063] [0063] 16 , 18 Piping system (discharge)
[0064] [0064] 19 , 24 , 34 Overflow pipe
[0065] [0065] 20 , 25 , 33 Overflow
[0066] [0066] 36 Cover
[0067] [0067] 21 Funnel shaped initial section
[0068] [0068] 22 Direction of movement
[0069] [0069] 23 Chamber
[0070] [0070] 27 Tank floor
[0071] [0071] 28 Tank
[0072] [0072] 28 . 1 Hydraulic Stabilizer
[0073] [0073] 29 Inlet opening
[0074] [0074] 37 Condenser
[0075] [0075] 38 Weir
[0076] H Ü , H Ü1 Overflow height L Ü , L Ü1 Overflow length S Direction of flow (arrow) α Aperture angle | The invention creates a device for deaerating fiber stock suspension including a horizontal cylinder tank, an inlet, an outlet opening, and a vacuum connection. An overflow tube may be positioned independently of the location of the inlet for the fiber stock suspension and the outlet for the deaerated fiber stock suspension. | 3 |
FIELD OF THE INVENTION
This invention relates to slitting machines and has special application to a cutter used in slitting cores for steel coils.
BACKGROUND OF THE INVENTION
Core cutters are machines which are associated closely with steel slitting operations. Namely, slit steel is recoiled onto cardboard cores which must closely approximate the width of each steel strand. Such cores are normally cut from long, thick cardboard tubes.
Prior art core cutters included machines which had a manually shiftable core support plate and a fixed cutter as shown in the attached John Dusenberry advertisement. Such core cutters were simple to operate and took up little space, but were not accurate and also slow in operation.
An automatic adjustable core cutter such as the machine shown in U.S. Pat. No. 5,170,684 utilized a fixed core and a movable cutter. Machines with movable cutters are not preferred because they require constant width support mandrels which are bulky and expensive. Since typical users of core cutters often use up to seven different diameters of cores, stocking and replacing these mandrels is both time consuming and costly.
SUMMARY OF THE INVENTION
The core cutter of this invention includes an axially fixed main support shaft which carries a stationary outboard core support plate and a shiftable inboard core support plate. A power motor serves to rotate a screw connected to a carriage of the inboard core plate. The inboard plate shifts along the main shaft relative to the outboard plate. A second power motor serves to rotate the main shaft when core cutting is to be performed.
An adjustable cutter and core support rollers are connected to the machine frame. When the core has been properly positioned according to preprogrammed instructions fed into the machine's microprocessor and read by an encoder connected to the power driven screw, the rollers are adjusted to snugly accommodate the core and the cutter is drawn into contact with the rotating core to cut the core into the desired widths.
Because of the construction of the machine, positive support is provided for the core all during cutting and shifting operations. Also, due to the digital position sensors and the drive mechanisms, highly accurate core cutting is achieved rapidly and at relatively low cost when compared to prior art core cutting machines.
Accordingly, it is an object of this invention to provide for a novel and improved core cutting machine.
Another object is to provide for a core cutter which is rapidly and accurately adjusted to cut a single core into varying preselected widths.
Another object is to provide for a core cutter which is readily adapted to accommodate any of a number of core diameters.
Another object is to provide for a core cutter which is reliable and inexpensive to maintain.
Another object is to provide for a core cutter which positively supports the core at all times during core cutting operations.
Other objects will become apparent upon a reading of the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention has been depicted for illustrative purposes only wherein:
FIG. 1 is a perspective view of the core cutter of this invention with a cardboard core affixed.
FIG. 2 is an end elevation view of the core cutter showing a core fitted onto the support plates.
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2.
FIG. 4 is an end elevation view of the core cutter showing the motor drives.
FIG. 5 a sectional view similar to FIG. 3, but showing the core in a second cut position with the inboard housing shifted.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment herein described is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is chosen and described to explain the principles of the invention and its application and practical use to enable others skilled in the art to utilize its teachings.
Referring now to the drawings, reference numeral 10 generally designates the core cutting machine of this invention. Machine 10 is adapted for use in cutting a cylindrical core 12 into precise widths. Cut cores 14 (FIG. 5) are used in steel slitting operations at the recoiler machine (not shown) with slit steel being wound about the cores after slitting. Core 12 is generally a long cylindrical tube preferably formed of a treated paper or cardboard material. The widths of individual cut cores 14 are preferably the same width as the strips of slit steel which are to be wound about the cores.
Machine 10 preferably operates as a stand alone unit and includes a base frame 16 defined by outboard support legs 18, inboard support legs 20, braces 22 and a support table 24. Legs 18 and 20 are spaced apart a preset distance and are spanned by braces 22 as shown.
Table 24 has an elongated opening 26 therethrough. Guide rails 28 and 30 are connected to table 24 adjacent to opposite sides of opening 26. Each guide rail 28 and 30 has an outer groove 32, 34, respectively which runs down the long axis of each guide rail.
Inboard housing 36 is shiftably connected to support table 24. Inboard housing 36 includes frame 38 and a chuck 40. Chuck 40 includes core support disk 42 and has slots 44 which accommodate shiftable chuck clamps 46. Disk 42 is preferably of the same diameter as the inner diameter of core 12 and is removably fastened to chuck 40 as by fasteners 48 to allow rapid changes as needed.
Inboard housing 36 also includes guide runners 64 which are supportively connected to the inboard housing as by bracket 66 and wedges 68. Guide runners 66 preferably form a tongue and groove joint with guide rails 28 which allows lateral shifting of inboard housing 36 while preventing axial shifting thereof.
Machine 10 also includes core support bracket 50. Bracket 50 is connected to support table 24 as by fasteners 52 and is generally L-shaped as shown. Y-bracket 54 is shiftably carried by L-bracket 50 as by fasteners 56 which slide in slot 58. Rollers 60 are rotatably connected to Y-bracket 54 as by pins 62 and serve to support a rotating core 12.
Support frame 70 extends upwardly from table 24 and includes support bearing 72. Shaft 74 is rotatably housed in bearing 72 and extends through bearing 76 of chuck 40 and through chuck 40 and disk 42 as shown. Core support disk 78 is connected to the terminal end of shaft 74 as by collar 80. Disk 78, like disk 42 is preferably of the same diameter as the outer diameter of core 12. Disk 78 may have a circumferential groove 82 as shown. Shaft 74 includes elongated key 84 which mates with a groove (not shown) in chuck 40 to permit correlative rotation of the shaft and chuck.
Motor 86, preferably an AC electric motor, is connected to support table 24. Motor 86 includes rotatable drive shaft 88 and pulley 89. Flywheel 92 is connected to the proximal end of shaft 74. A drive belt 90 is connected between drive shaft pulley 89 and flywheel 90 to transmit rotational movement of the drive shaft to the flywheel and thence to shaft 74. Cover housing 94 encloses flywheel 90 as shown.
Machine 10 also includes motor 96, preferably a DC electric motor, supported by cross brace 23. Motor 96 has its drive shaft 98 connected to the proximal end of an elongated drive screw 100 as by bearing 102. Drive screw 100 has its distal end housed in bearing 104 which is carried by cross brace 23. Encoder 106 has a shaft 108 in communication with bearing 104 and serves to precisely measure the rotations of drive screw 100.
Connecting bracket 110 is connected to and extends downwardly from inboard housing 38. Threaded fitting 112 is carried by connecting bracket 110 with drive screw 100 extending through the fitting.
Microprocessor 114 is electrically coupled to encoder 106 as by electrical leads 116. Microprocessor 114 is also connected to a power source (not shown) and to motor 86 and serves to control the operation of machine 10 in response to both preprogrammed instructions and by manually operated switches 118.
Cutting assembly 120 includes cutting disk 122 which is rotatably carried by bearing 124 attached to cutting arm 126. Cutting arm 126 is pivotally connected to an extensible rod 128 of power actuated cylinder 130. Cylinder 130 is pivotally connected to clevis 132 which is secured to support table 24. Support post 134 is connected to and extends upwardly from table 24. Bearing 136 is connected between cutting arm 126 and post 134. Cutting disk 122 is formed of a durable, corrosion-resistant metal and honed to a sharp edge.
Machine 10 functions to precisely cut full length cardboard tube cores 12 into multiple sections 14. With inboard housing 36 at its full retracted position of FIG. 1, a core tube 12 is loaded into the machine with its first end against frame 38. Disks 42 and 78 are of preferably the same diameter as the inner diameter of core tube 12 and provide lateral support for the core while not impeding its sliding movement. Chuck clamps 46 are shifted in slots 44 and firmly seat against core 12 to prevent rotation of core 12 relative to disks 42, 78. Rollers 60 are then adjusted to cradle core 12 and provide support during cutting operations.
An operator next programs the desired widths of core sections 14 to be cut from core 12 into the microprocessor 114. Machine 10 is switched on and motors 86 activates to turn flywheel 92 and shaft 74 as described above. Due to the connection between shaft 74, chuck 40, clamps 46 and core tube 12, the core tube rotates at the same velocity as shaft 74.
Encoder 106 through its shaft 108 senses the position of inboard housing 36 by reading the number of revolutions of drive screw 100. When microprocessor 114 so instructs, (based on the preprogramming) motor 96 activates to turn drive screw 100. Due to the threaded connection of drive screw 100 and fitting 112, the fitting advances in a linear fashion, and the fitting connection to housing 36 allows the inboard housing to shift as well. When the core reaches its first cutting position (,as determined by the preprogramming as read by encoder 106), motor 96 switches off. Fluid is delivered to power cylinder 130 and causes rod 128 to extend. This pivots cutting arm 126 and cutting disc 122 with the disc penetrating and cutting into the rotating core 12. Cutting disc 122 is aligned with support disk 78 and particularly with groove 82 to provide radial support for the core and insure an even cut.
After cutting is complete, the motor 96 activates to advance inboard housing 36 and core 12 to the next preprogrammed position. This operation continues until all desired core sections 14 have been cut. Guide rails 28, 30 coact with runners 66 to ensure accurate linear movement of inboard housing 36 and core 12 relative to shaft 74 and support disk 78 (which remain stationary).
It is understood that the above description does not limit the invention to the precise form disclosed, but may be modified within the scope of the following claims. | An adjustable cardboard core cutter for precisely cutting cardboard tubes used as cores in steel slitting operations. The core cutter includes an axially fixed main shaft fixed core support plate, and an axially shiftable core support plate. Cores to be cut are clamped to the shiftable plate which axially shifts in response to preset instructions. An axially fixed cutter serves to cut the core into precise widths. | 8 |
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to electrical connectors, and more particularly to electrical connectors having means whereby the electrical contacts are shielded to reduce the risk of electrical shock.
SUMMARY OF THE INVENTION
The electrical connector of this invention is intended to provide electrical contact between a device, such as an electric iron, and a power supply. The electrical connector allows the simple connection and disconnection of a device from a power supply, while shielding live contacts. The electrical connector is generally of the plug and socket type.
The electrical connector comprises a plug, which carries an electrically conductive contact, or plug prong. The plug prong is connected in electrical union to a device to which electrical power is to be furnished. In one aspect of this invention, the plug is carried by an electrically operated device such as an electric iron, and the plug prong comprises a pair of contacts electrically connected to the iron's heating element.
The electrical connector also comprises a socket. The socket carries an electrically conductive contact, or socket contact. The electrical connector has means for establishing electrical union between the socket contact and a power supply. The socket also has a passage, which comprises one or more apertures, which are adapted to receive at least a portion of the plug prong in an initial position out of contact with the socket contact, and in a final position in contact with the socket contact.
In one aspect of this invention, the socket comprises a support assembly for an electric device, such as an electric iron. In that aspect, the socket contact comprises a pair of contacts. When supported by the support assembly, the iron is connected to a power supply, to provide electricity to the iron's heating element to heat the iron sole plate. When removed from the support assembly, the iron is disconnected from the power supply. In this manner, a cordless electric iron or other electric device is provided.
The socket also carries a shutter or baffle, which is movable to a closed position, in which a portion of the baffle is interposed between the passage and the socket contact to block access to the socket contact by the plug prong or by other objects. In the case of a cordless electric iron, it is desirable to shield the socket contacts from the user when the iron is removed from its support, to prevent inadvertent contact with the socket contacts by the user.
The baffle is also movable to an open position, in which the socket contact is exposed to the passage to allow access to the socket contact by the plug prong. The socket carries means for movably maintaining the baffle in its closed position. In one aspect of this invention, such means comprise a spring.
When closed, the baffle is locked into place to provide substantial resistance to physical access to the socket contact. The locking feature can be accomplished by providing a baffle which opens by moving in a direction other than the direction in which the plug prong moves as it enters the passage and moves toward the socket contact. In one aspect of this invention, the baffle comprises a rotor having an axis generally transverse to the direction of travel of the plug prong toward the socket contact. The rotor has a horizontal axis on a line which passes generally between the socket contact and the passage. Force applied through the passage to the rotor in the direction of travel of the plug prong as the plug prong moves toward the socket contact will not cause the rotor to rotate to an open position. In that aspect, the rotor has cut-outs such that in one rotational position access to the socket contact is blocked, and in another rotational position access to the socket contact is provided. In another aspect of this invention, the baffle comprises a slide or rotor which moves between the passage and the socket contact in a plane generally transverse to the line of travel of the plug as it travels through the passage to the socket contact.
The baffle is provided with a baffle control arm. The baffle control arm is adapted to move from a first position to a second position, cooperating with the baffle to move the baffle from its closed position to its open position. The plug carries a projection which is adapted to engage a surface of the baffle control arm as the plug prong is moved toward the socket contacts. As the plug prongs are moved toward the socket contacts, the plug projection engages the baffle control arm. As the plug prongs continue to move toward the socket contacts, the plug projection moves the baffle control arm, thereby moving the baffle to its open position. When the baffle is in its open position, the socket contact is exposed to the plug prong. The plug prong can then continue to be moved toward the socket contact, to engage the socket contact, establishing an electrical connection between the plug prong and the socket contact.
Because the baffle is opened by moving the baffle control arm, thus exposing the socket contact, it is necessary to provide a means to minimize the risk of inadvertent contact with the socket contact when the baffle is in its open position. In the preferred electrical connector of this invention, the engagement surface of the baffle control arm is separate from the surface of the baffle exposed to the passage when the baffle is in its closed position. The engagement surface is also isolated from the socket contact. An object inserted into the socket to engage the baffle control arm and open the baffle is separated from the socket contact by a separating means. In one aspect of this invention, the means comprises a wall between the engagement surface and the socket contact. In another aspect of this invention, the means comprises an opening in the socket distinct from the passage, proximate the baffle control arm.
The plug can be disengaged from the socket in a reverse manner. As the plug prong is moved away from the socket contact, the projection is disengaged from the baffle control arm. The baffle is moved to its normal closed position by means such as a coil spring.
In the aspect of this invention comprising a cordless electric iron, an iron support is provided in which the socket contacts are shielded when the iron is disengaged from the support.
In an additional aspect of this invention, the socket carries a switch connected between the power supply and the socket contacts. The switch is normally in the open position, in which the socket contacts are electrically isolated from the power supply. The plug is adapted to close the switch as the plug prong is moved toward the socket contact. One feature of this aspect comprises a switch control which is engaged by a leg carried by the plug. In a further aspect of this invention, the plug is adapted to close the switch after the plug prong is engaged with the socket contact, to minimize electrical sparking between the plug prong and the socket contact.
Other features, aspects, and embodiments of this invention will be apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a rear perspective view of one embodiment of the plug and socket assembly of this invention, with the plug and socket disengaged and the baffle closed;
FIG. 2 is a front cross-section view of the embodiment shown in FIG. 1, taken along plane 2--2.
FIG. 3 is a top partial section view of the socket shown in FIG. 1, showing the baffle unsectioned in its closed position.
FIG. 4 is a top partial view of the socket shown in FIG. 3, with the baffle rotated to an open position.
FIG. 5 is a side cross-section view of the device shown in FIG. 2, taken along plane 5--5.
FIG. 6 is a side cross-section view of the device shown in FIG. 2, taken along plane 6--6.
FIG. 7 is a bottom section view of the device shown in FIG. 5, taken along plane 7--7.
FIG. 8 is a front cross-section view of the device shown in FIG. 2, in its engaged position, with the baffle open.
FIG. 9 is a side cross-section view of the device shown in FIG. 8, taken along plane 9--9.
FIG. 10 is a side cross-section view of the device shown in FIG. 8, taken along plane 10--10.
FIG. 11 is a side cross-section view of another embodiment of this invention.
FIG. 12 is a side cross-section view of yet another embodiment of this invention.
FIG. 13 is a front perspective view of a cordless iron and support, incorporating the electrical connector of this invention.
FIG. 14 is a partial front cross-section view of the iron and base of FIG. 13, in an engaged position.
FIG. 15 is a partial side cross-section view of the iron and base of FIG. 14, taken along plane 15--15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the embodiment of the invention shown in FIGS. 1 through 10, the electrical connector of this invention comprises a socket 1 and a plug 2. The socket 1 comprises a housing 3, an electrical socket contact 4, means for establishing electrical union between socket contact 4 and a power supply, and a baffle 5. Socket contact 4 is mounted in the housing adjacent to passage 6, an aperture through which socket contact 4 can be reached.
FIGS. 1 through 10 show an embodiment preferred for use in connection with dual wire electrical leads, such as commonly used to transmit alternating current to electrical devices. In that embodiment, a second socket contact 7 is provided, along with a corresponding second aperture 8. The pair of apertures 6, 8 are located such that they can receive corresponding electrically conductive plug prongs 9, 10 carried by the plug 2 in a position of engagement with socket contacts 4, 7. In the preferred embodiment, socket contacts 4, 7 comprise contact surfaces 15, 16 and contact supports 17, 18. The contact supports 17, 18 comprise flexible members such as brass springs, to allow movement of contact surfaces 15, 16.
Socket contacts 4, 7 are shielded from access through apertures 6, 8 by a baffle 5. Baffle 5 is normally in a closed position, in which socket contacts 4, 7 are not exposed to apertures 6, 8. Baffle 5 is movable to an open position, in which socket contacts 4, 7 are exposed to apertures 6, 8. The purpose of baffle 5 is to prevent inadvertent contact with socket contacts 4, 7.
In a preferred embodiment of the electrical connector of this invention, means are provided to prevent inadvertent movement of baffle 5 to its open position. If a foreign object, such as a knife or screw driver, is used to probe apertures 6, 8 when plug 2 is disengaged, socket 1 should resist access to the socket contacts 4, 7. Socket 1 incorporates means to prevent movement of baffle 5 to the open position by force applied through one or both apertures 6, 8, and to allow movement of baffle 5 to the open position by force applied at some point other than a point on baffle 5 exposed to apertures 6, 8 when baffle 5 is in the closed position.
In the preferred embodiment of this invention, baffle 5 comprises a generally cylindrical rotor which can be rotated to an open position, allowing access to socket contacts 4, 7. Baffle 5 is rotatably supported at its ends 11, 12 by housing 3. Baffle 5 is biased to a closed position, in which baffle surfaces 21, 22 are interposed intermediate socket contacts 4, 7 and apertures 6, 8, serving as a shield to block access to socket contacts 4, 7. Baffle 5 is also movable to an open position in which baffle surfaces 21, 22 are offset out of alignment between apertures 6, 8 and socket contacts 4, 7 so that socket contacts 4, 7 are exposed to apertures 6, 8. Baffle 5 is biased to the closed position by a biasing element such as spring 20.
When in a closed position, baffle surfaces 21, 22 form a shield which is exposed to apertures 6, 8, as best shown in FIGS. 2 and 3. Baffle 5 is located such that baffle 5 will tend to resist rotation to an open position by a force applied to surfaces 21, 22 through one or both apertures 6, 8. To accomplish such resistance, baffle 5 is located such that substantially all of the motion of baffle 5 adjacent to apertures 6, 8 is in a direction substantially different than the direction of travel of plug prongs 9, 10 as they pass through apertures 6, 8 toward socket contacts 4, 7. In a preferred embodiment, the direction of motion of baffle 5 proximate apertures 6, 8 is in a direction at an angle of greater than about 45 degrees from the direction of travel of plug prongs 9, 10 through apertures 6, 8. In the most preferred embodiment, the direction of travel of baffle 5 proximate apertures 6, 8 is generally transverse to the direction of travel of plug prongs 9, 10 through the apertures 6, 8.
To provide the desired direction of travel in a rotating baffle, baffle 5 is preferably located with its axis generally transverse of the direction of travel of plug prongs 9, 10 as they travel through apertures 6, 8 toward socket contacts 4, 7. Preferably, the axis of baffle 5 is in a plane passing generally through apertures 6, 8 and socket contacts 4, 7. With the axis of baffle 5 in such a position, a line of force exerted on baffle 5 through apertures 6, 8 will tend to intersect the axis of baffle 5, and will be resisted by housing 3 supporting ends 11, 12 of baffle.
Baffle 5 is provided with cut-outs 13, 14 which accomodate contact surfaces 15, 16 and portions of socket contacts 4, 7 adjacent thereto when baffle 5 is in a closed position. Cut-outs 13, 14 receive plug prongs 9, 10 when baffle 5 is in its open position exposing socket contacts 4, 7. Baffle 5 is also provided with a cut-out 19 which accomodates a portion of a spring 20, preferably a coil spring. Spring 20 biases baffle 5 in a closed position. Spring 20 also limits movement of baffle 5 in a counter-clockwise direction as shown in FIG. 6. Spring arm 32 engages cut-out wall 33 as baffle 5 is moved in a counter-clockwise direction, biasing baffle 5 in a closed position.
A baffle control arm 23 is provided, which cooperates with baffle 5 to allow baffle 5 to be moved from its closed position to its open position. Baffle control arm 23 has an engagement surfaces 24, to which force can be applied to move baffle 5 to its open position. Engagement surface 24 is separate from baffle surfaces 21, 22, offset in such a manner that engagement surface 24 is not readily engageable through apertures 6, 8. Baffle 5 will resist opening if force is applied through apertures 6, 8 to baffle surface 21, 22 but will readily open if force is applied to engagement surface 24.
In the preferred embodiment of this invention, baffle control arm 23 is an integral part of baffle 5, and comprises a lever which projects axially from baffle 5 to provide engagement surface 24 removed from baffle surfaces 21, 22. Baffle control arm 23 extends radially a sufficiently great distance to provide an acceptable engagement surface 24, and to provide a sufficiently long moment arm so that the force required to rotate baffle 5 is within acceptable limits.
Plug 2 carries a projection 25 which is adapted to engage baffle control arm 23 when plug prongs 9, 10 are aligned with socket contacts 4, 7. As plug prongs 9, 10 are moved toward socket contacts 4, 7, in alignment with apertures 6, 8 projection 25 engages engagement surface 24 of baffle control arm 23. As plug prongs 9, 10 continue to move toward engagement with socket contacts 4, 7, projection 25 maintains engagement with baffle control arm 23 and moves baffle control arm 23 from its first position, corresponding to the closed position of baffle 5, to its second position, corresponding to the open position of baffle 5. Baffle control arm operates on baffle 5 by translating the generally linear motion of projection 25 to rotational motion to move baffle 5 from its closed position to its open position.
As plug 2 is moved toward socket 1, with plug prongs 9, 10 in alignment with apertures 6, 8, projection 25 may engage baffle control arm 23 either before or after plug prongs 9, 10 are received by apertures 6, 8, depending on the relative lengths of projection 25 and plug prongs 9, 10. It is preferred that baffle 5 remain closed until plug prongs 9, 10 are immediately adjacent to baffle 5. It is also preferred that plug prongs 9, 10 not engage baffle 5, since engagement would tend to retard the movement of baffle 5. In the preferred embodiment shown in FIGS. 1-12, baffle control arm 23 is a lever arm projecting radially from baffle 5. The distance between baffle 5 and plug prongs 9, 10 in their position when projection 25 is in initial engagement with baffle control arm 23 in its first position must be at least as great as the distance projection 25 must travel to move baffle control arm 23 from its first position to its second position. In the preferred embodiment, baffle 5 is located immediately adjacent apertures 6, 8. As plug 2 is moved toward engagement with socket 1, projection 25 engages baffle control arm 23 before plug prongs 9, 10 are received by apertures 6, 8.
In this manner, a plug and socket arrangement is provided in which socket contacts 4, 7 are shielded by baffle 5, and in which plug 2 cooperates with socket 1 to move baffle 5 to an open position as plug contacts 9, 10 are moved toward socket contacts 4, 7 for electrical engagement.
Means are provided to prevent movement of a foreign object from engagement with baffle control arm 23 into engagement with socket contacts 4, 7. In a preferred embodiment of the electrical connector of this invention, baffle control arm 23 is physically separated from socket contacts 4, 7 by a wall supported by socket 1. In the most preferred embodiment, the separating means comprises a baffle wall 26 adjacent to baffle control arm 23, formed by three sides of a cut-out in baffle 5 opposite socket cut-outs 13, 14. An object engaging engagement surface 24 of baffle control arm 23 is prevented from moving to socket contacts 4, 7 by baffle wall 26. Baffle wall 26 physically separates baffle engagement surface 24 and socket contacts 4, 7 in all positions of baffle 5 between its closed position and its open position. If the foreign object is removed from baffle control arm 23, biasing means 20 moves baffle 5 to its closed position.
In the preferred embodiment of the electrical connector of this invention, the separating means also comprises housing wall 27, which defines an opening 28 through which baffle control arm 23 is accessable. To minimize inadvertent contact with baffle control arm 23, it is recessed within opening 28. In the preferred embodiment, opening 28 is formed in the shape of a slot adapted to receive plug projection 25. As plug 2 is directed to socket 1, projection 25 is received by opening 28. When plug 2 is fully engaged with socket 1, and plug prongs 9, 10 are in their final position electrically engaged with socket contacts 4, 7, at least a portion of plug projection 25 resides within opening 28. A foreign object inserted into opening 28 in engagement with engagement surface 24 is blocked from contact with socket contacts 4, 7 by housing wall 27. Movement of the object from opening 28 to one of the apertures 6, 8 disengages the object from baffle control arm 23. When the object is disengaged from baffle control arm 23, spring 20 moves baffle 5 into its closed position.
The preferred embodiment of this invention contains an additional means to prevent inadvertent contact with live electrical contacts. Such means comprises a switch 29 connected between a power supply and one of the socket contacts 4, 7. When the plug 2 and socket 1 are disengaged, switch 29 is in the "off" position, and socket contacts 4, 7 are electrically dead. When plug 2 and socket 1 are fully engaged, so that plug prongs 9, 10 are engaged with socket contacts 4, 7, switch 29 is in the "on" position, and socket contacts 4, 7 are electrically live. Switch 29 isolates socket contacts 4, 7 from electrical power until socket contacts 4, 7 are isolated from inadvertent contact by engagement of plug 2 and socket 1.
Switch 29 is activated by button 30, which is depressed to close switch 29. Plug 2 has means for depressing button 30 to close switch 29 as plug 2 is engaged with socket 1. In the preferred embodiment, such means comprises projection 25. As plug 2 and socket 1 are engaged, plug projection 25 engages slide 31. Slide 31 is thereby moved to depress button 30, closing switch 29. In the preferred embodiment, switch 29 is closed only after plug prongs 9, 10 have engaged socket contacts 4, 7, to eliminate electrical sparking between plug prongs 9, 10 and socket contacts 4, 7. To allow the necessary movement of plug 2 toward switch 29 to close switch 29 after socket contacts 4, 7 have been engaged, socket contacts 4, 7 include yieldable contact supports 17, 18 preferably comprising flexible leaf springs.
The preferred embodiment of the electrical connector of this invention includes a further means to prevent accidental contact with live electrical contacts. Plug 2 and socket 1 are adapted to interfit in such a manner that socket contacts 4, 7 are hidden from user access when baffle 5 is open. Plug prongs 9, 10 are carried by a wall 75 surrounded by skirt 34. Wall 75 and skirt 34 define a recess into which plug prongs 9, 10 extend. Socket 1 has a raised portion 76, the external dimensions of which generally correspond to the internal dimensions of the recess. Plug prongs 9, 10 and apertures 6, 8 are located such that plug 2 and socket 1 can be mated. As plug 2 and socket 1 are mated, projection 25 opens baffle 5 only after skirt 34 shields apertures 6, 8 from external access.
In the preferred embodiment of this invention, the sequence of events as plug 2 is moved toward socket 1 is as follows: Plug 2 and socket 1 are generally aligned. As plug 2 is moved toward socket 1, the recess formed by skirt 34 and wall 75 on plug 2 receives raised portion 76 of socket 1, orienting plug prongs 9, 10 into alignment with apertures 6, 8 and also orienting projection 25 into alignment with opening 28. Opening 28 receives projection 25, to further align plug prongs 9, 10 with apertures 6, 8. As plug 2 is moved into further engagement with socket 1, skirt 34 conceals apertures 6, 8 and projection 25 engages baffle control arm engagement surface 24. As plug 2 continues to be moved into further engagement with socket 1, projection 25 depresses baffle control arm 23, moving it from its first position, causing baffle 5 to move. As plug 2 is moved into further engagement with socket 1, projection 25 continues to move baffle control arm 23 toward its second position, moving baffle surfaces 21, 22 out of interposition between plug prongs 9, 10 and socket contacts 4, 7. As plug 2 is moved into further engagement with socket 1, plug prongs 9, 10 move into the volume previously concealed by baffle surfaces 21, 22, and engage contact surfaces 15, 16 on socket contacts 4, 7. As plug 2 continues to move toward complete engagement, plug prongs 9, 10 move contact surfaces 15, 16, and projection 25 engages button 30 through slide 31, closing switch 29 and providing electrical power through socket contacts 4, 7 to plug projections 9, 10.
A side cross-section of a section embodiment of a socket of this invention is shown in FIG. 11. In that embodiment, baffle 35 comprises a paddle or door, pivoted on an axis 36 generally transverse to the direction of travel of plug 77 as it engages socket 37. Baffle 35 is prevented from rotating in a counter-clockwise direction, toward socket contact 38, by stop 39. Baffle 35 is biased against stop 39 by an axial spring 40. Baffle 35 is rotatable in a clockwise direction by force exerted through opening 41 against baffle control arm 42. The electrical connector of this second embodiment operates in substantially the same manner as described above with respect to the first embodiment. As plug 77 is directed toward socket 37, plug 77 is aligned by housing 43 to orient plug prong 78 toward aperture 44, and plug projection 79 through opening 41 toward baffle control arm 42. As plug 77 is moved into engagement with socket 37, plug projection 79 engages baffle control arm 42 and moves baffle 35 toward plug prong 78 out of alignment between plug prong 78 and socket contact 38. As in the previous embodiment, it is preferred that a switch be provided which energizes socket contact 38 after plug prong 78 is engaged with socket contact 38.
A third embodiment of the socket of this invention is shown in side cross-section in FIG. 12. In this embodiment, baffle 45 is slidable rather than rotatable. Baffle 45 is biased by spring 46 in a closed position, in which baffle surface 47 conceals socket contact 48. Socket 49 is provided with a baffle control arm 50, in engagement with baffle 45. Baffle control arm 50 has an engagement surface 51 which is oriented at an angle with respect to the direction of opening 52 and the direction of movement of plug prong 80. As plug 81 is engaged with socket 49, plug projection 82 enters opening 52 and engages engagement surface 51, moving baffle control arm 50, and thus baffle 45, to the left. When baffle 45 is moved to the left, baffle surface 47 is removed from interposition between plug prong 80 and socket contact 48, and orifice 53 is moved into alignment with aperture 54, allowing plug prong 80 to pass through orifice 53 and into engagement with socket contact 48. As in the previously described embodiments, it is preferred to provide a switch which prevents socket contact 48 from being electrically active until plug prong 80 is in engagement with socket contact 48.
As is evident from the above disclosure, other embodiments fall within the scope of the claims of this invention. For example, the socket may incorporate a baffle which rotates about an axis generally parallel to the direction of travel of the plug prongs. In a preferred embodiment of such a socket, the baffle is generally planar and moves in a direction generally transverse of the direction of the plug prongs. In side view, the plug and socket assembly appears similar to that shown in FIG. 12. Instead of sliding along a generally straight transverse line, the baffle movement in this embodiment describes a transverse arc.
In another embodiment, a single passage is provided through which a pair of socket contacts is accessible. In another embodiment, the baffle control arm and the baffle are separate elements, rather than integral.
In another embodiment, the direction of travel of the plug prong toward the socket contact is substantially different than the direction of travel of the plug prong from the point of engagement with the socket contact to the point at which the switch is closed to provide electrical power to the socket contact. In this embodiment, the plug prong is aligned with the passage, is moved into the passage in a generally straight line to engage the socket contact, and then is rotated in engagement with the socket contact to energize the socket contact. In cross-section, the embodiment resembles FIGS. 1-12, except that the means for engaging the switch requires a force directed transverse to the direction of travel of the plug prong as it engages the socket contact. The switch is provided with a button on its side, rather than on its top as shown in FIG. 6, which is engaged by the projection as the plug is rotated in the socket.
Another embodiment of this invention is shown in FIGS. 13-15. Those figures show a cordless iron which incorporates the electrical connector of this invention. Iron 55 incorporates plug 56 electrically connected to iron heating element 57. Iron control 58 operates conventionally to modulate heat produced by heating element 57. Plug 56 is adapted to be received by socket 59 carried by iron support 60, to support iron 55 when it is not in use, and to provide electrical power to iron 55. Socket 59 is connected to cord 61 and cord plug 62, by which socket 59 can be electrically connected to a power supply. Socket 59 comprises baffle 63, in the shape described above with respect to baffle 5. Baffle 63 is biased closed by coil spring 64 when plug 56 is not in engagement with socket 59. Projection 65 carried by plug 56 cooperates with baffle control arm 66 to open baffle 63 when plug 56 engages socket 59, exposing socket contacts 67 to plug prongs 68. As iron 55 is placed on support 60, plug 56 engages socket 59. Plug prongs 68 enter apertures 69 in socket 59, and projection 65 engages baffle control arm 66. As iron 55 is lowered into place on support 60, projection 65 cooperates with baffle control arm 66 to open baffle 63, and plug prongs 68 engage socket contacts 67. Socket contacts 67, incorporating springs 70, are deflected slightly downward by the weight of iron 55, allowing projection 65 to engage slide 71 which in turn engages button 72 of switch 73. Switch 73 is electrically connected between cord 61 and one of socket contacts 67. When switch 73 is turned on by depressing button 72, electrical power can be provided to socket contacts 67 via cord plug 62 and cord 61. Skirt 74 shields socket contacts 67 from user access when baffle 63 is in its open position as iron 55 is being lowered into place on support 60 and as it is being lifted from support 60.
Another feature of the cordless iron of this invention is rotary table 83 incorporated into support 60. Screw 84 holds table 83 and platform 85 together, and provides and axis about which table 83 can rotate. Table 83 is supported proximate screw 84 by ledge 86, which slides against edge 87 when table 83 is rotated on platform 85.
As is apparent from the above description, many other embodiments and features of this invention are included within the intent and scope of this invention as defined by the appended claims. | A shielded electrical connector usable in conjunction with a household electrical appliance such as a cordless iron. The connector comprises a plug and a socket, the socket having a movable baffle which is held closed when the plug is not engaged with the socket, to isolate the socket's electrical contacts behind a shield section of the baffle. The socket also has a baffle arm, isolated from the shield section of the baffle, by which the baffle may be opened. The plug bears a projection which engages the baffle arm as the plug engages the socket. The socket also has an electrical switch which activates the socket's electrical contacts after the plug is substantially engaged with the socket. | 3 |
FIELD OF THE INVENTION
The present invention relates to the construction of oil, gas, geothermal or other wells having a casing inserted into the well bore, and cemented into place. More particularly, but not exclusively, the present invention relates to improvements in casing installation equipment which may find application in the construction of centralizers, float shoes and float collars.
BACKGROUND OF THE INVENTION
The improvements in casing installation equipment described herein may find application in the construction of float collars, float shoes and such related components as are used in casing installation. The details of such improvements are discussed below with particular reference to casing centralizers, although it is understood that such techniques may be applied to the abovementioned related components.
When the drilling stage of a well is completed a casing string is lowered into the bore of the well. The casing serves to prevent the collapse of unstable portions of the formation through which the well is being drilled, provide a smooth bore through which the production fluids and/or gas may flow and prevent pressure loss and/or fluid and gas migration between zones.
The casing is secured within the well bore by cementing. In this process, a cement slurry is pumped downward into the casing and up within the annular volume created between the casing outer wall and the bore surface. It is essential that the cement provides a uniform shell of substantially constant thickness surrounding the casing. To this end, adequate stand-off must be maintained between the bore wall and the outside surface of the casing.
In practice, it is virtually impossible to produce a well bore which is perfectly straight. A consequence of this being that the casing frequently rests against the bore wall over portions of the well length. This problem is further exacerbated when drilling volcanic formations in which large hard rock intrusions ("ghoulies") are encountered. In this latter case the drill string departs from the vertical, thereby forming a deviated bore path through which the casing string must pass.
If insufficient stand-off is maintained, the upward flow of the cement slurry is impeded thus increasing the likelihood of forming cavities in the cement. Such voids can lead to the undesireable migration of gas or fluid from one zone to another. In some instances catastrophic failure of the well can result from migration of high pressure gas or fluid up the outside of the casing due to inadequate cement placement.
To provide the required degree of standoff, casing centralizers spaced apart at regular intervals along the casing string, are used to hold the casing in the center of the well bore.
Casing centralizers are generally constructed in the form of a metal cage incorporating two end collars with an internal diameter such that the casing fits closely within the bore of the centralizer collars. The two collars are connected longitudinally by bow springs thereby forming a cylindrical cage which holds the casing off from the formation via the resilient action of the bow springs.
Bow spring centralizers can fail in situations where pronounced well deviations produce lateral forces which compress the bow springs sufficiently to allow the casing to lie against the well bore. In this situation, inadequate standoff may produce cement voids leading to failures as described above. In addition, the relatively flimsy construction of such centralizers can result in mechanical failures and/or jamming under conditions often encountered downhole, such as passing through key seats. A further disadvantage of bow spring centralizers is that they exhibit high axial drag or "starting force" due to the sustained tension of each bow spring against the wall of the well bore.
An alternative type of centralizer commonly used incorporates rigid metal strips tapering at each end which replace the resilient bow springs discussed above. Centralizers of this type are rigid in construction and lend themselves to cast manufacturing techniques. The collars may extend over the entire length of the centralizer thereby forming an enclosed cylinder with solid metal stand-off elements which are cast integrally or attached separately. This type of centralizer, while providing positive casing standoff can also produce high frictional loads when `running` the casing into the well. These frictional loads, while lower than for a bow spring centralizer, can pose a significant problem in high displacement deviated and horizontal wells with there being many instances where the well could not be properly cased. This type of centralizer, when cast in aluminium or other soft materials, is prone to wear whilst in use leading to potential loss of standoff and consequent inferior cementation.
Many currently available centralizers exhibit hydrodynamic shortcomings including: high pressure drop; high turbulence without enhancing cementation; and a tendency to induce cement `roping` due to excessive turbulence and/or wide exit transitions.
Casing centralizers are generally secured to the casing at the junction of two casing sections. However, there is no strict requirement that the centralizer be located at this position and they may be located at any point along the casing string.
Centralizers are secured to the casing string via stop collars located above and/or below the centralizer body or they may be attached directly to the casing using set screws incorporated into the centralizer itself. In the latter case the centralizer is fixed axially and longitudinally and in the former it is free to rotate thereby aiding penetration downhole.
Float collars are collars screwed onto the casing string and usually connect the lowermost length of casing to the rest of the string. They contain one of more valves which normally may be operated by remote means by the drilling crew at the surface.
A float shoe is similar to a float collar except that it is screwed to the bottom of the lowermost length of the casing.
It is an object of the present invention to provide casing installation equipment which at least alleviates the abovementioned problems, or to at least provide the public with a useful choice.
SUMMARY OF THE INVENTION
In one aspect this invention provides for improved casing installation components comprising:
a component body;
a plurality of support pedestals protruding from the outer surface of said body positioned so that the casing is held substantially in the centre of the well bore, friction reducing means mounted in banks in axially and peripherally spaced relation on the outer surface of at least some of the support pedestals and adapted to reduce resistance to axial movement of the component and consequently the casing string through the well bore.
Preferably the support pedestals are, in plan, tear-drop shaped and taper towards their outer surface whereby the outer surface generally conforms to a cylinder having a central axis coincident with that of the body.
Preferably the friction reducing means comprises one or more rollers mounted via a roller securing means on the surface of or partially recessed into each support pedestal.
Preferably each roller may comprise one or more cylinders.
Most preferably each roller may comprise one or more tapering cylinders and/or barrels constructed and arranged so as to present a surface in contact with the well bore which is substantially congruent to the cross sectional shape of the well bore.
Preferably each roller may have an axis of rotation substantially perpendicular to the axis of the centralizer body and parallel to the support pedestal surface.
Preferably the roller securing means comprises a pin inserted through a bore machined into the support pedestal arranged so as to pass through a bore machined in the roller or rollers
Preferably the centralizer incorporates a securing means by which the centralizers longitudinal movement in relation to the drill string is substantially constrained.
Preferably the securing means comprise set screws or the like incorporated into the body of the centralizer.
Preferably the component is a float collar.
Preferably the component is a float shoe.
According to a further aspect there is provided an improved casing installation component comprising:
a component body;
a plurality of support pedestals protruding from the outer surface of said body being substantially tear-drop shaped in the axial direction of the body and positioned so that the casing is held substantially in the centre of the well bore;
friction reducing means mounted on the outer surface of at least some of the support pedestals and adapted to reduce the resistance to axial movement of the component and subsequently the casing string through the well bore.
The exemplary embodiment which follows is directed toward the particular application of the invention in the construction of a casing centralizer.
It is to be understood that the invention may be described in the context of other installation equipment detailed above, and is in no way restricted to the particular example which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention is now described by way of example in which:
FIGS. 1A and 1B illustrate a side and end elevation respectively, of a possible configuration of a roller centralizer.
FIG. 2. illustrates a detail of the roller and support pedestal along line II--II.
FIG. 3. illustrates a perspective view of the centralizer shown in FIGS. 1 and 2.
FIG. 4. illustrates an alternative embodiment having tear-drop shaped pedestals.
FIG. 5 illustrates a side view of the centralizer shown in FIG. 4.
FIG. 6 shows a cross-sectional view through line VI--VI of the centralizer shown in FIG. 4.
FIG. 7 shows a cross-sectional view of the centralizer shown in FIG. 5 through line VII--VII.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1A, 1B and 3, a roller centralizer 10 is shown. The centralizer body 1, is of a tubular form with a smooth bore with an internal diameter such that it fits snugly around the casing string. In use, the centralizer is positioned at either a casing joint or at a point between casing joints.
The roller centralizer is secured to the casing string (not shown) via a stop collar (not shown) positioned immediately above and/or below the roller centralizer. Any stop collars well known in the art may be used, such as collars in the form of rings incorporating set screws or compression means by which the stop collar is compressed around the circumference of the casing thus relying on friction to resist movement along the longitudinal axis of the casing string. Thus the roller centralizer is free to rotate around the casing but is constrained to a fixed position along the axis of the casing string.
It is also contemplated that the roller centralizer itself may incorporate securing means such as in the form of set screws adapted to fix the roller centralizer to the casing thereby inhibiting any rotational or longitudinal movement.
An advantage of allowing the roller centralizer to rotate with respect to the casing string is that in deviated wells a degree of casing rotation may be required to penetrate to the well bottom.
The roller centralizer body 1 is formed from rigid material satisfying the criteria of corrosion resistance and extreme durability (eg: a metal). To this end a solid cast construction is employed preferably using a ductile nodular iron. However, it is envisaged that other materials such as injection moulded plastics or carbon fibre may be suitable depending on cost and ease of manufacture.
Support pedestals 2 can be formed integrally with the roller centralizer body 1. As shown in FIG. 2, these pedestals are of a radial dimension such that sufficient stand-off is maintained between the casing string and the well bore.
Roller assembly 3 comprising two tapered rollers 3a and 3b is mounted in recesses in the surface of the support pedestal by means of pin 4 inserted sideways through a bore 5 machined in the support pedestal and the bore of the rollers.
The pin 4 is constrained within the bore 5 by means of a brazed or arc welded infill 6.
It is envisaged that the rollers may be constructed of metal. However, it is contemplated that other materials such as thermoplastics may be used.
The cross sectional shape of the rollers 3a and 3b is such that they conform to the internal surface of the well bore, thereby allowing the centralizer in conjunction with the casing string, to pass freely through the well bore.
In use, cement is pumped down the outside of the casing string. The pedestals are spaced apart in such a configuration on to allow the cement to flow downward to fill the volume between the casing and well bore completely. It is desirable that a degree of turbulent flow be maintained in the cement to enhance cementation, however under some conditions cement "roping" may occur resulting in cavities which can lead to casing failure as discussed above. To avoid this problem, it is envisaged that the pedestals may be tear-drop in shape, thus presenting a hydrodynamically smooth obstacle around which the cement must flow. An example of such a pedestal configuration is shown in FIGS. 4 to 7. The tear-drop shaped pedestals 7 lie parallel to a helix on the surface of the casing body 8 and producing a "fling" effect on the surface of the roller centralizer.
The rollers 9 are shaped so as to be accommodated in the particular pedestals configuration shown. It is to be understood that the roller position is not limited to that shown and other arrangements may be suitable.
The pedestal shape shown has been found to be particularly suitable, however, it is envisaged that a variety of pedestal cross-sections could be employed to provide a similar result depending on the conditions.
It is envisaged that other roller configurations are possible, such as roller elements comprising single hollow untapered cylinders, secured in a single recess in a manner similar to that described above. However, it has been found that the tapered roller configuration illustrated in FIG. 2 when compared to the solid centralizer without rollers as described above, has reduced the estimated coefficient of friction from 0.45 to 0.05--an approximately tenfold decrease.
It is anticipated that the means by which the pins 4 are secured in the support pedestals may include peened over pins, nuts, bolts, circlips, and split pins. However, these constructions are considered less reliable than the securing method shown in FIG. 2.
The distribution and number of the support pedestals on the surface of the roller centralizer body is generally as shown in FIG. 1, namely five pairs of pedestals spaced radially around the body surface, and each pair 2a and 2b aligned parallel with the roller centralizer body axis. However, any configuration which may be contemplated will be a compromise between the desired reduction in the running in friction and the hydrodynamic efficiency of the centralizer when pumping in the cement slurry.
Accordingly, other arrangements and numbers of pedestals are anticipated without departing from the principles of the novel technique of reducing the running in friction at the interface between the support pedestal and the well bore.
It is to be understood that the construction described above may be adapted to float shoes, float collars and other related items of casing installation equipment, where it is desirable to minimize running in friction.
The improved casing installation equipment may find application in a variety of drilling situations such as gas, geothermal and oil.
It is particularly suitable in situations where a casing string is to be lowered into a well bore thereby providing a conduit through which production fluids may pass thereby avoiding pressure loss and/or migration between zones.
Accordingly, it is to be understood that the scope of the invention is not limited to the described embodiment and therefore that numerous variations and modifications may be made to this embodiment without departing from the scope of the invention as set out in this specification. | Improvements in casing installation components are described. The modified construction comprises radial support pedestals (2) incorporating rollers (3) on the outside of the support pedestals so that the rollers reduce longitudinal friction between the component and the well bore. The improvements described may be adapted for use in the construction of casing centralizers, float shoes, float collars and similar equipment which is inserted into the well bore. | 4 |
FIELD OF INVENTION
The present invention relates generally to planing boats and more particularly to planing boats having a variable configuration hull.
BACKGROUND OF INVENTION
As a planing type boat moves along the surface of a body of water, it becomes increasingly susceptible to overturning or damage by impact with even minor waves as the speed of the boat increases. Therefore, it is desirable to reduce the effect of impact on the water by the hull of the boat. The present invention proposes to reduce the effects of impact on the water by varying the configuration of the hull as the speed of the boat increases.
There have been devised boats that have a variable configuration hull. One such boat is shown in the patent to Anderson, U.S. Pat. No. 4,458,622, issued on July 10, 1984. The patent to Anderson discloses a displacement hull designed for low resistance at relatively low speeds, and includes an aft section having a pair of services displaceable to a position and added to such that at higher speeds, the hull gives lift to the stern to facilitate a planing action. The displaceable portions of the hull may be in the form of plates but are more preferably solid bodies which fit into recesses in the hull that can be extended when needed.
While the patent to Anderson teaches a hull having displaceable portions, the basic configuration of the hull remains the same. No prior art teaches a hull which changes its basic configuration entirely. Moreover, no prior art teaches a hull which changes configuration in response to the increased speed of the boat.
SUMMARY AND OBJECTS OF INVENTION
The present invention provides a planing boat whose hull changes its basic configuration in response to the increased speed of the boat. The hull includes two side panels hingedly secured to opposite sides of an elongated keel panel. A motor is mounted on a plate which is pivotively secured to the keel panel. A pair of connecting arms extends from the plate to opposite side panels.
When the boat is sitting still or moving at relatively slow speeds, the side panels extend generally outwardly from the keel panel. As the speed of the boat increases, the motor and plate begin to pivot due to the thrust of the motor, which tends to pull the side panels upwardly. As the speed of the boat decreases, a tension spring secured to the plate urges the motor back to its original position causing the side panels to also return to their outwardly extending position.
Accordingly, it is an object of the present invention to provide a boat hull design which changes configuration depending upon the relative speed of the boat.
Another object of the present invention is to provide a boat hull design which reduces the effect of impact with the water.
Another object of the present invention is to provide a boat hull design that lessens the effect of wind on the underside of the hull as the boat planes across the surface of the water.
Another object of the present invention is to provide a boat hull design which facilitates the planing action of the boat.
Another object of the present invention is to provide a boat hull design wherein the hull varies configuration in response to the bodily rotation of the motor.
Another object of the present invention is to provide a boat hull design which has lighter weight construction.
Other objects and advantages of the present invention will become apparent from a study of the following description and the accompanying drawings which are merely illustrative of such invention.
BRIEF DESCRIPTION OF INVENTION
FIG. 1 is a perspective view of the boat of the present invention having a changeable configuration hull;
FIG. 2 is a longitudinal cross-section of the boat with a changeable configuration hull illustrating the position of the motor in a stable hull configuration;
FIG. 3 is a longitudinal cross-section of the boat with a changeable configuration hull illustrating the position of the motor in the planing hull configuration;
FIG. 4 is a transverse cross section illustrating the position of the side panels in the planing hull configuration; and
FIG. 5 is a transverse cross section illustrating the position of the side panels in the stable hull configuration.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, the boat with a variable configuration hull is shown therein and indicated generally by the numeral 10. Viewing boat 10 in more detail it is seen that the same includes variable volume primary boat hull structure indicated generally at 12 and a hull configuration control means indicated generally at 14.
Boat hull structure 12 includes a pair of side panels 16 and 18 secured to opposite sides of a central keel panel 20 by water tight hinges 22. Side panel 16 and 18 are moveable relative to keel panel 20 as can be clearly seen in FIGS. 4 and FIGS. 5. In FIG. 5, the hull structure is shown in what is referred to as the expanded position. In this configuration, the side panels 16 and 18 extend generally outwardly from keel panel 20.
In FIG. 4, hull structure 12 is illustrated in what is referred to as the retracted position. In this configuration, the side panels 16 and 18 are pulled upwardly with respect to keel panel 20 so that the boat can plane across the surface of the water on keel panel 20.
A seat support structure 24 extends upwardly from the rear portion of keel panel 20. An elongated seat 26 is mounted on top of seat support structure 24. A control panel 28 extends upwardly at an angle about the forward end of seat 26. Control panel 28 includes means for controlling the speed and direction of boat 10 such as a steering wheel 30 and throttle control 32. Appropriate instruments such as a tachometer/speedometer may also be included. The control panel 28, seat 26 and seat support structure 24 are preferably integrally formed with each other and with keel panel 20.
Referring now to FIGS. 2 and 3, the hull configuration control means 14 is illustrated. Hull configuration control means 14 includes a motor mount 34 which is pivotally secured along its lower edge to the stern end of keel panel 20. Mount 34 is moveable between a first position shown in FIG. 2 and a second position shown in FIG. 3.
A pair of connecting arms 36 and 38 interconnect mounting plate 34 with side panel 16 and 18. Connecting arms 36 and 38 are secured at one end to mount 34 by a bracket 40 and at the opposite end to respective side panels 16 and 18 by a securing plate 42 (FIGS. 4 and 5). Each connecting arm 36 and 38 includes a pair of ball joints 44 at each end thereof to permit universal pivotal movement of the connecting arms 36 and 38 with respect to both the mount 34 and side panels 16 and 18. It is appreciated therefore that as the mount 34 moves from the first position shown in FIG. 2 to the second position shown in FIG. 3, the connecting arms 36 and 38 will pull the corresponding side panels 16 and 18 upwardly into a retracted position. As the mount 34 moves back to the first position the side panels 16 and 18 will be pushed back down into an expanded position.
Mount 34 is biased to the first position as shown in FIG. 2. A hydraulic dampener 46 is pivotally connected at its respective ends to the mount 34 and keel panel 20. Hydraulic dampener 46 includes a piston cylinder 48 and a piston rod 50 extending outwardly therefrom as can clearly be seen in FIG. 3. A tension coil spring 52 is disposed about hydraulic dampener 46 and is fixedly secured to opposite ends thereof by a pair of end plates 54, one of which is attached to cylinder 48 and one of which is attached to rod 50. The tension coil spring 52 tends to compress hydraulic dampener 46 effectively biasing mount 34 to the first position shown in FIG. 2.
A pair of waterproof fabric partitions 35 are secured to opposite sides of mount 34 and to respective side panels 16 and 18 to enclose the open end of the hull structure 12 as can be clearly seen in FIG. 1.
An outboard motor 56 is mounted to motor mount 34 in the conventional manner. Steering wheel 30 and throttle control 32 are operatively connected to motor 56. When motor 56 is actuated and the propellor thereof is engaged, boat 10 will be propelled along through the water. The propelling force or thrust generated by motor 56 acts in the direction of the arrows shown in FIGS. 2 and 3. It is appreciated therefore that the actuation of motor 56 will cause the mount 34 to pivot from the forwardly extending position (FIG. 2) to the vertically extending position shown in FIG. 3. The degree of rotation of mount 34 will depend of course upon the power output of motor 56. Thus, mount 34 will rotate gradually from the first position (FIG. 2) to the second position (FIG. 3) as the power output of motor 56 increases. As the power to motor 56 is decreased, the mount 34 will of course rotate back towards the first position (FIG. 2).
Since the side panels 16 and 18 are operatively connected to mount 34 by connecting rods 36 and 38, the side panels 16 and 18 will be pulled upwardly as the power output of motor 56 increases and will be pushed back downwardly as the power output of motor 56 decreases. Therefore it is appreciated that as the speed of the boat increases the panels 16 and 18 are pulled upwardly out of the water. As the speed of the boat decreases, the panels 16 and 18 move downwardly toward the underlying water.
The movement of side panels 16 and 18 allows the boat hull structure 12 to assume an expanded position when the boat 10 is sitting still or moving at relatively slow speeds. Thus boat 10 will be relatively stable. At higher speeds where dynamic stability is attained, the side panels are pulled upwardly into the retracted position allowing boat 10 to plane across the surface of the water on keel panel 20. This allows the boat to achieve greater speed and lessens the effect of drag and wind on the underside of the hull structure as the boat planes across the surface of the water.
The present invention may be used in larger boats having inboard motors. In such circumstances the boat may be provided with speed sensing flaps which actuate hydraulic cylinders to raise and lower the side panels. Other electrical and mechanical devices may also be used to sense the speed of the boat and to cause the side panels to be raised and lowered.
The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. | A planing boat is provided having a variable configuration hull including two side panels hingedly secured to opposite sides of a keel panel. When the boat is sitting still in the water or moving at relatively slow speeds, the side panels extend generally outwardly from the keel panel providing the boat with a degree of stability. As the speed of the boat increases, and upon attaining dynamic stability, the side panels pivot upwardly thereby reducing the effect of impact on the water. When the speed of the boat decreases, the side panels return to their normal outwardly extending position. | 8 |
CROSS REFERENCE
This application is a divisional of copending application Ser. No. 174,942, filed Aug. 25, 1971 (now U.S. Pat. No. 3,784,515) which application was a continuation-in-part of earlier copending application Ser. No. 113,681, filed on Feb. 8, 1971 (now abandoned), and entitled "Rapid Curing Resin Compositions Comprising The Reaction Product of an Aldehyde Condensation Polymer With a Primary Aromatic Amine Further Reacted With a Curing Agent." Application Ser. No. 113,681 was a continuation-in-part of earlier copending application Ser. No. 821,996, filed on May 5, 1969, now abandoned, and entitled "Rapid Curing Resin Compositions Comprising the Reaction Product of an Aldehyde Condensation Polymer With a Primary Aromatic Amine Further Reacted With Additional Aldehyde." Application Ser. No. 821,996 was itself a continuation-in-part of application Ser. No. 639,270, filed May 18, 1967, entitled "Method of Making a Fast-Curing Adhesive and a Method of Bonding Members Utilizing Said Adhesives", now U.S. Pat. No. 3,518,159. While this application is directed to certain new methods of preparation of rapid curing resin compositions, to certain resin compositions per se, and to certain use of these resin compositions as adhesives, other methods, compositions and uses for the same purposes are disclosed and claimed in the copending application having a common assignee, Ser. No. 164,927, filed July 21, 1971 (now U.S. Pat. No. 3,773,721), and having a title identical to that of this application.
BACKGROUND OF THE INVENTION
This invention relates to the preparation of rapid curing resin compositions, to the resin compositions per se, and to the use of these resin compositions as adhesives.
For many years the adhesives used to bond wood together to make plywood, laminated beams, furniture, etc., have employed aldehyde condensation polymers of phenol, urea, resorcinol, and other similar compounds. These resins, however, produce adhesives having relatively slow curing rates.
The relatively slow cure rates of these resins have necessitated long press times with concurrent restriction on production when used in the manufacture of laminated beams, plywood and other construction uses. To overcome the slow cure rates many modifications of the above resins have been proposed. Other resins, such as the epoxies, have been proposed, but their expense and certain of their physical properties have limited their use. The resins of this invention employ aldehyde condensation polymers modified with particular amines. These resins not only have rapid cure rates but develop adequate adhesive bond strengths in a short amount of time at ambient temperature, thereby eliminating the need for long press times and application of heat to develop sufficient bond strength.
Mazzucchelli et al, in U.S. Pat. No. 2,557,922, describe the preparation of modified phenol-formaldehyde condensation products by the inclusion of mono-amino diphenyls, diaminodiphenyls, or amino diphenylmethanes alone or as condensation products with formaldehyde. The compositions, when mixed with suitable fillers, are used primarily as electrical insulators.
Edison, in U.S. Pat. No. 1,283,706, teaches that small amounts of p-phenylenediamine may be added to two-stage phenolic molding compound or varnish resins as a catalyst to accelerate the heat cure of these resins. Other patents of which U.S. Pat. Nos. 2,106,486, 2,511,913, 2,582,849, 2,875,160, 2,290,345, and 2,994,669 are exemplary, disclose the use of aromatic amines, especially m-phenylenediamine, in insoluble resins intended as ion exchange materials. It is also well known to make condensation resins from aniline and an aldehyde or to use aniline as a modifier for other condensation resins, as taught by Harvey in U.S. Pat. No. 2,766,218.
Cox et al. in U.S. Pat. No. 3,186,969 describe intermediate products which are further reacted with compounds containing the oxirane group to form vicinal epoxides. The intermediate products are reaction products of an aromatic primary amine, a phenol and an aldehyde. Reaction conditions, however, are carefully chosen to avoid any condensation between the phenol and aldehyde.
Bornstein in U.S. Pat. No. 3,471,443 teaches the use of aniline or aniline salts as cure accelerators in heat curing phenol-formaldehyde resins and gives the same teaching in regard to phenol-resorcinol-aldehyde resins in U.S. Pat. No. 3,476,706. The latter patent also teaches a so-called honeymoon glue system using the disclosed products.
German Pat. No. 358,195 describes resins made by using phenols having basic groups, such as aminophenols, as alkaline catalysts for the condensation of phenol with formaldehyde. The minor amount of catalyst, up to 3 parts per hundred parts of phenol, is cooked together with the phenol and formaldehyde to produce a product suggested as useful for electrical insulation.
Auer, in U.S. Pat. No. 2,309,088 teaches the manufacture of organic isocolloids through modification of resins with amine compounds. The isocolloids are useful, inter alia, as additives for varnishes to improve their alkali and hot and cold water resistance. Fusible phenolic resins containing a natural resin or resinous esters thereof are modified by Auer by heating with particular amines at elevated temperatures "to insure complete dissolution or dispersion of the modifying agent". It is not clear even to Auer whether any chemical reaction takes place between the phenolic resin and amine. However, if there was a reaction, the substituents such as carboxyl groups on the phenolic resins attributable to the natural resin or resinous esters thereof would result in the formation of amides, and not in the formation of the amine modified products of this invention. Amide modified condensation polymers have significantly lower reactivity for purposes of this invention than do amine modified condensation polymers, and are therefore to be avoided. Further, because Auer's phenolic resin starting materials are apparently permanently fusible, it can be inferred that they are novolaks and therefore contain no reactive alkylol groups, making them inappropriate for the practice of the present invention.
SUMMARY OF THE INVENTION
This invention relates to a process for the preparation of rapid curing resin compositions for use as adhesives, and to the resin compositions themselves, and particularly to the addition of a curing agent to the reaction product of a primary aromatic amine with an aldehyde condensation polymer having reactive alkylol groups. The resins of this invention are prepared by reacting together an aldehyde condensation polymer having reactive alkylol groups, with a primary aromatic amine of the formula: ##SPC2##
where:
X 1 is --NH 2 , --CH 2 NH 2 ;
X 2 is --X 1 , --OH, --alkoxy;
X.sub.3 is -X.sub.1COOHNHCOCH.sub.3NO.sub.2OHC.sub.1 to C.sub.5 alkylH-halogenhalogenated alkylalkoxy
X 4 is C 1 to C 4 alkyl, --H, --aryl; and
A is ##EQU2## --SO 2 --, --NH--, --O--, --S--, --C=C--, --S-S--, --N=N--; where Y 1 and Y 2 are hydrogen or alkyl radicals having from 1 to 3 carbon atoms and Z is an integer from 0 to 2, to produce an amine-modified polymer. This resinous product is then blended with a sufficient amount of curing agent to cause the resin to become infusible. On addition of the curing agent to the amine-modified condensation polymer, the material rapidly sets to an insoluble, infusible condition at ambient temperature. Optionally, heat may be applied to increase cure speed.
The resins can be used to bond wood to wood, metal to metal, wood to metal, fabric, and many other materials where durable, moisture-resistant, heat-resistant adhesive compositions are needed.
DETAILED DESCRIPTION OF THE INVENTION
Many of the aldehyde condensation polymers of phenol, resorcinol, urea, and melamine have been widely used as adhesives and their properties are well known. The aldehyde condensation polymers which can be used in this invention have reactive alkylol groups, and are well known and commercially available. "Polymers", as used herein, means resinous mixtures which do not crystallize nor have a sharp melting point. "Reactive alkylol groups" are alkylol groups capable of reacting with the primary aromatic amines used in this invention to modify the aldehyde condensation polymers. "Condensation" is used herein to mean a polymerization reaction in which a molecule, such as water, is eliminated and is to be distinguished from "addition" in which no by-product is formed. Further, the aldehyde condensation polymers used in this invention exclude those having dominant amide forming substituents.
Three classes of polymers are preferred: phenoplasts, aminoplasts, and ketone-aldehyde condensation polymers. They include such resins as the acid or base catalyzed phenol-aldehyde resins, urea-aldehyde resins, melamine-aldehyde resins, acetone-aldehyde resins, etc. The following references disclose methods of preparing the condensation resins useful in this invention: "The Chemistry of Synthetic Resins" by Carleton Ellis, Reinhold Publishing Co., 1935; "Phenolic Resin Chemistry" by N. J. L. Megson, Academic Press Inc., New York, 1958; "Aminoplasts" by C. P. Vale, Cleaver-Hume Press, Ltd., London, England; and British Pat. No. 480,316.
Specifically, the aldehyde condensation polymers which can be used include (1) phenoplasts comprising the condensation polymers of an aldehyde such as formaldehyde with a phenolic type material having open reactive positions, such as phenol, phenol-resorcinol, xylenol, cresol, resorcinol, and their derivatives, (2) aminoplasts comprising the condensation polymers of an aldehyde such as formaldehyde with compounds such as benzoguanamine, dicyandiamide, urea, melamine-urea, melamine, and their derivatives, and (3) ketone-aldehyde condensation polymers such as acetone-formaldehyde, methyl ethyl ketone formaldehyde, methyl isobutyl ketone formaldehyde, and the like. The preferred resins are water-soluble, liquid, thermosetting phenol-aldehyde resins.
A preferred resin is an ortho-condensed phenol-formaldehyde resin made by condensing 0.7 to 1.0 moles formaldehyde with 1 mole phenol in the presence of an ortho-directing catalyst such as calcium acetate. Such resins are known. Each of the aldehyde condensation polymers mentioned above is prepared and kept under conditions which prevent it from condensing to an infusible state by known methods. Although phenol is the preferred reactant the phenolic resins may be modified by incorporating into them predetermined amounts of other monohydric phenols or a dihydric phenol such as resorcinol or other polyhydroxy aromatic compounds.
The aldehyde used in preparation of the condensation polymer may be (1) monofunctional (i.e. a monoaldehyde), or (2) polyfunctional, having at least two aldehyde groups separated by at most one carbon atom, and can be, for instance, formaldehyde, paraformaldehyde, polyoxymethylene, trioxane, acrolein, and aliphatic or cyclic aldehydes such as glyoxal, acetaldehyde, propionaldehyde, butyraldehyde, and furfuraldehyde. Condensation, when using formaldehyde, furfuraldehyde, paraformaldehyde, polyoxymethylene or trioxane, is generally accomplished with the use of a mildly acid, alkaline, or no catalyst. When using acrolein, glyoxal, acetaldehyde, propionaldehyde, or butyraldehyde, condensation is generally accomplished by combining the reactants in the presence of a strongly acid catalyst, neutralizing the reaction product, adding more aldehyde, and further reacting in the presence of a mildly acid, or alkaline, catalyst.
The aldehyde condensation polymers mentioned above are modified by reaction with a primary aromatic amine to give an amine-modified polymer. It is necessary, in order to produce the low-temperature fast curing products of this invention, to first produce the aldehyde condensation polymer and then subsequently modify that polymer with the primary aromatic amine. Simultaneous reaction of all the reactants, i.e., phenol, formaldehyde and amine, produces an inferior, heterogeneous mass, i.e., comprising essentially an amine-formaldehyde condensation polymer containing free phenol.
The amount of amine used to react with the condensation polymer may range from about 0.05 to 2.0 parts by weight of the amine to each part of the condensation polymer and preferably 0.1 to 1.0 parts by weight of the amine to each part of the condensation polymer. More than 2.0 parts by weight of the amine to each part of the aldehyde condensation polymer can be used but there is little advantage in doing so. Most of the amines disclosed react with the aldehyde condensation polymers at room temperature, but to insure complete reaction the mixtures are usually heated to reflux. Many of these reactions are exothermic in nature and cooling is required to control the reaction. This exothermic nature of the reaction is in some instances controlled by slow addition of the amine to the prepared polymer. It may be desirable under some circumstances, however, to add the polymer to a solution of the amine. When the resin is ready to be used a curing agent is blended therein.
The amines for modifying the aldehyde condensation polymers include primary aromatic amines having the formula: ##SPC3##
where:
X 1 is --NH 2 , --CH 2 NH 2 ;
X 2 is --X 1 , --OH, --alkoxy
X.sub.3 is -X.sub.1COOHNHCOCH.sub.3NO.sub.2OHC.sub.1 to C.sub.5 alkylH-halogenhalogenated alkylalkoxy
X is C 1 to C 4 alkyl, --H, --aryl; and
A is ##EQU3## --SO 2 --, --NH--, --O--, --S--, --C=C--, --S--S--, --N=N--; where Y 1 and Y 2 are hydrogen or alkyl radicals having from 1 to 3 carbon atoms and Z is an integer from 0 to 2. The following amines are exemplary of those that may be used in the preparation of these resins: 4-aminosalicylic acid; 3,5-diamino benzoic acid; m-hydroxyaniline; o-phenylenediamine; m-phenylenediamine; p-phenylenediamine; 1,2,4-triaminobenzene; 1,3,5-triaminobenzene; m-xylylenediamine; 2-aminoresorcinol; m-methoxyaniline; 2,4,6-triaminotoluene; 2,4-diaminodiphenylamine; 2-amino-5-nitrophenol; 1,3-diamino-4-methoxybenzene; 1,3-diamino-4-nitrobenzene; 1,4-diamino-2-nitrobenzene; 2,4-diaminophenol; 1,3-diamino-4-chloro benzene; 2,4-diaminotoluene; o-hydroxyaniline; and 2,4-diaminoacetanilide. The preferred amines from the standpoint of economics and adhesive properties include m-hydroxyaniline and m-phenylenediamine.
Primary aromatic amines having the basic structures of those suggested above, but further substituted with non-interfering substituents, are also useful in this invention. By "non-interfering substituents" is meant those substituents which do not detract from the usefulness of the primary aromatic amines in this invention. For example, halogen, ether, alkyl, aryl, cyano, sulfide, and mercaptan groups are non-interfering substituents which could be attached to the carbon ring of the suggested primary aromatic amines without reducing their usefulness, i.e., without significantly changing resin shelf life or adhesive cure speed. A primary aromatic amine containing such a non-interfering substituent which would be satisfactory for purposes of this invention is 2,4-diamino toluene.
Also useful for purposes of this invention are the acid salts of the suggested primary aromatic amines, which salts are formed by the reaction of such primary aromatic amines with nonoxidizing acids such as the hydrohalide acids, sulphuric acid, phosphoric acid, acetic acid, propionic acid, butyric acid, and the like. These salts are equivalent, for purposes of this invention, to the free primary aromatic amines, and will normally be present in the reaction system when the aldehyde condensation polymer is reacted with the primary aromatic amine under acidic conditions.
The amine-modified aldehyde condensation polymers useful in this invention are generally prepared by reacting the amine compounds described with previously prepared aldehyde condensation polymer, usually under reflux conditions, in the presence of a small amount of water, methanol, water-methanol mixture, or other suitable carrier vehicle. These polymers make up the first component of the resin composition. The first component is prepared so as to have a relatively long storage life so it can be shipped and stored for fairly long periods of time withoug gelation.
The second component of the resin composition is a curing agent which may be an alkylene donating compound, a di- or poly-isocyanate, or an epoxide, used either alone, in combination with one another, and/or mixed with conventional thickening agents. The curing agent is blended with the amine-modified aldehyde condensation polymer when needed. Other materials that readily donate alkylene bridges to the polymer system are also generally suitable. Reaction takes place at ambient temperature and the blended mixture gels rapidly to an insoluble infusible state. The preferred resins of this invention set to an insoluble infusible state within a few minutes. "Insoluble" is intended to mean not soluble in common solvents such as water, alcohols, ketones, hydrocarbons, esters, glycols, and the like. Optionally, heat may be applied to the curing composition if desired to further decrease the required cure time.
Sufficient curing agent is added to the first component to form an infusible product. The amount of curing agent is not critical and may range from 0.02 to 2.0 parts by weight per part of amine-modified condensation polymer; as stoichiometric proportions are approached and surpassed the completeness of the cure approaches 100%.
The preferred curing agent is an aldehyde such as formaldehyde, though the formaldehyde-forming compounds polyoxymethylene, trioxane and paraformaldehyde are quite satisfactory. Other aldehydes may be also used, for example, aliphatic or cyclic aldehydes having from 1 to 8 carbon atoms such as acrolein, glyoxal, acetaldehyde, propionaldehyde, butyraldehyde, and furfuraldehyde. Phenolic resoles and other similar polymers having free methylol groups are also efficient curing agents. Suitable di-isocyanate curing agents comprise toluene di-isocyanate, phenylene di-isocyanate, 1,6 di-isocyanoto-hexane, and the like, while suitable epoxy curing agents comprise diglycidyl ether of bisphenol A, epoxidized phenolic novolacs, epoxidized polyglycols and the like.
When the first component comprising the amine-modified condensation polymer and the second component comprising the curing agent are mixed together the composition becomes insoluble and infusible in a very short period of time. When bonding materials together the two components are kept separate until they are needed. They are then intimately mixed and spread on the material to be bonded by any conventional means. An automatic mixing-dispensing gun is most useful in this regard.
Certain of the resin compositions of this invention have such rapid cure times that they begin to cure before they can be spread on the material to be bonded. To overcome this problem the first component can be spread on one surface of the material to be bonded and the second component spread on the second surface to be bonded. Such a process is described, for example, in U.S. Pat. Nos. 2,557,826 and 3,476,706 using phenol-resorcinol-formaldehyde resins. When the surfaces are brought into contact the first and second resin components react forming an infusible glue line between the materials.
If desired, other ingredients can be added to the adhesive compositions. Such ingredients include conventional fillers, pigments, plasticizers, and the like, in amounts ordinarily employed for such purposes.
The compositions of this invention do not need additional catalyst or heat to cure them. They are curable at ambient temperatures and in very short time periods after mixing of the two components. Additionally the resin compositions develop bond strengths sufficient to hold articles together in a relatively short amount of time.
The following examples illustrate this invention. Parts and percents where used are intended to be parts and percents by weight, unless otherwise specified.
EXAMPLE 1
This example illustrates the fast cure rates of the resin compositions of this invention. Cure rate was determined by means of "gel" time. Gel time was determined by weighing out a 10 gram aliquot of the first component, adjusting the pH to the desired point, and mixing the second component with the first component. The time elapsed from mixing to gelling of the composition is termed gel time. In each instance, the compositions were formulated by mixing an amine-modified phenol-formaldehyde polymer with additional formaldehyde.
The phenol-formaldehyde polymer was prepared by mixing 42.06 parts by weight phenol, 4.51 parts water, 11.35 parts flake paraformaldehyde (91%) and 0.46 parts calcium acetate monohydrate. The mixture was brought to reflux (approximately 109°C.) in about 60 minutes at a uniform rate and held at reflux for 120 minutes, thus producing an aldehyde condensation polymer having reactive alkylol groups. To separate 100 gram aliquots of this polymer were added 0.305 moles of each of the respective amines shown in Table 1. The mixture in each case was refluxed for 2.25 hours, cooled, and 26.3 grams of methanol stirred into the mixture. The gel time of each of the adhesive compositions was determined as set forth above. The solution pH has some effect on the gel time of the resins. This pH effect is dependent primarily on the particular amine being used, but also on the solvent used and the concentration of the amine.
Table 1 lists the amines used, the gel time and the pH range over which the gel times were obtained. Though the cure rates of many of the resins are pH dependent, the determination of the optimum pH for a desired gel time can be determined easily by a skilled technician.
TABLE 1__________________________________________________________________________Compound Gel Time pH Range__________________________________________________________________________4-aminosalicylic Acid Less than 100 sec. 1-103,5-diaminobenzoic Acid " 1-7m-hydroxyaniline " 0-10m-phenylenediamine " 0-2, 6-10p-phenylenediamine " 6-121,2,4-triaminobenzene " 2-121,3,5-triaminobenzene " 1-121,3-diamino-4-methoxybenzene " Greater than 91,3-diamino-4-nitrobenzene " Less than 31,4-diamino-2-nitrobenzene Less than 10 min. 4-52,4-diaminotoluene Less than 100 sec. 6-10o-hydroxyaniline Approx. 10 min. Greater than 9.5m-methoxyaniline Less than 100 sec. Less than 5o-phenylenediamine " Approx. 7.52,4-diaminodiphenylamine " 5-9__________________________________________________________________________
EXAMPLE 2
A mixture of 100 grams of high solids phenol-formaldehyde prepolymer prepared as described in Example 1 and 0.305 moles of 4-aminosalicylic acid were refluxed for 2.25 hours, cooled, and 26.3 grams methanol stirred into the mixture. A 10 gram aliquot of the amine-modified resin was weighed out, 0.5 grams concentrated hydrochloric acid added to adjust the pH, and 5.0 grams of a curing agent added. The curing agent comprised a solution of 55% formaldehyde in methanol and water, thickened with a small quantity of refined chrysotile asbestos (96.4% formaldehyde solution and 3.6% asbestos.) The adhesive composition was used in a standard cross-lap test (see Marra, A., "Geometry as an Independent Variable in Adhesive Joint Studies," Forest Products Journal, Vol. XII, No. 2, pp. 81-90, 1962.)
The cross-lap test is conducted by spreading the adhesive composition on the central area of a piece of Douglas fir wood 1 inch wide by approximately 3/4 inch thick and 23/4 inch long. A similar piece of Douglas fir wood is immediately laid over the first with the grain direction at right angles. A measured quantity of adhesive may be used or an excess may be applied with the surplus resin allowed to squeeze out of the joint. The latter method has been used for the examples given here. As soon as the cross-lap is laid on the first piece, a pressure of 40 pounds is applied for the desired length of time. The joint is then broken in tension and the bond strength recorded. At the end of 12 minutes press time the tensile strength necessary to separate the cross-lap of this example was 159 lbs. per sq. in.
Normally wood failure begins to occur at a value of about 150 psi. For many purposes, however, a bond strength well below this value is wholly satisfactory. It should also be noted that strength usually continues to increase significantly for at least a 24-hour period after initial assembly.
EXAMPLE 3
To 100 grams of high solids phenol-formaldehyde polymer, prepared as described in Example 1, was added 0.305 moles of 2,4-diaminoacetanilide. The mixture was refluxed for 2.25 hours, cooled, and 26.3 grams of methanol stirred into the mixture. A 10 gram aliquot of the amine-modified resin was weighed out, and 5.0 grams of an asbestos thickened solution of 55% formaldehyde in methanol and water added. The mixture was stirred rapidly and used in a cross-lap test. At the end of 12 minutes press time the tensile strength necessary to separate the cross-lap was 282 lbs. per sq. in.
EXAMPLE 4
A resin was made using the molar ratios of ingredients of Example 1 with m-hydroxyaniline as the amine. A 4-liter reactor was charged with 1913.3 grams of 91.5% phenol, 457.2 grams of 94.7% paraformaldehyde, 58.8 grams of water and 19.2 grams of calcium acetate monohydrate. Heat and agitation were applied and the temperature raised to reflux (about 109°C.) in 60 minutes. It was held at reflux for 2 hours to form an aldehyde condensation polymer having reactive alkylol groups, then cooled slightly to 101°C. and 808.4 grams of m-hydroxyaniline added. The temperature dropped to 80°C. but was again raised to reflux in 15 minutes and held for 3 hours. At that time the temperature was 104°C. The reaction product was cooled to 60°C. and 186.0 grams of methanol added and thoroughly mixed in. The resin was then cooled to 25°C. and removed to storage. The final viscosity was W on the Gardner series.
To 10 parts of the above resin was added 0.5 parts of concentrated hydrochloric acid to bring pH into a more optimum range and 5 parts of the thickened aldehyde curing agent of Example 2. These ingredients were rapidly mixed together and used in a cross-lap test. At 2 minutes press time a tensile strength of 105 psi was obtained. Tensile strength rose to 230 psi after 4 minutes press time. The gel time of the adhesive composition was 20 seconds.
EXAMPLE 5
A resin was made using essentially the molar ratios of ingredients of Example 4 except that m-phenylenediamine was used in place of m-hydroxyaniline. A 4-liter reactor was charged with 2213.2 grams of 88.8% phenol, 518.8 grams of 93.5% flake paraformaldehyde and 21.6 grams of calcium acetate monohydrate. The resin was cooked in identical fashion to that of Example 4 up to the point of addition of amine. At this time 914.4 grams of m-phenylenediamine was added and cooked as before except that the time was shortened to 21/2 hours. After cooling to 60°C. 718.7 grams of methanol was stirred in and the product cooled further to 25°C. Finally 219.3 grams of concentrated (38%) hydrochloric acid was added and thoroughly mixed.
A cross-lap test was made using an adhesive comprising 10 parts of the above resin and 5 parts of the thickened aldehyde curing agent of Example 2. Tensile strength values of 50 psi were noted after 4 minutes press time. Cross-lap strength increased to 70 psi after 12 minutes press time. The gel time of the adhesive composition was 12 seconds.
EXAMPLE 6
A mixture of 100 grams of the phenol-formaldehyde polymer, prepared as described in Example 1, and 0.305 moles of 2,4-diaminotoluene were refluxed in a reaction vessel for 2.25 hours, cooled, and 26.3 grams of methanol stirred into the mixture. This resin was used as the adhesive in a cross-lap test by taking 10 grams of the resin and 5 grams of the asbestos-thickened aldehyde curing agent of Example 2, mixing rapidly and spreading on a cross-lap joint. After 12 minutes press time a joint strength of 70 psi had been reached. The gel time of the adhesive composition was 20 seconds.
EXAMPLE 7
A mixture of 100 grams of the phenol-formaldehyde polymer prepared as described in Example 1 and 0.305 moles of m-xylylenediamine were refluxed in a reactor for 2.5 hours, cooled and 26.3 grams of methanol mixed into the product. In a cross-lap test 10 grams of this resin were mixed with 1.2 grams of concentrated hydrochloric acid and 5 grams of the asbestos-thickened aldehyde curing agent of Example 2. After 12 minutes press time the cross-lap had developed a tensile strength of 45 psi. Gel time of the adhesive was 10 seconds.
EXAMPLE 8
Two parts by weight of 2,4-diaminoacetanilide was dissolved with gentle heating in one part of N,N-dimethylformamide. To the reactor containing the amine solution were added with agitation and gentle warming 6 parts by weight of a urea-formaldehyde resin (Amres 255, a product a Pacific Resins and Chemicals Co.). Amres 255 is typical of many general purpose liquid urea-formaldehyde adhesive resins readily available on the market. It is made with an approximate 2 to 1 mole ratio of formaldehyde to urea, is cooked to a Gardner viscosity of U at a pH of 8.0, and contains 65% resin solids in a water solution. A discussion of preparation of resins of this type is made in "Aminoplasts" by C. P. Vale and published by Cleaver-Hume Press, Ltd., London, England, and especially to pages 12-46.
Five parts by weight of the amine-modified resin was mixed with 0.45 parts of concentrated hydrochloric acid and 2.5 parts of the asbestos-thickened aldehyde curring agent of Example 2. The mixture was stirred rapidly and used in the cross-lap test. At the end of the 12 minute press time the tensile strength necessary to separate the cross-lap was 230 lbs. per sq. in. The gel time of the adhesive composition was 120 seconds.
EXAMPLE 9
Ten grams of 2,4-diaminoacetanilide was charged to a reaction vessel and 20 grams of N,N-dimethylformamide was added with stirring. To this mixture was added 30 grams of a melamineurea-formaldehyde resin (Melurac 400, a product of American Cyanamid Co.). Melurac 400 is a solid spray dried adhesive resin typical of many similar products commercially available which are intended for hot press or radio frequency bonding of wood products. Resins of this type are described on page 201 of the Vale reference mentioned earlier and are also described in British Pat. No. 480,316.
The mixture was heated to 60°C. and a slow addition begun of 12.5 grams of a 55% solution of formaldehyde in methanol and water. An exothermic reaction took place that increased the temperature to 74°C. After a short period of additional mixing the resin was cooled to 25°C.
The above resin was tested in the standard cross-lap by taking a 10 gram sample of the resin, adding 0.3 gram of HCl for pH adjustment and 5 grams of the thickened solution of formaldehyde in methanol of Example 2. The cross-laps developed a tensile strength of 55 psi after pressing 8 minutes and 155 psi after pressing 12 minutes. The gel time of the adhesive composition was 90 seconds.
EXAMPLE 10
Twenty grams of m-xylylenediamine was charged to a reaction vessel and 20 grams of N,N-dimethylformamide was added with stirring. When a uniform mixture was obtained 6 grams of Melurac 400 resin was added with gentle heating. After all evidence of reaction had ceased the product was cooled and withdrawn to storage. A cross-lap was made using as the adhesive a mixture of 10 grams of the above resin, 1.5 grams of concentrated hydrochloric acid and 5 grams of the asbestos-thickened aldehyde curing agent of Example 2. After 12 minutes press time the joint had developed a tensile strength of 135 psi. Gel time of the adhesive was 30 seconds.
EXAMPLE 11
A 4-liter reactor was charged with 2468.9 grams of 90.4% phenol, 120.3 grams of water and 1226.8 grams of flake paraformaldehyde. The temperature was adjusted to 25°C. and 34.0 grams of 49.5% NaOH was added. Heating was begun with agitation and the temperature was raised at a uniform rate to 85°C. in 82 minutes. Above 60°C. intermittent cooling was required to control the exotherm. Heating was continued under reflux conditions for an additional 5 hours until a Gardner viscosity of about Z 1 had been reached, whereupon the resin was cooled to 25°C. The molar ratio of formaldehyde to phenol in this resin was 1.6 to 1.
A second 4-liter reactor was charged with 1075.6 grams of m-hydroxyaniline and 273.7 grams of methanol. Heating and agitation was applied and the temperature brought to reflux at about 84°C. and held until a smooth slurry was formed. This slurry was then cooled to 70°C. and 1662.2 grams of the above phenolic resole was added slowly over a 10-minute period. The mixture was again heated to reflux at about 95°C. and held approximately 30 minutes until all the m-hydroxyaniline had dissolved. The reaction mixture was now cooled to 60°C. and 254.1 grams of concentrated HCl added. The temperature was held at 65°C. for 15 minutes, then 234.5 of a 55% solution of formaldehyde in methanol was slowly added so as to maintain the temperature between 65° and 75°C. After completion of this addition the resin was heated to reflux for 15 minutes, cooled to 25°C. and removed to storage.
Ten parts of the above resin was mixed with 5 parts of the asbestos-thickened curing agent of Example 2 and used in a cross-lap test on Douglas fir. After only 1 minute under pressure the tensile strength of the cross-lap was 85 psi. In 2 minutes a value of 290 psi was recorded and in 4 minutes the value was 405 psi. The gel time of the adhesive composition was 30 seconds.
EXAMPLE 12
An acetone-formaldehyde resin was prepared by charging 17,746 grams of 50% formalin, 1270 grams water and 4173 grams of acetone into a 5-gallon reactor. Temperature of the mixture was adjusted to 40°C., and 45.4 grams of 49.5% sodium hydroxide added with agitation. The mix was further cooled to 30°C. and a second 45.4 gram portion of 49.5% sodium hydroxide added. The temperature was then allowed to rise uniformly to 65°C. over the next hour using cooling as required to control the exotherm. After reaching the maximum temperature the mixture was held at 65°-70°C. for an additional 20 minutes until the exotherm had completely subsided. The acetone-formaldehyde resin was then cooled to room temperature and removed to storage.
An amine-modified acetone-formaldehyde resin was prepared by charging 1777.6 grams of m-hydroxyaniline and 890.0 grams of methanol into a 4-liter reactor. Heating and agitation were now begun and the temperature was brought to reflux (about 75°C.) and held until all of the amine had dissolved. The amine solution was cooled to 60°C. and addition of 1332.4 grams of the above acetone-formaldehyde resin was begun. This was added in small increments in order to control the highly exothermic reaction which occured. Temperature was controlled between 60°C. and 70°C. until all of the acetonealdehyde resin had been added and the exothermic reaction subsided. At this time the temperature was raised to reflux (about 80°C.) and held for 30 minutes after which it was cooled to room temperature and removed to storage. The final viscosity was A, on the Gardner scale.
Cross-lap tests were made by rapidly mixing 10 parts of the above amine-modified resin, 0.5 parts of concentrated HCl and 5 parts of the thickened aldehyde curing agent of Example 2. After only 2 minutes press time a tensile strength of 80 psi was measured. After 4 minutes press time the tensile strength was 235 psi. The gel time of the adhesive composition was 30 seconds.
EXAMPLE 13
This experiment indicates that it is preferred that the condensation type polymer should be prepared first and the amine added, rather than adding the components simultaneously in order to obtain a polymer useful for the purposes desired.
To a reactor was added the following: 945.8 grams, 90% phenol, 396 grams m-hydroxyaniline, 12.2 grams water and 9.6 grams calcium acetate monohydrate. The mixture was heated to 30°C. and 223.8 grams paraformaldehyde slowly added to avoid an excessive exothermic reaction. The temperature rose to about 85°C. After all the paraformaldehyde had been added the mixture was heated to reflux (about 105°C.). The mixture was then cooled. A gelled solid formed on cooling which could not be dissolved and could not be used. Analysis indicated a large excess of unreacted phenol.
EXAMPLE 14
This experiment shows that epoxides are effectively used as curing agents for the resin compositions of this invention. A mixture was made of 42.5 grams of the resin of Example 4, a m-hydroxyaniline modified phenol-formaldehyde novolac, with 23.4 grams of an epoxidized phenol-formaldehyde novolac having an average of 2.2 epoxy groups per molecule (Dow Chemical Co. epoxy resin DEN 431). The resulting mixture had a 30°C. gel time of 39 minutes.
To show that any amino groups of the Example 4 resin are not acting in a conventional manner to simply homopolymerize the epoxy resin the following experiments were made. The amount of m-hydroxyaniline and phenol-formaldehyde novolac present in the above Example 4 resin were held separately, before any reaction together, and each was mixed with 23.4 grams of the above epoxy resin using 7.9 grams of methanol as a solvent carrier to insure compatibility. When 29.8 grams of the phenol-formaldehyde prepolymer alone in methanol was mixed with the epoxy a gel time greater than 2 weeks was measured. Mixing 10.8 grams of m-hydroxyaniline in methanol with the epoxy resulted in a composition having a 30°C. gel time of 355 minutes, nearly ten times that of the Example 4 resin. No additional aldehyde was present in any of the three tests.
EXAMPLE 15
Isocyanates also function as effective curing agents for the resins of this invention as is shown by this example. To the resins of Example 4, made with m-hydroxyaniline and of Example 5, made with m-phenylenediamine was added 2,4-toluene diisocyanate using a molar equivalence of --NCO groups to the --NH 2 groups of the amine used in the resin. Thus to 10 grams of the resin of Example 4 were added 1.65 grams of TDI. To 10 grams of the Example 5 resin 3.31 grams of TDI were added. The mixture was vigorously stirred immediately after addition of the hardener and the time to gelation noted visually. Additional experiments were made in which the pH of both resins are adjusted from the ambient nearly neutral or very slightly alkaline level to values of pH 6 and pH 4, using concentrated HCl, before addition of the isocyanate. Gel times as follows were obtained.
______________________________________ Example 4 Resin Example 5 Resin______________________________________Ambient pH 6.8 seconds 3 secondspH 6.0 7.1 seconds 11 secondspH 4.0 150 seconds 10 seconds______________________________________
EXAMPLE 16
This example shows the suitability of substituted phenols for making the aldehyde condensation polymers of this invention. Three polymers were made and designated A, B, and C in which the phenol of Example 1 was replaced by ortho, meta or para-cresol, respectively. These polymers were then used in the preparation of m-hydroxyaniline resins according to the teachings of Example 4.
The polymers were prepared by adding 244.6 grams of the cresol, 23.7 grams of water, 56.4 grams of 93.2% paraformaldehyde and 2.35 grams of calcium acetate to a reaction vessel. The temperature was raised to reflux over 60 minutes and held until free formaldehyde had dropped below 0.5% based on samples withdrawn from the reactor. Time at reflux for the ortho-cresol exceeded 23 hours before the free formaldehyde had dropped to the desired level. Cooking time after reflux was only 20 minutes for meta-cresol and 3 hours for para-cresol. At this time, the temperature was reduced slightly to 100°C. and 98.2 grams of m-hydroxyaniline added. The temperature was allowed to increase again to the reflux point and the resin was reacted for an additional 21/2 hours. A marked viscosity increase occurred near the end of this cooking period on the B and C resins although this was not observed on the A resin. The resins were then cooled to 50°C. and 77.7 grams of methanol added. After cooling to room temperature 17.25 grams of concentrated HCl was added to the resins to bring pH into the desired range. Finally 11.6 grams of refined crysolite asbestos was added and mixed in for 30 minutes for penetration control.
Ten gram samples of the resin were mixed with 5 grams of 55% formaldehyde in a methanol-water solvent and cross lap and gel tests run. Results are shown below:
Resin A Resin B Resin C______________________________________Viscosity, Gardner* A1-A U-V E-FpH 3.7 4.6 4.0Gel Time, sec. 55 40 70-75Cross Lap Strength, psi. 85 65 10______________________________________ *Before addition of HCl, asbestos or hardener.
EXAMPLE 17
The aldehyde condensation polymers used in this invention can suitably be made with lower polyfunctional aldehydes such as glyoxal. As an example 202.5 grams of 90.5% phenol, 109.2 grams of 40% glyoxal and 5.0 grams of calcium hydroxide were placed in a 500 ml. reactor. The temperature was raised to reflux over a 60 minute period and held at reflux for 5 hours until titration of a sample showed essentially no free glyoxal. At this point the temperature was dropped to 80°C. and 84.4 grams of m-hydroxyaniline added. The temperature was again raised to reflux and held for 21/2 hours. Temperature of the resin was dropped to 50°C. at which time 66.8 grams of methanol, 9.9 grams of refined crysolite asbestos and 14.8 grams of concentrated hydrochloric acid were added. Mixing was continued for an additional half hour at this temperature after which the resin was cooled and drawn to storage.
A 10 gram sample of the above resin was mixed with 5 grams of 55% formaldehyde in a methanol-water solution and the gel time and cross lap strength determined. The mixed composition gelled in 30-35 seconds. A 12-minute cross lap strength using Douglas-fir of 10 psi was measured.
EXAMPLE 18
Polyfunctional aldehydes are also suitable as curing agents for amine modified condensation resins. A resin very similar to that of Example 4 was mixed with 40% aqueous glyoxal in the ratio of 30 grams of resin to 15 grams glyoxal solution. A gel time of 55 seconds was measured. The cross lap test using Douglas fir wood showed a glue line strength of 200 psi after 12 minutes. | This invention describes resin products having particular utility as rapid curing adhesives for wood and other materials, and processes for making the resin compositions. The reaction products are made by reacting an aldehyde condensation polymer, such as a phenol-formaldehyde condensation polymer, with a primary aromatic amine having the formula: ##SPC1##
Where
X 1 is --NH 2 --CH 2 NH 2 ;
X 2 is --X 1 --OH--alkoxy;
X.sub.3 is -X.sub.1
COOHNHCOCH 3 NO 2 OHC 1 to C 5 alkylH-halogenhalogenated alkylalkoxy
X 4 is C 1 to C 4 alkyl, --H--aryl; and
A is ##EQU1## where Y 1 and Y 2 are hydrogen or alkyl radicals having from 1 to 3 carbon atoms and Z is an integer from 0 to 2,
--SO 2 ----NH----O----S---- C----S--S----N=N--, to obtain an amine-modified polymer. On blending an appropriate hardening agent with the amine-modified polymer, the composition cures very rapidly at ambient temperature. When pieces of wood or other materials are spread with the preferred adhesives employing the resin compositions of this invention and brought into contact with another wood or other surface the bond strength develops within minutes. | 2 |
FIELD OF THE INVENTION
The invention relates to a measuring method suitable particularly for system which measures the function of at least one organ of a user non-invasively, and comprises a transmitter unit which is attached to the user's body, and a receiver unit. The transmitter unit transfers its measurement data associated with at least one organ or organs to the receiver unit, and at least one sensor measures additional properties other than the function of the user's organs when the user uses an exercise device.
The invention further relates to a measuring system which measures particularly the function of at least one organ of a user non-invasively, and comprises a transmitter unit attached to the user's body, and a receiver. The receiver is arranged to transfer its measurement data associated with at least one organ to the receiver unit, and least one sensor is arranged to measure additional properties other than the function of the user's organs when the user uses an exercise device.
BACKGROUND OF THE INVENTION
Telemetric measuring methods are, for instance, used for measuring a person's heart rate. Equipment solutions are usually such that the unit for measuring and transmitting the heart rate data is arranged around the person's chest as a transmitter belt, from which the measurement data is telemetrically transferred by means of inductive coupling to a receiver unit, often implemented as a receiver wristband on a person's wrist. In cycling, the receiver unit can be secured to a bicycle handlebar, for example.
The transmitters of heart rate measurement devices transmit a burst of approximately 5 kHz each time the transmitters detect an ECG signal. The transmitter circuit of the transmitter unit comprises a resonance unit of a coil and a capacitor, the resonance circuit being activated and controlled by the heart rate. The receiver unit computes the pulse frequency on the basis of the time difference between successive transmitted signals, i.e. the time difference of the bursts, the information to be transmitted, i.e. the heart rate, being thus included in the transmission coded in the interval between the pulses.
Currently, however, a need has arisen for telemetric transmission of measurement data from several different sensors, for instance heart rate, pedaling speed and pedaling cadence, to the same receiver. In the prior art, the sensors transmit a measurement signal as a pulse group. In a pulse group, three pulses form two intervals which differ from the intervals of the pulse groups of other variables. Such a 3-pulse-coding is called a 3-pulse transmission. The receiver unit identifies each measurement variable on the basis of the pulse group interval.
Many applications, however, require higher-rate data transfer than the 3-pulse transmission is able to offer. In addition, the receiver unit is only capable of distinguishing a limited number of sensors from each other due to the coding employed in the 3-pulse transmission.
BRIEF DESCRIPTION OF THE INVENTION
An object of the invention is thus to provide a method and an apparatus implementing the method such that the above problems can be solved. This is achieved with a method of the type described in the introduction, the method being characterized in that the measuring system comprises a holder comprising a data collection unit, and a receiver is secured to the holder. At least one sensor transfers its measurement data to the data collection unit of the holder; and the data collection unit of the holder transfers the collected measurement data to the receiver unit by means of inductive interaction.
The system of the invention is characterized in that the measuring system comprises a holder further comprising a data collection unit, and a receiver unit is arranged to be secured to the holder. At least one sensor is arranged to transfer the collected measurement data to the receiver unit by means of inductive interaction.
Several advantages are achieved with the method and system of the invention. Data transfer rate to the receiver unit can be increased. Transmission power necessary for data transfer can be decreased, and the measuring system of the invention is more efficient in data processing than the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is now described in greater detail in connection with the preferred embodiments with reference to the accompanying drawings, in which
FIG. 1 shows a prior art measuring system, and
FIG. 2 shows a measuring system formed in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
The solution of the invention can be applied when at least two different measurement variables are provided, but it can be particularly applied to cycling, where the measurement variables include the cyclist's heart rate, speed of the cycle, pedaling cadence and/or other characteristics of the user or the environment.
FIG. 1 shows three transmitter units used in a prior art method and a receiver unit in a cycling environment. The application is, for instance, a bicycle 100, pedaled by a user 102. The apparatus comprises for example three measuring and transmitter units 110 to 116, one receiver unit 120 to which each measuring and transmitter unit telemetrically transfers measurement data as pulse groups, and a holder 122 of the receiver.
In FIG. 1, a first measuring and transmitter unit 110, i.e. a heart rate transmitter, is provided for measuring and transmitting the heart rate. The first measuring and transmitter unit 110 comprises an ECG sensor (an ECG amplifier), a control block and an oscillating resonance circuit controlled by heart rate. The oscillating resonance circuit comprises a coil and a capacitor, coupled in parallel (not shown in the figure). Hence, the heart beat data is transferred to the receiver 120 by means of inductive interaction, since the receiver 120 also comprises the oscillating circuit formed by a coil and a capacitor.
In FIG. 1, a second measuring and transmitter unit 112, i.e. a speed transmitter, is provided for measuring the speed of an exercise device. The second measuring and transmitter unit 112 comprises a speed sensor, a control block and an oscillating resonance circuit controlled by a speed signal. The oscillating resonance circuit comprises a coil and a capacitance, coupled in parallel (not shown in the figure).The speed sensor can be implemented, for instance, by a magnetic switch sensor such that a magnet 114 is secured to a wheel 104 of the bicycle 100, and the switch part of the magnet is in its place on a front fork 106 of the bicycle. The case the speed measurement is based on detecting the movement of the magnet past the switch part. In a preferred embodiment, the speed sensor 112 further comprises for instance a 1/4 divider, which makes the sensor issue a pulse only after the magnet has revolved four times past the switch part. In this way, by using the divider, high speeds can be measured, whereas lower speeds can be measured without the divider being utilized.
In FIG. 1, a third measuring and transmitter unit 116, i.e. a cadence transmitter (a transmitter indicating the pedaling cadence) provided for measuring the pedaling cadence of the user 102 of the exercise device, i.e. the person pedaling. The third measuring and transmitter unit 116 comprises a cadence sensor, a control unit, an amplifier and an oscillating resonance circuit controlled by a cadence signal. The oscillating resonance circuit comprises a coil and a capacitance, which is coupled in parallel (not shown in the figure). The cadence sensor can be implemented by a magnetic switch sensor such that a magnet 118 is secured to a pedal of the bicycle 100 or to a crank 108 of the pedals. The switch part of the sensor and the actual transmitter unit are secured, for instance, to the frame tube of the bicycle 100, in which case the measurement of the pedaling cadence is based on detecting the movement of the magnet past the switch part of the sensor. In such a prior art solution, the receiver 120 directly receives the measurement signals transmitted by the sensors 112, 116, and the holder 122 only serves as a mechanical securing means of the receiver unit 120 to the exercise device.
FIG. 2 shows a measuring system in accordance with the inventive solution. Superficially, the measuring system of the invention may seem to be similar to the prior art solution, but the operation potential of the system of the invention is substantially greater than that of the prior art solution. The system comprises a holder 206 secured to, exercise device, the holder comprising a data collection unit 204. The holder 206 with its data collection unit 204 is substantially different from the prior art and enables much more efficient data transfer and data processing. The holder 206, in accordance with FIG. 2 and the holder in FIG. 1, are thus secured to the bicycle in a similar manner. The difference is the functional activity of the holder 206, which is enabled by the data collection unit 204. Sensors 208, 210, 212, 214 transmit their measurement data to the data collection unit 204. Data transfer between the sensors 208, 210, 212, 214 and the data collection unit 204 can take place through a wire. In FIG. 2, this is illustrated by a wire 209, which combines the sensor 208 and the data collection unit 204. Data transfer can also take place wirelessly. In this case, the data transfer of the sensor 210 to the data collection unit 204 takes place by means of inductive interaction. The actual mode of data transfer is not essential in the inventive solution, but the fact that the data collection unit 204 collects the measurement data transmitted by the sensors 208, 210, 212, 214 is important. The data collection unit 204 can also change the coding of the measurement data received and transfer the measurement data to the receiver unit at a substantially higher data transfer rate than the data transfer rate between the sensor or sensors and the data collection unit 204. The data collection unit 204 preferably processes the measurement data received. Consequently, the data collection unit 204 can for instance compute the speed of the exercise device from the pulses received from the speed sensor, and instead of transmitting the pulses from the sensor further to the receiver unit 202, the data collection unit 202 can transmit the computed speed information. In the prior art, the signal of a sensor can only be comprised of, for instance, pulses of the 3-pulse transmission that are generated when the magnet passes the switch part, as mentioned in the description of FIG. 1. In the inventive solution, information on which or what kind of sensor the measurement data originates from is transmitted together with the measurement data of each sensor 208, 210 to 214. Hence, the measurement data of the sensors 208, 210 to 214 can be separated from each other. It is also ensured that the measurement data from the different sensors 208, 210 to 214 is not mixed up when transferred between the data collection unit 204 and the receiver unit 202.
In the inventive solution, the data collection unit 204 can form a new performance parameter from measurement data received from one sensor. When, for example, the speed of the bicycle is measured by the speed sensor, the data collection unit computes from the speed data received for the new performance parameter statistical variables such as speed change, speed mean value or speed deviation. The performance parameter is transferred to the receiver unit in accordance with the inventive solution. The user can thus analyze and modify his or her exercise technique.
The inventive solution also enables measurement data issued from two or more sensors to be combined into a new performance parameter. For example, cadence data and speed data, or data from other sensors can be combined into a performance parameter in such a manner that instantaneous or statistical cadence and speed data are compared with each other. The ratio between the cadence and the speed thus formed is preferably transferred to the data collection unit 204.
The inventive solution also allows heart rate transmitted by the transmitter 200 to be directly received by the data collection unit 204. The data collection unit 204 transfers the heart rate data to the receiver 202 by means of inductive interaction.
The inventive solution enables the transmitter unit 200 to transmit its measurement data to the data collection unit 204, but in a preferred embodiment of the invention the transmitter unit 200 transfers its measurement data directly to the receiver unit 202 by means of inductive interaction using different modulation and/or coding than in the data transfer between the data collection unit 204 and the receiver unit 202. The data collection unit transfers the measurement data to the receiver unit 202 using a higher data transfer rate than the wireless data transfer rate taking place between the sensors 210 to 214 and the data collection unit 204. This enables the measurement data produced by the sensors 208, 210 to 214 to be transferred to the receiver unit 202 sufficiently fast. The data transfer is preferably performed in serial mode. Serial-mode data transfer is preferably similar to that of the prior art solutions wherein the receiver unit 202 communicates with the data transfer unit. The data collection unit 204 identifies the attachment of the receiver unit 202 to the holder 206. The identification is performed by means of a switch, for example. On the basis of the identification, the data collection unit 204 transmits a handshake signal to the receiver unit 202. The handshake signal can comprise a number of pulses, for example. After receiving the handshake signal, the receiver unit 202 sets its operational mode to be suitable for the exercise device. In connection with the exercise device, the receiver unit 202 receives data measured by the sensors 208, 210 to 214 by means of the data collection unit 204.
The sensor or sensors 208, 210 to 214 transfer measurement data to the data collection unit at least partly wirelessly. The sensor 208, 210 to 214 thus transfers its measurement data to the data collection unit 204 preferably by means of inductive interaction. In the measuring system of the invention, the coil (not shown in the figure) of the sensor 208, 210 to 214 participating in the inductive interaction can readily be directed for data transfer to the data collection unit 204. Hence, the transmission power of the sensor 208, 210 to 214 can be kept low. At least one sensor 208, 210 to 214, in accordance with the number of the sensors, measures one or more characteristics, such as the speed of the exercise device, ambient temperature and pressure. Furthermore, when the exercise involves repeating a particular motion, the cadence of the repetitive motion can be measured. The exercise device is preferably a bicycle, in which case at least two sensors 208, 210 to 214 are provided, which measure the speed and pedaling cadence of the bicycle.
The receiver unit comprises at least two modes. The first mode is such that the user does not exercise on the exercise device and the receiver unit 202 is in inductive interaction with, for example, the transmitter unit 200, having no interaction with the data collection unit 204. Such a mode enables the receiver unit 200 to be used in accordance with the prior art when the user is running, for example. The second mode is such that the user exercises on the exercise device and the receiver unit 202 is in inductive interaction with at least the data collection unit 204.
The invention can also be applied to exercise devices other than a bicycle. Such devices include watercraft, in which case the measurement variables include a person's heart rate, speed and operating cadence of a watercraft, such as paddling or rowing cadence. Furthermore, the invention can be applied to an application where a substantial part of the measurement variables or even all measurement variables are measurements related to the human body, such as two or more of the following: heart rate, blood pressure, temperature, blood glucose content and blood oxygen content. The inventive solution also enables the condition of the exercise device to be measured by means of different sensors. In connection with a bicycle, the sensors can measure for example the brakes (brake wear or brake force), gears (gear shift and gear wear), shaking of the bicycle, tightness of the chain or the power used.
Although the invention has been described with reference to the example of the accompanying drawings, it is obvious that the invention is not restricted thereto but can be modified in many ways within the scope of the inventive idea disclosed in the attached claims. | The invention relates to a measuring method and a measuring system, particularly suited for measuring the function of at least one organ of a user non-invasively. The system comprises a transmitter unit (200) attached to the user's body, and a receiver unit (202). The transmitter unit (200) transfers its measurement data associated with at least one organ to the receiver unit (202), and at least one sensor (208, 210 to 214) measures other properties than the function of the user's organs when the user uses an exercise device. The measuring system includes a holder (206) having a data collection unit (204). The receiver unit (202) is secured to the holder (206), and at least one said sensor (208, 210 to 214) transfers its measurement data to the data collection unit (204). The data collection unit (204) transfers the collected measurement data to the receiver unit (202) by means of inductive interaction. | 8 |
FIELD
[0001] The present teachings relate to a handheld power tool having readily interchangeable cutting elements for trimming and cutting vegetation. More particularly, the present teachings relate to a resiliently biased driving element formed on a main body portion of the power tool that automatically engages various interchangeable blade carrier assemblies to allow a user to perform different types of cutting processes in a quick and safe manner.
BACKGROUND
[0002] Known power tools having interchangeable blades are cumbersome and potentially dangerous to manipulate. For example, U.S. Pat. No. 3,959,848 to Irelan et al., discloses a convertible portable electric tool having interchangeable tool pieces. Each of the interchangeable tool pieces include two parts, a stationary element and a moving element, which are pivoted together at a pin. The stationary element includes a comb of teeth and, likewise, the moving element includes a comb of teeth. The rearward end of the moving element includes an elongated opening for receipt of a drive member. The drive member is rotated by a gear and the resulting circular movement oscillates the moving element about the pivot pin. As a result, the stationary element and the moving element lap one another to cut grass between the teeth upon oscillation of the moving element.
[0003] Before attaching a tool piece assembly to the power housing, the user must first rotate the drive member to a predetermined position, such as a top dead center position. Similarly, the user must manually orient the moving element into a predetermined position with respect to the stationary element. After completing these preliminary steps, the drive member can be fitted within the elongated opening of the moving element upon bringing the stationary element into proper registry relative to the power housing. Once the stationary tool element is brought into proper registry and located over guide posts, additional means are provided to maintain the tool piece releasably secured against the housing.
[0004] Accordingly, the attachment of tool pieces to a power housing as disclosed by Irelan et al. is a cumbersome process requiring various manual alignment steps to be performed by the user with respect to both the tool piece and the power housing. Generally, known power tools do not provide fool-proof mechanisms to allow easy, safe, and automatic alignment and attachment of cutting elements. Instead, users are required to spend time handling and adjusting cutting blades and other movable parts until precise alignments are achieved before a cutting element can be properly attached. Not only is this time consuming, but the user is also exposed to sharp cutting surfaces and powered moving parts in the process.
[0005] A need exists for a power tool having interchangeable cutting assemblies that can automatically align themselves into an operative position without requiring cumbersome and dangerous operated-assisted adjustments. A need also exists for interchangeable cutting assemblies that can be readily and safely latched to and selectively released from an operative position whenever desired by the user. There also exists a need for interchangeable cutting assemblies that can be safely and easily manipulated by a user.
SUMMARY
[0006] The present teachings relate to a power tool and system having readily interchangeable cutting assemblies for cutting and trimming vegetation. The present teachings also relate to a method of attaching a blade carrier assembly to a power tool main body.
[0007] According to various embodiments, the power tool includes a main body portion including a housing, a selectively actuatable motor operatively arranged with the housing and including a rotary output, and a rotary drive element arranged in operative contact with the rotary output of the motor and including a resiliently biased drive pin. A blade carrier assembly is capable of being selectively and removably attached to the main body portion. The blade carrier assembly includes a moveable blade portion having a drive pin slot. Upon attaching the blade carrier assembly to the main body portion and actuating the motor, the resiliently biased drive pin is rotatable to a position such that the drive pin is resiliently forced into the drive pin slot of the moveable blade portion.
[0008] According to various embodiments, the power tool system includes a main common body portion including a housing, a selectively actuatable motor operatively arranged within the housing and including a rotary output, and a rotary drive element arranged in operative contact with the rotary output of the motor. The rotary drive element includes an engageable drive structure. A plurality of blade carrier assemblies each include a blade carrier cup that is capable of being removably attached to the main common body portion by way of a latching mechanism. The blade carrier cup is arranged to support a cutting blade assembly such that the cutting blade assembly can be safely handled by the user by manipulation of the blade carrier cup. The cutting blade assembly includes a moveable blade portion capable of operative connection with the engageable drive structure of the rotary drive element.
[0009] According to various embodiments, the method of attaching a working assembly to a power tool main body is provided. The method includes providing the power tool main body with a selectively actuatable motor arranged to drive a rotary drive element including a resiliently biased drive pin and providing the working assembly, such as a blade carrier assembly, with a moveable working piece portion having a drive pin engageable structure. The method further includes connecting the working assembly to the power tool main body such that the resiliently biased drive pin is displaced if the drive pin is not aligned with the drive pin engageable structure, and then actuating the motor to rotate the rotary drive element to a position such that the drive pin is resiliently forced into the drive pin engageable structure to actuate the working assembly.
[0010] Additional features and advantages of various embodiments will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of various embodiments. The objectives and other advantages of various embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the description herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a power tool device and system including an additional, unattached blade carrier assembly according to various embodiments;
[0012] FIG. 2 is a perspective view of the power tool device of FIG. 1 showing a blade carrier assembly in an unlatched position according to various embodiments;
[0013] FIG. 3 is a top perspective view of an interchangeable blade carrier assembly according to various embodiments;
[0014] FIG. 4 is a bottom perspective view of the main body of the power tool device of FIG. 1 with the interchangeable blade carrier assembly removed
[0015] FIG. 5 is an exploded perspective view of a drive motor assembly including a first embodiment of a resiliently biased rotary drive element;
[0016] FIG. 6 is a perspective view of a second embodiment of a resiliently biased rotary drive element including a spur gear having a resiliently mounted drive pin arranged thereon; and
[0017] FIG. 7 is a perspective view of the second embodiment of the resiliently biased rotary drive element of FIG. 6 shown in a disassembled condition.
[0018] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are intended to provide an explanation of various embodiments of the present teachings.
DESCRIPTION
[0019] A power tool device 10 and a system for cutting and trimming vegetation is shown in FIG. 1 . The power tool device 10 can be a handheld unit for cutting grass, weeds, and other types of vegetation around a house or business, or any other location where unwanted growth is found. The power tool device 10 can be part of a system or kit that allows a user to perform various different cutting functions using a common main tool body 12 . The power tool system can include a plurality of interchangeable blade carrier assemblies 14 , 15 that can be releasably attached to the common main body portion 12 . For example, as shown in FIG. 1 , the common main tool body 12 is shown attached to an interchangeable blade carrier assembly 14 that comprises a shrubber blade subassembly 16 . Furthermore, adjacent to the power tool device 10 is an unattached interchangeable blade carrier assembly 15 that comprises a shear blade subassembly 17 . Referring to the unattached interchangeable blade carrier assembly 15 , each blade carrier assembly can include a blade carrier cup portion 18 and one of a plurality of different blade subassembly portions 17 . In the preferred embodiment, the blade carrier cup portion 18 is the same for both the shrubber blade 16 interchangeable blade carrier assembly 14 and the shearing blade 17 interchangeable blade carrier assembly 15 . As will be discussed below, the blade carrier cup portion 18 allows the interchangeable blade carrier assembly 14 , 15 to be safely handled and manipulated by a user, as well as easily attached and removed from the common main tool body portion 12 .
[0020] Referring to FIG. 2 , a close-up view of the power tool device 10 of FIG. 1 is provided. The power tool device 10 is shown in a position whereby an interchangeable blade carrier assembly 14 (including a shrubber blade subassembly 16 ) is in the process of being latched onto or unlatched from the common main tool body 12 . The positioning of the structure shown in FIG. 2 shows how power can be transferred from the common main tool body 12 to the blade subassembly portion 16 of an interchangeable blade carrier assembly 14 .
[0021] On the common main tool body 12 , a trigger switch 24 allows the user to selectively control power to a motor arranged within the housing of the common main tool body 12 . In a preferred embodiment, the main tool body also includes a battery pack for providing energy to the motor enabling the power tool device to be cordless device. The details of the drive motor assembly will be described below with respect to the discussion of FIG. 4 . According to various embodiments, the motor is operable to rotate a rotary drive element 26 . As shown in FIG. 2 , the rotary drive element 26 can include a drive plate 28 and a drive pin 30 . The drive pin 30 may be integrally attached or formed with the drive plate 28 . The drive pin 30 can be eccentrically arranged on the drive plate 28 .
[0022] On the interchangeable blade carrier assembly 14 , one or more movable blades 32 , 33 can be reciprocally arranged with respect to the blade carrier cup 18 . In a preferred embodiment, the power tool device 10 has one moveable blade 32 which sits on top of and works with a stationary blade 33 for providing a cutting action. As shown in FIG. 2 , the movable blade 32 includes a drive pin slot 34 for engagement with the drive pin 30 of the rotary drive element 26 . The blade carrier cup 18 can attach to the common main tool body 12 by way of a latching mechanism. The latching mechanism may include one or more latch apertures or detents 36 formed on the blade carrier cup 18 . The apertures or detents 36 may be completely cut through the blade carrier cup 18 housing as shown in FIG. 2 or may be a recess on the interior housing of the blade carrier cup 18 and, therefore, not visible or evident from the exterior housing of the blade carrier cup assembly 18 . The latching mechanism might also include one or more resiliently biased latch elements 38 formed on the common main tool body 12 . The resiliently biased latch elements 38 may be partially or fully retractable into the common main tool body 12 and are resiliently biased outwardly in their non-actuated position. As will be further described in conjunction with FIG. 3 , the blade carrier cup 18 may have mating hook 40 for mating with and insertion into a recess or aperture in the main tool body 12 . The blade carrier cup 18 is attached to the main tool body 12 by inserting the mating hook 40 into an aperture 45 (see FIG. 4 ) in the main tool body 12 and then bringing the forward end of the blade carrier cup 18 into engagement with the main tool body 12 until the latch elements 38 snap into engagement with the latch apertures or detents 36 formed on the blade carrier cup 18 . In the engaged position, the power tool device 10 is assembled and ready to perform a cutting operation.
[0023] On the common main tool body 12 , one or more latch release pushbuttons 42 can be arranged in a position for convenient actuation by the fingers and/or thumb of a user. The one or more latch release pushbuttons 42 can be mechanically coupled with the latch elements 38 . Accordingly, the latch elements 38 can be retracted from the blade carrier cup 18 by depressing at least one of the latch release pushbuttons 42 thereby releasing the blade carrier assembly 14 from the common main tool body 12 .
[0024] A detailed top view of a blade carrier cup portion 18 of an interchangeable blade carrier assembly 14 is shown in FIG. 3 . The blade carrier cup portion 18 may have a concave shape that defines a generally concave interior. The concave interior of the cup portion 18 can be defined by a bottom surface and at least one sidewall surface. The blade carrier cup portion 18 can be arranged to engage a complimentary convex-shaped portion of the main common body portion 12 . In a preferred embodiment, the blade carrier cup 18 is made of a hard resilient plastic which covers the complete underside of the blade subassembly 16 , 17 (except for the cutting end) to enable a user to grab the blade carrier cup 18 and attach or remove the interchangeable blade carrier assembly 14 , 15 without needing to touch the blades 32 , 33 .
[0025] In FIG. 3 , an interchangeable blade carrier assembly 14 , 15 is shown with a shrubber blade subassembly 16 operatively connected a bottom interior surface of the blade carrier cup portion 18 . As discussed above, in a preferred embodiment the shrubber blade subassembly 16 may include at least two cutting elements or blades, an upper movable cutting element 32 and a lower stationary cutting element 33 . The lower stationary cutting element 33 can include a stationary blade end 48 that can be secured in the blade carrier cup 18 . A movable blade end 49 of the upper movable cutting element 32 may also be arranged within the blade carrier cup 18 . A drive pin slot 34 may be formed in movable cutting element blade 32 for engagement with the drive pin 30 of the rotary drive element 26 . A track or guide mechanism 52 can be arranged on either side of the stationary cutting element 33 or the movable cutting element 32 for placement during fabrication or to guide the movable cutting element 32 as it reciprocates in a direction into and away from the housing.
[0026] At one end of the blade carrier cup portion 18 , a blade carrier cup hook 40 can be arranged for engagement with the common main tool body 12 . The blade carrier cup hook 40 may be inserted into an aperture 45 , as seen in FIG. 4 , in the main tool body 12 to provide engagement at the back end of the blade carrier cup 18 with the main tool body 12 . When the blade carrier cup 18 is disengaged the common main tool body 12 , as shown in FIG. 2 , the blade carrier cup hook 40 can be disengaged from the common main tool body 12 and replaced with a different interchangeable blade carrier assembly 14 , 15 .
[0027] FIG. 4 , provides a perspective view of the bottom of the main body 12 of the power tool device 10 . The drive pin 30 , drive plate 28 and rotary drive element 26 can be seen as the interchangeable working assembly 14 , 15 is removed. Further, the latch release pushbuttons 42 may be mechanically coupled with the latch elements 38 for securing and releasing the interchangeable working assemblies or blade assemblies 14 , 15 . In addition, the main body 12 includes an aperture 45 for mating with and receiving the cup hook portion 40 of the blade carrier cup 18 .
[0028] Referring to FIG. 5 , a drive motor assembly 50 for the power tool device 10 is shown. The drive motor assembly 50 may include an electric motor 56 that can power a resiliently biased rotary drive element 26 . As shown in FIG. 5 , the electric motor 56 can be operatively attached to a gearbox assembly 58 that can provide power to a drive gear 66 . The gearbox assembly 58 may include a gear train, including, for example, a planetary gear arrangement 60 . A support surface 62 can be arranged along a portion of the drivetrain of the drive motor assembly. For example, the support surface 62 can be arranged adjacent to the planetary gear arrangement 60 . The support surface 62 can provide a smooth surface upon which a spring 64 , such as, for example, a spring washer 64 , can be supported.
[0029] The drive gear 66 can be operatively connected with the planetary gear arrangement 60 and can provide rotary power to the rotary drive element 26 . As shown in FIGS. 2, 4 and 5 , the rotary drive element 26 can include a drive plate 28 having an eccentrically arranged drive pin 30 arranged or formed thereon. The rotary drive element 26 can rotate with respect to a rotary drive element housing 68 . The rotary drive element housing 68 can attach with the gearbox assembly 58 to form the drive motor assembly structure.
[0030] In the assembled state of the drive motor assembly 50 structure, the spring 64 resiliently forces the rotary drive element 26 in a direction away from the motor 56 such that the rotary drive element 26 is forced against the rotary drive element housing 68 . The rotary drive element 26 can move a distance into the rotary drive element housing 68 against the resilient force of the spring 64 . For example, referring to FIGS. 2, 4 , and 5 , the rotary drive element 26 would be forced into the rotary drive element housing 68 against the force of spring 64 , if the drive pin 30 is not aligned with the drive pin slot 34 of moveable blade 32 when the blade carrier assembly 14 is brought into engagement with the main tool body 12 . When the motor 56 is energized by having the user depress the trigger 24 , the drive plate 28 , and in turn, the drive pin 30 are rotated until the resiliently biased drive pin 30 snaps or clicks into the drive pin slot 34 of one or more moveable blades 32 . Once engaged in the drive pin slot 34 , the drive pin 30 can continue to be rotated by the motor 56 to reciprocate moveable blade 32 and achieve a cutting action against stationary blade 33 . Thus, there is no need for the user to make any preliminary alignments with respect to the drive pin 30 , the drive pin slot 34 , or the blade carrier assembly 14 , 15 .
[0031] To replace or interchange blade carrier assemblies 14 , 15 , for example, to change from a shrubber blade assembly 14 to a shear blade assembly 15 , the user can depress one or more of the latch release pushbuttons 42 . Depressing the latch release pushbuttons 42 results in the latch elements 38 being retracted such that they no longer project into or through the latch apertures or detents 36 formed on the blade carrier cup portion 18 of the blade carrier assembly 14 , 15 . The user can then remove the blade carrier assembly 14 by moving the blade carrier cup 18 downwardly with respect to the common main tool body 12 and removing the cup mating hook 40 from the recess or aperture 45 within the main tool body 12 . At this point, the blade carrier assembly 14 can be safely detached from the common main tool body 12 and discarded by grasping the blade carrier cup portion 18 and removing it from the common main tool body 12 .
[0032] A new blade carrier assembly 14 , 15 can then be attached to the common main tool body 12 by the user grasping the blade carrier cup portion 18 and placing the blade carrier cup hook 40 into the main tool body recess or aperture 45 within the common main tool body 12 . The front portion of the blade carrier cup portion 18 can then be brought into engagement with the main tool body 12 until the resilient latch elements 38 engage with the latch apertures or detents 36 formed on the carrier cup 18 . As discussed above, when the trigger 24 is depressed, the resiliently biased rotary drive element 26 will rotate until the spring biased drive pin 30 snaps or clicks into engagement with the moveable blade drive slot 34 of the blade assembly 16 .
[0033] Referring to FIGS. 6 and 7 , another embodiment of a resiliently biased rotary drive element is shown. The resiliently biased rotary drive element can include a spur gear 72 that can be driven by a drive motor assembly by way of a drive gear 90 . The spur gear 72 can be arranged to support an eccentrically located and resiliently biased drive pin 74 . The drive pin 74 can be resiliently biased in a direction away from the spur gear 72 and can be pushed in a direction towards and into the spur gear 72 against the resilient force. Thus, the resiliently biased rotary drive element includes a rotatable spur gear 72 and a resiliently biased drive pin 74 supported thereon.
[0034] Referring to FIG. 7 , details of the resiliently biased rotary drive element are shown. To more clearly show the structural details, the drive pin 74 is shown removed from a countersunk or stepped aperture formed in the spur gear 72 , along with a disassembled C-clip 78 and spring 76 . The drive pin 74 can include a shaft portion 75 and an enlarged head portion. In an operative position, the shaft portion 75 of the drive pin 74 can be arranged to extend in a throughhole 82 that passes through the spur gear 72 . An enlarged, coaxially arranged borehole 84 formed in the spur gear 72 can accommodate the enlarged head portion of the drive pin 74 .
[0035] The drive pin 74 can be resiliently biased by way of a spring 76 . One end of the spring 76 can engage a flat surface formed at the intersection between the throughhole 82 and the enlarged aperture borehole 84 , and the other end of the spring 76 can engage a backside of the head portion of the drive pin 74 . The spring 76 can be arranged about the shaft portion 75 and is operable to bias the drive pin 74 such that the enlarged head portion is forced beyond a surface of the spur gear 72 .
[0036] To secure the drive pin 74 within the aperture of the spur gear 72 , a drive pin securing mechanism 78 , such as a C-clip, can be used to engage an end of the shaft portion 75 of the drive pin 74 . The C-clip 78 can clamp onto the drive pin 74 at the back side of the spur gear 72 . For example, the C-clamp 78 can clamp into a groove 80 formed on the end of the drive pin 74 . The securing mechanism 78 operates to prevent the spring 76 from forcing the drive pin 76 out of the aperture formed in the spur gear 72 .
[0037] Referring to FIG. 7 , an exemplary gear train arrangement for transferring power from the motor (not shown) to the spur gear 72 is shown. The gear train arrangement can include a motor-driven input drive gear 86 , a lower gear 88 , and an upper gear 90 coaxially arranged with the lower gear 88 and in driving engagement with the spur gear 72 . According to various embodiments, other gear train arrangements could also be employed to drive the spur gear 72 .
[0038] The attachment of an interchangeable blade carrier assembly 14 to the main body portion including the resiliently biased rotary drive element of FIGS. 6 and 7 will now be described. As shown in FIG. 6 , the resiliently biased drive pin 74 will be forced into the spur gear 72 if the drive pin 74 is misaligned with the drive pin slot 34 of the moveable blade 32 . In such a misaligned position, when the motor is energized, the spur gear 72 , and in turn, the drive pin 74 are rotated until the resiliently biased drive pin 74 snaps or clicks into the drive pin slot 34 of moveable blade 32 . Once engaged in the drive pin slot 34 , the drive pin 74 can continue to be rotated by the motor thereby reciprocating moveable blade 32 and providing a cutting action against stationary blade 33 . Thus, there is no need for the user to make any initial alignment of the drive pin 74 with the drive pin slot 34 .
[0039] The present invention provides the user with a hassle-free working assembly or blade assembly attachment mechanism and process which provides automatic engagement between the motor and drive pin to the working assembly or blade assembly. Further, the partial housing or casing around the blade assembly enables the user to attach and remove the interchangeable blades without the concern of touching the working members or blades. Still further, the quick release and latch mechanisms enable the user to quickly and easily disengage the working assemblies through the use of the release buttons or mechanism which are located separate from the working assemblies providing a safe release mechanism enabling the user to release and remove the working assemblies without the need to contact the working members or blades.
[0040] Those skilled in the art can appreciate from the foregoing description that the present teachings can be implemented in a variety of forms. Therefore, while these teachings have been described in connection with particular embodiments and examples thereof, the true scope of the present teachings should not be so limited. Various changes and modifications may be made without departing from the scope of the teachings herein. | A power tool and system for trimming and cutting vegetation are disclosed. A method of attaching a working assembly, such as blade carrier assembly, to a power tool is also disclosed. The power tool includes interchangeable cutting elements that can be readily attached and detached from a main body portion without any preliminary alignment steps. The main body portion of the power tool includes a selectively actuatable motor including a rotary output and a rotary drive element including a resiliently biased drive pin. Blade carrier assemblies are capable of being selectively and removably attached to the main body portion and each include a moveable blade portion having a drive pin slot. Upon attaching a blade carrier assembly to the main body portion and actuating the motor, the resiliently biased drive pin is rotatable to a position such that the drive pin is resiliently forced into the drive pin slot of the working piece to actuate the working assembly. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
The subject matter of this invention is related to concurrently filed, co-pending applications: U.S. patent application Serial No. 09/377,001, [Eaton Docket No. 97-PDC-505,] filed Aug. 18, 1999, entitled "Circuit Breaker With Easily Installed Removable Trip Unit"; U.S. patent application Ser. No. 09/377,013, [Eaton Docket No. 99-PDC-153,] filed Aug. 18, 1999, entitled "Circuit Breaker With Externally Lockable Secondary Cover Latch"; U.S. patent application Ser. No. 09/376,897, [Eaton Docket No. 99-PDC-220,] filed Aug. 18, 1999, entitled "Circuit Breaker With Lockable Trip Unit Adjustment Cover"; U.S. patent application Ser. No. 09/376,920, [Eaton Docket No. 99-PDC-221,] filed Aug. 18, 1999, entitled "Circuit Breaker With Combined Slot Motor, Reverse Loop And Terminal Strap"; U.S. patent application Ser. No. 09/376,248, [Eaton Docket No. 99-PDC-222,] filed Aug. 18, 1999, entitled "Circuit Breaker With Combination Push-To-Trip And Secondary Cover Latch"; U.S. patent application Ser. No. 09/376,265, [Eaton Docket No. 99-PDC-223 ] filed Aug. 18, 1999, entitled "Multi-Pole Circuit Breaker With Multiple Trip Bars"; U.S. patent application Ser. No. 09/376,816, [Eaton Docket No. 99-PDC-225,] filed Aug. 18, 1999, entitled "Circuit Breaker With Trip Unit Mounted Tripping Plunger And Latch Therefore", U.S. patent application Ser. No. 09/377,018, [Eaton Docket No. 99-PDC-226,] filed Aug. 18, 1999, entitled "Circuit Breaker With Non-Symmetrical Terminal Collar"; and U.S. patent application Ser. No. 09/376,254, [Eaton Docket No. 99-PDC-247,] filed Aug. 18 1999, entitled "Circuit Breaker With Dial Indicator For Magnetic Trip Level Adjustment".
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject matter of this invention is related generally to molded case circuit breakers and more specifically to auxiliary device levers for molded case circuit breakers.
2. Description of the Prior Art
Molded case circuit breakers are well known in the art as exemplified by U.S. Pat. No. 5,910,760 issued Jun. 8, 1999 to Malingowski et al., entitled "Circuit Breaker with Double Rate Spring" and assigned to the assignee of the present application. The foregoing is incorporated herein by reference.
Molded case circuit breakers include a set of separable main contacts, one of which is usually fixed and one of which is movable for automatically opening upon the occurrence of an overload or short circuit electrical current in the network which the circuit breaker is provide to protect. The separable main contacts are opened as a result of the functioning of a latched operating mechanism, which is interconnectable by way of an operating handle to a region outside of the circuit breaker. The operating handle may be used to trip the circuit breaker manually or to reset and close the circuit breaker contacts once they have been opened automatically. The reset action is required because circuit breakers must be mechanically charged to be in a state to reopen immediately upon closure in the event that the fault which cause the tripping in the first place has not disappeared. The reset action charges the circuit breaker for that purpose. Molded case circuit breakers have trip units, which are often removably insertable in the circuit breaker case. The trip unit in addition has at least two calibratable functions, one of which is generally identified as thermal tripping and the other of which is generally identified as magnetic tripping. The trip unit includes a rotatable trip bar, which when rotated will actuate a latchable tripping operation within the operating mechanism to automatically open the circuit breaker contacts. The rotatable trip bar is usually actuated in one of two ways. The first way is in response to what is called a magnetic tripping of the circuit breaker. This occurs when the amount of current flowing through the separable main contacts of the circuit breaker is so high as to represent a potential catastrophic failure and which therefore requires exceedingly quick opening action of the circuit breaker. In such a case a electron magnetic core, which produces magnetic flux in proportion to the amount of electrical current flowing through the separable main contacts attracts a movable armature, the movement of which eventually causes the trip bar to move to thus cause the tripping action. The second tripping occurrence is in response to a relatively low amount of overload current, which eventually will cause overheating of the electrical wires in the circuit to be protected, but which does not necessitate the instantaneous action a short circuit requires and thus does not require the magnetic action spoken of previously. In this case a bi-metal element is heated by a heater element which conducts the electrical current flowing through the separable main contacts. As the bi-metal element flexes or moves it impinges upon the tripping bar causing it to flex and move correspondingly, until eventually a point is reached in which the tripping bar causes the circuit breaker to unlatch and trip automatically. Both the magnetic trip mechanism and the thermal trip mechanism usually require initial calibration.
In one half of an AC cycle, the electrical current flows through the circuit interrupter from the load by way of a terminal collar to the load terminal of the circuit breaker and from there into the trip unit where it flows through the previously mentioned heater which in turn is serially connected to the electron magnetic member of the magnetic trip device. From there it is interconnected by way of a flexible cable to one end of a moveable contact arm and from there to the main contact on the moveable contact arm. When the contact arm is closed, it is closed upon a fixed contact which is supported usually on unshaped conductor, which in turn is interconnected with a line terminal and there to the line terminal collar and finally to the electrical line. In addition the circuit breaker usually has an arc chute for assisting in diminishing the electrical arc drawn between the separating contacts during the opening operation for extinguishing of the arc. The circuit breaker also has a slot motor arrangement, which is utilized to interact magnetically with the electrical current flowing in the opening contact arm to accelerate the opening of the contact arm magnetically. The operating mechanism usually consists of a series of levers and linkages, which are interconnected with the separable main moveable contact arm, the handle mechanism, and by way of a latch arrangement with the aforementioned trip bar. Description and operation of all of the above may be found in the previous mentioned, incorporated by reference '760 patent.
Circuit breakers often have pockets for bell alarms and the like in the circuit breaker cases. Into this pocket may be inserted an accessory, such as a bell arm which has a actuating protrusion which fits sideways into an opening in an inner side wall of the case for interaction with the circuit breaker operating mechanism for being actuated by the circuit breaker operating mechanism. Such an example is found in U.S. Pat. No. 5,921,380 issued Jul. 13, 1999 to Beck et al., and entitled "Circuit Interrupter with Covered Accessory Case with Accessory Having Lock-End Feature and Pull Tab". It would be advantageous if an arrangement such as that could be found, which was easily installed in a circuit breaker pocket.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a circuit interrupter having a housing with a pocket for an auxiliary device. There is an operating mechanism disposed within the housing. Separable contacts are disposed within the housing in cooperation with the operating mechanism for being opened by the operating mechanism. An adjustable trip unit is disposed within the housing in cooperation with the operating mechanism for actuating the operating mechanism for opening the separable contacts. The operating mechanism has an operating mechanism member which attains a predetermined position in the housing upon the occurrence of a circuit interrupter status. The operating mechanism member is accessible through an opening in the housing at the pocket. An auxiliary device having a reaction member for reacting to the occurrence of the circuit interrupter status is present. A lever, separate from both the auxiliary device and the housing, and movable in the pocket for interlinking the operating mechanism member with the reaction member by way of the opening in the housing interconnects the axuiliary device and the operating mechanism.
BRIEF DESCRIPTION OF THE DRAWINGS
In accordance with the invention, reference may be had to the preferred embodiment thereof, shown in the accompanying drawings in which:
FIG. 1 is an orthogonal view of a three-phase molded case circuit breaker employing embodiments of the present invention;
FIG. 2 is a cut away side elevation section of the circuit breaker of FIG. 1, depicting the circuit interrupter in the closed state;
FIG. 3 is a side elevation view similar to that shown in FIG. 2, concentrating on the circuit breaker operating mechanism and trip unit;
FIG. 4 is similar to FIG. 2, but depicts the circuit interrupter in the tripped state;
FIG. 5 shows the circuit breaker apparatus of FIG. 1 in an orthogonal view from the opposite side;
FIG. 6 shows the arrangement of FIG. 5 with the primary and secondary covers removed;
FIG. 7 shows the arrangement of the circuit breaker cradle and the operating-mechanism-to-accessory lever in orthogonal view;
FIG. 8 depicts the arrangement of FIG. 7 in side view;
FIG. 9 depicts the interconnection of the lever arrangement of FIGS. 7 and 8 with an accessory member in orthogonal view;
FIG. 10 is a side view of the arrangement of FIG. 9; and
FIG. 11 is a side view of the circuit interrupter of FIG. 5, partially broken away and partially in section, showing the arrangement of FIGS. 7 and 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and FIGS. 1 through 4 in particular, there is shown a molded case circuit breaker or interrupter 10 having a main base 12 and primary cover 14. Attached to the primary cover 14 is a secondary cover 16. A handle 18 extends through a secondary escutcheon 22A in the secondary cover 16 and aligned primary escutcheon 22B in the primary cover 14. An operating mechanism 20 is interconnected with the handle 18 for opening and closing separable main contacts in a manner which will be described hereinafter. This circuit breaker has a line end 15 and load end 17. The circuit breaker or interrupter includes a removable trip unit 24. Removable trip unit 24 has an underlapping lip 24X. There are also depicted a load terminal 26, a right side accessory region or pocket 27 and a left side accessory pocket or region 31.
Referring now more specifically to FIGS. 2, 3 and 4, there are depicted a separable movable contact 28 disposed upon a moveable contact arm 32 and a fixed contact 30 disposed upon a fixed contact support or u-shaped member 34. Line terminal 36 is disposed to the left in FIG. 2, for example, at the line end 15 of the circuit interrupter in a terminal cave or pocket 29. A load terminal 26 is disposed to the right in FIG. 2, for example, in a load terminal cave or pocket 29. To the left on the line terminal 36 is disposed a line terminal collar 38 which will be described in more detail hereinafter, and to the right is provided a load terminal jumper-to-movable contact arm conductor 802. Connected to conductor 802 is a flexible conductor 39, which is interconnected with movable contact arm 32 as shown schematically. The load terminal jumper or frame conductor 802 is interconnected at its other end with a bi-metal heater 180, which in turn is interconnected at its other end with the terminal 26. Consequently, when the circuit interrupter separable main contacts 28 and 30 are closed upon each other, there is a complete circuit through the circuit interrupter from right to left starting with line conductor 26 through bi-metal heater 180, through load terminal jumper or frame conductor 802, through flexible conductor 39, through the movable contact arm 32, through contact 28 to contact 30 and from there through the fixed contact support or u-shaped member 34 to line terminal 36.
There is provided a operating mechanism 20 for assisting in opening and closing the separable main contacts 28 and 30. In particular, the operating mechanism includes a cradle 52, which is pivoted on one end at a cradle fixed pivoted pin 54 by way of an opening 54A in the cradle for placement of the cradle fixed pivoted pin therein. The cradle includes a cradle-to-side accessory region side protrusion 55. There is provided an upper toggle link 46 and a lower toggle link 48. They are joined pivotally by an upper and lower toggle link pin 50. There is provided a lower toggle link to movable contact arm main pivot assemble attachment pin 56, which is affixed to the movable contact arm 32 at an opening 56A. There is also a cradle to upper toggle link pivot pin 58, by which the upper toggle link 46 is placed in physical contact with the cradle 52. There is also provided a movable contact arm main pivot assembly 59, which movably, rotatably pivots on a pivot 60. There is also provided a primary frame latch 62 which operates or rotates on a primary frame latch pivot 64. The primary frame latch 62 cooperates with a secondary frame latch 68, which rotates on a secondary frame latch pivot 70. The operating power for the tripping operating of the circuit breaker is provided by a charged main toggle coil spring 72. The main toggle coil spring is interconnected with a handle yoke 44 by way of a handle yoke attachment post 45. The other end of the spring 72 is attached to the toggle link pin 50. Cradle 52 has a cradle lip 73, which is captured or held in place by the primary latch 62 when the separable main contacts 28 and 30 are closed. No tripping of the circuit breaker can take place by way of the operating mechanism until the aforementioned primary frame latch 62 has been actuated away from the cradle lip 73 in a manner which will be described hereinafter. There is provided a combination secondary-frame-latch-primary-frame-latch torsion spring 78, which exerts force against both latches sufficient to cause appropriate movement thereof at the appropriate time. The secondary frame latch has a laterally extending trip protrusion 79, the purpose of which will be described later hereinafter. Actuation of the primary and secondary frame latches occurs exclusively by way of the utilization of a resetable trip unit trip plunger 74, which is contained entirely within the removable trip unit 24. The trip unit trip plunger 74 is controlled or latched by way of a plunger latch or interference latch 75. The secondary frame latch 68 is in disposition to be struck by the moving trip unit plunger abutment surface 288. Upon opening of the separable main contacts 30 and 28, an electric arc is drawn therebetween which is exposed to an arc chute 77. The secondary frame latch 68 has a bottom portion 89, upon which is disposed an arcuate stop surface 90 for the primary frame latch 62. There is also provided above that arcuate stop surface and as part of the acruate stop member a latch surface 92.
The operating mechanism described herein may be the same as found in U.S. Pat. No. 5,910,760 issued Jun. 8, 1999 to Malingowski et al., entitled "Circuit Breaker with Double Rate Spring". Thought the primary and secondary frame latches are disposed within the case 12, the trip unit plunger 75 is responsible for initiating all tripping action from the trip unit 24 into the region of the secondary latch 68. Alternatively, the secondary latch 68 may be actuated by a push-to-trip button in a manner, which will be described hereinafter. The secondary latch 68 is actuated to rotate to the left as shown in FIGS. 2, 3 and 4, for example, in direction 81 about its pivot 70. As this occurs the acruate stop surface 90 for the secondary frame latch 68 rotates away from the bottom of the primary frame latch 62 until the lateral latch surface 92 rotates into a disposition to allow the bottom of the primary frame latch 62 to rotate to the right under the force of the cradle 72. This causes the primary frame latch 62 to clear the lip 73 of the cradle 52 to allow the cradle 52 to rotate upwardly about its pivot 54 in a direction 82 under the power of the now collapsing coil spring 72 by way of the force exerted thereupon by the upper toggle link 46 acting against the cradle-to-upper-toggle link connecting pin 58. As the toggle spring 72 relaxes, the upper and lower toggle links collapse, which in turn causes the lower toggle link to movable contact arm pivot assembly 56 to rotate upwardly in the direction 86 about its pivot 60. This, of course, causes the contact arm 32 to rotate similarly in the direction 88, thus opening the separable main contacts 28 and 30 and in most cases establishing an electrical arc of conducting electrical current there across. The action of the secondary frame latch 68 can be duplicated by causing secondary latch push-to-trip member side laterally extending trip protrusion 79 to rotate in the direction 81 by operation of a push-to-trip member which will be described later hereinafter. Resetting of the circuit breaker is accomplished in a matter well known in the prior art and described and shown with respect to the aforementioned U.S. Pat. No. 5,910,760. The important part of the operation with respect to this feature is the movement of the secondary frame latch point 76 in the direction opposite to direction 82, against the plunger face 288 in a manner, which will be described later hereinafter. However, if movement of the plunger face 288 in the rightward direction against its plunger spring, as will be described hereinafter, is prevented because of the latching of the plunger member 74, in a manner which will be described hereinafter, then the circuit breaker can not be reset. An important feature of the invention lies in the fact that the ultimate control of the resetting of the circuit breaker and tripping of the circuit breaker can be accomplished only from the removable trip unit 24, rather than from the operating mechanism 20.
Referring now to FIGS. 5 through 11, an embodiment of the invention is depicted. In particular, FIG. 5 shows the circuit breaker 10 in a 180 degree rotated disposition with respected to that shown in FIG. 1. In this depiction the load end 17 is shown to the left and the line end 15 is shown to the right. In the primary cover 14 is disposed in the right accessory case opening 27, a side wall opening 502 in the vertical side wall 500.
FIG. 6 depicts the circuit breaker 10 in the same arrangement but with the primary cover 14 removed and only the base 12 remaining. In this case, a protruding side protrusion 55R on the cradle 52 of the operating mechanism 20 is accessible from the region 27 through the opening 502 (not shown).
Referring to FIGS. 7 and 8, the arrangement of the cradle 52 and the embodiment of the present invention is set forth, and the single operating-mechanism-to-accessory-lever main body 504 is depicted. Element 506 is the operating mechanism lever arm, which is disposed to make contact with the outwardly, sidewardly, protruding member 55R of the cradle 52 for operation. Arm 508 depends at a right angle from the arm 506 and is generally flat. There is provided in arm 508 a capture crook or u-shaped concave region 510 having a bearing surface at 511. Thus it can be seen that as cradle member 52 rotates upwardly on its pin 54 (see FIG. 2), which may extend through opening 54A therein, member 55R will catch or abut against arm 506 and cause lever main body 504 to move depending upon how it is anchored or supported at its other arm 508.
Referring now to FIGS. 9, 10 and 11, the support for arm 508 is clearly shown. Arm 508 is disposed flush against the vertical casing of auxiliary device 520, which may be an auxiliary switch and/or bell alarm device such as is well know in the art. There maybe provided, depending outwardly from the case of the auxiliary device 520 a post 521 around which the crook 510 and bearing surface 511 of the main body lever 504 rotates. Sufficient rotation of the arm 506 by the member 55R in the counterclockwise direction (as viewed in FIG. 9) around the post 521 will cause the arm 508 to impinge upon movable auxiliary lever 524 in the auxiliary device 520. This in turn drives a micro switch or reaction member 520A in the auxiliary device 520, which may cause electrical activity to take place in the wiring 522. This in the present embodiment of the invention, will cause a bell alarm to actuate. Arm 506 is driven in the counterclockwise direction by the member 55R in response to a tripping action of the circuit breaker as represented by the movement of the cradle 52 in a counterclockwise direction around its rotational axis 54 (FIG. 2). The vertical support for the main body 504 is against the side 500 as described previously and shown in FIG. 11. | This concerns a molded case circuit breaker having separable main contacts and an operating mechanism utilized to cause the separable main contacts to open and close. A trip unit is provided to actuate the operating mechanism in desirable circumstances. Disposed within the circuit breaker casing is a region for the installation of an auxiliary device, such as a bell alarm device, shunt trip device etc. The case of the auxiliary device has an opening disposed therein through which a movable auxiliary device lever protrude. The opening of the circuit breaker case has a region for interfacing with the operating mechanism of the circuit breaker. A separate lever is disposed between the operating mechanism and the auxiliary device lever member. This separate lever member is driven by the operating mechanism of the circuit breaker and actuates the lever of the auxiliary device. It is pivoted about a protrusion on the auxiliary device. | 7 |
This application is a continuation-in-part of U.S. patent application Ser. No. 09/459,460 filed Dec. 13, 1999 now abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 09/313,182 filed May 18, 1999 now issued as U.S. Pat. No. 6,349,405 on Feb. 19, 2002.
FIELD OF THE INVENTION
The invention relates to programmable state machines and more particularly to programmable packet classification state machines for use in high-speed communication.
BACKGROUND OF THE INVENTION
In the past, programmable state machines were provided with procedural programming. This permits flow from one state to another state upon certain conditions according to a desired sequence. Because a state machine effectively controls a sequence of processing steps, the concept of a truly non-procedural programming method for a state machine appears contradictory. To this end, many “non-procedural” methods of programming state machines have been proposed. Nevertheless, upon analysis these have been found to be procedural or somewhat procedural. The concept of branches and loops is common in these methods and a flow diagram of operation is often evident.
Until now because of the procedural nature of state machines, non-procedural methods of programming the state machines have been regarded as having few advantages. Some of the “non-procedural” methods of programming a state machine focus on reuse of programming code and modularity of the code. Therefore, procedural elements within each state are not only permitted, but are viewed as somewhat essential. Different states, however, are commonly easily reused or assembled into a whole classification description.
When reprogramming a state machine, it is important to consider a concept of a truly non-procedural method of implementing a programmable state machine. Changes to state machine programming are then added without concern for state flow, since the description of the state machine is non-procedural. Further, implementation of the state machine is performed by the compiler and does not require significant design by a state machine designer or, more importantly, an end user.
Reprogramming of a state machine having procedural programming is considered a straightforward task. State machine execution is paused, new programming is loaded into program memory and then the state machine is restarted. The process of pausing the state machine often involves halting data flow, which is undesirable. For use in firewalls and other security applications, a change in programming often results from a change in security procedures. As such, it is important to load the change as quickly as possible. Of course, it is evident to one skilled in the art that it is often impractical to shut down a system during reprogramming and, hence reprogramming of a system often only occurs at certain times. This is inconvenient.
Another problem is encountered with current reprogramming techniques for programmable state machines when several state machines share a common program memory. When upgrading the programming for any of the state machines, all state machines are paused. This is a significant problem that is possibly avoided by duplicating program memory in order to allow all but one state machine to remain operative during a reprogramming operation. Another method of avoiding this problem is to provide each state machine with dedicated state machine memory.
A current area of research in high-speed state machine design is the area of digital communications. Commonly, in digital communication networks, data is grouped into packets, cells, frames, buffers, and so forth. The packets, cells etc, contain data and classification information. It is important to classify packets, cells, etc. for routing and correctly responding to data communications. An approach to classifying data of this type uses a state machine.
For Gigabit Ethernet, it is essential that a state machine operate at very high speeds to process data in order to determine addressing and routing information as well as protocol-related information. Unfortunately, at those speeds, memory access is a significant bottleneck in implementing a state machine or any other type of real time data processor. This is driving researchers to search for innovative solutions to increase classification performance. An obvious solution is to implement a classification state machine completely in hardware. Non-programmable hardware state machines are known to have unsurpassed performance and are therefore well suited to these high data rates; however, the implementation of communication protocols is inherently flexible in nature. A common protocol today may be obsolete in a few months. Therefore, it is preferable that a state machine for use with Gigabit Ethernet is programmable. In the past, solutions for 10 Mbit and 100 Mbit Ethernet data networks required many memory access instructions per state in order to accommodate programmability. This effectively limits operating speeds of the prior art state machines.
A programmable state machine for classification of data can be implemented entirely in software. Of course, software state machines are often much slower than their hardware equivalents. In a software state machine, each operation is performed by a software instruction and state changes result in branch operations. As is evident to those of skill in the art, to implement a high-speed state machine in software for packet classification, requires many instructions per second—many more than a billion—requiring expensive parallel processors or technologies unknown at present. In fact, a severe limitation to performance is the speed of memory devices. For example, should a 7 ns memory device be used, less than one memory access per memory device is possible for each bit of a Gigabit Ethernet stream. Thus, if each byte—8 bits—of data is processed in a single state, only one memory access operations is possible for each state. To implement such a system as a purely software solution is impractical and unlikely.
Current state of the art integrated memory devices achieve performance in the area of 7 ns per memory access when timing and other factors are taken into account. Therefore, pure hardware implementations of state machines fast enough to implement a Gigabit Ethernet packet classifier are possible so long as only one memory access is required for every 8 bits within the Ethernet data stream. Prior art implementations of such a state machine use a branching algorithm to allow state transitions within the time frame of a predetermined number of bits. The address data for the branching algorithm is stored in program memory. When the predetermined number of bits is 8, each state transition occurs within 8 ns. One method of achieving this performance is to store a table of data having 256 entries for each possible state. The table address is then concatenated with 8 bits from the data stream to determine a next state address. This continues until a value indicative of a classification or a failure to classify is encountered.
Unfortunately, the amount of memory required to implement a system, such as that described above, is prohibitive. For example, using 8 bits at a time requires up to 256 entries per table, 16 bits at a time requires 65,536 entries. The exact number of tables also depends on a number of terminal states. Since integrated memory having a high storage capacity is not available, implementation of a prior art programmable packet classification state machines having large numbers of edges in integrated memory is currently not feasible.
It has been found that a programmable hardware state machine for use in packet classification of high-speed data communications wherein reprogramming of the state machine is performed according to a non-procedural method, would be advantageous.
It would also be advantageous to provide a method of programming a state machine such that easy modification of state machine programming is possible during operation of a plurality of state machines using the same program memory.
OBJECT OF THE INVENTION
In order to overcome these and other limitations of the prior art, it is an object of the invention to provide state machine architecture for supporting a plurality of state machines simultaneously.
It is another object of the present invention to provide a method of reprogramming state machine program memory without requiring disruption of state machine operation.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a reprogrammable state machine comprising: a program memory for storing programmable data relating to at least one of state machine states and state machine state transitions; and, a start address memory location supporting one of atomic and pseudo-atomic write operations of data to the entire location and for storing data indicative of a start address of state machine programming stored within the programmable memory, the data indicative of a start address reprogrammable during operation of the state machine, where no other memory access operation is performable by the reprogrammable state machine during the duration of the one of the atomic and pseudo-atomic write operation once the one of the atomic and pseudo-atomic write operation has commenced.
In accordance with the invention there is provided a reprogrammable state machine memory for simultaneous use by a plurality of state machines, the reprogrammable state machine memory comprising: a program memory for storing data relating to states within each state machine, the data for each state stored at a state address; a plurality of initial state address memory locations, each initial state address memory location for storing a first state address of a state machine from the plurality of state machines, means for storing the data within the program memory, data relating to each new state stored at a state address for said new state and data relating to the new first state stored at the new first state address, the data stored in storage locations unoccupied by data forming part of any of the plurality of state machines; and, means for once the data corresponding to each new state is stored, storing the new first state address within the first state address location one of atomically and pseudo-atomically, where no other memory access operation is performable by a state machine from the plurality of state machines during a duration of the one of the atomic and pseudo-atomic storing operation once the one of the atomic and pseudo-atomic storing operation has commenced.
In accordance with the invention there is provided a method of reprogramming state machine memory, the state machine memory comprising a plurality of storage locations and a first state address storage location, comprising the steps of: providing data corresponding to each new state, the data including data corresponding to all states from which each new state is reachable including a new first state; storing the data within the program memory, data relating to each new state stored at a state address for said new state, the data stored in storage locations unoccupied by data for use with currently executing state machines; storing data relating to the new first state at the new first state address, the data stored in an storage location unoccupied by data for use with currently executing state machines; and once the data corresponding to each new state is stored, replacing data within the first state address location with data indicative of the new first state address one of atomically and pseudo-atomically, where no other memory access operation is performable by a state machine during a duration of the one of the atomic and pseudo-atomic replacing operation once the one of the atomic and pseudo-atomic replacing operation has commenced.
In accordance with the invention there is provided a method of programming state machine memory, the state machine memory comprising a plurality of locations and a first state address storage location, comprising the steps of: providing an image of current state machine memory on a computer; altering the state machine programming; determining states that are modified within the current state machine; determining states from which the states that are modified are reachable including a new first state; determining memory locations within the current state machine memory unoccupied by data associated with a state machine in execution; compiling the modified states and the states preceding the states that are modified for storage in memory locations within the current state machine memory unoccupied by data associated with a state machine in execution to form reprogramming data; storing the reprogramming data within the memory locations within the current state machine memory unoccupied by data associated with a state machine in execution; once the reprogramming data is stored, replacing data within the first state address location with the new first state address; and, updating the image of the current state machine.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of the invention will now be described in conjunction with the attached drawings, in which:
FIGS. 1 a and 1 b are simplified state diagrams for classification state machines according to the prior art;
FIG. 1 c is a simplified state diagram for classification state machines according to the invention;
FIG. 2 is a simplified flow diagram of a method of reprogramming a state machine during execution according to the invention;
FIG. 3 is a simplified flow diagram of a method of reprogramming a plurality of state machines during execution according to the invention;
FIG. 4 is simplified state diagram of a greatly simplified state machine;
FIG. 5 is simplified state diagram of the greatly simplified state machine of FIG. 4 with modifications thereto;
FIG. 6 is a simplified state diagram of the combined state machines of FIGS. 4 and 5 ;
FIG. 7 is a simplified flow diagram of a method of memory recovery according to the invention; and,
FIG. 8 is a simplified state diagram of a cyclic state machine for explanation of the present inventive method.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term data packet encompasses the terms buffer, frame, cell, packet, and so forth as used in data communications. Essentially a data packet is a grouping of data that is classifiable according to a predetermined classification. Classifications are commonly codified by standards bodies, which supervise communication standards.
In the state diagrams presented in the Figures, a state represented by a rectangle is a terminal state. Other than terminal states are represented by triangles.
Referring to FIG. 1 a , a simplified state diagram for a state machine supporting a single data access operation per data cycle is shown. Each state is in the form of a look-up table at a state address. The states are represented as blocks having four state transitions, each shown as a line to another state. Sometimes, several state transitions lead to a same next state. A predetermined number of bits (2 for the simple diagram of FIG. 1 a ) is loaded into the lowest order bits of the address, and data from the newly formed address is read. When the data comprises another state address, the next predetermined number of bits from the data stream is loaded into the lowest order bits. Otherwise an action such as filtering or packet classification is performed.
Generally, in order to reprogram such a state machine it is necessary to interrupt operation of the state machine, which results in unwanted “downtime”. New programming is stored in the state machine memory after which state machine execution proceeds. Unfortunately, data flow does not stop when filtering or classification is unavailable. In light of the above, it will be evident that interruption of a single state machine's processing capabilities has negative implications. Therefore, a method of reprogramming the state machine without interrupting the operation of the state machine is desirable.
For example, when such a programmable state machine is implemented in hardware, the address of block I is fixed. Typically, the address is 0. Of course another fixed address is possible. Since writing a single block, for example 1, often requires storing data in each of several locations thereby requiring more than a single clock cycle, there is a time during reprogramming when the block is partially reprogrammed. If the state machine reaches the block while it is partially programmed, indeterminate results occur. This is undesirable.
Referring to FIG. 1 b , three state machines stored within a single memory are shown. Each has completely separate blocks and, as such, each is independent of the others. In order to reprogram one of the state machines, it alone needs to be interrupted. Unfortunately, there is little benefit in storing programming of several state machines within a single memory when they are truly independent. In contrast, where a plurality of state machines share a single memory and share some programming, reprogramming of one of the plurality of state machines results in “downtime” for all the state machines that share the single memory. Referring to FIG. 1 c , shown is a similar state diagram to that of FIG. 1 b in which the three state machines share a same program memory and similar blocks, for example 6 , 6 b , and 6 c , are stored as a same block ( 6 ). As is evident from FIG. 1 c , each state machine executes a different programming. Presently, it is difficult to reprogram the state machine memory of FIG. 1 c without interrupting execution of all three state machines.
Referring to FIG. 2 , a simplified flow diagram of a method according to the invention is shown. A state machine executes a classification function. Preferably, the classification function is an acyclic classification function, but this need not be so. The state machine is based on a table look-up for each state transition and information relating to each state transition is stored as a table of data at a state address. In operation, a first state address is read from a first state address storage location. The first state address is an address that is read at a start of state machine operation. The first state address indicates a first table.
A programmer of the state machine comprises a processor for differentiating between storage locations that contain state machine data and those that do not. Commonly, this is performed by maintaining information relating to locations where current state machine information is stored. The programmer is provided with modifications to current state machine programming. For example, a table of data relating to a second state of the state machine is modified. The programmer writes any new information to the memory in storage locations that are unused by current state machines. Unused storage locations do not contain current state machine programming data.
As is evident to those of skill in the art, in order to link the newly written states into the existing states within the state machine requires modification of some states, which is not easily performed during operation of one or more state machines. One approach to solving this problem is to stop operation of the state machine until the reprogramming is complete. Stopping operation of the state machine prevents data being processed and is therefore undesirable. According to the invention, each state preceding any modified states is also written to program memory unused by current state machine programming. The newly written states form a start of the state machine programming from a beginning of state machine operation until a point in the state machine programming from which no further modifications are being made. Once the data is written, the first state of the newly written data is a first state of the state machine. Therefore, by modifying the information stored in the first state address location, the newly written state data is used during a subsequent execution of the state machine—the modified state machine is executed. Preferably, this operation is performed atomically. An atomic operation is a single indivisible operation that takes place in a length of time. A pseudo-atomic operation is an operation that takes place in a length of time, where no other operation can interrupt the pseudo-atomic operation once the pseudo-atomic operation has started. In accordance with the present invention, atomic and pseudo-atomic operations relate specifically to interposed memory access operations. As such, a pseudo-atomic operation is an operation that takes place, where no other memory access operation is performable during the duration of the pseudo-atomic operation once the pseudo-atomic operation has started. It is possible to ensure that no first state address location is read during a non-atomic first state address write operation; however, this results in a small amount of downtime for the state machine and is, therefore, undesirable. The term “modified state” as used herein denotes states that are modified as well as those states that are newly created. It will be apparent from the above description that reprogramming of the state machine memory is now possible during state machine operation absent pausing state machine execution or with minimal pause when other than an atomic operation is used to store the first state address. Once the first state address is updated, a subsequent execution of the state machine uses the programming of the modified state machine. However, until the first state address is updated, the unmodified programming of the state machine is executed.
Of course, once the first address is updated, storage locations associated with states that are modified—state data was rewritten for those states—become unused storage locations given that data for those states is not in use by another different state machine. The resulting storage locations unused by current state machine programming are then “recovered” for use in further processes of reprogramming the state machine memory.
Typically, the first state address is stored in a first hardware register to enable fast access to the address. When a hardware register is used, an atomic operation to write the first state address is typically used. For example, the number of bits stored in a single clock cycle is equal to the number of bits within the register. Alternatively, a pseudo-atomic operation is used. For example, the write operation writes a number of bits per available cycle and those bits are all simultaneously clocked into the register once the entire address is available. Further alternatively, a second other register is written in several clock cycles and a flag bit is then updated to cause the newly written register to be read as the first state address instead of the first hardware register. Other methods of making the changeover from the first hardware register with an old first state address to a hardware register with the new first state address atomically will be evident to those of skill in the art based on the above disclosure.
Alternatively, the first state address is stored at a fixed address within the program memory from which it is capable of being loaded and into which it is capable of being stored in an atomic or pseudo atomic fashion. Preferably, the first state address is accessible in a single clock cycle.
Referring to FIG. 3 , a method of reprogramming a state machine during execution and according to the invention is shown. The method shown is for a state machine program memory in concurrent use by a plurality of state machines.
Each state machine executes a classification function. Preferably, the classification function is an acyclic classification function, but this need not be so. The state machines, similar to the state machine described with reference to FIG. 2 , are based on a table look-up for each state transition and information relating to each state transition is stored as a table of data at a state address. In operation, a first state address is read from a first state address storage location. The first state address is an address that is read at a start of state machine operation of each state machine. When state machines are individually programmable, each state machine has an associated first state address.
A programmer of the state machine comprises a processor for differentiating between storage locations that contain state machine data and those that do not. Commonly, this is performed by maintaining information relating to locations where information of current state machines is stored. The programmer is provided with modifications to programming of current state machines. For example, a table of data relating to a second state of the first state machine is modified. The programmer writes any new information to the memory in storage locations that are unused by current state machine programming. Unused storage locations do not contain state machine programming data relating to any current state machine. According to the invention, each state preceding any modified states is also written to program memory unused by current state machine programming. The newly written states form a start of the state machines'programming from a beginning of state machines' operation until a point in the state machines' programming from which no further modifications are being made. Once the data is written, the first states of the newly written data are first states of the state machines. Therefore, by modifying the information stored in the first state address locations the newly written state data is used during subsequent executions of the state machines, i.e., the modified state machines are executed.
As noted above, it is important that the modification of the first state address occurs in an atomic or pseudo-atomic fashion. Alternatively, state machine operation is paused during writing of the first state address. Otherwise, it is possible that the first state address is accessed during writing of the first state address and that the address loaded for starting execution of the state machine is non-sensical.
It will be apparent from the above description that reprogramming of the state machine memory is possible during execution of any number of state machines. Once one of the first state addresses is updated, any subsequent execution of the associated state machine involves the modified state machine programming. Until a first state address is updated, unmodified state machine programming is executed. In this manner, when each state machine is in execution of different programming, the present invention permits reprogramming of one state machine without interrupting operation of other state machines.
Once a new first state address is stored, it is possible to recover memory. Even though memory recovery is optionally performed immediately, reprogramming should not be performed until the currently executing state machines restart. This prevents the possibility that a state of the previous state machine that is in execution is overwritten during execution. A method of memory recovery is outlined below.
With the data associated with each state a counter indicating a number of states referencing that state is provided. When the first state address register is changed, a counter associated with data at the address pointed to by the contents of the first state address register prior to the change is decremented since there is one less reference to that state data. When the counter is zero, memory locations associated with that state are recovered and counters associated with data referenced from the data in the recovered memory locations are decremented. The memory recovery operation proceeds recursively until all counters having a zero value have been processed.
In an alternative embodiment, a timer is provided for providing a timing signal to pause state machine execution when the timer has expired. This is useful for programming of the programmable memory where a program must be stored by a certain time but also may be stored anytime prior. The program is entered and reprogramming is performed according to the above-described method. If reprogramming is not completed within the specified time, the state machine is paused between classification operations and the programming is completed.
According to another embodiment of the invention, when a buffer is used to buffer data prior to its provision to the state machine, the timer may be implemented to determine an amount of processing time to devote to the reprogramming task. For example, when new programming is introduced, it may be desirable to provide 10% of the processing power or the state machine devoted to reprogramming. Of course, when the state machine requires less than 90% of its processing power, the reprogramming operations may consume the available processing time. A non-limiting example of an application of the present invention is shown with reference to FIGS. 4 , 5 , and 6 . FIG. 4 is a state diagram of a current state machine having states 1 to 11 . When it is desired to modify states 6 , 10 , and 11 , prior art devices require pausing of state machine execution. For ease of description, the state diagram is shown with eleven states, however, in practice the number of states is only limited by the memory size of the state machine and the operation performed. Alterations are made to an image of the state machine of FIG. 4 resulting in a state machine represented by the state diagram of FIG. 5 having modified states 6 n , 12 , 13 and 14 . As one skilled in the art will appreciate, it is possible to modify or add many new states, the number of which is only limited by the memory size of the state machine memory. Memory contents for the state machine illustrated in FIG. 4 are shown in FIG. 6 along with the modified states In, 2 n and 6 n . Data relating to the new and/or modified states, i.e., In, 2 n and 6 n are written into memory storage locations unused by currently executing state machine programming. In FIG. 6 the state machine programming for both state machines, that of FIG. 4 and that of FIG. 5 , are evident within the state diagram. From state 1 a first state diagram proceeds and from state 1 n a second other state diagram proceeds. The states 3 , 4 , 5 , 7 , 8 , and 9 are common to both state diagrams. In fact, state In is similar to state 1 but since state 2 n is different, it is also different. Similarly state 2 n is similar to state 2 but since state 6 n is different, it is also different In order to distinguish between the state machine of FIG. 4 and that of FIG. 5 , one must determine the start address of the state machine. Once all the new and/or modified state data are stored in memory the start address of the state machine is updated with a new first state address, that of state in. The operation is performed atomically or pseudo-atomically. The next time the state machine begins execution, it uses the newly stored data. Sufficient state machine memory is provided to allow use of either state machine programming depending on the selected start address. Thus, even if three state machines use identical programming, it is possible to modify the programming of one and not the others, given three separate first state address locations. It is important that state transitions are maintained during modification of state machine programming to prevent “downtime”. When the start address is that of state in, the state machine diagram of FIG. 5 is the current state machine diagram having modified states 1 n , 2 n and 6 n . Memory locations associated with states that are not accessed by any state machine—in this case by the single state machine—are now “free” storage locations or storage locations unused by current state machine programming.
It is evident to those of skill in the art that all memory locations are occupied and that the term “unoccupied” as used herein refers to memory locations that are not occupied by current state machine program data.
Of course, when two or more banks of memory are used, switching between banks allows for reprogramming of the off-line bank while execution of programming in the on-line bank occurs. Effectively, in some situations, the two banks of memory are program memory and the start addresses in each bank are identified by a current bank. Therefore, the indicator for identifying the current bank forms a start address storage location. When two banks are used, the start address storage location need only accommodate one bit of data, which is necessarily written one of atomically and pseudo-atomically.
Though the start address is described above as stored in a location, it is possible to devote two locations to the first state's programming and to select between the two locations based on an indicator bit. In these cases, the indicator bit forms the start address —address 0 or address 1 —and the data may be stored in a flip-flop or in another conventional fashion.
Optionally, when two or more banks of memory are used, another indicator bit is provided that is used to determine whether to copy program data between data banks. The copying of program data from an online bank to an offline bank facilitates providing of similar programming data in the offline data bank prior to being selected for having program data stored therein executed.
Also, though the step of loading the current state address at the beginning of state machine execution refers to loading the address from the start address location, when a flip flop is used to indicate a current bank of memory, the address of the first state's programming is typically fixed except for selection of the appropriate bank. Therefore, the current state address is loaded with the fixed address though the memory location that the programming data is retrieved from is dependent upon the content of the data relating to the start address. In this case, the current state address register contains less than the necessary address data to determine the current state address and the start address location forms part of the current state address in so far as it determines which of the available fixed start addresses to use.
Referring to FIG. 7 , a simplified flow diagram of a method of recovering memory unused by any currently executing state machine is shown. When new state data is stored in the program memory, the existing state data remains unchanged. Once the first state address of each modified state machine is updated to reflect a new first state address for that state machine, the replaced state machine data is identified and noted as unused state machine memory.
In order to identify unused memory locations, a value is stored with state data for each state indicating a number of references to that state data. The state data to which the previous first state address referenced is accessed and the value therein is decremented. If the value is 1 or greater, then their still exists a reference to that state data and it is not noted as unused memory. If the value is zero, then the state machine data at that location is not referenced and it is noted as unused. All state machine data referenced from that data is then accessed and the value associated therewith is decremented. The method proceeds, recursively, until there remains only state machine data with associated values of 1 or more. Of course, the method could also be implemented iteratively if so desired.
The use of such a method makes memory recovery simple and allows for self-contained state machine programming including all necessary information for programming and reprogramming of same. It is therefore advantageous.
Though states are described as preceding other states or following other states, this terminology is most applicable to an acyclic state machine. For cyclic state machines, the term “reachable from” is a more accurate statement of a state that follows another state. For example, state A is reachable from state B is, for an acyclic state machine, equivalent to state A follows state B. A cyclic state machine is shown in FIG. 8 in which A is reachable from B. Incremental programming according to the invention is still useful. For modifying a single node all nodes from which the modified single node is reachable are then updated. If from a part of the graph the updated nodes are not reachable, that part of the graph need not be modified.
Numerous other embodiments of the invention are envisioned without departing from the spirit or scope of the invention. | A method of reprogramming classification data in a packet classification state machine without interrupting the operation of the state machine is disclosed. Data relating to a plurality of new nodes from a starting node of the classification tree within a classification tree are stored such that they accurately indicate subsequent nodes within the existing data structure. Once the data is stored, a new first node address is stored in a predetermined location. Thereby causing subsequent state machine executions to begin at a new node. Preferably, the new first node address is stored using an atomic operation such that no reading of the first node address is possible during the store operation. The method allows a plurality of state machines to simultaneously use a same classification data memory because the method does not involve overwriting existing data. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to vapor compression cycle devices of variable capacity and, more particularly, to a means and a method for controlling the capacity modulation of a vapor compression cycle device.
To better accommodate varying heating or cooling demands, a vapor compression cycle device should be provided with a means to vary its capacity. Several methods have been disclosed which enable such a capacity modulation, including the method disclosed in copending patent application Ser. No. 926,510, filed July 20, 1978, now U.S. Pat. No. 4,217,760 and assigned to the assignee hereof. This particular approach utilizes the thermodynamic properties of certain multi-component working fluid mixtures in a two accumulator device to enable the variation of the capacity of that device. The present invention discloses an improved means and method for controlling the capacity modulation of a device of this type.
Capacity modulation in devices such as that disclosed in U.S. Pat. No. 4,217,760 is achieved by exploiting certain thermodynamic equilibrium properties between interfacing liquid and vapor phases of a miscible multi-component working fluid mixture. In particular, advantage is derived from the fact that the density of mixture vapor is a function of the composition of an interfacing mixture liquid. Accordingly, by connecting a compressor suction line of a device with an accumulator in which a charge of mixture liquid is maintained, changes in the composition of the liquid will have a direct affect on the density of the vapor entering the compressor, and thus can directly affect the device capacity. The composition of this liquid is in turn varied by regulating the flow rate of mixture liquid from a high pressure accumulator of the device, which liquid typically has a different composition than does the liquid contained in a low pressure accumulator.
Control of the mixture liquid flow rate from the high pressure accumulator, and thus control over device capacity modulation, has typically been accomplished through the use of an adjustable flow-restricting device located in a flow path intermediate the high and low pressure accumulators. Although this is an effective control system, a simpler, more dependable and less costly control system would be preferable in many applications, such as in refrigerators. Accordingly, the present invention is an improvement over prior variable capacity vapor compression cycle devices of this type in that it provides a simplified, dependable control system.
Additionally, the present invention may beneficially extend the lifetime of compressors which have previously been adversely affected in conventional vapor compression cycle devices by high startup loads following periods of inoperation, such as after defrost cycles in refrigerator applications. The present invention as described hereinbelow achieves a decrease in compressor startup load by storing additional working fluid in a high pressure accumulator of the device prior to shutting off the system compressor. Thus, the compressor is confronted with a decreased load during a subsequent startup, thereby beneficially extending the lifetime of the compressor.
Accordingly, it is an object of the present invention to provide a new and improved vapor compression cycle device.
It is a further object of the present invention to provide a simplified means and method for controlling the capacity modulation of a vapor compression cycle device.
Still another object of the present invention is to extend the lifetime of a vapor compression cycle device compressor through a reduction of compressor startup loads.
SUMMARY OF THE INVENTION
The above and other objects and benefits are achieved in a means and a method for controlling the capacity modulation of a vapor compression cycle device. The pressure in a high-pressure accumulator of the device is regulated by varying the temperature of a multi-component working fluid mixture contained therein, causing mixture to either enter or leave the accumulator, thereby directly affecting the composition of the mixture liquid contained in a low pressure accumulator of the device. The variation of liquid composition in the low pressure accumulator affects the molar flow rate through a cooperating compressor and accordingly varies the capacity of the device. Similarly, the regulation of pressure in the high pressure accumulator enables the storage of additional mixture therein prior to device shutdown to provide a reduced load for the system compressor upon subsequent startup, whereby compressor lifetime may be beneficially extended.
BRIEF DESCRIPTION OF THE DRAWING
For a better understanding of the invention reference may be had to the accompanying drawing wherein:
FIG. 1 is a schematic representation of a vapor compression cycle device constructed in accordance with an embodiment of the invention; and
FIGS. 2 and 3 are schematic representations of portions of vapor compression cycle devices constructed in accordance with alternative embodiments of the invention, which portions vary markedly from the otherwise similar device depicted in FIG. 1.
DESCRIPTION OF THE INVENTION
A vapor compression cycle device according to the present invention includes a multi-component working fluid mixture circulated through a closed working fluid circuit. The working fluid mixture must be miscible over the operating temperature range of the device to enable the exploitation of the mixture thermodynamic properties noted above. Examples of suitable working fluid mixtures include the following: R-22 and R-114; R-13B1 and R-152A; and R-23, R-22 and R-114.
The working fluid circuit of the device includes an operating segment and a storage segment. As illustrated in FIG. 1, an operating segment typically includes a compressor 1 connected in series with a condensing heat exchanger 2 and a flow restricting device 3. An evaporating heat exchanger 4 and an associated low pressure accumulator 5 are connected in flow communication intermediate the flow restricting device 3 and the compressor 1. Although depicted as following the evaporating heat exchanger 4, it is understood that the low pressure accumulator 5 may be positioned within the evaporator 4 as disclosed in copending patent application Ser. No. 052,971, filed June 28, 1979, and assigned to the assignee hereof. However, in either arrangement, the suction line of the compressor 1 is in flow communication with a vapor bearing portion of the low pressure accumulator 5.
The storage segment of the device working fluid circuit includes a high pressure accumulator 6 connected to the operating segment of the working fluid circuit. In the embodiment depicted in FIG. 1, the high pressure accumulator 6 is connected to a vapor bearing portion of the working fluid circuit operating segment. In particular, the accumulator 6 may be in vapor communication with a line 7 connecting the outlet of the condensing heat exchanger 2 and the flow restricting device 3. The storage segment of the device illustrated in FIG. 1 also includes a liquid flow restricting device 8 which is adapted to allow vapor to flow into the accumulator 6 while restricting the flow of liquid out of the accumulator. In the embodiment illustrated in FIG. 1, the flow restricting device 8 is a sufficiently necked down portion of a tube connecting the accumulator 6 with the line 7.
In the embodiments of the invention depicted in FIGS. 2 and 3 the storage segment of the working fluid circuit also includes an accumulator 6. However, in the embodiment depicted in FIG. 2, the accumulator 6 is in flow communication with a liquid bearing portion of the working fluid circuit operating segment, such as the line 7. Accordingly, the storage segment of the embodiment of FIG. 2 does not require a liquid flow restricting device as in the embodiment illustrated in FIG. 1.
The storage segment of the embodiment illustrated in FIG. 3 is similar to the high pressure accumulator of a vapor compression cycle device disclosed in copending patent application Ser. No. 929,339, filed Aug. 3, 1979, now U.S. Pat. No. 4,179,898 and assigned to the assignee hereof. In particular, the accumulator 6 is connected by an inlet 9 to a vapor bearing portion of the working fluid circuit which may include a vapor-liquid separator 10. The inlet 9 includes a unidirectional flow restricting device 11 which limits the flow of mixture out from the accumulator 6. The high pressure accumulator 6 in the embodiment of the invention depicted in FIG. 3 also includes an outlet 12 connecting a liquid bearing portion of the accumulator 6 with the operating segment of the working fluid circuit. Liquid flow restricting device 13 on the outlet line 12 limits the flow of mixture into the accumulator 6. Although the outlet line 12 is depicted in FIG. 3 as connected intermediate the condenser 2 and the flow restricting device 3 it is understood that the outlet 12 may be alternatively connected to the working fluid circuit operating segment at a point between the flow restricting device 3 and the compressor 1 provided a suitable liquid flow restricting device 13 is employed compatible with the decreased pressure characteristic of that portion of the working fluid circuit.
Pressure within the high pressure accumulator 6 is varied by a means 14. As depicted in the drawing, the means 14 preferably includes an electrical resistance heater 15 disposed in heat exchange relationship with a mixture storage portion 16 of the high pressure accumulator 6. The means for varying pressure in the high pressure accumulator 6 may also include a means for cooling disposed in heat exchange relationship with the mixture storage portion of the accumulator 6. In a typical refrigerator application, for example, the means for cooling may be provided by placing the high pressure accumulator in thermal contact with a refrigerated portion of the refreigerator.
The means for varying pressure in the high pressure accumulator 6 is selectively controlled by a means for sensing thermal demand 17. This demand sensing means 17 may be a conventional thermostat connected in series with an electric resistance heater 15 and an associated voltage supply 18.
In operation, the multi-component working fluid mixture in the device depicted in FIG. 1 is compressed in the compressor 1 and circulated through the condensing heat exchanger 2 where it is at least partially condensed. The mixture is transferred to the evaporating heat exchanger 4 after negotiating the flow restricting device 3. At least most of working fluid mixture is evaporated in the evaporating heat exchanger 4 and is circulated to the low pressure accumulator 5. Mixture liquid is maintained therein at a low pressure and in thermodynamic equilibrium with mixture vapor. The density of this vapor in the low pressure accumulator 5 is dependent upon the composition of the mixture liquid maintained therein. Similarly, since the compressor is in vapor communication with the low pressure accumulator 5, the molar flow rate through the compressor and thus the device capacity is also dependent upon the composition of the mixture liquid maintained in the low pressure accumulator 8.
Modulation of device capacity is accomplished through the addition or withdrawal of working fluid mixture from the storage segment of the working fluid circuit including the high pressure accumulator 6. Thus, in the embodiment depicted in FIG. 1, upon decreased demand as sensed by the thermostat 17 the electrical resistance heater 15 is inactivated and the temperature of the high pressure accumulator 6 drops steadily as a result of thermal contact with the cooling means. Consequently, the pressure inside the high pressure accumulator 6 drops below the prevalent pressure in the vapor bearing portion of the line 7, thereby causing mixture vapor to enter the accumulator due to the pressure differential. This vapor undergoes condensation in the accumulator 6 and is maintained as a liquid therein. The vapor transferred into the high pressure accumulator 6 is naturally enriched in a lower boiling point component of the working fluid mixture. Thus, the storage of this condensed vapor results in an alteration of the composition of the mixture flowing into the low pressure accumulator 5. This change is reflected in a change in mixture liquid composition in the accumulator 5 and in an associated decrease in vapor density therein and of the molar flow rate through the compressor 1.
Upon sensed increased demand by the thermostat 17 the electrical resistance heater is activated, heating the mixture contained in the accumulator 6 thereby causing the pressure to rise steadily in the accumulator 6 until sufficient pressure is generated to force an amount of mixture liquid out of the high pressure accumulator 6 and into the line 7. This liquid is enriched in the low boiling point component of the working fluid mixture, as noted above, and its addition thus causes a change in the composition of the liquid contained in the low pressure accumulator 5. More specifically, the liquid in the accumulator 5 is enriched in the low boiling point component of the working fluid mixture, causing an increase in vapor density therein and an associated increase in the molar flow rate through the compressor 1 resulting in an increase in device capacity.
The operation of the device depicted in FIG. 2 is similar to the operation of the device depicted in FIG. 1 as described above. However, since the liquid stored in the accumulator 6 in FIG. 2 is not condensed vapor as in the embodiment of FIG. 1, the liquid contained in the accumulator 6 of FIG. 2 is not as enriched in the low boiling point component of the working fluid mixture as is the liquid in the accumulator 6 of FIG. 1. Accordingly, the range of capacity modulation available in the device depicted in FIG. 2 is somewhat less than that available in the device depicted in FIG. 1.
In the embodiment of the invention depicted in FIG. 3 working fluid vapor and liquid are disassociated in the separator 10. During periods of decreased demand the pressure in the high pressure accumulator 6 is decreased by thermal contact with the cooling means resulting in a transfer of working fluid vapor into the accumulator 6 through the line 9 wherein it is condensed and stored. Upon increased demand as sensed by the means 17, the electrical resistance heater 15 is activated, thereby heating the stored mixture liquid and increasing the pressure in the accumulator 6. The flow of mixture out of the accumulator 6 through the line 9 is limited by the flow restricting device 11. Instead, mixture liquid is ejected into the working fluid circuit from the accumulator 6 through the line 12. As in the embodiment depicted in FIG. 1, the liquid ejected from the accumulator 6 is condensed mixture vapor which is naturally enriched in the low boiling point component of the mixture. Accordingly, as described above, the composition of the liquid contained in the low pressure accumulator 5 is varied resulting in an increase in device capacity.
In another mode of operation the present invention may be employed to decrease the compressor startup load following a period of inactivation. The pressure in the high pressure accumulator 6 is decreased as described hereinabove, resulting in the storage of additional mixture in the accumulator 6 and an associated decrease in compressor load. As depicted in FIG. 2, a valve 19 may be advantageously employed in the present invention to isolate the accumulator 6 during periods of inactivation. Upon restarting, the load on the compressor 1 is less than that normally encountered, and may be gradually increased to meet sensed demand through operation of the electrical resistance heater as noted above. This storage of working fluid has the additional benefit of lessening the risk of compressor lubricant degradation by decreasing the mixture inventory which might otherwise come into contact with the lubricant while the compressor is inoperative.
The above described embodiments of this invention are intended to be exemplative only and not limiting and it will be appreciated from the foregoing by those skilled in the art that many substitutions, alterations and changes may be made to the disclosed means and methods without departing from the spirit or scope of the invention. | Adjustments in working fluid mixture composition directly effecting the capacity of an associated vapor compression cycle device are achieved by varying the inventory of mixture stored in a device high-pressure accumulator through the controlled regulation of the accumulator pressure. | 5 |
STATEMENT OF RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/964,630, filed Aug. 14, 2007, entitled “Pre-Hospital Cooling.”
[0002] This application also claims the benefit of U.S. Provisional Patent Application Ser. No. 60/978,069, filed Oct. 5, 2007, entitled “Methods and Systems For Inducing Therapeutic Hypothermia In A Pre-Hospital, Field, or Ambulance Setting.”
[0003] This application also claims the benefit of U.S. Provisional Patent Application Ser. No. 61/007,642, filed Dec. 14, 2007, entitled “Methods and Systems For Inducing Therapeutic Hypothermia In A Pre-Hospital, Field, or Ambulance Setting.”
[0004] Each of the above-referenced prior applications is incorporated herein by reference in its entirety.
BACKGROUND
[0005] The benefits of therapeutic hypothermia have been well-documented. One way of causing a therapeutic state of hypothermia in a patient is by the use of surface cooling techniques such as ice baths. Recently, intravascular techniques have gained a foothold due to their increased controllability and speed. However, both of these techniques are typically administered in a hospital or clinical setting due to their difficulty in field administration.
[0006] Nevertheless, physicians desire to initiate significant cooling in the field, e.g., enroute to the hospital or ER. Therapeutic hypothermia has been suggested to be induced in the field by direct venous or arterial infusion of chilled solutions, typically 0.9% saline (e.g., Lactated Ringer's Solution) which is available in most clinical settings. If this fluid is injected at a temperature near 0° C., the effective ‘cooling power’ applied to perfused tissue is directly proportional to body temperature and the rate of infusion. Increasing the mass flux of infusate will result in a greater rate of heat extraction from perfused tissue, but there is a limit to the rate and ultimate amount of fluids that may be safely infused. This requirement is made stricter by certain clinical conditions such as AMI (heart attack patients are not typically given large amounts of fluid in order to minimize stress to which the heart is subjected).
[0007] Therapeutic hypothermia has also been suggested to be induced by infusing a slush mixture. In particular, if the total volume of fluid which can be administered to AMI patients is limited, then raising the effective heat capacity of the infused fluid may allow effective application of therapeutic hypothermia. If the infused fluid were a slush, or a mixture of water ice and a saline solution chosen so that the bulk composition matches that of 0.9% saline, then in addition to the heat capacity of the liquid saline, the total heat absorbed during equilibration with body temperature would include the latent heat available in the infused ice. This technique increases the effective ‘cooling power’ available by infusion of chilled fluids. However, creating and maintaining a proper source and mixture of slush is complex.
[0008] In general, current techniques for administering such cooling tend to be non-standard and non-reproducible. Added to the above difficulties is that EMS care to cardiac arrest survivors tends to be very turbulent and hectic, and the availability of proper liquids, refrigeration capability, and delivery protocols is minimal.
SUMMARY
[0009] Provided herein are methods, systems and apparatuses for use in delivering a cooled liquid to the vasculature of a subject in need thereof. As such, the methods, systems and apparatuses of this disclosure may be used, for example, to reduce the body temperature of a subject or to induce a therapeutic state of hypothermia in a subject. The methods, systems and apparatuses are of particular use in an emergency room or settings outside of a hospital. In some embodiments, the apparatuses are configured to fit and/or be used in an emergency vehicle (such as an ambulance, helicopter or other emergency medical services (EMS) vehicle). In some embodiments, the apparatuses or portions of the apparatuses are portable so that they can be used in the field and/or during transport of the subject. Accordingly, cool liquid can be provided to the subject as soon as possible and continuously until further treatment can be begin, if necessary.
[0010] In one embodiment, the invention provides an apparatus for use in delivering a cooled liquid from a liquid-containing package to the vasculature of a subject in need thereof, the apparatus comprising a portable unit adapted to contain at least one liquid-containing package and a fixed based unit, the portable unit being attachable and detachable to the fixed base unit. The fixed base unit includes a power supply system and a means for cooling a liquid-containing package when the package is contained by the portable unit. The apparatus is for use with a liquid-containing package that has a dispensing port for discharging the liquid therethrough and the portable unit or the package is adapted to receive a line for delivering the liquid to the subject.
[0011] In one embodiment, portable unit of the apparatus for use in delivering a cooled liquid from a liquid-containing package to the vasculature of a subject in need thereof includes a pressurizer adapted to be in pressure communication with the package to cause a set pressure to be incident in the package, wherein the liquid is caused to flow out of the package upon activation of a valve. In some embodiments, the portable unit includes a battery that powers the pressurizer. In some embodiments, the portable unit is adapted to contain two liquid-containing packages. In some embodiments, the liquid-containing package is a pressurizable package, such as a bag.
[0012] In some embodiments, the cooled liquid may be delivered to the subject without the use of a pressurizer. In such cases, the liquid may be delivered through a large bore needle and or in conjunction with a agent which facilitates liquid infusion in tissue.
[0013] Embodiments of the invention provide standard and reproducible methods and systems for inducing an artificial and therapeutic state of hypothermia in a patient, especially in emergency or pre-hospital settings. In certain embodiments, cold biocompatible liquid is infused into a patient at a defined temperature and pressure. The cold liquid may be infused at a fairly rapid rate to quickly induce hypothermia. In embodiments employing IV bags, unlike many such systems, operation is independent of the effects of gravity, and may be carried any with bags in any orientation or elevation, such as in a rescue helicopter.
[0014] In one embodiment, cold liquid is forced out of a refrigerated bag, the pressure on the bag arising from air pressure on the bag, an infusor cuff, or any other pressurization technique. The cold liquid may be cooled in advance of the infusion or via a cold plate which forms a portion of the system. The cold plate may be separated from the cold liquid and pressurization system prior to use. In another embodiment, the cold liquid is provided from a flowing source.
[0015] In one aspect, the invention is directed towards a method for inducing a therapeutic state of hypothermia. Steps include accessing a blood vessel of a patient, such that an intravenous line is fluidically coupled at a distal end to the interior of the patient's blood vessel; attaching a source of cooled liquid to a proximal end of the intravenous line, wherein the temperature of the cooled liquid is between about 0° C. and 10° C.; and pressurizing the source of cooled liquid such that cooled liquid is forced into the patient's blood vessel at a pressure of between about 100-500 mmHg+/−20%.
[0016] Implementations may include one or more of the following. The pressurizing may be such that between 0.5 and 2 liters of cooled liquid are delivered to the patient in a period of between about 15 minutes and 1 hour, and/or such that the patient's core temperature is depressed between about 0.5° C. and 2° C. over a period of time of between about 15 and 45 minutes. The source may be a flexible bag, and the pressurizing may include pressurizing the flexible bag. For example, the pressurizing may be performed by increasing the air pressure adjacent the bag or by mechanically squeezing the bag or by attaching a pump to the bag. The source of cooled liquid may be pre-cooled, such as by storing the source in an environment below room temperature, such as a cooler. The flexible bag may be an IV bag, and the pressurizing may be performed by an infusor bag. Air may be prevented from entering the patient's blood vessel by placing an air in-line eliminator between the source of cooled liquid and the patient's blood vessel.
[0017] Advantages of certain embodiments of the invention may include one or more of the following. The system and method may be highly standard and reproducible, leading to predictable delivery of cold liquids. The system and method are convenient to administer, and allow cooling for therapeutic hypothermia to be initiated rapidly following, for example, a heart malady or other ischemic situation.
[0018] Other details, features, and advantages will be apparent from the description that follows, including the drawings and figures.
BRIEF DESCRIPTION OF THE FIGURES
[0019] FIG. 1 shows a schematic diagram of a first embodiment of the system, employing a fixed source of liquid.
[0020] FIG. 2 shows a schematic diagram of a second embodiment of the system, employing a constantly-flowing source of liquid.
[0021] FIG. 3 shows an exemplary pressurizer.
[0022] FIG. 4 shows details of the control system.
[0023] FIG. 5 shows a first embodiment of the method of the invention.
[0024] FIG. 6 shows a second embodiment of the method of the invention.
[0025] FIG. 7 shows a third embodiment of the system, employing a fixed source of liquid.
[0026] FIG. 8 shows a system diagram which may be employed in the third embodiment of the invention.
[0027] FIG. 9 shows a third embodiment of the method of the invention, which may employ the system of FIGS. 7-8 .
[0028] FIG. 10 shows an embodiment of a circuit diagram which may be employed in the invention for control of pressure.
DETAILED DESCRIPTION
[0029] In this description, where the same component or same type of component is used in different embodiments, it retains the same reference numeral. Also, terms like “fluidically coupled” and “pressure communication” refer to the situation where an increase of pressure at one point is communicated to another point due to the general incompressibility of liquids. In particular, these terms are used to describe a situation between two points in a flow or in a standing fluid. If pressure is applied at one point, the second point will eventually feel effects of the pressure if the two points are in pressure communication. Any number of valves or elements may be disposed between the two points, and the two points may still be in pressure communication if the above test is met. For example, for a standing fluid in a pipe, any number of pipe fittings may be disposed between two pipes and, so long as an open path is maintained, points in the respective pipes may still be in pressure communication.
[0030] The system 10 and 10 ′ ( FIGS. 1-4 ) and method 80 and 100 ( FIGS. 5 and 6 ) include the following components: a source of liquid, a catheter to introduce the liquid into a vein or artery of a patient (in most cases a vein), and a pressurization system. In some systems, such as where the source of liquid is not pre-cooled, the components further include a refrigeration system.
[0031] The source of liquid may be either contained, such as from an IV bag, or flowing. In the first case, as shown in FIG. 1 , the source of liquid is shown as a bag 12 . In this case, the pressurizer 16 pressurizes the source of liquid 12 and the same is transported into the patient via catheter 14 , which may be an IV line.
[0032] In FIG. 1 , the pressurization system may include an air-tight chamber (see also FIG. 3 ) into which the source of liquid is placed. By pressurizing the chamber pneumatically, i.e., by introducing pressurized air into the air-tight chamber, the source of liquid may be compressed and the liquid within forced out of the bag via an outlet tube 15 . The pressure within the air-tight chamber may be monitored and/or fed back to a controller to maintain constant pressurization and/or to eliminate overpressure situations. In an alternative embodiment, the pressurizing may occur via a pressure plate which directly contacts and exerts pressure on the source of liquid. In this embodiment, the pressure plate may be driven pneumatically or mechanically (e.g., including via a clutched driving mechanism or spring). In a further embodiment, the pressurizer may be a pump that forces the liquid into the catheter and thus into the patient; in this embodiment, suitable types of pumps may include roller pumps, peristaltic pumps, diaphragm pumps, vane pumps, gear pumps, and other pumps that can deliver on the order of 5-10 psi (above atmospheric pressure). In a system employing feedback to eliminate overpressure situations, the fed-back signal may be delivered to the pump controller rather than to a pneumatic or mechanical pressure plate controller. Various valves may be disposed at locations within the system and circulation set to stop or allow flow as necessary.
[0033] The liquid may be pre-cooled, in which case no refrigeration is necessary (e.g., the liquid bag may be stored in a cooler or refrigerator prior to use). If the liquid is not pre-cooled, then the pressurizer may be used in conjunction with a refrigeration system 17 to cause the liquid to be cooled prior to or contemporaneous with infusion. For example, where a pressurizer forces liquid from a bag, one wall of the pressurizer may be formed of the cooling unit of a refrigerator. To enhance heat transfer, the non-pre-cooled liquid may flow through a serpentine path (such as in a cassette) that is in thermal communication with the refrigeration system. The cassette may contact the wall of a thermoelectric generator (TEG) or may be situated within a cold water bath (which may in turn be cooled by, e.g., a TEG). Alternatively, the entire pressurizer may be subject to the cooling action of a refrigeration system. Any refrigeration system may be employed which results in cooling and temperature reduction of the liquid as well as to maintain the temperature of the cooling liquid at a target value.
[0034] If the source of liquid is constantly flowing, such as from a tap source and as shown in FIG. 2 , the liquid may be from a source 22 that provides a constant flow of medical-grade and biosafe liquid. Alternatively, the liquid may be passed through a filter 24 so that the emerging liquid is safe for intravenous introduction (filters may in some cases be desired in the embodiment of FIG. 1 as well). In the embodiment of FIG. 2 , the source may emerge with enough pressure such that no pressurizer is needed. Alternatively, the pressurizer 28 may be a pump. Suitable types of pumps include those listed above. A pump or other pressurizer, including those discussed above in connection with FIG. 1 , may be employed in combination with the constantly-flowing source of liquid 22 . If the liquid is flowed at a low temperature, no cooler is needed. Otherwise, cooler 17 may be employed to cool the liquid. The cooler 17 may be of a cassette or other type as described above.
[0035] Whether the liquid is pumped or pressurized for pneumatic or mechanical pressure, the liquid may be forced into the patient via the intravenous line 14 . To overcome the blood pressure, the liquid pressure may be greater than the blood pressure. Suitable pressures may be between about 100-500 mmHg+/−20%, more preferably 300 mmHg+/−10%, such as 300 mmHg (relative to ambient air pressure). Generally, the pressure has to be greater than that necessary to overcome the blood pressure in the blood vessel. In many cases, a maximum infusion pressure may be about 500 mmHg. The temperature of the infused liquid may be between about 0° C. and 10° C., more preferably 4° C. to 5° C.
[0036] Whatever the pressure, the pressurization should be such as to be able to infuse at a flow rate of, e.g., 100 ml/minute. In particular, if the clinical need is for, e.g., 30 mg/kg (30 milligrams of cold liquid per kilogram of patient body mass) over 15-30 minutes, then a 70 kg patient would require approximately 2 liters infused over the course of 30 minutes.
[0037] In any embodiment, as an additional safety feature, an air in-line eliminator 26 may be employed to remove any air bubbles from the fluid prior to its introduction into the patient. In this way, the chance of air entering the patient's bloodstream is reduced.
[0038] In any embodiment, suitable liquids that may be infused include saline, lactated Ringer's solution, or any other such biosafe liquid. In addition, the device or method can be used to administer a variety of liquids including, but not limited to, saline solutions, blood, blood volume expanding fluids, drugs, solutes, nutrients and other physiologic fluids.
EXAMPLE
[0039] As noted above, in one system, it is desired to infuse up to 2 liters of cold saline in 30 minutes. The exemplary system of FIG. 3 provides one system to perform this infusion. The system 50 includes two 1000 ml IV bags 52 and 54 of appropriate liquid, such as saline. Clamps 56 and 58 may arrest liquid flow prior to the desired infusion, and the IV lines may conveniently meet at a Y-connector 59 , so that switching between bags is simplified. The bags rest against a cold plate 60 , which may be the cold plate of a TEG. An air in-line eliminator 62 , e.g., a bubble trap, may be situated between the bag and the patient to prevent infusion of dangerous air bubbles. A door 64 may close over the bags, and the door 64 may be clear so that liquid levels may be observed. The door 64 provides an air-tight enclosure, so that when air is forced into the chamber with the IV bags, the pressurized air efficiently compresses the bags, and does not leak to the exterior. The air pump may be disposed in section 66 of the system and may emerge via inlet 68 . One pressure that may be employed is 5.8 psi within the chamber, or 300 mmHg.
[0040] The system and method may employ a pressure feedback system to ensure that the infusion pressure does not reach beyond the desired pressure or to deleterious levels or that the infusion pressure maintains the desired liquid flow rate. In more detail, to ensure that the pressure is maintained at an appropriate level and does not reach unsafe levels, a pressure monitor may be employed that generates a signal that is fed back to a pressure controller. The pressure monitor may have a sensor that senses the pressure applied to a bag or other source of liquid, where that sensed pressure can be correlated with the pressure of the liquid infused. Alternatively, the pressure sensor may directly monitor the pressure of the liquid infused, such as via an in-line pressure sensor. Both such sensors may also be employed simultaneously in some systems. In any case, the pressure controller need not be a separate unit; rather, it may form a portion of a pump or a controller or the pressurization system. In particular, as shown in FIG. 4 , a pressure sensor 72 may send a signal corresponding to the pressure via signal path 74 to a controller 70 , which in turn sends a signal via path 76 to the pressurizer, to raise or lower the pressure as desired. In pump systems, the speed of the pump is controlled. The controller may be contained within the pressurizer, or may be a separate unit. Similarly, a temperature sensor 72 ′ may send a signal corresponding to the temperature via a signal path to the controller 70 , which may then be used to control the pressure, the speed of the pump, the temperature of the fluid (if modifiable), or other parameters.
[0041] Embodiments of the method of the invention are shown in FIG. 5 and FIG. 6 . In FIG. 5 , a method is employed which may advantageously use the system of FIG. 3 (as well as other such systems). In FIG. 6 , a cassette cooler system is used to cool the liquid en route to the patient.
[0042] In FIG. 5 , an EMS call is received (step 82 ). The EMS service provider may retrieve a pre-cooled bag (or other source of liquid) (step 84 ), or may begin to cool a non-pre-cooled bag (step 86 ) by placing the same in a refrigeration unit. If the bag is non-pre-cooled, the EMS service provider may perform the step during the transport period to the patient. If the system is employed in an ER setting, the bags may typically be pre-cooled, although this is not strictly required. The bag is placed in a pressurizer (step 88 ). An IV line is installed in the patient (step 90 ). A clamp or other valve may be opened (step 92 ), permitting liquid infusion. The system is pressurized (step 94 ), the pressure is monitored (step 96 ), and the sensed pressure is employed as a control for the pressure administration.
[0043] In FIG. 6 , again an EMS call is received (step 82 ). Once on-site, or before, the EMS service provider may install a non-pre-cooled bag in the pressurizer (step 98 ). A non-pre-cooled bag may also be installed before-hand, if desired. The EMS service provider may operate any employed refrigeration unit so that the system is ready when infusion liquid is pumped through the same. An IV line is installed in the patient (step 90 ), and the proximal end of the IV line is attached to the outlet of a cassette (step 102 ). The outlet tube of the bag or other source of liquid is attached to the inlet of the cassette (step 104 ). The cassette is inserted in a cold bath or is contacted with a cold plate or is otherwise cooled (step 106 ). A clamp or other valve may be opened (step 108 ), permitting liquid infusion. The system is pressurized (step 112 ), the pressure is monitored (step 114 ), and the sensed pressure is employed as a control for the pressure administration.
[0044] In another embodiment, as shown in FIG. 7 , a system is employed in which a liquid-containing package, such as a pressurizable liquid-containing (e.g., IV) bag, in a portable unit, may be removed from a cold environment or from contact with a cold plate in a fixed base unit and hung on an IV pole for ease of administration to a patient, in the field or in any other emergency setting.
[0045] In particular, the system may be employed in an ambulance setting. To secure to an ambulance shelf, the fixed base unit may have a width of less than about 32″, a height (when combined with the portable unit) of less than about 16″, and a depth of less than about 20″. As such cabinets are generally several feet in front of the patient's head, any connections from the system to the patient may generally travel in front of the ambulance's side door to the patient. This travel is generally inconvenient, and thus the embodiment of FIG. 7 allows removal of a disposable/reusable portable unit from a fixed base unit so that the portable unit may be placed adjacent the patient at the time of infusion.
[0046] This system includes a fixed base unit 120 and a portable unit 110 , the portable unit being attachable and detachable from the fixed base unit. The fixed base unit includes a cold plate 144 for cooling (or heating, if necessary) a liquid-containing bag such as an IV bag. The fixed base unit generally operates on wall-provided power, as may be available in an ambulance or a hospital, and an on/off switch 146 control delivery of this power to the cold plate 144 . The system may also operate using the 12 volt battery system in an ambulance. To secure the fixed base unit against movement, the same may be locked down to the appropriate shelf in the ambulance. A temperature display 148 shows the temperature of the cold plate by virtue of a temperature sensor disposed in thermal communication with the same.
[0047] The portable unit 110 (which includes some disposable components and some reusable components, “disposable/reusable”) includes one and preferably two 1-liter IV bags 116 and 118 which may be placed and secured within pressurizable bags, such as infusor bags 122 and 124 , respectively, which are in turn secured against a conductive plate 132 so that heat from the IV bags may be removed when the conductive plate 132 is placed atop the cold plate 144 . In this way, the temperature of the IV bags is lowered as the liquid-containing bags are in thermal communication with the cold plate.
[0048] It is noted that while two 1-liter IV bags are discussed here, any number of such bags and infusor bags may be employed, according to the dictates of the user. Moreover, multiple IV bags may be placed within one infusor bag. Additionally, the liquid-containing bags need not be placed within the pressurizable bags; rather, any adjacent arrangement that allows the pressurizable bag to impart pressure on the liquid-containing bag may be employed. Finally, if sufficient thermal communication exists between the liquid-containing bags and the cold plate (often through the pressurizable bag), the conductive plate may be made smaller or eliminated.
[0049] When in preparation for use, the disposable/reusable portable unit 110 is placed (and optionally secured) to the fixed base unit 120 , and the fixed base unit 120 is operated so as to cool the IV bags. When being readied for use with a patient, the disposable/reusable portable unit 110 is removed from the fixed base unit 120 and hung on an IV pole or other such attachment via IV tabs 126 and 128 . For example, the disposable/reusable portable unit 110 may be hung from a hangar on the ceiling of the ambulance.
[0050] In some embodiments, the portable unit system generally includes the conductive plate, the infusor bag or bags, the IV bag or bags, as well as a pump, a pump battery, and monitoring circuitry for the pressurization. As noted above, the conductive plate may be omitted in arrangements where adequate thermal contact may be achieved directly between the cold plate and the combination of the IV bag and infusor bag. The pressurization may be via an air pump that is powered by a battery that forms part of the portable unit, and the battery may be recharged automatically upon contact with the fixed base unit. That is, the fixed base unit can recharge the pump battery when the portable unit is placed thereon. As discussed below, the pump may be controlled by appropriate monitoring circuitry.
[0051] The pump may also be operated by other techniques, include those involving gas cylinders or springs. Some other techniques, such as the use of pressurized gas, may eliminate the need for a pump: in this system, a controlled valve release air pressure that in turn pressurizes the liquid-containing bag.
[0052] The infusor bags 122 and 124 are pressurized to force fluid out of the IV bags at a set or determinable pressure. Some suitable pressure infusors that may be used are available from CasMed, Inc., Smiths Medical (and their Medex® unit), Cardinal Health (and their division Alaris® Medical Systems), Nellcor Puritan Bennett LLC (a division of Tyco Healthcare), and Mallinckrodt, Inc. (a division of Tyco Healthcare). Partial control of the flow of the fluid may be via a valve 142 . The valve 142 is shown downstream of the y-connector 138 , but similar valves may be disposed upstream of the y-connector 138 as well. A manometer may be included in the system, and the sensor for the same may be in one or more fluid lines from the IV bags 116 and 118 , although in general the sensor may be located in any location that allows the same to measure the pressure of the liquid entering the patient. A pressure-setting knob 134 may be disposed on the system, as well as a pressure display 136 . Various software or hardware or firmware may be employed to set a threshold pressure level, or maintain a specified pressure or flow rate, as well as to turn off the system if the threshold is exceeded. Alternatively, a physician may visually monitor display 136 for the in-line pressure, and control the same manually.
[0053] FIG. 8 shows a diagram of an exemplary circuit 150 that may be employed in the system of FIG. 7 . AC wall power is shown with a hot line 154 , return 156 , and ground 158 feed into a power supply 178 . The wall power also powers a battery charger 152 . The power supply 178 further powers (through a transformer) air pump driver electronics 162 , which are controlled by a switch 176 . The power supply in addition powers the thermoelectric controller 168 which controls the thermoelectric cold plate 174 . Feedback for the thermoelectric cold plate 174 is provided by a thermoelectric control temperature sensor 172 . A solenoid pressure purge valve 170 is also provided to guard against overpressure situations as well as to purge or to “bleed off” pressure if necessary. A temperature sensor 166 provides a temperature display 164 . One of ordinary skill in the art will recognize that numerous other circuit arrangements may also be employed.
[0054] FIG. 9 shows an exemplary method 180 that may employ the system of FIG. 7 . A submethod 181 is shown that is used to prepare the system for use, and a submethod 183 is shown to infuse cold fluid into a patient to induce a therapeutic state of hypothermia.
[0055] The method begins with installing one or more IV bags in a corresponding number of infusor bags (step 182 ). It is understood that various arrangements may be employed with specially-designed infusor bags such that more than one IV bag may be installed per infusor bag. The infusor bags may then be secured onto the conductive plate 132 , or in some embodiments the infusor bags may be permanently secured thereon. If no conductive plate is employed, the pressurizable bags may be secured onto the housing containing the pump, pump battery, and monitoring circuitry. The monitoring circuit may also have a circuit arranged to monitor the temperature of the liquid in the liquid-containing bags.
[0056] The disposable/reusable portable unit 110 with the installed IV bags is then placed on the fixed base unit 120 (step 184 ). The fixed base unit 120 is operated so as to cool the bags (step 186 ). Power for the fixed base unit may be by way of a wall outlet in for example a hospital, an outlet in an emergency vehicle, for example an ambulance, which is powered by the vehicle battery, or an outlet in an emergency vehicle that is powered by an external power hook-up connected to the vehicle. Once the IV bag or bags are cooled to a suitable temperature, e.g., 4° C., the system is ready for use.
[0057] An EMS call may be received (step 188 ), and the system may travel to the patient (step 192 ). Of course, it is understood the system may be employed elsewhere, such as in a hospital or clinic setting. In any case, prior to and/or during any transit time to the patient, the fixed base unit 120 may operate to cool the bags within the disposable/reusable portable unit 110 so that their temperature is minimized by the time the system arrives at the patient (step 194 ) and infusion of cooled fluids is begun.
[0058] A first step in the method of treatment is to remove the disposable/reusable portable unit 110 from the fixed base unit 120 (step 196 ). The disposable/reusable portable unit 110 may then be installed on an IV pole or any other such device (step 198 ). As in embodiments above, an IV line may be installed in the patient (step 202 ). If a clamp or other valve mechanism has been employed on the administration or introduction set, the same is opened (step 204 ). The pressure is set on the disposable/reusable portable unit 110 , and the infusor bags are appropriately and automatically pressurized (step 206 ) such that the pressure in the line achieves the set pressure. The pressure is monitored (step 208 ) and fed back to the system so that the set pressure is maintained to an appropriate degree of tolerance. The pressure may be set to the values described above.
[0059] As noted above, in any embodiment, the pressurization may occur via mechanical or pneumatic bag compression, via a separate pump, via an infusor cuff surrounding the source of liquid as described above, or via any other technique for forcing a liquid into a pressurized environment.
[0060] It should be noted that if packages, bags or other sources of liquid are only partially pre-cooled, the same may in addition undergo the refrigeration or other cooling steps noted above. The above steps are not intended to be mutually exclusive. Suitable refrigeration units may be available from, e.g., Engel USA, Sawafuji Electric Co. Ltd. (Japan). Suitable TEG systems are available from, e.g., TE Technology Inc. (Traverse City, Mich.).
[0061] Generally no anti-shivering drugs are required when the patients are comatose and no shivering response is activated. However, in the case where a shivering response is activated, anti-shivering drugs may be administered, such as meperidine, Demerol®, nefopam, buspirone, fentanyl, BuSpar, or any other anti-shivering drug.
[0062] The invention has been described with respect to a number of embodiments. One of ordinary skill in the art will recognize, however, that variations may be made within the scope and spirit of the invention. For example, while the invention has been generally described above in the context of an ambulance setting, the system and method may be used in an ER setting or in a hospital setting or in the field at the location of an injured individual (including e.g., nursing homes, military/battlefield sites). For example, in an ambulance setting, the system and method may be employed during a 20-30 minute ambulance ride to a treatment facility. Accordingly, the system described herein includes apparatus which are portable and powered by an AC and/or DC power source, including standard batteries or rechargeable batteries. Embodiments of the invention may be advantageously employed as part of a “crash cart” in an ambulance or hospital setting. Embodiments of the invention may be particularly useful in the treatment of cardiac arrest, stroke, traumatic injuries, unanticipated hyperthermia or hypothermia, and other such maladies. The system and method have been described primarily in the context of thermoelectric refrigerators, but conventional refrigerators and even non-refrigerated (but initially cooled, such as via ice packs) coolers may be employed. The system can be used for warming as well as cooling. In this case, the liquid should be delivered at a temperature greater than that of the body temperature, but usually less than about 42° C.
[0063] Accordingly, the invention is to be limited only by the claims appended hereto. | Systems and methods are provided for inducing a therapeutic state of hypothermia in a patient. Cold biocompatible liquid is infused into a patient at a defined temperature and pressure and at a fairly rapid rate to quickly induce hypothermia. In one system, cold liquid is provided from a flowing source. In another, cold liquid is forced out of a refrigerated bag, the pressure on the bag arising from air pressure on the bag, an infusor cuff, or any other technique which may apply such pressure. The cold liquid may be cooled in advance of the infusion or via a cold plate which forms a portion of the system. | 0 |
FIELD OF THE INVENTION
This invention relates generally to the field of utility and similar interconnections, and in particular, to providing ways of simplifying the connection and disconnection of habitable vehicles such as recreational vehicles and houseboats to docking station utility services.
BACKGROUND OF THE INVENTION
Recreational vehicles, boats, and similar habitable vehicles are widely used throughout the United States and elsewhere. These vehicles enable their users to travel to distant, varied locations, while having available to them many of the comforts of home. These comforts include, but are not limited to, such utility services as hot and cold running potable water, sewage lines for the disposal of non-potable water and waste, electric power, telephone service, cable television, high-speed computer data lines, and a cleaning vacuum. Each of these utility services, of course, needs to be established by interconnecting external service lines with the internal wiring, plumbing, etc. of the habitable vehicle.
It is often the case that the users of a habitable vehicle will wish to set up camp at a given camp site docking station for an extended period of time, but will from time to time leave that location, in their habitable vehicle, to travel for a more limited period of time to another nearby temporary location such as a beach, restaurant, shopping center, etc. Each time the vehicle leaves and later returns to the docking station, it is necessary for the users to disconnect and later reconnect each and every one of these utility service connections. This is a very cumbersome and time-consuming process.
While this problem might be envisioned in terms of a recreational vehicle at a camp site, it is also a problem that applies, for example, to a boat which is docked at a marina overnight, then leaves for the day, and returns for the next night. More generally, this is a problem for any sort of habitable vehicle for which it is necessary to establish a multiplicity of utility connections at a single base location, and to repeatedly disconnect and reconnect these utility connections each and every time the vehicle leaves and returns to this base location.
The prior art discloses numerous varieties of fluidic and electrical connectors, as well as devices incorporating two or more such connectors in parallel. For example, U.S. Pat. No. 3,602,869 discloses a pair of plate members enabling “a plurality of hydraulic and/or electrical couplings connected or disconnected by joining or separating the panel members.” (abstract) The coupling panel according to this disclosure is used “for simultaneously connecting and disconnecting a plurality of fluid and/or electrical conduits, for example, between the engine and cab of a truck.” (column 1, lines 6-8).
U.S. Pat. No. 3,602,869, however, does not in any way identify the constant disconnection and reconnection of multiple utility couplings for habitable vehicles as a specific problem requiring resolution, nor is it even remotely suggestive that this is a problem. Further, this disclosure does not teach or suggest its combination with any type of structural components that would enable this invention to be connected with a habitable vehicle and used to alleviate this constant disconnection and the reconnection of multiple utility couplings, since this reference is individually complete by itself and such structural components are not at all necessary. Further, this disclosure does not teach or suggest any form of structure for protecting the various panel couplings from the adverse weather, since this panel, in use, would not be exposed to the elements in the same way as panels used to establish multiple utility connections to a habitable vehicle. Further, this disclosure does not in any way teach or suggest any use of or application to the types of utility conduits that would be necessary to enable human habitation of a habitable vehicle, since these types of conduits are irrelevant to what is needed to connect a truck engine and cab. Finally, this disclosure does not provide any way of maintaining the integrity of electrical, telephone and similar “signal” connectors separately from that of potable water connectors, and of these two types of connector separately from sewage connectors, so that, for example, a sewage leak does not contaminate the potable water, or a potable water leak does not short the electrical connection. In this way too, U.S. Pat. No. 3,602,869 is individually complete by itself, and since this reference does not at all deal with utility connections of the type needed to supply, e.g., power, water, and sewage discharge for a habitable vehicle, the need to maintain these connections with separate integrity from one another would be unnecessary and irrelevant as regards U.S. Pat. No. 3,602,869.
In short, problem faced by habitable vehicle owners of constantly disconnecting and reconnecting multiple utility couplings is completely unrecognized by U.S. Pat. No. 3,602,869. This reference is individually complete and functional in and of itself, so there would be no reason to add any components enabling the panel of this reference to be used for the disconnection and reconnection of multiple utility couplings for habitable vehicles.
U.S. Pat. Nos. 3,614,538; 4,133,021; 4,519,657; 4,785,376; 4,873,600 and U.S. Pat. No. Re. 31,359 all disclose various mounting pedestals for utilities, and are examples of types of fixed docking stations used to provide multiple utility services to habitable vehicles stationed at a camp site, marina, etc. But these references do not disclose or suggest any way to easily and repeatedly disconnect and reconnect a habitable vehicle with the utility services provided by these mounting pedestals. Nor do they even identify the need to repeatedly disconnect and reconnect a habitable vehicle to these docking station utility services as a problem. Nor do they in any way disclose or suggest a combination with the teachings of, for example, U.S. Pat. No. 3,602,869 in order to resolve this unidentified problem. Finally, because U.S. Pat. Nos. 3,614,538; 4,519,657; 4,785,376; 4,873,600; and U.S. Pat. No. Re. 31,359 all deal particularly with the issue of delivering multiple utility services to a camp site, marina, etc., the inventors thereof would certainly have had ample opportunity to identify the repeated disconnection and interconnection of habitable vehicles to these utility services as a problem, and would have had ample opportunity to make suggestions regarding the resolution of this problem. Yet they did not do so.
Another example of a composite multi connector is disclosed, for example, in U.S. Pat. No. 4,652,064. This reference also, does not in any way disclose or suggest that the repeated disconnection and reconnection of habitable vehicles with docking station utility services is a problem. Nor does it disclose or suggest any way of solving this problem. Nor would it be necessary this reference to do so, since it is fully complete in and of itself.
U.S. Pat. No. 4,778,399 discloses an outlet module “for making connection to various electrical systems such as power, telephone, computer systems, television antenna etc.” (abstract) This patent, however, also does not disclose or suggest how to establish and terminate all of these interconnections, simultaneously and repeatedly, in a simple manner. Nor does it in any way disclose or suggest that the repeated disconnection and reconnection of habitable vehicles with such utility services is a problem. Nor does it disclose or suggest any combination with a reference such as U.S. Pat. No. 3,602,869 in order to resolve this unidentified problem. Further, because of the configuration of this outlet module, it would in fact be impossible or extremely difficult to achieve such a simplification of disconnection and reconnection.
U.S. Pat. No. 5,030,128 discloses a docking module used to facilitate “conversion of a portable computer between a lap-top mode of operation and a desk-top mode of operation by permitting simultaneous attachment of the computer to a plurality of electrical connectors thereby ease eliminating the need for individual cable connections between the computer and the respective individual apparatus.” (abstract) This reference, however, is non-analogous prior art, since it is from a very different technical field. Further, it does not in any way disclose or suggest that the repeated disconnection and reconnection of habitable vehicles with docking station utility services is a problem. Nor does it disclose or suggest any application of its teachings to this unidentified problem of habitable vehicle utility connection.
OBJECTS OF THE INVENTION
It would be desirable, therefore, for the user of a habitable vehicle to be able to disconnect the multiple docking station utility services provided to this vehicle all at once when the vehicle is ready to temporarily leave its docking station at, e.g., a camp site, marina, etc., and to reconnect these docking station utility services all at once when the vehicle returns to the docking station, without having to reestablish each and every utility connection individually. While the connection and disconnection of each distinct utility service is still necessary at the beginning and at the end of a vacation or similar excursion based primarily at the docking station, it would certainly be desirable to avoid having to make this multiplicity of utility connections and disconnections for each and every coming and going of the habitable vehicle to and from the docking station throughout the entire vacation or similar excursion.
It is also desirable to protect any connectors used for this purpose from damaging exposure to weather.
It would also be desirable to maintain any connectors used for this purpose in a manner that maintains their integrity, and in particular, ensures that a leak from or damage to any one connector does not damage any of the other connectors or their connections.
SUMMARY OF THE INVENTION
A habitable vehicle utility docking apparatus comprises a fixed-half quick connect panel fixed to a habitable vehicle such as a recreational vehicle or a boat, and a removable-half quick connect panel matable therewith. The fixed-half quick connect panel maintains a permanent pre-connection to utilities inside the habitable vehicle. The removable-half quick connect panel is connected via commonly-used hoses and wires to external docking station utility services at a campsite, marina, etc. docking station. When the removable-half quick connect panel is so-connected to such external docking station utility services, and when it is also mated to fixed-half quick connect panel, these docking station utility services are supplied to the habitable vehicle. The preferred method of use is to disconnect removable-half quick connect panel from fixed-half quick connect panel while leaving all the external utility connections intact when the habitable vehicle is about to leave the docking station temporarily, and to later reattach these panels together thereby reestablishing all the utility connections to the habitable vehicle when the vehicle does return. This avoids the time and inconvenience of having to make a multiplicity of utility connections and disconnections for each and every coming and going of the habitable vehicle to and from the docking station.
BRIEF DESCRIPTION OF THE DRAWING
The features of the invention believed to be novel are set forth in the appended claims. The invention, however, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawing(s) in which:
FIG. 1 is a schematic illustration of the prior art, showing a habitable vehicle such as a recreational vehicle connected to a plurality of docking station utility services in such a manner that requires the disconnection and reconnection of each and every such service, each and every time the vehicle leaves and returns to its docking station.
FIG. 2 is a schematic illustration of a preferred embodiment of the invention, depicting a habitable vehicle utility docking system comprising a fixed-half quick connect panel connecting to utility conduits within the habitable vehicle, and a removable-half quick connect panel connecting to the docking station utility services at the docking station, as well as the method by which these services are quickly and easily disconnected and reconnected whenever the vehicle leaves and returns to the docking station.
FIGS. 3 a and 3 b illustrate front and top detailed plan views of, respectively, the fixed-half and removable-half quick connect panels in a preferred embodiment of the invention.
FIG. 4 illustrate top plan views of the mating between the fixed-half and removable-half quick connect panels of FIG. 3, as well as the connection of the fixed-half quick connect panel to internal utility conduits within the habitable vehicle and of the removable-half quick connect panel to external utility conduits receiving docking station utility services from outside of the habitable vehicle.
FIGS. 5 a - 5 c illustrate top plan views of preferred embodiments for several weather tight coverings use to protect the panels and various utility connectors of FIGS. 3 and 4 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the manner in which a habitable vehicle 1 such as a recreational vehicle is typically connected to docking station utility services according to the prior art. Generally these services may include, but are not limited to, potable water 11 , electrical power 12 , cable television 13 , telephone 14 , and these days, high-speed computer data 15 . Frequently, the aforementioned incoming services are all delivered from a utility pedestal 16 such as is disclosed by aforementioned U.S. Pat. Nos. 3,614,538; 4,519,657; 4,785,376; 4,873,600; and U.S. Pat. No. Re. 31,359. Additionally, these docking station utility services also include outgoing sanitary sewage service 17 . For sanitary reasons, the location of sewage service 17 is typically removed by a suitable distance from the location of utility pedestal 16 which delivers the aforementioned incoming utility services. Not specifically illustrated, but also desirable, are such services as a cleaning vacuum.
Each of these docking station utility services is delivered to habitable vehicle 1 via a series of external utility conduits each of which must be disconnected each time habitable vehicle 1 leaves the docking station and reconnected each time the vehicle returns. These external utility conduits include, but are not limited to, potable water line 110 , electric power line 120 , cable television line 130 , telephone line 140 , computer data line 150 , and sewage line 170 .
As noted in the discussion earlier, the need to disconnect and reconnect each of these individual external utility conduits each time habitable vehicle 1 leaves and returns to the docking station is quite time-consuming and undesirable.
FIG. 2 illustrates a quick connect panel system according to a preferred embodiment of the invention, comprising a fixed-half quick connect panel 21 and a removable-half quick connect panel 22 .
Fixed-half quick connect panel 21 is permanently pre-attached to habitable vehicle 1 in a location and manner readily accessible from outside said habitable vehicle 1 (such as proximate the outer surface of habitable vehicle 1 ), and leads via utility conduits internal to habitable vehicle 1 to various locations within habitable vehicle 1 where these utility services are actually used. These internal conduits are illustrated using unnumbered, truncated, hidden line elements emanating from fixed-half quick connect panel 21 into habitable vehicle 1 . This permanent pre-attachment of fixed-half quick connect panel 21 to habitable vehicle 1 is achieved either by retrofitting fixed-half quick connect panel 21 to a preexisting habitable vehicle 1 , or alternatively, by manufacturing habitable vehicle 1 so as to already have fixed-half quick connect panel 21 integral therewith at the outset.
To retrofit fixed-half quick connect panel 21 to preexisting habitable vehicle 1 , fixed-half quick connect panel 21 may be mounted below habitable vehicle 1 or installed in a compartment. Or, it mat be necessary or desirable to remove a portion of the outer body of habitable vehicle 1 and mount fixed-half quick connect panel 21 substantially flush with the outer surface of habitable vehicle 1 . In any event, it is necessary to run all of these internal conduits to reach the location where fixed-half quick connect panel 21 is to be attached, permanently pre-connect these internal conduits to the inside, non-mating surface (surface facing into the vehicle) of fixed-half quick connect panel 21 , and finally, permanently pre-attach fixed-half quick connect panel 21 to habitable vehicle 1 . This attachment of fixed-half quick connect panel 21 into combination with habitable vehicle 1 may be achieved through a variety of panel-to-vehicle attachment means, including, but not limited to, screwing, bolting, gluing, and/or welding.
An outer, non-mating surface of removable-half quick connect panel 22 (the surface which faces outward from habitable vehicle 1 ) is directly connected to, for example not limitation, potable water 11 , electrical power 12 , cable television 13 , telephone 14 , high-speed computer data 15 , and sanitary sewage 17 services, via the aforementioned external utility conduits, namely, potable water line 110 , electric power line 120 , cable television line 130 , telephone line 140 , computer data line 150 , and sewage line 170 , respectively. A cleaning vacuum exemplifies another service which may also be desired and have its own connection, however, to avoid drawing clutter, is not specifically illustrated here. The enumeration of specific utility-type services and corresponding interconnections in this disclosure and its associated claims is not limiting, which is to say that it would be an obvious extension of this disclosure and would fall within the scope of the associated claims to include other, non-enumerated utility-type services as well according to the apparatus and method disclosed herein. Also, it should be clear that a subset of the aforementioned utility services might also be provided, and some of these services omitted, also still within the scope of this disclosure and its associated claims.
The aforementioned connection of removable-half quick connect panel 22 to these various external utility conduits is established one time only, when habitable vehicle 1 first arrives at the docking location to begin a vacation or similar extended stay. Similarly, removable-half quick connect panel 22 is disconnected from these various external utility conduits one time only, when habitable vehicle 1 is about to depart the docking station at the end of the vacation or similar extended stay.
Fixed-half connect panel 21 and removable-half quick connect panel 22 are then designed to mate directly with one another, in such a manner that all of the external utility conduits connected to removable-half quick connect panel 22 will further connect directly to the corresponding internal conduits within habitable vehicle 1 as a result of this mating.
A latching system discussed further in connection with FIGS. 3 and 4 is a non-limiting example of one way to secure a tight-fitting mated connection between fixed-half quick connect panel 21 and removable-half quick connect panel 22 , and between the two halves (external and internal) of the respective utility conduits attached to these panels. One or more weather tight covers discussed in connection with FIGS. 5 are used to protect these panels and their utility conduit interconnections from the elements in various situations.
A preferred method of using this quick connect panel system is as follows: When habitable vehicle 1 first arrives at the docking station, removable-half quick connect panel 22 will typically already be connected (fully mated) and latched (secured) to fixed-half quick connect panel 21 . All of the external utility conduits such as potable water line 110 , electric power line 120 , cable television line 130 , telephone line 140 , computer data line 150 , sewage line 170 , and, e.g., not illustrated cleaning vacuum need therefore simply be connected to removable-half quick connect panel 22 , in the customary manner. Once this has occurred, and the connections at the docking station are turned on, all of the utility connections become fully activated. It is to be noted that the connection of these various external utility conduits to removable-half quick connect panel 22 is achieved using precisely the same connector interfaces as would be used to connect these various external utility conduits to an ordinary habitable vehicle which does not employ this invention, such as is illustrated in FIG. 1 . Of course, the order of the aforementioned mating and connection steps does not matter: removable-half quick connect panel 22 may already be connected (fully mated) and latched to fixed-half quick connect panel 21 before the external utility conduits are connected to removable-half quick connect panel 22 , or the external utility conduits may be connected to removable-half quick connect panel 22 before removable-half quick connect panel 22 is mated and latched to fixed-half quick connect panel 21 .
Before habitable vehicle 1 leaves the docking station temporarily, and is to return in the near future, removable-half quick connect panel 22 is simply unlatched and disconnected (unsecured and unmated) from fixed-half quick connect panel 21 . This disconnection (and subsequent reconnection to be discussed) is illustrated by double arrow 23 . All of the connections of the external utility conduits to removable half quick connect panel 22 , however, are maintained as is, without detachment. While habitable vehicle 1 is temporarily gone from the docking station, removable half quick connect panel 22 remains at the docking station with all of its utility connections intact.
After habitable vehicle 1 returns to the docking station, removable-half quick connect panel 22 is simply reconnected and relatched (re-mated and re-secured) to fixed-half quick connect panel 21 , and all of the utility connections are then immediately in place for reactivation. This method of unlatching and disconnecting removable half quick connect panel 22 from fixed-half quick connect panel 21 when the vehicle is about to leave the docking station, and then reconnecting and relatching removable half quick connect panel 22 to fixed-half quick connect panel 21 when the vehicle returns to the docking station, is iteratively repeated over and over, as often as necessary, throughout the entire vacation or similar extended stay.
Finally, when it is time for habitable vehicle 1 to leave the docking station for the final time, such as at the end of the vacation or similar extended stay, the external utility lines are all disconnected from removable half quick connect panel 22 , and then the vehicle leaves the docking station with both halves of the quick connect panel system.
It is to be noted again that the connection of the various utility lines to removable-half quick connect panel 22 is achieved using precisely the same connector interfaces as would be used to connect these various utility lines to an ordinary habitable vehicle which does not employ this invention, such as in FIG. 1 . Typically, many of these interfaces require more than simply “plugging in” the utility lines to the connector interface. Often, for at least some of the interfaces such as water and sewage, some form of screwing and/or clamping is required, which adds to the time and complexity of making these connections and disconnections.
Because the mating of removable half quick connect panel 22 with fixed-half quick connect panel 21 is achieved by the simple operation of merely pressing and then latching these two panels together, not only is the number of interconnections being made reduced from several (in these illustrations, six) to one, but the complexity of making these connections is significantly reduced, insofar as connection operations such as screwing or clamping are eliminated, and replaced by the single operation of mating and securing removable half quick connect panel 22 with fixed-half quick connect panel 21 . The same considerations apply to disconnection (un-securing and un-mating) as well.
FIGS. 3 a and 3 b illustrate these panels in further detail. FIG. 3 a illustrates fixed-half quick connect panel 21 comprising “first half” connectors for each of potable water 302 , cable television 304 , electrical power 306 , telephone 308 , computer data 310 , and sewage 312 . FIG. 3 b illustrates removable-half quick connect panel 22 comprising “second half” connectors for each of potable water 352 , cable television 354 , electrical power 356 , telephone 358 , computer data 360 , and sewage 362 . Each one of the “first half” connectors can be either male or female connectors; the “second half” connector corresponding to a given “first half” connector will of course be of opposite gender. These connector halves can be any suitable “press-together” connectors presently known or which may in the future become known in the art. The side plan views of FIGS. 3 a and 3 b show the “mating” surface of each of the fixed-half 21 and removable-half 22 quick connect panels (the surfaces which are pressed together), and obscure the “non-mating” surfaces thereof. The top views project along the “dash-dot” projection lines of these FIGS.
Potable water connectors 302 and 352 , for example not limitation, may comprise a domestic water quick connect, Hubbell model 1269 brass water connector. Other acceptable manufacturers for potable water connectors 302 and 352 include, for example not limitation, Nibco and Nelson. Cable television connectors 304 , 354 may comprise, for example not limitation, quick connect Hubbell model HBL320R4W and HBL320P4W connector halves. Other acceptable manufacturers for cable television connectors 304 , 354 include, for example not limitation, Crose Hinds and Arrow Hart. Electrical power connectors 306 , 356 may comprise, for example not limitation, Hubbell model HBL430R12W and HBL430P12W connector halves. Other acceptable manufacturers for electrical power connectors 306 , 356 include, for example not limitation, Crose Hinds and Arrow Hart. Telephone connectors 308 , 358 may comprise, for example not limitation, Hubbell model HBL420R12W and HBL420P12W connector halves. Other acceptable manufacturers for telephone connectors 308 , 358 include, for example not limitation, Crose Hinds and Arrow Hart. Suitable computer data connectors 310 , 360 are also provided, for example not limitation, by Crose Hinds and Arrow Hart. Finally, sewage connectors 312 , 362 may comprise, for example not limitation, a sanitary quick connect Prest-O-Fit model 15934 universal sewer hose female adapter mating with a 3 inch PVC male pipe connection. Other acceptable manufacturers for sewage connectors 312 , 362 include, for example not limitation, Camco, Thetford, Valterra, and E-Z Coupler.
Also illustrated in FIGS. 3 are securing means such as an illustrated pair of latch plates 322 and corresponding latch clamps 372 mating and latching therewith. These may comprise, for example not limitation, Carr Lane latch system model 5E651, or any similar suitable securing means known in the art. Also illustrated are a pair of hand grips 374 such as the illustrated gripping handles, as well as alignment guides such as the illustrated four male guide rods 330 and female guide rod receptacles 380 mating therewith used to establish a proper mating alignment. Variations in these latching (securing), gripping and alignment guide elements would be well known in the art and are considered to be within the scope of this disclosure and its associated claims.
Also illustrated are elongated female slots 332 and elongated male ridges 382 mating therewith, which separate the electrical and telephone connectors 304 , 306 , 308 , 310 , and 354 , 356 , 358 , 360 from the potable water connectors 302 and 352 , and all of the aforementioned connectors from the sewage connectors 312 and 362 . These elongated female slots 332 and elongated male ridges 382 thereby define three distinct, segregated connector regions of removable half quick connect panel 22 and fixed-half quick connect panel 21 .
Finally, FIG. 3 a illustrates panel-to-vehicle pre-attachment means 340 about the perimeter of fixed-half quick connect panel 21 , such as but not limited to, screws, bolts, glue, and/or welds which are used to attach fixed-half quick connect panel 21 to habitable vehicle 1 , particularly when the utility docking apparatus disclosed herein is retrofitted to habitable vehicle 1 . Panel-to-vehicle attachment means 340 are illustrated in this Figure, for example only, as a plurality of weld spots. Of course, as noted earlier, habitable vehicle 1 can also be manufactured so as to already comprise fixed-half quick connect panel 21 integral therewith at the outset. It is understood that male and female connectors can easily be reversed with respect to what is illustrated in the drawings within the scope of this disclosure and its associated claims.
Referring now to FIG. 4 a , panel gripping handles 374 are used as a gripping means to move removable-half quick connect panel 22 into proper mating position relative to fixed-half quick connect panel 21 . These two panels are oriented and aligned so that their mating surfaces face one another and each connector first half lines up with its corresponding connector second half. Aligning guides such as male guide rods 330 and female guide rod receptacles 380 are similarly aligned with each other, as are elongated female slots 332 and elongated male ridges 382 . All of these alignments are highlighted by the centerlines drawn between the various mating elements of fixed-half quick connect panel 21 and removable-half quick connect panel 22 . Removable-half quick connect panel 22 is then moved together as illustrated by double arrow 23 and pressed firmly against fixed-half quick connect panel 21 until each connector first half lines mates with its corresponding connector second half. Finally, latch clamps 372 and latch plates 322 are mated and latched together so as to secure both panels and all connectors firmly together.
FIG. 4 b illustrates fixed-half quick connect panel 21 and removable-half quick connect panel 22 once these have been somated and latched together. This FIG. also illustrates the external utility conduits, namely, potable water line 110 , electric power line 120 , cable television line 130 , telephone line 140 , computer data line 150 , and sewage line 170 earlier shown and discussed in FIGS. 1 and 2, as well as, in broken lines, the unnumbered internal conduits within habitable vehicle 1 which are permanently pre-connected to the non-mating inner surface of fixed-half quick connect panel 21 that were earlier shown and discussed in FIG. 2 . As such, this FIG. illustrates not only the interconnection of fixed-half quick connect panel 21 with removable-half quick connect panel 22 , but the full interconnection of all the docking station utility services to and with habitable vehicle 1 . Note that in this drawing, the connector halves attached to removable-half quick connect panel 22 are shown to be inside of those attached to fixed-half quick connect panel 21 by virtue of the broken (hidden) lines as drawn, and are thus male connectors. Again, however, any set of male/female orientations as between these two panels and their respective connectors, alignment guide rods 330 and receptacles 380 , elongated slots 332 , and ridges 382 , etc., is considered to be within the scope of this disclosure and its associated claims. The unlatching (un-securing) and disconnection (un-mating) of fixed-half quick connect panel 21 from removable-half quick connect panel 22 simply follows the inverse of the steps described above for mating these two panels.
Referring also to the side views of FIGS. 3 a and 3 b , it is important to observe that once fixed-half quick connect panel 21 and removable-half quick connect panel 22 have been mated and secured together as shown in FIG. 4 b , elongated female slots 332 and elongated male ridges 382 mate together in such as way as to form a fluid-impenetrable and debris-impenetrable barrier partition between the sewage connectors 312 , 362 and the potable water connectors 302 , 352 , as well as between these aforementioned connectors and the signal connectors 304 , 306 , 308 , 310 , 354 , 356 , 358 , 360 which carry the cable television, electrical power, telephone, and computer data signals. By maintaining such a barrier between the sewage connectors and the potable water connectors, any leakage that might occur in the sewage connectors will be blocked from affecting the potable water supply, thus avoiding any potential contamination. Similarly, by segregating the signal connectors from the potable water and sewage connectors, any leakage from the potable water or sewage connectors will not contact the electrical circuit or similar and cause a short circuit or similar disruption. Nor would such a leak cause any type of damage to the remaining signal connectors. It may also be desirable to similar segregate any cleaning vacuum utility service as well, to the contamination of other conduits by vacuum debris.
FIGS. 5 a - 5 c illustrate various weather tight covers used to protect fixed-half quick connect panel 21 and removable-half quick connect panel 22 in various situations. In particular, it is to be observed that when these two panels are disconnected from one another, for example, when habitable vehicle 1 leaves the docking station for a few hours to go to a beach, restaurant, etc., that the connector halves on each panel will be exposed to weather and other damage unless they are suitably protected. When removable-half quick connect panel 22 is detached from fixed-half quick connect panel 21 but still attached to the various external utilities, a rainstorm, for example, can result in water actually entering the open connectors, causing shorting in the electrical conduit, and causing potential damage such as corrosion to the other connectors as well. Similarly, the exposed connectors of fixed-half quick connect panel 21 also need to be protected from the elements.
Thus, FIG. 5 a illustrates a fixed-half weather cover 51 which mates and latches (secures) together with fixed-half quick connect panel 21 very similarly to how removable-half quick connect panel 22 mates with fixed-half quick connect panel 21 as earlier described in connection with FIG. 4 a . Note the presence of cover latch clamps 516 on fixed-half weather cover 51 which are substantially similar to latch clamps 372 earlier discussed. However, fixed-half weather cover 51 comprises a number of “dummy” second half connectors which are designed merely to close and protect the exposed connector first halves on fixed-half quick connect panel 21 when they are not mated with their second halves. These dummy connectors include one or more dummy second half signal connectors 510 which comprise dummy connectors mating with one or more of the first half electrical, cable television, telephone, and computer data connectors. These also comprise a dummy second half potable water connector 511 , and a dummy second half sewage connector 512 , each mating with its first half counterpart 302 and 312 . Male guide rods 330 are aligned to weather cover female guide rod receptacles 513 , and elongated female slots 332 are aligned to weather cover elongated male ridges 514 , just as was earlier described in connection with FIG. 4 a . Also illustrated are one or more cover gripping handles 515 similar to and used for the same purpose as earlier described panel gripping handles 374 .
FIG. 5 b illustrates a removable-half weather cover 52 which mates and latches together with removable-half quick connect panel 22 very similarly to how fixed-half quick connect panel 21 mates with removable-half quick connect panel 22 as earlier described in connection with FIG. 4 a . Note the presence of cover latch plates 526 on removable-half weather cover 52 which are substantially similar to latch plates 322 earlier discussed. However, although similar to fixed-half quick connect panel 21 , removable-half weather cover 52 comprises a number of “dummy” first half connectors which are designed merely to close and protect the exposed connector second halves on removable-half quick connect panel 22 when they are not mated with their first halves. These dummy connectors include one or more dummy first half signal connectors 520 which comprise dummy connectors mating with one or more of the second half electrical, cable television, telephone, and computer data connectors. These also comprise a dummy first half potable water connector 521 , and a dummy first half sewage connector 522 , each mating with its second half counterpart 352 and 362 . Weather cover male guide rods 523 are aligned to female guide rod receptacles 380 , and weather cover elongated female slots 524 are aligned to elongated male ridges 382 , also, just as was earlier described in connection with FIG. 4 a.
FIG. 5 c illustrates, for example not limitation, two alternatives for covering both fixed-half quick connect panel 21 and removable-half quick connect panel 22 , when these are both attached to habitable vehicle 1 but are not connected to any external utility conduits. This would be the usual state of affairs for habitable vehicle 1 when it is not being used for habitation, but, for example, is parked in a driveway or docked at a marina during a period of nonuse. In this situation, fixed-half quick connect panel 21 and removable-half quick connect panel 22 are mated together as in FIG. 4 b (but without the external utility connections to the docking station), and the object is to cover both of these, or at least to cover the exposed ends of the connectors on the non-mating surface of removable-half quick connect panel 22 .
A first option uses one or more dummy connector caps which mate with the external connector interfaces on the outer, non-mating surface of removable-half quick connect panel 22 . These connector caps use connector interfaces similar to those that are used to connect the various external utility conduits to these external connector (docking station) interfaces. Thus, one or more dummy signal connector caps 530 mate with and cover the external interface of the electrical, cable television, telephone, and computer data connectors. A dummy potable water connector cap 531 mates with and covers the external interface of the potable water connector. Finally, a dummy sewage connector cap 532 mates with and covers the external interface of the sewage connector. Unnumbered double arrows illustrate the movement of these various caps toward and over the external connector interfaces.
A second option uses a single weather tight cover 540 placed over the entire outer, non-mating surface of removable-half quick connect panel 22 , which is then latched in place using any type of suitable latch (schematically illustrated by 542 ) known or which may become known in the art. This creates an improved appearance over the first option, since one cannot see each of the individual external connector interfaces when looking at the vehicle, but rather sees only weather tight cover 540 .
Unnumbered double arrows also illustrate the movement of weather tight cover 540 over fixed-half quick connect panel 21 and removable-half quick connect panel 22 .
If fixed-half quick connect panel 21 is permanently pre-attached to be sufficiently recessed beneath habitable vehicle 1 , or is inside a compartment rather than flush with the outer surface of habitable vehicle 1 , then the covering of fixed-half quick connect panel 21 and removable-half quick connect panel 22 together, as well as the covering of fixed-half quick connect panel 21 alone as in FIG. 5 a , becomes somewhat simplified. In this situation, weather tight cover 540 can comprise a flat panel pivoting door mounted flush with the outer surface of habitable vehicle 1 , or a compartment door, which covers any and all panels recessed beneath this outer surface. Suitable door closure and/or locks can be added as desired. In this situation, fixed-half weather cover 51 is rendered unnecessary, because weather tight cover 540 can be used whether or not removable-half quick connect panel 22 is mated with fixed-half quick connect panel 21 . The only additional protection that is needed is supplied by removable-half weather cover 52 in order to protect removable-half quick connect panel 22 when it is left behind, and connected to the docking station while habitable vehicle 1 is driven elsewhere. A suitable latch, strap, or similar weather cover retainer 544 can be added to the inside (unexposed) surface of weather tight cover 540 to retain removable-half weather cover 52 when it is not being used. If weather cover retainer 544 comprises a pair of sturdy elastic straps, for example, these can simply be looped over, and will naturally tighten around, cover latch plates 526 so as to conveniently store removable-half weather cover 52 when removable-half weather cover 52 is not in use.
While only certain preferred features of the invention have been illustrated and described, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. | A habitable vehicle utility docking apparatus comprises a fixed-half quick connect panel fixed to a habitable vehicle such as a recreational vehicle or a boat, and a removable-half quick connect panel matable therewith. The fixed-half quick connect panel maintains a permanent connection to utilities inside the habitable vehicle. The removable-half quick connect panel is connected via commonly-used hoses and wires to external docking station utility services at a campsite, marina, etc. docking station. This avoids the time and inconvenience of having to make a multiplicity of utility connections and disconnections for each and every coming and going of the habitable vehicle to and from the docking station. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application for a patent claims priority to U.S. Provisional Application No. 60/468,424 as filed May 7, 2003.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention pertains to the field of matching two or more parties having similar interests, and more particularly, relates to matching recruiters and potential employees.
[0004] 2. Discussion of the Prior Art
[0005] One of the primary challenges in the staffing industry is to match potential candidates with potential job openings. Often a recruiter must manually review hundreds of resumes, applications and other related documents and assess the potential employees' skills in view of hundreds of potential employers' needs. The recruiter often finds himself with a matrix containing the various technical aspects of potential employees and the various elements desired in an employee by potential employers.
[0006] To add further complications to the matter, there is not a standard format of candidate credentials and resumes submitted by potential candidates or a standardized form used by potential employers to identify the qualities wanted from an employee. Thus, the recruiter must take extra time to search out the needed information on each paper submitted by a potential employee and potential employer before a match can be made between a potential employee and potential employer.
[0007] Even when reviewing a resume, however, there may be a question regarding the integrity of the information provided by a potential employee. It is not uncommon for a potential employee to embellish and/or enhance his/her qualifications.
[0008] Recruiters may typically not be privy to certain employment openings and/or potential employees searching for positions. Thus, some recruiters may not be in as large of a pool of information about potential employers and potential employees as would be desired.
[0009] Further, once a recruiter manually makes a match between a potential employee and potential employer, the recruiter may end up serving as a “middle-man” between the potential employee and potential employer. Having such a “middle-man” may slow the reviewing, interviewing and/or employment-offering process, as well as add expenses.
[0010] Thus, what is needed is a system for pooling reliable and updated information about potential employees and potential employers using a standard format and allowing for direct notification to potential employees and potential employers of employment opportunities matching their respective qualifications.
SUMMARY
[0011] The various exemplary embodiments of the present invention comprise a computer-implemented system for assisting potential acquirees and potential acquirers to be matched together based on one or more sets of criteria, the system comprising: one or more computers, wherein the one or more computers are connected via Internet; one or more databases stored on the one or more computers comprising information, wherein the information is one or more sets of desired criteria respective of the one or more potential acquirers and one or more sets of actual criteria respective of the one or more potential acquirees; one or more computer interfaces, wherein one or more persons representing the one or more potential acquirees inputs the one or more actual criteria respective of the one or more potential acquirees via the one or more computer interfaces, such that the one or more actual criteria respective of the one or more potential acquirees is input as a pre-determined standardized format; wherein one or more persons representing the one or more potential acquirers inputs the one or more desired criteria respective of the one or more potential acquirers via the one or more computer interfaces, such that the one or more desired criteria respective of the one or more potential acquirers is input as a pre-determined standardized format; an automatic matching means, wherein the one or more desired criteria of the one or more potential acquirers and the actual criteria of the one or more potential acquirees are compared to each other, scored on a weighted scale, and matched if a score between the desired criteria and the actual criteria is greater than or equal to a pre-determined value; and an automatic notification means, wherein each of the one or more potential acquirers and the one or more potential acquirees are notified if a score between the desired criteria and the actual criteria is greater than or equal to the pre-determined value.
[0012] The various exemplary embodiments of the present invention further comprise a method for matching one or more potential acquirees and one or more potential acquirers via a computer-implemented system, comprising: inputting one or more sets of desired criteria respective of the one or more potential acquirers, wherein the one or more desired criteria are input as a pre-determined standardized format; inputting one or more sets of actual criteria respective of the one or more potential acquirees, wherein the one or more actual criteria are input as a pre-determined standardized format; comparing the one or more sets of desired criteria input and the one or more sets of actual criteria, and determining a score of a comparison between the one or more sets of desired criteria input and the one or more sets of actual criteria on a weighted scale; determining a match between the one or more sets of desired criteria input and the one or more sets of actual criteria if the score is greater than or equal to a pre-determined value; and notifying the one or more potential acquirers and the one or more potential acquirees if the score is greater than or equal to a pre-determined value.
DESCRIPTION
[0013] In the various exemplary embodiments of the present invention, a computer-implemented system assists potential acquirees and potential acquirers to be matched together based on their respective expertise and/or products and needs and/or desires.
[0014] A potential acquirer may be, for example, an individual, a company, a non-profit organization, a government entity, and the like. The one or more potential acquirers may be seeking to employ an individual, hire a contractor, or purchase goods.
[0015] A potential acquiree may be, for example, an individual, a company, a non-profit organization, a government entity, and the like. The one or more potential acquirees may be seeking to volunteer, be employed or seeking to sell goods.
[0016] The computer-implemented system of the various exemplary embodiments comprises one or more computers connected to the Internet and one or more databases stored on one or more computers. The databases comprise information, wherein the information is one or more sets of criteria related to each of the one or more potential acquirees and the one or more potential acquirers.
[0017] In the various exemplary embodiments of the present invention, the computer-implemented system further comprises one or more computer interfaces. The one or more computer interfaces of the various exemplary embodiments allows for one or more persons representing the one or more potential acquirees to input actual criteria associated with the one or more potential acquirees, that is, for example, the work experience, technical skills, or detailed product description, into the computer-implemented system.
[0018] The one or more computer interfaces of the various exemplary embodiments allows for one or more persons representing the one or more potential acquirers to input desired criteria of the one or more potential acquirers, that is, for example, the work experience desired of an employee or contractual hire, technical skills desired of an employee or contractual hire, or detailed preferred product description, into the computer-implemented system.
[0019] One or more persons representing the one or more potential acquirees in the various exemplary embodiments can be, for example, the one or more potential acquirees, a broker, a recruiter, or other third party. The one or more persons representing the one or more potential acquirers in the various exemplary embodiments can be, for example, the one or more potential acquirers, a broker, a recruiter, or other third party.
[0020] In preferred embodiments of the present invention, the one or more persons representing the one or more potential acquirees and the one or more persons representing the one or more potential acquirers are not the same individual.
[0021] In various exemplary embodiments of the present invention, it is preferred that the one or more persons representing the one or more potential acquirees are not the one or more potential acquirees when the computer-implemented system is for filling staffing and/or employment needs of a potential acquirer. It is preferred that the one or more persons representing the one or more potential acquirees is a third party in order to provide a greater assurance of the integrity of the information regarding the one or more potential acquirees. That is, the one or more persons, as a third party, is presumed to review the accuracy of the actual criteria regarding the one or more potential acquirees.
[0022] In the various exemplary embodiments, it is preferred that the actual and desired criteria are input into the computer face in a pre-determined standardized format for one or more particular industries, technical fields of concentration, or companies.
[0023] Upon inputting the actual criteria of a potential acquiree and/or the desired criteria of a potential acquirer, an automatic matching means compares and/or contrasts the actual criteria and desired criteria to each other. The automatic matching means of the various exemplary embodiments then provides a score based on a weighted scale of the relation between one or more comparisons and/or contrasts of the actual criteria and the desired criteria. The weighted scale is pre-determined based on, for example, a standard weighing of one or more criteria values, a weighing of one or more criteria values set by the one or more persons representing the one or more potential acquirers, or combinations thereof.
[0024] The automatic matching means in various exemplary embodiments comprises artificial intelligence to provide matching between actual criteria and desired criteria.
[0025] The automatic matching means of the various exemplary embodiments, unlike manual review by a recruiter, is able to work twenty-four hours a day, seven days a week.
[0026] If the score between the actual criteria and the desired criteria is greater than or equal to a pre-determined value, in the various exemplary embodiments of the present invention, a match is deemed to occur.
[0027] The score in the various exemplary embodiments of the present invention is in the form of, for example, a numeric value, a percentage, a fraction, a letter grade, a textual message, a symbol, or a combination thereof.
[0028] Upon the occurrence of a match, an automatic notification means contacts each of the one or more potential acquirers of the actual criteria of one or more potential acquirees input into the computer-implemented system. Further, the automatic notification means contacts each of the one or more potential acquirees of the desired criteria of the one or more potential acquirers input into the computer-implemented system if a match is deemed to occur.
[0029] In the various exemplary embodiments, the automatic notification means is an electronic message (“e-mail”) sent to the electronic address (“e-mail address”) of each of the one or more potential acquirers and one or more potential acquirees.
[0030] The automatic notification means to the one or more potential acquirers of the various exemplary embodiments may comprise the actual criteria of the one or more potential acquirees, the score between the actual criteria of the one or more potential acquirees and the desired criteria of the one or more potential acquirers, information on contacting the one or more potential acquirees, or combinations thereof.
[0031] The automatic notification means to the one or more potential acquirees of the various exemplary embodiments may comprise the desired criteria of the one or more potential acquirers, the score between the actual criteria of the one or more potential acquirees and the desired criteria of the one or more potential acquirers, information on contacting the one or more potential acquirers, or combinations thereof.
[0032] Thus, upon receiving the automatic notification, the one or more potential acquirees and/or potential acquirer can contact one another and arrange a meeting, an interview, employment contract, purchasing contract, and the like depending on the needs of each party.
[0033] In various exemplary embodiments of the present invention, the one or more actual criteria of the one or more potential acquirees are purged from the computer-implemented system after a pre-determined period of time. Purging the system assists in data integrity by ensuring the actual criteria of potential acquirees are updated and/or that potential acquirees that are employed no longer keep their actual criteria posted. In other words, the actual criteria is kept from becoming stale.
[0034] In various exemplary embodiments, the one or more desired criteria of the one or more potential acquirers are purged from the computer-implemented system after a pre-determined period of time. Purging the system of the desired criteria ensures that staffing needs that are filled and/or that sought-after goods that are purchased are no longer matched.
[0035] Purging the system of actual criteria and desired criteria after a pre-determined period of time also saves memory space on the computer-implemented system.
[0036] In the various exemplary embodiments of the present invention, the system may further comprise a rating means. The rating means allows the one or more persons representing the one or more potential acquirers to rate other persons representing potential acquirers. In another embodiment, the one or more persons representing the one or more potential acquirers may rate the one or more persons representing the one or more acquirees.
[0037] The rating system may also permit the one or more persons representing the one or more potential acquirees to rate the persons representing the one or more potential acquirers. In yet another embodiment, the one or more persons representing the one or more acquirees can rate other persons representing potential acquirees via the rating means.
[0038] The rating means of the various exemplary embodiments of the present invention allows persons accessing the system to evaluate, for example, effectiveness, speed, integrity, truthfulness, response to questions, etc. of other persons accessing the system.
[0039] The rating means according to the various embodiments according to the present invention may be responses in the form of numbers, text, symbols, yes/no answers, true/false answers, written comments, or combinations thereof.
[0040] While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention. | The present invention is a system and method for matching employers with employees by way of the Internet using standardized formats for inputting qualifications and desired abilities, comparing the qualifications and abilities of employees with those wanted by an employer, scoring the comparison and notifying the employer and/or employee of a match if their qualifications and abilities match those desired by the employer. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates to a method for removing phosphorus-containing constituents and steryl glycosides from crude oil or pre-degummed oil of vegetable or animal origin by using enzymes. Crude oil is understood to be expressed oil and oil extracted from a press cake by means of hexane or ethanol.
PRIOR ART
[0002] Methods for the enzymatic degumming of oils and for the enzymatic breakdown of glycoside in the oil are known.
[0003] EP 0 513 709 B2 describes a method for reducing the content of phosphorus- and iron-containing constituents in pre-degummed oil, from which the hydratable phosphatides are removed, by enzymatic breakdown by means of a phospholipase. In this method, an organic carboxylic acid and an enzyme solution, which contains the phospholipases A1, A2 and B, are stirred into the oil by forming an emulsion. The resulting breakdown products of the non-hydratable phosphatides pass over into the water phase and are removed with the same by centrifugation.
[0004] The separation of steryl glycosides from the oil is not discussed in this document.
[0005] WO 2009/106360 A2 describes a method for separating glycoside, in particular steryl glycoside, by enzymatic breakdown from a biodiesel precursor, biodiesel or mixtures thereof and also from oils and fats, in particular degummed oils and fats with a reduced lecithin content. The enzyme is mixed into the substrate in an aqueous solution. The sugar content of the split steryl glycoside passes over into the aqueous phase and is separated with the same.
[0006] The separation of phosphatides from the oil is not discussed in this document. Since each of these method steps, i.e. separation of the phosphatides and separation of the glycosides, performed separately according to the prior art, means a considerable equipment expenditure, it was the object to combine these method steps in terms of equipment.
DESCRIPTION OF THE INVENTION
[0007] The object is solved by a method which is characterized by the following method steps to be carried out one after the other:
a) setting a temperature of the oil which is suitable for the succeeding method steps as regards the effectiveness of the enzymes and the production of an emulsion; b) admixing an aqueous pH buffer solution whose pH value is 4 to 5, wherein the quantity of the solution is to be chosen so large that it is sufficient for absorbing the constituents precipitated from the oil in the succeeding method steps; c) emulsifying the mixture by means of a dispersing tool; d) holding the emulsion, until a phosphorus concentration of below 30 ppm in the oil phase has been obtained; e) joint addition of enzymes of the type phospholipase and glucosidase; f) emulsifying the mixture by means of a dispersing tool; g) holding the emulsion, until the desired content of phosphorus-containing constituents and steryl glycosides in the oil has been obtained; h) breaking the emulsion by heating; i) separating the aqueous phase from the oil by gravity or centrifugation.
[0017] Our own experiments surprisingly have shown that enzymes of the type phospholipase or glucosidase can jointly be processed in one method step, i.e. under the same technical conditions in terms of temperature, residence time and shear forces exerted by the dispersing tool, and that the two enzymes do not hinder each other in their effectiveness.
Preferred Aspects of the Invention
[0018] A preferred aspect of the invention is characterized in that the temperature of the treated oil phase in method steps a) to g) lies in the range from 20 to 60° C., preferably in the range from 40 to 50° C. In this temperature range, a high effectiveness of the enzymes does exist. At this temperature it is also possible to produce a particularly fine and stable emulsion.
[0019] A further preferred aspect of the invention is characterized in that the pH buffer solution consists of sodium hydroxide and citric acid monohydrate in a molar ratio of 1:1. This buffer solution is particularly suitable, because citric acid and its monohydrate acts as complexing agent for metal ions, such as Fe, Mg and Ca, so that these ions are removed from the oil and pass over into the aqueous phase.
[0020] A further preferred aspect of the invention is characterized in that the phospholipase used in method step e) is of the type A 2 . This type is particularly suitable, because fatty acid thereby is split off at the C 2 site of the phospholipid. As a result, the phospholipid becomes water-soluble and passes over into the aqueous phase, where it forms a sludge which can be separated from the oil e.g. by means of a centrifuge.
[0021] A further preferred aspect of the invention is characterized in that in method steps c) and f) a dispersing device of the type Ultra-Turrax is used. These devices have proven successful for producing an emulsion with small droplet size.
[0022] A further preferred aspect of the invention is characterized in that in method steps f) and g) the emulsion has a droplet size of the aqueous phase of 10 to 40 μm. Such an emulsion provides a sufficiently large surface for the reaction of the enzymes and a sufficient stability. Even finer droplets would require too high an influence of shear forces on the mixture, whereby the enzyme might become inactive.
[0023] A further preferred aspect of the invention is characterized in that in method step h) a temperature in the range from 65 to 75° C. is set for breaking the emulsion. In this temperature range, breaking the emulsion is possible with sufficient speed. At the same time a damage by oxygen—the reaction does not take place under the exclusion of air—is not yet given at these temperatures.
[0024] Further developments, advantages and possible applications of the invention can also be taken from the following description of exemplary embodiments.
[0025] All features described form the invention per se or in any combination, independent of their inclusion in the claims or their back-reference.
EXAMPLES
Example 1 (Comparative Example)
[0026] Water-degummed soybean oil with a phosphorus content of 120 ppm and a steryl glycoside content of 160 ppm was mixed with an aqueous pH buffer solution consisting of sodium hydroxide and citric acid monohydrate in a molar ratio of 1:1. The pH value of the buffer solution was 4.3. The amount of the aqueous pH buffer solution in the mixture was 1.1 wt-%. The temperature of the mixture was adjusted to 45° C. The mixture was dispersed by means of the Ultra-Turrax dispersing device. The mean droplet size of the produced emulsion was 25 μm.
[0027] The dispersion was allowed to stand at a constant temperature of 45° C. and the time course of the phosphorus (P) and steryl glycoside (SG) content in the oil phase was measured. For this purpose the emulsion of the sample taken was broken by heating to 70° C., and the aqueous phase and the oil phase were separated by centrifugation. The measurement results are listed in the following table:
[0000]
Elapsed
P content
SG content
Reaction time [min]
[ppm]
[ppm
Addition of pH buffer
0
120*)
160*)
60
20
67
120
20
64
180
20
60
240
15
57
300
15
57
*)measured before addition of the pH buffer
[0028] The measurement results reveal that the buffer solution alone, due to its citric acid content, already has noticeable effect for lowering the phosphatide and SG content. A part of the phosphatides is rendered hydratable by the citric acid and a part of the steryl glycosides is split into a glucose and a styrene part.
Example 2 (Invention)
[0029] After a dwell time of 30 min, a phospholipase A2 enzyme of the grade Lecitase Novo, PPW 6199 in a dosage of 376 LEU/kg of oil and a glucosidase enzyme of the grade Multifekt GO 5000/L in a dosage of 3 g/kg of oil is added to an emulsion prepared as in Example 1. In the following table, the course of the P and SG content in the oil phase is indicated:
[0000]
Elapsed
P content
SG content
Reaction time [min]
[ppm]
[ppm
Addition of pH buffer
0
120*)
160*)
Addition of enzymes
30
60
15
10
120
12
<5
180
10
<5
240
5
<5
300
5
<5
*)measured before addition of the pH buffer
[0030] The distinctly lower values for the P and SG content, as compared to the Comparative Example, reveal the effect of the jointly added enzymes.
[0000] Measurement methods, terms:
[0031] determination of the P content according to standard DGF methods, C-III 16a (03)
[0032] determination of the SG content according to DIN EN 14 105
[0033] LEU, Lecitase Units, Compendium of food additive specifications, Food and Nutrition Paper 52, Addendum 13, page 31, ISBN 92-5-105355-3 | A method for the enzymatic breakdown of phosphorus-containing constituents and glycosides, in particular steryl glycoside, from crude oil or pre-degummed oil of vegetable or animal origin, wherein for both cases the addition of the enzymes is effected in one method step. | 2 |
[0001] This application claims the benefit of U.S. provisional application No. 60/704,525 filed Aug. 1, 2005, which is incorporated by reference.
BACKGROUND
[0002] The present invention relates generally to crystal oscillators, and more specifically to low-noise, high-stability crystal oscillators.
[0003] Crystal oscillators are extremely useful circuits. They provide clocks and periodic signal sources for telecommunications, wired and wireless networks, and myriad other electronic applications. For example, crystal oscillators are commonly used to time data transfers between integrated circuits. In these applications, crystal oscillator phase noise and jitter degrades performance, causes data transmission errors, and limits data throughput. Thus, it is desirable to provide crystal oscillators having low-noise and high-stability.
[0004] The signal-to-noise ratio for a crystal oscillator can be improved by increasing its signal strength. One way to increase signal strength or amplitude is to generate a differential signal, as opposed to a single-ended signal. A differential signal not only provides a signal that is nominally twice the amplitude of a single-ended signal, but provides a level of common-mode rejection as well, which further reduces noise. Also, a buffer receiving these larger oscillator signals can operate at a lower gain resulting in less noise.
[0005] Unfortunately, excessively large crystal oscillator signals can cause jitter or instability in the oscillator circuit. As these signals become excessive, they may become limited by one or both of a pair of supply voltages for the crystal oscillator. Specifically, electrostatic discharge (ESD) diodes to these supplies can begin to conduct current. This clips the oscillator signals, which adds harmonics and spurious frequency components to the otherwise single-tone signal. These harmonics pull or shift the oscillator operating frequency, resulting in center frequency inaccuracies.
[0006] Also, signals from crystal oscillators typically need to be AC coupled to an integrated circuit that is using the oscillator. If the DC level of the crystal oscillator signals could be well controlled, it would be possible to design an input buffer that could directly connect to the crystal without using the AC coupling capacitors. This would reduce component count, save board space, and reduce costs. This would also help prevent the oscillator signals from being clipped by the ESD diodes.
[0007] Thus, what is needed are circuits, methods, and apparatus that provide crystal oscillators having large, amplitude-controlled differential signal outputs and mechanisms for controlling their DC levels.
SUMMARY
[0008] Accordingly, embodiments of the present invention provide circuits, methods, and apparatus that provide low-noise, high-stability crystal oscillators having large differential output signals and DC level controls. One exemplary embodiment of the present invention provides a crystal oscillator having two feedback loops, one for setting the DC levels of its signals, the other for adjusting the amplitude of those signals. Various embodiments of the present invention may incorporate either one or both of these loops, as well as one or more of the features described herein.
[0009] A specific embodiment of the present invention provides a feedback loop arranged to control the DC level of a crystal oscillator's signals. The DC level can be set to a voltage midway between two supply voltages, to a reference voltage, or to any other appropriate voltage. For example, the voltage may be a ground-referenced voltage that is equal to one-half the minimum supply voltage for the oscillator circuit. This voltage may be a function of either power supply or other condition such as temperature. Alternately, this voltage may be independent of these parameters.
[0010] This embodiment further provides an amplitude-control feedback loop. This loop sets the amplitude of the output of the crystal oscillator signal to be within a range. The amplitude can be set to give a maximum swing without clipping either supply voltage in order to provide high-stability and minimal jitter. The amplitude control circuit can also be digital for improved noise performance. If this control loop is digital, a startup circuit can be included. In a specific embodiment, the startup circuit is an analog control loop that is disabled in favor of a digital control loop once the crystal oscillator circuit starts.
[0011] The time constants or bandwidths of these two loops can be separated such that instabilities are avoided. Specifically, interaction between the loops is minimized by setting the bandwidth of the amplitude control loop to be much lower than the bandwidth of the DC level control loop.
[0012] An exemplary embodiment of the present invention provides an integrated circuit. This integrated circuit includes a means for driving a resonant element to generate the first oscillator signal, means for adjusting a DC level of the first oscillator signal, and means for adjusting an amplitude of the first oscillator signal.
[0013] This or other embodiments may further provide means for driving the resonant element by providing a drive signal to the resonant element, wherein the drive signal is responsive to the resonant element. This or other embodiments may further provide means for providing the drive signal with a gain circuit. This or other embodiments may further provide for the gain circuit being a MOS transistor. This or other embodiments may further provide means for adjusting the DC level of the first oscillator signal by comparing the first oscillator signal with a bias voltage, and providing an output responsive to the comparison. This or other embodiments may further provide for the gain element being a MOS transistor responsive to the output of the amplifier. This or other embodiments may further provide means for adjusting the DC level of the first oscillation signal to be between two supply voltages received by the integrated circuit. This or other embodiments may further provide means for measuring an amplitude of the first oscillation signal, and means for providing a measurement of the amplitude of the first oscillation signal. This or other embodiments may further provide means for measuring the amplitude of the first oscillation signal using a peak detector. This or other embodiments may further provide for the amplitude of the first oscillation signal being measured using a diode and a capacitance. This or other embodiments may further provide means for comparing the measurement of the amplitude of the first oscillation signal with a high threshold and a low threshold, and means for providing one or more signals in response to the comparison. This or other embodiments may further provide means for decrementing an output value when the amplitude of the first oscillation signal is greater than the high threshold, means for maintaining the output value when the amplitude of the first oscillation signal is less than the high threshold and greater than the low threshold, and means for incrementing the output value when the amplitude of the first oscillation signal is less than the low threshold. This or other embodiments may further provide means for generating a bias current in response to the output value. This or other embodiments may further provide means for providing the bias current to a gain circuit, the gain circuit providing the drive to the resonant element. This or other embodiments may further provide means for setting the DC level of the second oscillation signal using the DC level of the first oscillation signal. This or other embodiments may further provide means for DC coupling the DC level of the first oscillation signal to generate the DC level of the second oscillation signal.
[0014] Embodiments of the present invention may be implemented in code, for example, code to be used in a digital signal processor or compiled using VHDL. One such exemplary embodiment of the present invention provides code of an oscillator including code for a gain element configured to drive a resonant element, code for a DC control loop configured to adjust a DC level of a signal at an output of the gain element, and code for an amplitude control loop configured to adjust an amplitude of the signal at the output of the gain element.
[0015] This or other embodiments may further provide code for a gain element having an input responsive to a first node of the crystal and a crystal having a second node responsive to the output of the gain element. This or other embodiments may further provide code for the gain element being a transistor. This or other embodiments may further provide code for the transistor being a MOS transistor. This or other embodiments may further provide code for the DC control loop comprising an amplifier configured to compare the signal at the output of the gain element to a bias voltage and provide an output responsive to the comparison. This or other embodiments may further provide code for the gain element being a MOS transistor responsive to the output of the amplifier. This or other embodiments may further provide code for the DC level of the signal at the output of the gain element adjusting to a voltage that is between two supply voltages received by the integrated circuit. This or other embodiments may further provide code for the amplitude control loop comprising an amplitude measurement circuit configured to provide a measurement of an amplitude of the signal at the output of the gain element. This or other embodiments may further provide code for the amplitude measurement circuit comprising a peak detect circuit. This or other embodiments may further provide code for the peak detect circuit comprising a diode and a capacitance. This or other embodiments may further provide code for the amplitude control loop further comprising a comparator configured to compare the measurement of the amplitude of the signal at the output of the gain element with a high threshold and a low threshold, and further configured to provide one or more signals in response to the comparisons. This or other embodiments may further provide code for the amplitude control loop further comprising a counter configured to increment, decrement, or maintain an output value in response to the one or more signals provided the comparator. This or other embodiments may further provide code for the amplitude control loop further comprising a digital-to-analog converter configured to convert the output of the counter to a current. This or other embodiments may further provide code for the current being provided to the gain element. This or other embodiments may further provide code for the DC level of a signal at an output of the gain element being used to set a DC level of a signal at an input of the gain element. This or other embodiments may further provide code for the DC level of the signal at the output of the gain element being DC coupled to the input of gain element using a resistor.
[0016] A better understanding of the nature and advantages of the present invention may be gained with reference to the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a block diagram of a low-noise, high-stability crystal oscillator according to an embodiment of the present invention;
[0018] FIG. 2 is a block diagram of a low-noise, high-stability Pierce crystal oscillator according to an embodiment of the present invention;
[0019] FIG. 3 is a schematic of a DC biasing loop for a crystal oscillator according to an embodiment of the present invention;
[0020] FIG. 4 is a flowchart showing the operation of the DC biasing loop, such as the DC biasing loop of FIG. 3 ;
[0021] FIG. 5 is a schematic of a digital amplitude control loop for a crystal oscillator according to an embodiment of the present invention;
[0022] FIG. 6 is a flowchart showing the operation of an amplitude control loop, such as the amplitude control loop of FIG. 5 ;
[0023] FIG. 7 is a schematic of an analog amplitude control loop used to start a crystal oscillator according to an embodiment of the present invention; and
[0024] FIGS. 8A-8H illustrate various implementations of exemplary embodiments of the present invention.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0025] FIG. 1 is a block diagram of a low-noise, high-stability crystal oscillator according to an embodiment of the present invention. This figure includes a crystal X 1 110 , gain circuit A 1 120 , amplifier A 2 130 , amplitude detection circuit 140 , resistors R 1 150 and R 2 160 , and capacitor C 1 170 . This figure, as with the other included figures, is shown for illustrative purposes and does not limit either the possible embodiments of the present invention or the claims.
[0026] The crystal X 1 110 is driven by the gain element A 1 120 . In this and other embodiments of the present invention, the crystal X 1 110 may be a crystal or other resonant element or circuit, for example, it may be an L-C tank circuit. The gain element A 1 120 provides a net inversion and may be as simple as a transistor, though it may alternately be one or more inverters or buffers in series, so long as the combination provides a net signal inversion. The gain element A 1 120 provides the gain necessary to drive crystal X 1 110 .
[0027] In operation, the signal V 2 on line 114 , the output terminal of the gain device A 1 120 , oscillates above and below a DC voltage. This DC voltage is the DC component of the signal V 2 on line 114 ; the oscillation is the AC signal component. Resistor R 1 120 equalizes the DC component of the signal V 1 on line 112 with the DC component of the signal V 2 on line 114 . The two signals, V 1 on line 112 and V 2 on line 114 , are nominally phase shifted by 180 degrees and each are ideally sinusoidal in nature.
[0028] The DC voltage component of V 2 on line 114 is compared to a bias voltage on line 132 by the amplifier A 2 130 . In various embodiments, other voltages can be compared to the bias voltage on line 132 . For example, the DC component of the signal V 1 on line 112 can be compared. In other embodiments, the resistor R 1 120 is a number of resistors in series, and a voltage at a node between two of these resistors can be compared to the bias voltage on line 132 . In a specific embodiment of the present invention, the bias voltage on line 132 is set to a ground-referenced voltage that is equal to one-half a minimum supply voltage for the oscillator. In other embodiments of the present invention, this bias voltage may be equal to a reference voltage. For example, the bias voltage on line 132 may be equal to a bandgap voltage. In other embodiments of the present invention, the bias voltage may be a function of VCC, temperature, or other condition; alternately, the bias voltage on line 132 may be independent of one or more of these parameters.
[0029] The amplifier A 2 130 receives the signal V 2 on line 114 . The amplifier compares the DC component of the signal V 2 on line 114 to the bias voltage received on line 132 . This comparison generates a signal at the output of the amplifier A 2 130 . This voltage is then used to set the DC voltage for the signal V 1 on line 112 .
[0030] The DC control feedback loop operates as follows. As the DC component of the signal V 2 on line 114 increases, the voltage at the output of the amplifier A 2 130 decreases. This lowers the DC component of the signal V 1 on line 112 . Since the signal V 2 on line 114 is DC coupled to V 1 on line 112 , V 2 on line 114 is similarly reduced, thus compensating for the original increase.
[0031] The amplitude detection circuit 140 receives the signal V 1 on line 112 , and provides a bias current or voltage to the gain circuit A 1 120 . The amplitude detection circuit 140 compares the oscillation amplitude of the signal V 1 on line 112 to one or more thresholds. As the amplitude of the signal V 1 on line 112 increases, the amplitude detection circuit 140 decreases the gain of gain circuit A 1 120 , thus reducing the drive to the crystal X 1 110 . This in turn lowers the amplitude of the voltage swing of the signal V 2 on line 114 . Conversely, as the amplitude of the signal V 1 on line 112 decreases, the amplitude detection circuit 140 increases the gain of gain circuit A 1 120 , which increases the amplitude of V 2 on line 114 . In this way, feedback is provided such that the amplitude of the signal V 2 on line 114 is maintained at a certain level (or within a range of levels, depending on the exact implementation.)
[0032] Again, the gain circuit A 1 120 can be as simple as a single transistor in some embodiments of the present invention. When it is a transistor, such as a MOS transistor, this oscillator can be referred to as a Pierce oscillator. In this configuration, the crystal X 1 110 oscillates in the parallel resonance mode. Other types of oscillators may also be improved by embodiments of the present invention. These include Pierce, Colpitts, Hartley, Armstrong, Clapp, and other types of oscillators. An example of a Pierce oscillator is shown in the next figure.
[0033] FIG. 2 is a block diagram of a low-noise, high-stability Pierce crystal oscillator according to an embodiment of the present invention. This figure includes a crystal X 1 210 , transistor M 1 220 , bias current source 230 , amplifier A 1 240 , amplitude detection circuit 250 , resistors R 1 245 and R 2 215 , and capacitors C 1 225 , C 2 255 , and C 3 247 .
[0034] In this configuration, transistor M 1 220 provides the gain necessary to drive crystal X 1 210 . The crystal X 11 210 is AC coupled through capacitor C 1 225 to the base of M 1 220 . This separates the DC level of the crystal oscillator signal V 1 on line 222 from the bias voltage at the gate of transistor M 1 220 . As before, resistor R 2 215 is a large value resistor that biases the DC voltage of the signal V 1 on line 222 such that it equals the DC voltage of the signal V 2 on line 224 . Since the resistor R 2 215 is a large resistor, care should be taken to avoid leakage currents, for example through capacitor C 1 225 , or other capacitors that have been omitted for clarity.
[0035] The DC component of the signal V 2 on line 224 is compared to the bias voltage on line 242 by the amplifier 240 . Again, other voltages can be compared to the bias voltage on line 242 . For example, the resistor R 2 215 can be two or more resistors in series, with a voltage at a node between two of these resistors compared to the bias voltage on line 242 . The amplifier 240 provides a voltage output across C 3 247 that is coupled to the gate of transistor M 1 220 by resistor R 1 245 . In a specific embodiment, the amplifier A 1 240 is a transconductance or gm amplifier that provides a current which generates a voltage across capacitor C 3 247 . This output voltage sets the operating point for M 1 220 , which in turn sets the DC component of the signal V 2 on line 224 . Resistor R 1 254 and capacitor C 3 247 provide reverse isolation for the output of the amplifier A 1 240 from the large AC swings on the gate of transistor M 1 220 .
[0036] More specifically, when the DC component of the signal V 2 on line 224 is higher than the level of the bias signal on line 242 , the output voltage of the amplifier A 1 240 is reduced. This reduces the gate-to-source voltage of M 1 220 , which increases the DC voltage of the signal V 2 on line 224 .
[0037] The signal V 1 on line 222 is AC coupled through capacitor C 2 255 to the amplitude detection circuit 250 . The amplitude detection circuit adjusts the bias current provided by the current source IBIAS 230 . As the amplitude of the signal V 1 on line 222 increases, the current provided by the bias current source 230 is decreased, thereby reducing the amplitude of the signals V 2 on line 224 and V 1 on line 222 . Conversely, as the amplitude of the signal V 1 on line 222 decreases, the current provided by the bias current source 230 is increased, thereby increasing the amplitude of the signals V 2 on line 224 and V 1 on line 222 .
[0038] There are various ways in which the DC components of the oscillator voltage signals can be set or controlled. The feedback loops used to accomplish this may be analog, digital, or a combination thereof. One analog circuit that may be used is shown in the next figure. The subsequent figure shows a method of setting these DC components; the method may be implemented in an analog or digital manner.
[0039] FIG. 3 is a schematic of a DC biasing loop for a crystal oscillator according to an embodiment of the present invention. This figure includes a crystal X 1 310 , transistor M 1 320 , current source IBIAS 330 , amplifier A 1 340 , resistors R 1 315 , R 2 317 , and R 3 350 , and capacitors C 1 360 , C 2 365 , C 3 370 , C 4 345 , and C 5 375 . An amplitude detection circuit may be used to adjust the current provided by the current source IBIAS 330 , but has been omitted for clarity.
[0040] The crystal X 1 310 is driven by transistor M 1 320 . The crystal signal on line V 1 322 is AC coupled to the gate of M 1 320 by capacitor C 1 360 . A series combination of resistors R 1 315 and R 2 317 are used to set the DC levels of the signals V 1 on line 322 and V 2 on line 324 such that they are equal to the DC level of the signal V 4 on line 344 . Capacitors C 3 370 and C 5 375 are used to pull or tune the crystal's frequency. In various embodiments, these capacitors can include arrays of switchable capacitors allowing the crystal's frequency to be tuned or modulated, for example as part of an FM modulator.
[0041] Again, transistor M 1 320 provides the drive current for the crystal X 1 310 . As the gate voltage of the transistor M 1 320 increases, the drain current of the device increases rapidly. Accordingly, the DC bias voltage of M 1 320 is typically near ground, that it is biased below the threshold of the transistor M 1 320 , such that the transistor M 1 320 is typically off, turning on to provide a pulse of current to the crystal X 1 310 once every oscillation cycle.
[0042] It is desirable for the signal V 1 on line 322 to have a large amplitude. However, if this large signal were AC coupled directly to the gate of transistor M 1 320 , the gate of transistor M 1 320 would require a DC bias below ground, otherwise it would provide excess drive current to the crystal 310 . However, the amplifier A 1 340 is not capable of driving below ground. One alternative is to provide a negative supply voltage for the amplifier A 1 340 , for example with a charge pump. This solution provides excellent noise performance. Alternately, the signal V 1 on line 322 can be reduced in amplitude.
[0043] Accordingly, in this specific example, capacitor C 2 365 is connected from the gate of M 1 322 to ground. In this way, capacitors C 1 316 and C 2 365 form a capacitive divider that reduces the amplitude of the signal seen at the gate of M 1 320 . This allows the gate of transistor M 1 320 to have a DC bias above ground. In a specific embodiment, the DC bias for the gate of M 1 320 is approximately 200 mV, which can be supplied by the amplifier A 1 340 without requiring a negative supply voltage.
[0044] The DC component of the signal V 4 on line 344 is set by a feedback loop including amplifier A 1 340 , resistor R 3 350 , and transistor M 1 320 . Specifically, the voltage signal V 4 on line 344 is compared to the bias signal received on line 342 by the amplifier A 1 340 . The signals V 2 on line 324 and V 1 on line 322 are each large oscillating signals that are 180 degrees out of phase. Accordingly, if the resistors R 1 315 and R 2 317 are equal, the signal V 4 on line 344 has approximately the same DC level as the signals V 1 on line 322 and V 2 on line 324 , but with little or no AC component. Thus, the signal V 4 on line 344 provides a good voltage for comparison to the bias voltage on line 342 by the amplifier A 1 340 .
[0045] The amplifier A 1 340 provides a voltage output across capacitor C 4 345 . The capacitor C 4 345 can be used to limit the bandwidth, time constant, or frequency response of this loop. In a specific embodiment, the amplifier A 1 340 provides a current output that is converted to a voltage by the capacitor C 4 345 . The output voltage of the amplifier A 1 340 sets the DC bias voltage for transistor M 1 320 . The gate-to-source voltage of transistor M 1 320 determines the operating point for the transistor, including its drain voltage, the signal V 2 on line 324 .
[0046] FIG. 4 is a flowchart showing the operation of the DC biasing loop, such as the DC biasing loop of FIG. 3 . According to this method, a signal from an oscillator is compared to a bias voltage. The comparison is used to set a bias condition for a transistor. The transistor then sets the DC level of the oscillator signal.
[0047] Specifically, in act 410 , a first signal is received from a crystal. The DC level or component of the crystal signal is compared to a bias level in act 420 . Again, this bias level may be set to be between two supply voltages, to a bandgap or other bias voltage, and it may be designed to track or be independent of supplies, temperature, processing, or other condition. For example, it may be set to a ground-referenced voltage that is approximately one-half a minimum supply voltage for the oscillator signal. Alternately, this bias level may be designed to be independent of one or more of these parameters.
[0048] A correction signal based on the comparison is generated in act 430 . This correction signal is then used to set the DC level of the first crystal signal. There are many ways that this may be done, and they may depend on the particular circuit topology that is used. For example, the comparison may be done digitally, where the first crystal signal is filtered, digitized, and compared to a second digital value. In other embodiments of the present invention, the loop is analog.
[0049] In this specific example, the correction signal is used to set a bias voltage for a transistor in act 440 . In act 450 , the transistor is used to set a DC level for the first crystal signal. A resistor is used to set a DC level of a second crystal signal in act 460 . Additionally, other resistors can be used to set other crystal signals.
[0050] Embodiments of the present invention and can include an amplitude detection circuit. The amplitude detection circuit can set the drive level for a transistor or other circuit used to provide gain for a crystal in a crystal oscillator circuit. This loop can be analog, digital, or a combination thereof. Again, to avoid interaction with a DC control loop, the bandwidth of the amplitude detection circuit can set to be lower than the bandwidth of the DC control loop. In other embodiments, other arrangements can be made; for example, the bandwidth of the amplitude detection circuit can set to be higher than the bandwidth of the DC control loop. In one specific embodiment of the present invention, the amplitude detection circuit is predominantly digital, and the bandwidth of the loop is set by a frequency and at which a value of an accumulator or counter is clocked or updated. One specific circuit that can detect an amplitude and use this information to adjust the amplitude's level is shown in the next figure, while one specific methodology of detecting an amplitude is shown in the subsequent figure.
[0051] FIG. 5 is a schematic of a digital amplitude control loop for a crystal oscillator according to an embodiment of the present invention. The digital amplitude control loop includes an AC coupling capacitor C 1 510 , DC restoration resistor 515 , a negative peak detector made up of a diode D 1 520 and capacitor C 2 530 , window comparator 540 , accumulator 550 , current digital-to-analog converter (DAC) 560 , and a low-pass filter 570 . An oscillator signal is received on line V 1 512 by the AC coupling capacitor C 1 510 . The current DAC 560 generates a bias current that is filtered by the low-pass filter and provided as current IBIAS on line 562 . In a specific embodiment, the bias current on line 562 supplies current to a transistor, such as transistor M 1 320 in FIG. 3 .
[0052] Again, an oscillator signal V 1 is received on line 512 and AC coupled as signal V 2 on line 512 by AC coupling capacitor C 1 510 . The input signal V 1 on line 512 may correspond to one of at least two signals, for example, V 1 on line 322 or V 2 on line 324 in FIG. 3 . Detecting the amplitude of V 1 on line 322 provides isolation between the amplitude detector input and IBIAS current output on line 562 . The size of capacitor C 1 510 should be large in comparison to the parasitic capacitances of diode D 1 520 and resistor R 1 515 in order to avoid signal losses that would be caused by the resulting capacitive divider. The resistor R 1 515 sets the DC component of the signal V 2 on line 515 to an appropriate bias voltage, BIAS on line 516 in this example. In an exemplary embodiment of the present invention, the resistor R 1 515 may be connected to a bias line that is midway between two supplies such as VCC and ground. In various embodiments, R 1 515 is connected to the same or similar bias line as the BIAS voltage on line 342 in FIG. 3 .
[0053] The negative peak of the signal V 2 on line 517 is detected by the diode D 1 520 and capacitor C 2 530 in order to generate a peak detected output signal V 3 on line 532 . In other embodiments, a positive peak detector can be used, for example, by reversing diode D 1 520 . In other embodiments, other peak detectors or envelope detectors can be used. As the voltage of the signal V 2 on line 517 decreases, the voltage of the signal V 3 on line 532 follows. As the signal V 2 on line 517 reaches its minimum value or peak, the signal V 3 on line 532 reaches a corresponding voltage, plus a diode drop caused by the diode D 1 520 . In various embodiments of the present invention, other peak detectors that compensate for, or do not include this diode drop, are used. As the level of the signal V 2 on line 517 increases, the diode D 1 520 reverse biases, and is effectively disconnected from the capacitor C 2 530 , which holds the negative peak voltage.
[0054] The window comparator 540 compares the signal V 3 on line 532 to two thresholds, a high threshold and a low threshold. When the voltage of the signal V 3 is lower than the low threshold, signal VL on line 546 is active. When the voltage of the signal V 3 on line 532 is between the high threshold and the low threshold, the signal VM on line 544 is active. When the voltage of the signal V 3 on line 532 is higher than the high threshold, the signal VH on line 542 is active. In various embodiments of the present invention, the signal VM on line 544 is not required. In various embodiments, the window comparator can be two comparators, one that compares the signal V 3 on line 532 with a high threshold, and one that compares the signal V 3 on line 532 with a low threshold.
[0055] The accumulator 550 can be an up/down counter that provides a digital word to the current DAC 560 . When the signal VL on line 546 is active, the accumulator 550 counts down by one bit. When the signal VH on line 542 is active, the accumulator 550 counts up by one bit. When the signal VM on line 544 is active, the accumulator 550 does not change value. In other embodiments, the accumulator may count in a different manner, so long as the peak detector, accumulator 550 , and DAC 560 operate together to properly control the amplitude of the oscillator signals.
[0056] The accumulator can be clocked by a signal that controls the rate at which the accumulator output can change state. The frequency of this clock signal controls the bandwidth of the amplitude detection circuit. In one specific embodiment of the present invention, in order to avoid interactions with a DC control loop, the bandwidth of this amplitude detection circuit is set to be lower than the bandwidth of the DC control loop. The accumulator can alternately be an analog-to-digital converter, such as a flash converter. Also, more complicated functions can be implemented. For example, transfer functions that include poles and zeros can be implemented to more specifically tailor the frequency response of the amplitude detection circuit. The locations of these poles and zeros can also be programmable or otherwise adjustable.
[0057] The current DAC 560 receives a digital word from the accumulator 550 . The digital word can be binarily weighted or thermally decoded, or have some other weighting or combination thereof. The current DAC 560 is typically a number of switches each configured to turn a current source on or off. The resulting current can be filtered and provided to a gain element or transistor, such as transistor M 1 320 in FIG. 3 . The filtering is performed in this specific example by the low-pass filter 570 . This filter removes the high frequency components of the current DAC output, protecting the oscillator gain element from these transients. The current sources may be configured to be independent of supply, temperature, or processing. In one embodiment of the present invention, as the digital word increases in value, the DAC provides more current to the gain device. In other embodiments, the DAC may provide less current as the digital word increases.
[0058] In other embodiments, the voltage of signal V 3 on line 532 is compared to a single threshold. In this case, a single output indicating whether the voltage of signal V 3 on line 532 is higher or lower than the threshold is provided. In this configuration, during operation, the comparison signal tends to alternate between one state and another, causing the accumulator to toggle between two levels, and resulting in the current DAC 560 switching between two bias current levels. This tends to add digital switching noise to the oscillator circuit. Using two thresholds provides a window in which the device may operate without changing the output of the accumulator 550 or the resulting bias current level provided by the current DAC 560 .
[0059] FIG. 6 is a flowchart showing the operation of an amplitude control loop, such as the amplitude control loop of FIG. 5 . In this embodiment of the present invention, an oscillation signal from a crystal is peak detected and compared to a high and a low threshold. The comparison results are used to control an accumulator, which in turn provides an output that is converted to a bias current, the bias current used to drive the gain device or circuit in the oscillator. The peak detection described here detects positive peaks, though negative peak detection can alternately be used.
[0060] Specifically, in act 610 , an oscillation signal is received from a crystal. This signal is AC coupled, such that its DC component is removed in act 620 . In act 630 , the DC component of the oscillation signal is peak detected.
[0061] The peak detected level is then compared to a high and a low threshold in act 640 . In act 650 , it is determined whether the peak level is above a high threshold. If it is, the accumulator is decremented in act 660 . If the peak level is not above a high threshold, it is determined whether the peak level is below the low threshold in act 670 . If it is, the accumulator is incremented in act 680 . If the peak detected value is lower than the high threshold, but higher than the low threshold, the value in the accumulator is maintained in act 690 . Again, in various embodiments of the present invention, the accumulator may increment or decrement in different ways according to the exact implementation used.
[0062] The value of the accumulator is converted into a current in act 695 . Again, this current can be used to drive a transistor or other circuit that is providing gain to the crystal that is generating the oscillation signal.
[0063] The amplitude detection circuits of the previous figures may have a stable state where the crystal does not oscillate or provide an output signal of sufficient amplitude to properly clock the accumulator 550 in FIG. 5 . Although the presence of noise typically starts these oscillators, in order to provide a robust and fast start-up, an analog amplitude detection circuit can be used. Once the oscillator is running, the analog amplitude detection circuit can be disabled in favor of a digital amplitude detection circuit, such as the circuit shown in FIG. 5 . One analog amplitude control circuit that may be used at start-up is shown in the following figure.
[0064] FIG. 7 is a schematic of an analog amplitude control circuit used to start a crystal oscillator according to an embodiment of the present invention. This figure includes gm amplifier 710 and a p-channel current mirror including transistors M 1 720 and M 2 730 , and decoupling capacitor C 3 725 .
[0065] An input signal V 1 is received on line 702 by the gm amplifier 710 . The gm amplifier 710 provides a current output that is mirrored by the p-channel current mirror transistors M 1 720 and M 2 730 . Transistor M 2 730 can be connected in parallel with the current DAC in the digital amplitude detector circuit. In a specific embodiment, the signal V 1 on line 702 is the negative peak detected signal V 3 on line 532 in FIG. 5 , though in other embodiments, it can be a different signal. As the amplitude of the crystal oscillator signals increase, the voltage V 1 on line 702 decreases, thus decreasing the current provided by the gm amplifier 710 to the p-channel current mirror.
[0066] Again, once the oscillator is running, this circuit can be disabled in favor of an amplitude detection circuit, such as the amplitude detection circuit shown in FIG. 5 , or other detection circuits consistent with embodiments of the present invention. This circuit can be disabled in favor of a digital amplitude detection circuit when the crystal oscillator signals are of sufficient amplitude to properly clock the accumulator circuit. Hysteresis can also be used to avoid a condition where this circuit toggles between its on and off states.
[0067] The transistors in the above examples are shown as MOS transistors. In other embodiments of the present invention, the devices may be bipolar, HBTs, MESFETS, HFETs, or other types of devices. The capacitors shown may be metal-to-metal capacitors, thin-oxide capacitors, or any other appropriate capacitors, such as the gate of a MOS device. The resistors may be polysilicon resistors, base resistors, implant resistors, or other appropriate type of resistor. The crystals may be crystals operating in parallel or series resonance modes. Alternately, they may be other resonance devices.
[0068] Referring now to FIGS. 8A-10G , various exemplary implementations of the present invention are shown. Referring to FIG. 8A , the present invention may be embodied in a hard disk drive 800 . The present invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 8A at 802 . In some implementations, signal processing and/or control circuit 802 and/or other circuits (not shown) in HDD 800 may process data, perform coding and/or encryption, perform calculations, and/or format data that is output to and/or received from a magnetic storage medium 806 .
[0069] HDD 800 may communicate with a host device (not shown) such as a computer, mobile computing devices such as personal digital assistants, cellular phones, media or MP3 players and the like, and/or other devices via one or more wired or wireless communication links 808 . HDD 800 may be connected to memory 809 , such as random access memory (RAM), a low latency nonvolatile memory such as flash memory, read only memory (ROM) and/or other suitable electronic data storage.
[0070] Referring now to FIG. 8B , the present invention may be embodied in a digital versatile disc (DVD) drive 810 . The present invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 8B at 812 , and/or mass data storage 818 of DVD drive 810 . Signal processing and/or control circuit 812 and/or other circuits (not shown) in DVD 810 may process data, perform coding and/or encryption, perform calculations, and/or format data that is read from and/or data written to an optical storage medium 816 . In some implementations, signal processing and/or control circuit 812 and/or other circuits (not shown) in DVD 810 can also perform other functions such as encoding and/or decoding and/or any other signal processing functions associated with a DVD drive.
[0071] DVD drive 810 may communicate with an output device (not shown) such as a computer, television or other device via one or more wired or wireless communication links 817 . DVD 810 may communicate with mass data storage 818 that stores data in a nonvolatile manner. Mass data storage 818 may include a hard disk drive (HDD) such as that shown in FIG. 8A . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. DVD 810 may be connected to memory 819 , such as RAM, ROM, low latency nonvolatile memory such as flash memory, and/or other suitable electronic data storage.
[0072] Referring now to FIG. 8C , the present invention may be embodied in a high definition television (HDTV) 820 . The present invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 8C at 822 , a WLAN interface and/or mass data storage of the HDTV 820 . HDTV 820 receives HDTV input signals in either a wired or wireless format and generates HDTV output signals for a display 826 . In some implementations, signal processing circuit and/or control circuit 822 and/or other circuits (not shown) of HDTV 820 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other type of HDTV processing that may be required.
[0073] HDTV 820 may communicate with mass data storage 827 that stores data in a nonvolatile manner such as optical and/or magnetic storage devices. At least one HDD may have the configuration shown in FIG. 8A and/or at least one DVD may have the configuration shown in FIG. 8B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. HDTV 820 may be connected to memory 828 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. HDTV 820 also may support connections with a WLAN via a WLAN network interface 829 .
[0074] Referring now to FIG. 8D , the present invention implements a control system of a vehicle 830 , a WLAN interface and/or mass data storage of the vehicle control system. In some implementations, the present invention implements a powertrain control system 832 that receives inputs from one or more sensors such as temperature sensors, pressure sensors, rotational sensors, airflow sensors and/or any other suitable sensors and/or that generates one or more output control signals such as engine operating parameters, transmission operating parameters, and/or other control signals.
[0075] The present invention may also be embodied in other control systems 840 of vehicle 830 . Control system 840 may likewise receive signals from input sensors 842 and/or output control signals to one or more output devices 844 . In some implementations, control system 840 may be part of an anti-lock braking system (ABS), a navigation system, a telematics system, a vehicle telematics system, a lane departure system, an adaptive cruise control system, a vehicle entertainment system such as a stereo, DVD, compact disc and the like. Still other implementations are contemplated.
[0076] Powertrain control system 832 may communicate with mass data storage 846 that stores data in a nonvolatile manner. Mass data storage 846 may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one HDD may have the configuration shown in FIG. 8A and/or at least one DVD may have the configuration shown in FIG. 8B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. Powertrain control system 832 may be connected to memory 847 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. Powertrain control system 832 also may support connections with a WLAN via a WLAN network interface 848 . The control system 840 may also include mass data storage, memory and/or a WLAN interface (all not shown).
[0077] Referring now to FIG. 8E , the present invention may be embodied in a cellular phone 850 that may include a cellular antenna 851 . The present invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 8E at 852 , a WLAN interface and/or mass data storage of the cellular phone 850 . In some implementations, cellular phone 850 includes a microphone 856 , an audio output 858 such as a speaker and/or audio output jack, a display 860 and/or an input device 862 such as a keypad, pointing device, voice actuation and/or other input device. Signal processing and/or control circuits 852 and/or other circuits (not shown) in cellular phone 850 may process data, perform coding and/or encryption, perform calculations, format data and/or perform other cellular phone functions.
[0078] Cellular phone 850 may communicate with mass data storage 864 that stores data in a nonvolatile manner such as optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one HDD may have the configuration shown in FIG. 8A and/or at least one DVD may have the configuration shown in FIG. 8B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. Cellular phone 850 may be connected to memory 866 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. Cellular phone 850 also may support connections with a WLAN via a WLAN network interface 868 .
[0079] Referring now to FIG. 8F , the present invention may be embodied in a set top box 880 . The present invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 8F at 884 , a WLAN interface and/or mass data storage of the set top box 880 . Set top box 880 receives signals from a source such as a broadband source and outputs standard and/or high definition audio/video signals suitable for a display 888 such as a television and/or monitor and/or other video and/or audio output devices. Signal processing and/or control circuits 884 and/or other circuits (not shown) of the set top box 880 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other set top box function.
[0080] Set top box 880 may communicate with mass data storage 890 that stores data in a nonvolatile manner. Mass data storage 890 may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one HDD may have the configuration shown in FIG. 8A and/or at least one DVD may have the configuration shown in FIG. 8B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. Set top box 880 may be connected to memory 894 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. Set top box 880 also may support connections with a WLAN via a WLAN network interface 896 .
[0081] Referring now to FIG. 8G , the present invention may be embodied in a media player 872 . The present invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 8G at 871 , a WLAN interface and/or mass data storage of the media player 872 . In some implementations, media player 872 includes a display 876 and/or a user input 877 such as a keypad, touchpad and the like. In some implementations, media player 872 may employ a graphical user interface (GUI) that typically employs menus, drop down menus, icons and/or a point-and-click interface via display 876 and/or user input 877 . Media player 872 further includes an audio output 875 such as a speaker and/or audio output jack. Signal processing and/or control circuits 871 and/or other circuits (not shown) of media player 872 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other media player function.
[0082] Media player 872 may communicate with mass data storage 870 that stores data such as compressed audio and/or video content in a nonvolatile manner. In some implementations, the compressed audio files include files that are compliant with MP3 format or other suitable compressed audio and/or video formats. The mass data storage may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one HDD may have the configuration shown in FIG. 8A and/or at least one DVD may have the configuration shown in FIG. 8B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. Media player 872 may be connected to memory 873 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. Media player 872 also may support connections with a WLAN via a WLAN network interface 874 .
[0083] Referring to FIG. 8H , the present invention may be embodied in a Voice over Internet Protocol (VoIP) phone 883 that may include an antenna 839 . The present invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 8H at 882 , a wireless interface and/or mass data storage of the VoIP phone 883 . In some implementations, VoIP phone 883 includes, in part, a microphone 887 , an audio output 889 such as a speaker and/or audio output jack, a display monitor 891 , an input device 892 such as a keypad, pointing device, voice actuation and/or other input devices, and a Wireless Fidelity (Wi-Fi) communication module 886 . Signal processing and/or control circuits 882 and/or other circuits (not shown) in VoIP phone 883 may process data, perform coding and/or encryption, perform calculations, format data and/or perform other VoIP phone functions.
[0084] VoIP phone 883 may communicate with mass data storage 502 that stores data in a nonvolatile manner such as optical and/or magnetic storage devices, for example hard disk drives HDD and/or DVDs. At least one HDD may have the configuration shown in FIG. 8A and/or at least one DVD may have the configuration shown in FIG. 8B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. VoIP phone 883 may be connected to memory 885 , which may be a RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. VoIP phone 883 is configured to establish communications link with a VoIP network (not shown) via Wi-Fi communication module 886 . Still other implementations in addition to those described above are contemplated.
[0085] The above description of exemplary embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. | Circuits, methods, and apparatus that provide low-noise, high-stability crystal oscillators having controlled-amplitude differential output signals and DC level control. A crystal oscillator circuit has two feedback loops, one for setting the DC level of its signals, the other for adjusting the amplitude of those signals. The DC level feedback loop can set the DC component of the oscillator signals to a voltage midway between two supply voltages. The amplitude control loop sets the amplitude of the output of the crystal oscillator signal to be within a range. The amplitude can be set to provide a maximum swing without clipping the supply voltages in order to provide high-stability and minimal jitter. The amplitude control circuit can also be digital for improved noise performance. The time constants of these two loops can be separated such that instabilities are avoided. | 7 |
TECHNICAL FIELD
[0001] This invention pertains to the field of heating, ventilation and air-conditioning (“HVAC”) systems and, more specifically, pertains to improved strategies, especially automated or software-implemented methods, for sequencing parallel equipment such as centrifugal chillers, pumps and fans in order to improve the overall operating efficiency of HVAC systems that incorporate such equipment.
BACKGROUND
[0002] Chilled water plants are employed to provide cooling for building comfort loads and for industrial process loads and are a major user of electrical power. Chilled water plants generally employ multiple chillers, and some chillers employ multiple compressors. This permits equipment to be staged to meet the changing loads, which usually vary from very low loading up to as much as 100% of plant capacity, depending on design and operating environment. Multiple chillers also permit designs that incorporate fail safe operation with backup available in case of a failure of one of the machines.
[0003] Medium and large size cooling plants often incorporate centrifugal compressors due to their superior operating efficiency and larger capacities. A chiller consists of one or more compressors mounted on a set of heat exchangers which, along with additional piping, refrigerant and other equipment, cools a fluid that flows through one heat exchanger while rejecting the heat absorbed at a higher temperature to a fluid flowing through the second heat exchanger. The fluid flowing through both heat exchangers is usually water. Each set of one or more compressors and two heat exchangers is called a chiller, and medium to large chiller plants consist of multiple chillers.
[0004] FIG. 5 is a simplified diagram of components of a conventional water chiller plant with four chillers ( 501 - 504 ) arranged in parallel and connected to chilled water pumping and piping system ( 520 ). Each chiller has an individual chiller controller ( 531 - 534 ) each of which is in communication with a controller ( 540 ). The individual chiller controllers may communicate via a network such as an Ethernet network. The central controller preferably has a processer and associated memory which are configured to read a computer program. The central controller may be a digital computing system, for example, a personal computer or a programmable logic controller. The central controller is configured to receive information from each individual chiller such as head pressure readings, fluid temperatures and the current vane settings. The central controller also controls various aspects of the chiller plant including pump speed, chiller loading and switching a chiller on or offline.
[0005] FIG. 1 illustrates the major components of a variable speed centrifugal chiller. Medium and large chiller plants typically employ from two to as many as a dozen or more such chillers for comfort conditioning applications or to serve process cooling needs in a manufacturing application. In a typical water chiller plant with variable speed centrifugal chillers, each chiller has one or more motor/compressor unit ( 109 ), which may be a hermetic type or open type. The motor or engine that drives the compressor is powered by a power unit commonly called a variable speed drive ( 110 ) that can vary the rotational speed of the motor or engine in the compressor unit.
[0006] Each compressor draws low pressure refrigerant gas from the cooler ( 111 ) through a connection ( 112 ), compresses it, and discharges it as a higher pressure hot gas through a connection ( 113 ) into the condenser ( 114 ). In the condenser, hot gaseous refrigerant is condensed into a liquid by rejecting heat to condenser water that is supplied through a piping connection ( 140 ) from a cooling tower or some other means of conducting heat from the fluid. The condenser water flows through tubes in the condenser, absorbs heat from the refrigerant and cools it to a high pressure liquid. The heated condenser water then leaves the condenser through a piping connection ( 141 ) to return to the cooling tower or other method of heat rejection.
[0007] The condensed liquid refrigerant then flows through an expansion device ( 133 ) that regulates the flow of refrigerant into the cooler ( 111 ), which is held at a low pressure by the operation of the compressor continuously drawing expanded gaseous refrigerant from it. The low pressure environment causes the refrigerant to change state to a gas and as it does so, it absorbs the required heat of vaporization from the chilled water circulating into the cooler via pipe connection ( 151 ), then through tubes in the cooler where the boiling refrigerant absorbs heat from the chilled water and the chilled water then exits through a pipe connection ( 152 ) at the desired temperature to cool the comfort or process loads to which the chiller plant is connected. The low pressure vapor is drawn into the inlet of the compressor and the cycle is continuously repeated. The chilled and condenser water are typically circulated by pumps not shown. Control of all elements within the chiller is provided by an on-board control panel ( 162 ). Though the configuration of many chillers is similar to that shown in FIG. 1 , there are variations to this basic design.
[0008] FIG. 2 is a cross section that shows in some greater detail the elements of the motor/compressor unit (see 109 , 110 in FIG. 1 ) of a centrifugal compressor used in centrifugal chillers. The compressor unit consists of a motor or engine ( 210 ) that rotates a shaft upon which an impeller ( 212 ) is mounted that rotates within a housing ( 214 ). The compressor inlet ( 216 ) is connected to the evaporator (not shown) which may be configured in a number of variations. As the gas to be compressed, which is called “refrigerant,” is drawn into the compressor by the rotation of the impeller, it must first pass through inlet vanes ( 218 ) which are segmented. The vanes are closed and opened by coordinated rotation of each segment around its central axis (shown as a vertical axis in FIG. 2 ). We call this rotational position the current vane position or setting. When closed, only a small hole in the center of the segments is open for gas to pass. When the vanes are set to open, virtually the entire inlet area is open. As the vanes begin to close from full-open; their coordinated movement causes the gas flowing by to be rotated in the direction of the rotation of the compressor impeller ( 212 ). This rotational movement of the gas entering the compressor impeller which is rotating in the same direction reduces the flow into and through the impeller. As the vanes continue to close, the vanes further reduce the flow of refrigerant into the compressor inlet by creating a pressure difference across the vanes. The impeller draws the gas in at low pressure and imparts energy to the gas to discharge it at a higher pressure in the volute ( 220 ) of the housing ( 222 ) where it is collected and routed to the condenser.
[0009] Variable speed compressors can reduce their operating capacity in two ways, first, by closing the inlet vanes as described above, and second, by slowing the speed of the compressor impeller. However, impeller rotational speed must always be maintained sufficiently high to maintain the flow of refrigerant gas through the impeller at the current pressure difference between the condenser and evaporator of the chiller. If the speed falls below a minimum speed that depends on this pressure difference across the impeller, the impeller will stall and flow will abruptly stop. The phenomenon in chillers is called “surging.” The impeller stalls and flow stops, this reduces the pressure difference and flow restarts only to stall again. Surging results in inefficient operation and can under some circumstances cause damage to elements of the compressor.
[0010] To ensure surging does not develop, the internal chiller or compressor controls of variable speed chillers incorporate some method of maintaining a minimum compressor speed that is usually based on the pressure across the impeller. When operating conditions require a certain pressure differential across the compressor (commonly called compressor “head”) such that the impeller speed cannot be reduced due to a risk of stalling and surging, and at the same time a lower capacity is required from the chiller, then instead of slowing the speed of the impeller to reduce capacity, the impeller is maintained at the appropriate minimum speed and the vanes are closed to reduce the capacity, sacrificing efficiency of the chiller.
[0011] There is a need for improvement in operating efficiency of systems of the type described above.
SUMMARY
[0012] As compressor inlet vanes close beyond a certain point, overall compressor efficiency is reduced due to losses caused by the effect of the vanes on the flow into the inlet of the compressor. In accordance with one aspect of the present invention, in a variable speed compressor, the vane settings and the compressor (impeller) speed are coordinated so as to maintain a desired cooling capacity at current compressor head conditions. The vanes are employed to reduce capacity when compressor speed cannot be reduced due to the risk of an impeller stall condition. According to another aspect of the present invention, namely, an improved method of compressor sequencing, a current setting of the compressor vanes is employed in the decision to add or shed compressors, or to add or shed chilling units with single compressors, so that overall system capacity is achieved with optimal efficiency.
[0013] Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a diagram that shows the basic elements of a centrifugal chiller.
[0015] FIG. 2 is a diagram that shows the elements of typical variable speed centrifugal compressors.
[0016] FIG. 3 depicts a simple compressor or chiller add and shed decision flow chart that reflects prior art.
[0017] FIG. 4 is an example of a decision flow chart that reflects an embodiment of the present invention.
[0018] FIG. 5 is a simplified block diagram of a chiller plant.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] Because chillers that provide chilled water for comfort conditioning or process cooling are normally subject to very wide variations in cooling loads, the ability to adjust capacity of individual chillers along with a method of sequencing chillers or compressors on and off line is employed to accommodate load changes and achieve efficient plant operation. In prior art, the control of the capacity of each individual chiller is accomplished by internal chiller or compressor controls that maintain a predetermined temperature of the chilled water leaving the unit.
[0020] The control of the number of chillers or compressors on line is dynamically accomplished by separate control algorithms, generally based on the loading or power draw of the online compressors. See my U.S. Pat. No. 6,185,946 in which sequencing is based on comparing current point of operation to the curve of optimal efficiency, called the natural curve, of the device. Other methods are known, but these known methods do not account for characteristics of the internal controls that may result in a variation of compressor speed and vane control such that a point of operation is actually less efficient than expected.
[0021] That is what is new and is the focus of this invention, the use of the inlet vane position of one or more of the online chiller compressors to operate, adjust, or modify the algorithm that is employed to reduce the number of online chillers.
[0022] It is known that all variable speed compressors have a property called a natural curve which is the curve of points of compressor capacity at which optimum compressor operating efficiency is achieved as a function of compressor head conditions. It is also known that the compressor head is a function of the chilled water and condenser water temperature and flow conditions and that the natural curve property can be applied to the entire chiller as a function of condenser water and chilled water temperature. Furthermore, it is known that the pumps, fans, and any other power consuming equipment typically incorporated into chiller plants also have natural curves. For optimal plant operation, the number and relative loading of chiller plant chillers, pumps, cooling towers, etc., depends not only on the plant loading, but also on the current operating conditions under which the plant must operate, most notably the ambient outdoor conditions to which the heat is rejected and the temperature at which the chilled water is supplied.
[0023] Using this information, it is possible to construct tables or algorithms that are applied to select the correct number of chillers to operate in the plant optimally under all possible load and external operating conditions. A detailed description of such an optimal chiller sequencing algorithm is provided in U.S. Pat. No. 6,185,946 B1. However, in some instances it is found that the internal controls of the chiller, or the compressors on the chiller, cause the compressor to act to conditions somewhat differently than may be expected. In such instances, actual points of operation may be less efficient than expected. In other instances the exact characteristics of the compressor (called a compressor map) are not available or are uncertain so that the natural curve of the compressor and therefore the chiller cannot be determined with certainty. While there may be a number of reasons for the compressors to operate differently than might be expected, the loss of efficiency in such situations is commonly caused by the internal controls of the compressor operating the speed of the compressor at a speed that is higher than expected, and the vanes of the compressor less open than expected. In such situations by monitoring the vanes, and in some instances the speed, of the operating compressors, then when the vanes are determined to be opened beyond a threshold value at a point at which a compressor or chiller would normally be added; similarly when the vanes are determined to be closed beyond a threshold value at a point at which the compressor or chiller would normally be shed, and using that information to automatically adjust the nominal algorithm controlling the adding or shedding of compressor and/or chiller stages in order to ensure plant operating efficiency is kept as high as possible. This is the new method of control that is the basis of this invention.
[0024] The present invention discloses a new means of adjusting and improving the optimized sequencing techniques discussed in prior art. In such art, the sequencing of chillers is intended to ensure the total energy use for the chillers and heat rejection systems is continuously optimized. Chillers are sequenced on and off to keep the on-line equipment operating at all times as close as possible to the natural curve of that equipment which is the point of highest operating efficiency at the load condition. With this new method, the previous methods can be more easily implemented and then automatically adjusted ensuring sequencing does result in optimum plant efficiency. Selection of the number of chillers or compressors online is aimed at maintaining the desired plant capacity while optimizing the overall energy use of the system.
[0025] A chiller sequencing flow chart for a plant employing one method (the natural curve method) of optimal chiller/compressor sequencing is shown in FIG. 3 the enhanced method using this invention is shown in FIG. 4 . FIG. 3 illustrates a portion of the logic used to control the adding and subtracting of chillers or compressors in response to changing operating conditions. In this case it is the natural curve method of sequencing chillers which is based on calculated head pressure fractions and other current operating factors where the head pressure fraction is the ratio of the average current compressor head pressures compared to the design maximum for the operating compressor(s). The head pressure fractions may also be developed directly from the condenser and evaporator refrigerant temperatures or from the condensing and chilled water temperatures. In FIG. 3 as the control logic is executed, the calculated compressor head pressure to add a compressor or chiller is made ( 312 ). This value is compared with the current head pressure fraction ( 314 ). If the calculation of the head pressure fraction of the existing system is greater than the current operating requirements, then a chiller or compressor is added to bring the system closer to its natural curve ( 318 ) and the remainder of the sequencing process is bypassed ( 320 ). If it is not, then the next step is to calculate the head pressure fraction to shed a chiller or compressor ( 340 ). This is then compared to the current operating head pressure fraction and if it is less than this current operating value, then a compressor or chiller is shed ( 346 ) before returning to the start of the process ( 348 ). If no action is taken during this execution of the program, then the process is ended and returned to start ( 354 ).
[0026] This present invention adds to the prior art with improvements to the decision process for adding or shedding chillers regardless of the basic approach to optimized sequencing. FIG. 4 is a chiller and/or compressor sequencing flow chart for a chiller plant consisting of multiple chillers and/or multiple compressors on each chiller wherein the natural curve sequencing method of FIG. 3 has been enhanced with the method disclosed in this new invention. As in prior art, the first step in the sequencing decision path is to calculate the current HPFA value ( 412 ) and to compare this value with the current HPF of the operating chillers and/or compressors to see if adding a compressor or chiller is desired. If the HPFA calculation is greater than the current HPF conditions, then it means the head conditions and capacity requirements are such that the online compressors are likely operating above their natural curves. In this operation, the compressors are at speeds above their most efficient for the current conditions to meet the capacity requirements. Thus, adding a compressor or chiller will reduce the speed requirements for each online compressor or chiller so the compressors will operate closer to their natural curve and plant efficiency will be improved.
[0027] If the value of HPFA is greater than that of HPF, indicating a need to add a chiller or compressor, then this invention adds a step before doing so. A check is made of the vane position ( 416 ). If the vane is substantially closed such that a loss of efficiency is occurring due to the vane restrictions, then the online compressors are shown to be operating at their restricted minimum speed and adding a chiller will only require additional vane closure to reduce the capacity of each. This would further reduce compressor operating efficiency. In this case, instead of initiating the chiller add sequence, this information is employed to apply a mathematical offset or adjustment to the calculations to decrease the HPFA and HPFS calculations in the future ( 422 ). However, if the vanes are substantially open beyond a point of reduced efficiency, then the chiller add sequence is initiated ( 418 ).
[0028] If the HPFA calculation is not larger than the current HPF value, then the program continues to the HPFS calculation ( 440 ), which is made and the result is compared to the current HPF value to see if a compressor or chiller shed action should be taken. If the HPFS calculation is less than the current HPF value, it means the online compressors are likely operating below their natural curves. At this operation, the online compressors are likely to be restricted by minimum speed, and their capacity is being controlled by closure of the inlet vanes. Thus, shedding a compressor or chiller will increase the capacity requirements for each online compressor or chiller so that vanes will open and plant efficiency will be improved by moving the operating point of the active chillers closer to their natural curve. However, with this invention, before shedding a chiller, a check is made of the vane position ( 444 ). If the vanes are already open such that they are not encumbering the compressors with a loss of efficiency, then the online compressors are shown not to be operating below their natural curve and are not restricted by minimum speed. In this event shedding a chiller will only require the compressor speed to be raised to serve additional capacity requirements of each and operate further below their natural curves, reducing compressor operating efficiency. In this case instead of initiating the chiller shed sequence, this information is employed to apply a mathematical offset or adjustment to the calculations to increase the HPFA and HPFS calculations in the future ( 450 ). However, if the vanes are substantially closed beyond a point of reduced efficiency, then the chiller shed sequence is initiated ( 446 ) before returning ( 452 ) to the start of the program ( 410 ) for the next execution cycle.
[0029] This is a simple embodiment of the invention. However, there are many other means of implementing this invention. For example, a nominal model of compressor speed and vane position may be continuously calculated and then compared with the actual values of the compressor speed and vane position to develop a “map” of each compressor and then the continuously updated map employed to ensure sequencing for optimal efficiency in a simple sequence flow similar to that shown in FIG. 3 .
[0030] The invention described above may be carried out by a digital computing system. By the term digital computing system we mean any system that includes at least one digital processor and associated memory, wherein the digital processor can execute instructions or “code” stored in that memory. (The memory may store data as well.) A digital processor includes but is not limited to a microprocessor, multi-core processor, DSP (digital signal processor), processor array, network processor, etc. A digital processor may be part of a larger device such as a laptop or desktop computer, a PDA, cell phone, iPhone PDA, Blackberry® PDA/phone, or indeed virtually any electronic device. In FIG. 9 , each of the display system, the presence detector and the web server comprises a digital computing system.
[0031] The associated memory, further explained below, may be integrated together with the processor, for example RAM or FLASH memory disposed within an integrated circuit microprocessor or the like. In other examples, the memory comprises an independent device, such as an external disk drive, storage array, or portable FLASH key fob. In such cases, the memory becomes “associated” with the digital processor when the two are operatively coupled together, or in communication with each other, for example by an I/O port, network connection, etc. such that the processor can read a file stored on the memory. Associated memory may be “read only” by design (ROM) or by virtue of permission settings, or not. Other examples include but are not limited to WORM, EPROM, EEPROM, FLASH, etc. Those technologies often are implemented in solid state semiconductor devices. Other memories may comprise moving parts, such a conventional rotating disk drive. All such memories are “machine readable” in that they are readable by a suitable digital processor as further explained below for the benefit of the USPTO.
[0032] This invention may be implemented or embodied in computer software (also known as a “computer program” or “code”; we use these terms interchangeably). Programs, or code, are most useful when stored in a digital memory that can be read by a digital processor. We use the term “computer-readable storage medium” (or alternatively, “machine-readable storage medium”) to include all of the foregoing types of memory, as well as new technologies that may arise in the future, as long as they are capable of storing digital information in the nature of a computer program or other data, at least temporarily, in such a manner that the stored information can be “read” by an appropriate digital processor. By the term “computer-readable” we do not intend to limit the phrase to the historical usage of “computer” to imply a complete mainframe, mini-computer, desktop or even laptop computer. Rather, we use the term to mean that the storage medium is readable by a digital processor or any digital computing system. Such media may be any available media that is locally and/or remotely accessible by a computer or processor, and it includes both volatile and non-volatile media, removable and non-removable media.
[0033] Where a program has been stored in a computer-readable storage medium, we may refer to that storage medium as a computer program product. For example, a portable digital storage medium may be used as a convenient means to store and transport (deliver, buy, sell, license) a computer program. This was often done in the past for retail point-of-sale delivery of packaged (“shrink wrapped”) programs. Examples of such storage media include without limitation CD-ROM and the like. Such a CD-ROM, containing a stored computer program, is an example of a computer program product.
[0034] It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present invention should, therefore, be determined only by the following claims. | An improved method for sequencing variable speed centrifugal compressors on and off line to ensure optimal operating efficiency in a liquid cooling system under all operating circumstances is described. The present disclosure teaches modifying equipment sequencing decisions (to add or shed a unit), based in part on the position of the compressor inlet vanes. This new approach achieves improved energy efficiency of the overall system by taking into account operating conditions of individual compressors or chillers that may be sub-optimal. | 5 |
FIELD OF THE INVENTION
The present invention generally relates to temperature sensitive paints. More particularly, the invention relates to temperature sensitive paints comprising a binder for forming a polymer matrix and a probe substance embedded in the binder which displays a temperature dependent fluorescence. Even more particularly, the invention relates to a temperature sensitive paint which forms a solid coating when applied to a surface, and which allows for measuring the temperature at the surface by measuring the present intensity of fluorescence light emitted by the probe substance when excited for fluorescence by excitation light typically having a shorter wave length than the fluorescence light. Due to the fluorescence depending on the temperature, the actual intensity of the fluorescence light represents to the actual temperature at the surface coated with the temperature sensitive paint.
BACKGROUND OF THE INVENTION
A temperature sensitive paint comprising a binder for forming a polymethylene methacrylate matrix and a rare earth complex as a probe embedded in the binder which displays a temperature dependent fluorescence is known from U.S. Pat. No. 5,971,610. The full disclosure of this patent is incorporated herein by reference. The particular rare earth complexes disclosed in U.S. Pat. No. 5,971,610 as temperature probes include Eu(tfc) 3 and Eu(hfc) 3 complexes. An alternative binder mentioned in U.S. Pat. No. 5,971,610 is polystyrene. The fluorescence of the rare earth complexes according to U.S. Pat. No. 5,971,610 shows a maximum relative temperature sensitivity within a temperature range of about 100 to 160 Kelvin. It is told that between Eu(tfc) 3 and Eu(hfc) 3 complexes, the entire temperature range of 30 to 300 Kelvin can be covered. None of the disclosed temperature sensitive paints however, can cover this temperature range alone.
The basic procedure according to U.S. Pat. No. 5,971,610 of using the disclosed temperature sensitive paint is applying the paint to a surface of an electronic device and to obtain power-on and power-off fluorescence images of the coated device with the device being powered or not. A variation of this basic technique employs a paint which emits radiation at two wavelengths with quantum yields that depend differently on temperature. Here, the ratio of the image made at the two different wavelengths yields a correctly normalized temperature map without the need to acquire images at two power levels. This method requires that the radiation emitted at both wavelengths is emitted at the same time, i.e. at the same temperature.
A temperature sensitive paint comprising a binder for forming a polyurethane matrix and a transition metal complex embedded in the binder displaying a temperature dependent fluorescence is known from US 2005/0040368 A1. The full disclosure of this patent application is also incorporated herein by reference. The transition metal complex used as a temperature probe is a ruthenium complex, particularly a Ru(trpy) complex. The temperature sensitive paint known from US 2005/0040368 A1 is particularly suitable for use on the surfaces of models in cryogenic wind tunnels. It displays an usable temperature sensitivity in the temperature range of about 100 to 240 Kelvin. However, the fluorescence light intensity of the known temperature sensitive paint rapidly becomes very weak, when the temperature rises to more than 230 Kelvin. As a result, temperature measurements in a range above 230 Kelvin are actually impossible when employing this known temperature sensitive paint.
Thus, there is a need for a temperature sensitive paint suitable for use in cryogenic wind tunnels which allows for measuring temperatures at the surface of a model in such a wind tunnel within an extended temperature range.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a temperature sensitive paint comprising a binder for forming a polymer matrix, a transition metal complex embedded in the binder and displaying a temperature dependent fluorescence, the fluorescence of the transition metal complex showing a maximum relative temperature sensitivity at a first temperature, and a rare earth complex also embedded in the binder and displaying a temperature dependent fluorescence, the fluorescence of the rare earth complex showing a maximum relative temperature sensitivity at a second temperature, the second temperature being higher than the first temperature by 50 to 150 Kelvin.
The relative temperature sensitivity is the percentage of a change in the fluorescence light intensity per Kelvin change in temperature under otherwise unchanged conditions.
The difference in the temperatures of maximum relative temperature sensitivity also result in a difference of the maximum temperatures at which the two temperature probes still emit fluorescent light at a sufficient intensity to be evaluated. The temperature probe having the higher temperature of maximum relative temperature sensitivity also has a higher maximum temperature at which it still emits enough fluorescent light to be evaluated.
In the temperature sensitive paint according to the invention, the second temperature is typically higher than the first temperature by 60 to 120 Kelvin. Thus, the extension of the temperature range covered by the temperature sensitive paint according to the invention is maximized without a gap of temperature sensitivity being formed between the temperature subranges of both temperature probes.
Preferably, the transition metal complex in the temperature sensitive paint according to the invention is rare transition metal complex, and even more preferably it is a ruthenium complex. Most preferably, it is a Ru(trpy) complex. At the same time the rare earth complex in the temperature sensitive paint according to the invention preferably is a europium complex. Most preferably, it is an Eu(tfc) 3 or an Eu(hfc) 3 complex.
With these particular ruthenium and europium complexes, for example, fluorescence light emitted by the transition metal complex and fluorescence light emitted by the rare earth complex have essentially same wavelengths. At least both wavelengths of the fluorescence lights can be registered by a single sensor comprising a narrow bandwidth filter.
Nevertheless, both probes in the temperature sensitive paint according to the invention can be measured, i.e. excited for fluorescence, separately, as an excitation light range for exciting the fluorescence of the transition metal complex and an excitation light range for exciting the fluorescence of the rare earth complex have different wavelengths when using the above mentioned ruthenium and europium complexes, for example.
Vice versa, the two probes in the temperature sensitive paint according to the invention can also be measured separately, if fluorescence light emitted by the transition metal complex and fluorescence light emitted by the rare earth complex have distinguishable wavelengths. In this case, an excitation light range for exciting the fluorescence of the transition metal complex and an excitation light range for exciting the fluorescence of the rare earth complex may comprise same wavelengths at which both complexes can be excited simultaneously.
The binder of the temperature sensitive paint according to the invention preferably forms a polyurethane matrix. Such a polyurethane matrix is advantageously suited for use under cryogenic conditions in wind tunnels.
In a further aspect, the present invention provides a temperature sensitive paint comprising a binder for forming a polyurethane matrix, a Ru(trpy) complex which is embedded in the binder and displays a temperature dependent fluorescence, the fluorescence of the transition metal complex showing a maximum relative temperature sensitivity at a first temperature, the Ru(trpy) complex serving as a first temperature probe in a first temperature range about the first temperature, and a europium complex selected from an Eu(tfc) 3 complex and an Eu(hfc) 3 complex which is also embedded in the binder and displays a temperature dependent fluorescence, the fluorescence of the rare earth complex showing a maximum relative temperature sensitivity at a second temperature, the europium complex serving as a second temperature probe in a second temperature range about the second temperature, the second temperature being higher than the first temperature by 60 to 120 Kelvin, fluorescence light emitted by the transition metal complex and fluorescence light emitted by the rare earth complex having essentially same wavelengths, and an excitation light range for exciting the fluorescence of the transition metal complex and an excitation light range for exciting the fluorescence of the rare earth complex having different wavelengths.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and the detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention, as defined by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified cross section through a layer of the temperature sensitive paint according to the invention located on a screen layer on a surface of a model to be placed in a cryogenic wind tunnel.
FIG. 2 is a structural formula of a ruthenium complex to be used in the temperature sensitive paint according to the invention.
FIG. 3 is a structural formula of a first europium complex to be used in the temperature sensitive paint according to the invention.
FIG. 4 is a structural formula of an optical isomer of the europium complex shown in FIG. 3 which is also suitable for use in the temperature sensitive paint according to the invention.
FIG. 5 is a structural formula of another europium complex for use in the temperature sensitive paint according to the present invention.
FIG. 6 is an optical isomer of the europium complex according to FIG. 5 which is also suitable for use in the temperature sensitive paint according to the present invention.
FIG. 7 shows the excitation and emission spectra of a first embodiment of the temperature sensitive paint according to the present invention using the complexes according to FIGS. 2 and 5 .
FIG. 8 shows the excitation and emission spectra of the temperature sensitive paint according to the invention comprising the complexes of FIGS. 2 and 3 .
FIG. 9 is a plot of the intensity changes of fluorescence light from the complexes according to FIGS. 2 , 3 and 5 by temperature; and
FIG. 10 is a plot of the relative temperature sensitivity of the complexes according to FIGS. 2 , 3 and 5 by temperature.
DETAILED DESCRIPTION
In a typical measurement campaign in cryogenic wind tunnels, the tunnel temperature is decreased from 300 K down to 100 K according to the Reynolds number selected for the actual experiment. The operation of the wind tunnel becomes more expensive for the lower temperatures because more liquid nitrogen is permanently needed for cooling. Therefore, all system checks are performed at ambient temperatures (around 300 K) before cooling down. With a single probe temperature sensitive paint it is not possible to both check the temperature measurement arrangement at ambient temperature and use it at cryogenic temperatures. If the single probe temperature sensitive paint is tuned to the cryogenic temperature range, possible failures of the temperature measurement setup can only be detected after cooling the wind tunnel down, and additional adjustment or repair requires warming the complete wind tunnel up, resulting in a long and expensive delay. Furthermore, in a typical measurement campaign data for lower Reynolds numbers (for example Reynolds numbers in the range from 1 Million to 5 Million) is gathered as well as for high Reynolds numbers (for example in a range of 5 Million to 30 Million). This requires operation of the wind tunnel and temperature measurements in a large temperature range.
Referring now in greater detail to the drawings, FIG. 1 illustrates an active layer 1 of the temperature sensitive paint 2 according to the invention which comprises two different probes 3 and 4 for measuring temperatures in an extended temperature range. The probes 3 and 4 are ruthenium and europium complexes. In the cured layer 1 shown in FIG. 1 , both complexes are embedded in a polyurethane matrix 5 which has been formed by a binder upon curing of a liquid binder. This binder may for example be the polyurethane top coat Aerodur® Clearcoat UVR, available from Akzo Nobel Areospace Coatings of Waukegan, Ill., USA, which may be used according to the supplier's recommendations. The layer 1 has been applied to a screen layer 6 providing a uniformly colored background for the temperature sensitive paint 2 on a surface 7 of a model 8 to be placed in a wind tunnel. Neither the model 8 nor the layers 1 and 6 are depicted completely here. The screen layer 6 has a typical thickness of about 60 μm whereas the layer 1 of the temperature sensitive paint 2 has a typical thickness of 40 μm. For measuring the temperature using the probes 3 and 4 in the layer 1 , excitation light 9 is used to excite the probe 3 for fluorescence, and excitation light 10 having a different wavelength than the excitation light 9 is used for exciting the probe 4 for fluorescence. Both the intensities of fluorescence light 11 from the excited probe 3 and of fluorescence light 12 from the probe 4 change with changes of the temperature at the surface 7 . Thus, by comparing the actual intensities of the fluorescence light 11 and the fluorescence light 12 with their intensities at a known temperature, the actual temperature at the surface 7 can be determined.
The two different probes 3 and 4 in the temperature sensitive paint according to the invention extend the temperature range in which the temperature at the surface 7 can be measured by means of the intensity of the fluorescence light 11 and the fluorescence light 12 . To this end, the probes 3 and 4 are selected in such way that they display ranges of useable relative temperature sensitivity following each other with decreasing or increasing temperature, and only showing a minor overlap.
Generally, the probe 3 is a transition metal complex. Preferably it is a ruthenium complex, and most preferably it is the ruthenium complex which structural formula is shown in FIG. 2 . This ruthenium complex is Di(tripyridyl)ruthenium(II) (Ru(trpy) 2 2+ ). This ruthenium complex is, for example, commercially available from GFS Chemicals, Inc. of Powell, Ohio, USA as bis-(2,2′-2″-terpyridine)ruthenium(II)chloride (item #2377).
The probe 4 generally is a rare earth complex. Preferably it is a europium complex, and most preferable it is one of the following complexes:
Europium tris[3-(trifluoromethylhydroxymethylene)-(+)-camphorate] (denoted here as Eu(tfc) 3 ), Europium tris[3-(trifluoromethylhydroxymethylene)-(−)-camphorate] (optical isomer of Eu(tfc) 3 ), Europium tris[3-(heptafluoropropylhydroxymethylene)-(+)-camphorate] (denoted here as Eu(hfc) 3 ), and Europium tris[3-(heptafluoropropylhydroxymethylene)-(+)-camphorate] (optical isomer of Eu(hfc) 3 ).
The following table 1 further specifies these europium complexes which may be used as a probe 4 in the temperature sensitive paint 2 of FIG. 1 . Table 1 also indicates which figure shows the structural formula of the respective europium complex.
TABLE I
Europium tris[3-(trifluoromethylhydroxymethylene)-(+)-camphorate]
Synonyme:
Eu(facam) 3
Eu(tfc) 3
Europium(III) tris[3-(trifluoromethylhydroxymeth-
ylene)-d-camphorate]
Tris(3-trifluoroacetyl-d-camphorato)europium(III)
Tris[3-(trifluoromethylhydroxymethylene)-d-
camphorato]europium(III)
Molecular Formula:
C 36 H 42 EuF 9 O 6
Molecular Weight:
893.66
Structural Formula:
FIG. 3
Europium tris[3-
(trifluoromethylhydroxymethylene)-(−)-camphorate]
Molecular Formula:
C 36 H 42 EuF 9 O 6
Molecular Weight:
893.66
EG/EC Number:
2522329
Structural Formula:
FIG. 4
Europium tris[3-
(heptafluoropropylhydroxvmethylene)-(+)-camphorate]
Synonyme:
Eu(hfc) 3
Europium(III) tris[3-(heptafluoropropylhydroxy-
methylene)-d-camphorate]
Tris[3-(heptafluoropropylhydroxymethylene)-d-
camphorato]europium(III)
Molecular Formula:
C 42 H 42 EuF 21 O 6
Molecular Weight:
1193.71
CAS Number:
34788-82-4
EG/EC Number:
2522140
Structural Formula:
FIG. 5
Europium tris[3-
(heptafluoropropylhydroxymethylene)-(−)-camphorate]
Synonyme:
Europium(III) tris[3-(heptafluoropropylhydroxy-
methylene)-l-camphorate]
Tris[3-(heptafluoropropylhydroxymethylene)-l-
camphorato]europium(III)
Molecular Formula:
C 42 H 42 EuF 21 O 6
Molecular Weight:
1193.71
Structural Formula:
FIG. 6
Whereas the excitation light 9 for the ruthenium complex according to FIG. 2 as the probe 3 has a typical wavelength of 480 nm, the typical wavelength of the excitation light 10 for the europium complexes listed above is 325 nm. This difference in the wavelengths of the excitation light 9 and the excitation light 10 allows for selectively exciting the probes 3 and 4 for fluorescence. I.e. at 325 nm only the probe 4 is excited, and at 480 nm only the probe 3 is excited. The fluorescence light 11 und 12 from both probes 3 and 4 , however, have about same wavelengths. This can be seen from the excitation and emission spectra shown in FIG. 7 and FIG. 8 . The fluorescence light 11 and 12 from both probes 3 and 4 can thus be registered by a same sensor, i.e. a single camera/filter combination sensitive in a range of about 600 to 625 nm. By illuminating the temperature sensitive paint at different wavelengths, the probes 3 and 4 in the temperature sensitive paint can selectively be used to measure the temperature. The ruthenium complex used as the probe 3 is particularly suited for temperatures up to 230 Kelvin. This temperature range is limited towards high temperatures by the remaining small absolute intensity of the fluorescence light 11 which falls below suitable limits at high temperatures, see FIG. 9 . The relative temperature sensitivity of the ruthenium complex only reaches its maximum at about 240 Kelvin (see FIG. 10 ). In the temperature range beginning at about 210 to 230 Kelvin, the europium complexes employed as the probe 4 in the temperature sensitive paint according to the invention both display a suitable relative temperature sensitivity (see FIG. 12 ), and still provide a sufficient intensity of the fluorescence light 12 up to a temperature of 270 to 300 Kelvin (depending on the actual europium complex, see FIG. 9 ).
Many variations and modifications may be made to the preferred embodiments of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of the present invention, as defined by the following claims. | A temperature sensitive paint comprises a binder for forming a polymer matrix, a transition metal complex embedded in the binder and displaying a temperature dependent fluorescence, the fluorescence of the transition metal complex showing a maximum relative temperature sensitivity per Kelvin at a first temperature, and a rare earth complex also embedded in the binder and displaying a temperature dependent fluorescence, the fluorescence of the rare earth complex showing a maximum relative temperature sensitivity per Kelvin at a second temperature. The second temperature is higher than the first temperature by 50 to 150 Kelvin so that the overall temperature range covered by both complexes as temperature probes is extended. | 2 |
TECHNICAL FIELD
[0001] This invention relates to an energy absorption device for installation under the body of a vehicle to protect the vehicle and occupants from explosive forces caused by the detonation of a bomb, such as an improvised explosive device (IED). Hydraulic dampers combined with a blast deflecting-shaped hull absorb and redirect blast energy absorb away from the vehicle.
BACKGROUND
[0002] Improvised explosive devices (IEDs) may be bombs fabricated in an improvised manner from other explosive devices, such as an artillery shell. These devices may incorporate explosive materials, as well as fragmentation materials. IEDs may be remote controlled and/or triggered by infrared detectors, pressure bars, trip wires, and/or other suitable devices. Mines may be explosive devices placed on or in the ground. When in the ground, these mines may be referred to as land mines. These types of mines may be triggered by an operator and/or by the proximity of a vehicle, person, animal, and/or some other suitable object. The term IED may be inclusive of both improvised explosive devices as well as land mines.
[0003] IEDs may target the underside of conventional ground vehicles and armored vehicles. Various counter-measures may be employed to reduce and/or eliminate threats from IEDs. Some counter-measures include electronic jamming devices that may prevent the ignition of remotely controlled IEDs. These electronic counter-measures, however, may be ineffective against IEDs that use trip wires or other non-wireless trigger mechanisms, such as pressure switches used in land mines. Chemical detection may in some cases be successful in locating an IED. Although these and other counter measures may be useful in preventing the triggering of IEDs and/or detecting IEDs, these explosive devices may still detonate regardless of the precautions in place.
[0004] As a result, structures may be employed on the underside of vehicles to protect against pressures and forces generated when an IED explodes. These structures may take the form of blast plates. These blast plates can in some cases mitigate the effects of the explosive pressure and/or fragments to the occupants of a vehicle. These blast plates may be fabricated using armor similar to that used on the sides of armored personnel carriers and tanks. Likewise, it is known to design the plate with a V-shape in an attempt to redirect explosive forces outward and away from the underside of the vehicle.
[0005] Another problem is that extra weight reduces the fuel efficiency of a vehicle and increases operating costs. Further, the weight may increase the strain on other components of the vehicle resulting in more maintenance being performed. The weight of the blast plates also may reduce the acceleration, maneuverability, and/or performance of the vehicle during travel. V plates with steep V shapes can greatly reduce the ground clearance of the vehicle, thus diminishing vehicle performance. As such, it would be advantageous to have a shallow V shape that performs as well as a steep V design while preserving as much of the original vehicle ground clearance as possible.
[0006] Therefore, it would be advantageous to have a device that takes into account one or more of these issues, as well as possibly other issues.
SUMMARY
[0007] The present invention combines energy absorption and deflection in order to provide ground vehicle occupant protection and increased survivability in the event of an underbody explosive blast, especially those caused by improvised explosive devices (IEDs). Energy adsorption is accomplished by the use of one or more dampening systems in combination with an energy deflecting V-shaped hull design. The blast shield of this invention can be installed on the underbody of a ground vehicle, for example, a Humvee.
[0008] One advantageous embodiment of the present invention is a blast shield comprising a blast resistant panel, for example armor plating, having a left side edge, a right side edge, a front end, a rear end, a top surface and a bottom surface. An beam having a top and a bottom is connected to the top surface of the panel to form a V-shaped hull, preferably using a bolted connection and without using welds. A pair of dampers is positioned adjacent to and on either side of the beam with each damper having a bottom portion and a top portion. The bottom portion of the damper is in contact with the top surface of the panel and the top portion is adjacent to a channel cap connected to the top of the beam. The panel may also comprise two or more panels connected together without the use of welds to form the preferred V-shaped hull configuration. A preferred beam construction is one that has a cross-section in the shape of an “I,” sometimes referred to as an “I-beam,” however, beams having a different cross-section can be used.
[0009] Yet another advantageous embodiment of the present invention comprises a blast shield that uses a V-shaped hull fabricated with only bolted and braced connections and no welds. The absence of welds allows each of the materials of construction to retain its full inherent mechanical strength. A dampening system is positioned mechanically in series between the armor plate and the support structure that defines the V-shaped hull. The rigid armor plate or plates deflect the blast energy while the dampening system simultaneously absorbs this energy by taking advantage of the inertia differential between the blast shield acting on one side and the vehicle weight acting on the opposite side, thus creating the required displacement in the dampers to absorb the blast energy.
[0010] Another advantageous embodiment comprises a modular design with a fully bolted construction that allows ease of integration into retrofit kits for legacy vehicles and also can be integrated into clean sheet design for ground combat vehicles. This modular design includes the use of surface or connection bars that allow the blast shield to be fastened to the frame of the vehicle. The surface bars also provide rigid longitudinal support for the blast shield and are positioned along the right and left side edges of the panel. A crushable and compressible energy absorbing material can be sandwiched between the top surface of the panel and the bottom of the surface bar. Additionally, this deformable material can be used between truss ribs and the top surface of the panels and between end caps and the beam located on the centerline of the blast panel.
[0011] Another advantageous feature of the present invention is that the dampening system can be tuned for a desired energy absorption taking into account the specifics of the vehicle and the expected types of IEDs. Tuning can be achieved by changing the configuration of the internal components of the dampers, including, for example, changing the number adjustable orifices, the orifice size, or the type of working fluid. The use of the dampening system is believed advantageous because blast energy will first be absorbed by the dampening system before absorption by the armor blast plates.
[0012] Yet another advantageous embodiment of the blast shield of this invention includes the use of a plurality of truss ribs connected to the top surfaces of the panel and positioned to define a plurality of channels extending outward from the beam. Preferably, the channels house the dampening system of the present invention, where each channel can hold a damper contained between two adjacent ribs and covered by a channel cap, where the channel cap is connected to two adjacent truss ribs. The channel caps can be attached, preferably by screws or bolts, to the top of the beam.
[0013] Another advantageous embodiment includes a dampening system comprising a plurality of hydraulic dampers having a slidable piston within a reservoir, where the reservoir is filled with a working fluid, preferably a viscous fluid, for example, grease. A hollow cylinder portion of the damper defines the reservoir within the cylinder wall. The top portion of the damper preferably comprises a deformable shock absorbing material that in a first state will securely contact the damper to the channel cap and in a second state will fragment and collapse in response to a blast event. The bottom portion of the damper can be wedged shaped and comprise the same or different deformable shock absorbing material used to form the top portion. The damper piston has one or more orifices to allow the working fluid to flow out of the reservoir when the cylinder and piston slide relative to each other. The piston can also be hollow defining a lower reservoir having a moveable seal that can be biased by a compression spring configured to keep the working fluid trapped within the lower reservoir and to allow the dampers to be filled with the working fluid. The orifices also allow the dampers to be bled to remove trapped air. The spring can be configured with enough compression force to return the movable seal to a starting position after compression.
[0014] In yet another advantageous embodiment the blast shield comprises two end caps, one end cap is connected to the front end of the blast panel and the other end cap is connected to the rear end of the panel, where a deformable material is disposed between each end cap and the beam.
[0015] Another advantageous embodiment of the present invention is the inclusion of a second dampening system where a second plurality of dampers are used to absorb blast energy that causes the side edges of the panel to pull inward towards the beam during an explosive evident. As the blast forces are directed upwards against the bottom side of the blast panel the panel is deformed into a so-called “gull wing” shape where the top surface on either side of the beam deflects upwards towards the vehicle causing each side of the panel to pull inwards toward the beam. To diminish the effect of this retraction of the side edges, the panel can include a longitudinal slot or opening along each edge. Further, each surface bar can include one or more downwardly extending lugs that project into openings or slots located intermittingly along the panel edges. A plurality of hydraulic dampers can be positioned in these slots and in contact with the lugs such that the dampers absorb the forces causing the inward movement of the panel edges These dampers can be the same or similar in design to the dampers described above.
[0016] The present invention also includes a method of protecting the occupants of a vehicle from a blast event by providing a shield having one or more blast resistant panels connected to a beam where the top surface of the panel has opposing connection points, preferably along each side edge, for attaching the shield to the vehicle, preferably to the underneath of the vehicle and most preferably to the vehicle frame. The panel is connected to the panel to form a hull that directs blast forces away from the vehicle. A dampening system is coupled to the top surface of the panel(s) preferably such that at least a pair of dampers is positioned adjacent to and on either side of the beam. During a blast event the shield transforms from a pre-blast event state to a post-blast event state. This transformation caused to distance between the opposing connection points to move closer together. Stated differently, the opposing connection points are closer together in the post-blast state of the shield as compared to the pre-blast state. The method also results in one or more dampers moving from an uncompressed state to a compressed state when the shield transforms from a pre-blast event state to a post-blast event state.
[0017] The features, functions, and advantages that have been discussed can be achieved independently in various embodiments or may be combined in yet other embodiments further details of which can be seen with reference to the following description and drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0018] The present invention will become more fully understood from the more detailed description presented below and the accompanying drawings which are presented by way of illustration only, and thus, are not limitations of the present invention, and wherein:
[0019] FIG. 1 illustrates one possible advantageous embodiment of the present invention attached to the underbody of a ground vehicle;
[0020] FIG. 2 schematically illustrates a perspective view of one advantageous embodiment of the blast shield of the present invention; and
[0021] FIG. 3 presents a close up partial perspective view of the advantageous embodiment of the blast shield illustrated in FIG. 2 ;
[0022] FIG. 4 illustrates a perspective view of one embodiment of the damper of the present invention;
[0023] FIG. 5 illustrates a cross-sectional perspective view of one embodiment of the damper of the present invention;
[0024] FIG. 6 illustrates a close-up perspective of a side edge of one possible embodiment of the present invention using a second dampening system; and
[0025] FIG. 7 illustrates a close-up perspective of a side edge of one possible embodiment of the present invention using a second dampening system viewed from the bottom of the blast shield.
[0026] Corresponding parts are marked with the same reference symbols in all figures.
DETAILED DESCRIPTION
[0027] Referring now to the drawings illustrating possible embodiments of the present invention, FIG. 1 shows a blast shield 1 of the present invention connected to the underbody 101 of a ground vehicle 100 . Preferably, the blast shield system is bolted directly to the vehicle frame.
[0028] Ground vehicle 100 may take various forms, for example, without limitation, it may be a high mobility multi-purpose ground vehicle, a tank, an armored personnel carrier, a car, a truck, or some other suitable type of ground vehicle. Although a ground vehicle is shown, different advantageous embodiments may be applied to other vehicles, such as winged or rotor aircraft, naval vehicles, or even prefabricated temporary buildings.
[0029] FIG. 2 illustrates blast shield 1 as viewed from the top or looking downward from the vehicle underbody to which it is configured for attachment. A close-up cross sectional view of shield 1 is presented in FIG. 3 . A blast plate or panel 2 is shown connected to beam 5 , illustrated as an I-beam, through connections 3 , preferably using bolts, screws, or other removable connectors. As alternative to the I-beam illustrated, beam 5 can have a different shape and cross-section, for example a hat-shaped beam, or can be any other structural support member that provides multiple attachment points for one or more panels 2 . Preferably, welded connections are not used in order to preserve the mechanical strength properties of the panel and to allow for a modular construction design. Panel 2 is preferably a single sheet of blast proof armor and may be comprised of any material suitable for deflecting and/or absorbing blast energy. For example, without limitation, blast panel 2 may be comprised of a metallic material, aluminum, titanium, steel, a steel alloy, a ceramic material, a composite material, and/or some other suitable material. The panel may have multiple layers of these mentioned materials, a single layer of a selected material, and/or some other suitable configuration. When a single panel is used it preferably has a non-planar shape design to direct blast forces outwardly away from the centerline of the panel where beam 5 is preferably connected.
[0030] Panel 2 and beam 5 are connected through connectors 3 to form a V-shaped hull where the right and left sides of the panel project upwardly at angle Θ, which preferably is less than 90 degrees and more preferably in the range of from about 10 degrees to about 20 degrees upwardly from horizontal. (see FIG. 2 ). In alternative embodiments of the present invention the right and left sides may comprise individual panels that are joined together through connection to I-beam 5 . Attached to the front and rear ends of panel 2 are end caps 7 connected through connectors 13 . Truss ribs 9 are connected to panel 2 through connector lugs 11 and can be interconnected to each other through cross supports 33 . Ribs 9 extend outwardly from beam 5 and are positioned in adjacent rows transverse to the beam 5 and the centerline 300 , preferably forming an approximate right angle with respect to the centerline, although the ribs may form non-right angles with respect to the centerline and still perform their intended function. Each pair of adjacent ribs forms a channel 9 a. Channels 9 a are partially covered with a channel cap 8 that is connected to the top of beam and to the adjacent ribs. The ribs are preferably fabricated to match the shape of panel 3 , preferably having angled bottom edges 9 b matching angle Θ.
[0031] Each side edge of panel 2 has connecting or surface bars 10 that allow blast shield 1 to connect through connectors 11 to the underbody 101 of vehicle 100 . Positioned between surface bars 10 and the edge of panel 2 is a destructible and deformable material 12 . The same or like deformable material 12 and 14 can also be positioned between the bottom edge 9 b of ribs 9 and the top surface 2 a and between end caps 7 and beam 5 , respectively. The destructible and deformable material can be selected from a group of materials that will crush in a blast event allowing displacement of the components on either side of the material, which also allows displacement of a dampener system. The dampening system comprises a plurality of dampers 30 that are configured to absorb additional blast energy at the same time as the deformable material. Preferably, the deformable material is stiff enough to allow rigid attachment of the armor structure to the vehicle, but soft or yielding enough to allow inertia to move the V-shaped hull relative to the center structure during a blast event. Suitable deformable materials could include polyurethanes, aluminum foam, or combinations of these or like materials.
[0032] The dampening system of the present invention can comprise two separate systems. On system comprising a plurality of dampers 30 located in the channels 9 a formed by adjacent ribs 9 and located underneath channel caps 8 . The second dampening system, as discussed in more detail below, comprises a plurality of dampers 60 positioned in a slot 36 on the side edges of panel 2 . FIG. 3 shows a pair of dampers 30 arranged adjacent to beam 5 and positioned on either side of the beam. Multiple dampers can be positioned along the length of the centerline 300 , preferably having a damper in each channel 9 a and on each side of the beam 5 . FIGS. 4 and 5 illustrate a preferred damper design. Piston 34 is slidable within cylinder 33 . The top portion 32 of the damper is a cushion, preferably comprising a soft material, such as plastic, that isolates the rigid cylinder 33 from extreme shock loads, e.g., a metal on metal contact during a blast event. Although the exemplified dampers described here and shown in the figures are hydraulic dampers, other damper designs could be used, for example, those based on one or more springs, compressible materials, frangible materials, or designs that may incorporate a combination of such materials with hydraulic and/or spring features.
[0033] FIG. 5 shows the internals of a preferred damper design. A reservoir 35 is defined by the upper surface of the cylinder 33 , the cylinder walls and top surface 37 of piston 34 . Grease or other viscous working fluid 50 is contained in reservoir 35 . The top 37 of piston 34 may have one or more adjustable orifices 36 having orifice channels 38 . The adjustable orifices can allow the working fluid to flow from the reservoir 35 to a lower reservoir 39 upon compression of damper 30 during a blast event. This restricted flow of the working fluid provides the energy absorbing dampening effect of the dampening systems of the present invention. The adjustable orifices 36 can be configured to allow the dampening system to be tuned during the manufacturing process to allow the blast shield 1 to be used for different structures on different vehicles. Seals 45 , for example, piston rings, allow piston 34 to slide relative to cylinder 33 while preventing the working fluid 50 from leaking out of reservoir 35 . A return spring 40 can be used in conjunction with bladder umbrella seal 41 to trap any of the working fluid passing through orifices 36 . This combination of spring and bladder seal can allow the dampers to be filled and bled and/or to return the working fluid into reservoir 35 after compression.
[0034] In a preferred arrangement, each dampener 30 is provided with a bottom portion 15 made of the same cushion material as the top portion 31 or of the deformable material 32 . The bottom portion can be directly connected to the dampener 30 or be a separate component that is position on the top surface 2 a of panel 2 directly under the damper 30 . In ether case it is preferred that the bottom portion 15 is wedge shaped matching angle Θ. This allows the damper to be positioned vertically plum relative to the horizontal.
[0035] Referring again to FIGS. 2 and 3 , during an explosive event that occurs underneath the blast shield 1 , blast energy is directed upward against the bottom surface 2 b of panel 2 causing the right and left sides of the panel to bow or deflect upwards in the direction shown by arrows 20 a and 20 b. This deflection of the panel causes a gull wing shape because the rigid beam 5 resists upward movement. As the right and left portions of panel 2 move upwards, the sides of the panel are simultaneously pulled inwards towards the centerline 300 in the direction shown by arrows 21 a and 21 b. To minimize the effect of this inward pulling and the strain placed on connecting bars 10 and underbody 101 , a second dampening system can be used.
[0036] The optional second dampening system is shown in FIGS. 6 and 7 where one side edge of panel 2 is shown having a slot or opening 76 . FIG. 7 shows a view from looking up from the ground at the bottom side of panel 2 . One of a plurality of cut outs 90 in the blast panel is shown along with a plurality of connection points or holes 11 a that are shaped to allow lateral movement of the blast shield in the direction of arrow 77 relative to the vehicle body and connectors 11 . Surface bar 10 has a lug 75 extending downward into slot 36 of cut out 90 and has an inner wall 54 and outer wall 53 that is tapered to provide support for the second dampening system. The optional second dampening system can comprise a plurality of dampers 60 that are positioned in space 52 formed between inner wall 54 and wall 55 of panel 2 . As panel 2 is pulled in the direction shown by arrow 77 during a blast event the dampers 60 will compress as space 52 decreases and will absorb and dampen the blast energy. Dampers 60 are preferably of the same design as those described above for dampers 30 .
[0037] 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 application such specific embodiments without departing from the generic concept, and therefore such adaptations and modifications 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 herein is for the purpose of description and not of limitation. | A blast shield for underbody protection of vehicles is presented that combines energy absorption and deflection in order to provide occupant protection and increased survivability in the event of an underbody explosive blast, especially those caused by improvised explosive devices. Absorption of blast energy is accomplished by a dampening system comprising a plurality of spaced hydraulic dampers position on a hull that deflects forces outward from underneath the vehicle. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/454,046, filed Jun. 15, 2006, which is a continuation-in-part of U.S. patent application Ser. No. 10/686,325, filed Oct. 14, 2003, the entire contents of both of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a door edge construction and more particularly, to a replaceable door edge arrangement.
BACKGROUND OF THE INVENTION
[0003] One popular form of vertically hung doors typically comprises a wooden frame defining outer dimensions of the door, panels of sheet material, such as plywood, plastic or metal covering the frame or both sides, and a core within the frame, which may be solid or hollow.
[0004] In certain high traffic environments, for example, schools, hospitals and other types of health care institutions, doors are often subjected to impacts from carts, wagons, dollies, etc. which take their toll on the doors, particularly along their free edges and the hinged edges. Nicks, gouges and cracks produced along door edges by such impacts compromise a door's ability to effect a secure closure, which is particularly important where the door serves as a fire barrier as well as a closure, and mar its aesthetic appearance.
[0005] Heretofore, when a door edge was severely damaged, it was necessary either to replace the door in its entirety or to refinish it. With the latter expedient, the door panels may also have to be replaced and, in any event, the door will have to be refinished as well. The cost of maintaining the structural integrity and appearance of the many doors in a hospital, for example, can become substantial.
SUMMARY OF THE INVENTION
[0006] The object of the present invention is to minimize the necessity of replacing or refinishing doors that have been severely damaged along their edges by enabling a damaged door edge to be simply and inexpensively restored.
[0007] The foregoing object is achieved by constructing a door with a replaceable edge strip or stile which, when damaged, can be readily removed and replaced with a new one, thereby restoring the door's integrity and appearance. In accordance with the invention, this is achieved by so constructing the door such that the replaceable edge strip or the replaceable stile can be removed and replaced without affecting the door frame or door slab, thus eliminating the need for otherwise replacing or refinishing the door. The stile is so configured that it can be covered with a plastic cap that provides an extra layer of protection against damage and helps maintain a snug seal against a doorway or an opposite door.
[0008] Another feature of the invention is the incorporation in the replaceable door edge assembly of an intumescent (heat expanding) material such that in case of fire, the edge is expanded outwardly to effect a tighter seal with the surrounding doorway or opposite door. The fire safety rating of the door is thus improved.
[0009] Still another feature of the invention is the incorporation in the door edge construction of an accent material to provide a reveal, or line of color different than the door panel color, for aesthetic and/or identification purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing and other features and advantages of the invention will become apparent from the following detailed description thereof, taken in conjunction with the appended drawing, in which:
[0011] FIG. 1 is an oblique view partially cut away, of a door incorporating the present invention;
[0012] FIG. 2 is a cross-section of the door of FIG. 1 , taken along the line 2 - 2 ;
[0013] FIG. 3 is an enlarged view of the right-hand portion of the cross-section view of FIG. 2 showing one representative embodiment of the door edge construction of the invention in greater detail;
[0014] FIGS. 4A , 4 B and 4 C illustrate modifications of the door edge construction of FIG. 3 ;
[0015] FIG. 5 is an enlarged cross-sectional view similar to FIG. 3 illustrating the incorporation of an intumescent strip in the door edge construction of the invention;
[0016] FIG. 6 illustrates a modification of the door edge construction of FIG. 5 ;
[0017] FIGS. 7A , 7 B, 7 C and 7 D illustrate the replaceable door edge construction of the invention incorporating various types of accent strips or reveals;
[0018] FIGS. 8A and 8B illustrate variations of the invention embodying an alternate tongue and groove arrangement for securing the replaceable stile to the door edge;
[0019] FIG. 9 illustrates a variation of the invention in which the tongue and groove members are covered with metal channels;
[0020] FIG. 10 illustrates a modification of the arrangement of FIG. 9 ;
[0021] FIGS. 11 and 12 illustrate variations of the arrangement of FIG. 9 ;
[0022] FIG. 13 illustrates a replaceable stile arrangement in accordance with the invention in which the width of the replaceable stile is adjustable;
[0023] FIG. 14 is an enlarged view of the cross-section view of a second representative embodiment of the door edge construction in accordance with the invention;
[0024] FIGS. 15A , 15 B, and 15 C illustrate representative steps of preparing a door and door edge construction in combination in accordance with FIG. 14 ;
[0025] FIG. 16 is an enlarged cross-sectional view similar to FIG. 14 illustrating the incorporation of an intumescent strip in the door edge construction of the invention; and
[0026] FIGS. 17A , 17 B, and 17 C illustrate representative steps in preparing a door and door edge construction in combination in accordance with FIG. 16 .
DETAILED DESCRIPTION OF THE INVENTION
[0027] Turning now to the drawings, in particular FIGS. 1 , 2 and 3 , a door of the type commonly used in health care facilities and the like, but incorporating the present invention, is shown. Such a door 20 typically comprises vertical stiles 22 and top and bottom rails 24 , surrounding a core 26 . The stiles 22 and rails 24 preferably are made of hardwood and the core 26 of particle board, although other materials may be used to provide the necessary strength and rigidity.
[0028] Finish panels 28 cover the particle board core, top and bottom rails and stiles on both sides to provide strength, impact resistance and aesthetic appeal. As seen best in FIG. 3 , the panels 28 may comprise a hardboard layer 28 a covered by a decorative plastic cladding 28 b such as of ACROVYN®, a vinyl acrylic plastic manufactured by Construction Specialties, Inc., Lebanon, N.J. The layers 26 , 28 a and b are laminated together to form a 5-ply construction. Doors of the type illustrated are manufactured, for example, by Jeld-Wen, Inc.
[0029] Doors 20 may be made in dimensions to fit various size doorways in which they are mounted. As will be appreciated, the door 20 may be hinged to swing around along either vertical edge to suit the application. In a typical installation often found in health care facilities, a pair of such doors are hinged at opposite edges to close a wide hallway and are swingable in both directions so that rolling beds, carts, etc may be pushed through without the need to hold the door open.
[0030] As discussed above, such doors are subjected to repeated, severe impact by beds, carts, etc., as they are pushed through the doors, often resulting in significant damage to the free vertical edges of the doors. Not only is the appearance of the door thus marred, the integrity of the closure and its fire resistance capability are degraded. Heretofore, in the case of significant edge damage, it was necessary to completely replace a damaged door with a new one to restore the closure's appearance and integrity, at substantial cost.
[0031] In accordance with the present invention, the vertical edges of a door such as described herein are fabricated with separable edge assemblies that can be readily replaced if damaged, thereby avoiding the necessity of complete door replacement and greatly reducing the cost of restoring the door's appearance and integrity.
[0032] A preferred embodiment of the removal door edge arrangement of the invention is shown in FIGS. 1 , 2 and 3 ; most clearly in the enlarged section through a door edge of FIG. 3 . The vertical door stile is indicated at 22 and the replaceable edge assembly indicated at 30 . The latter comprises replaceable stile 32 , preferably of hardwood, extending the full length of the edge stile 22 and a plastic cover 34 secured over replaceable stile 32 . Stile 22 is milled with a longitudinal tapered groove 22 a and replaceable stile 32 with a longitudinally extending complementary tapered spline 32 a , forming a snug tongue-and-groove mating of stile 22 and replaceable stile 32 . A plurality, e.g., 4, of screws 36 , spaced along the door edge, firmly but releasably secure replaceable stile 32 to stile 22 . If desired, spots of glue may also be applied between stile 22 and replaceable stile 32 to more firmly hold them together, while still allowing replaceable stile 32 to be removed when required.
[0033] Cover 34 may be formed of ACROVYN® or other relatively hard but resilient material, such as aluminum or stainless steel, with inwardly directed flanges 34 a along both edges. Cover 34 is formed to be of the same shape as the outer surface of replaceable stile 32 , e.g., generally rectangular with rounded corners. Replaceable stile 32 is provided with rectangular indents 32 b along both inner longitudinal edges, such that when stile 22 and replaceable stile 32 are joined, rectangular grooves 32 b are formed therebetween extending the full length of the door. These grooves snugly receive the flanges 34 a of cover 34 . To remove a damaged cover from a door, one of the flanges 34 a is pried out of its groove and the cover bent away to release the other flange. To install a new cover, one of the flanges is inserted into its groove and the cover pressed toward the outer surface of replaceable stile 32 until the other flange snaps into the other groove.
[0034] It will be understood that the curvature of the corners of the stile and cover combination discussed and illustrated may be varied to suit the particular application. For example, for paired swinging doors, such as often found across hospital passageways, the corner curvature will be of greater radius than single doors, to provide the required clearance.
[0035] It will also be understood that the cover 34 need not be removable, but may be permanently secured to its replaceable stile 32 , such as by a suitable adhesive. In such an arrangement, flanges 34 a and indents 32 b may be unnecessary.
[0036] FIGS. 4A , 4 B and 4 C illustrate alternative forms of the tongue-and-groove coupling of FIG. 3 , with the screws omitted for the sake of clarity. In FIG. 4A , a dovetail spline 42 mates with a corresponding groove 44 ; in FIG. 4B , the spline 46 has a partially circular cross-section to mate with a partially circular groove 4 B; and in FIG. 4C , the spline 50 and groove 52 are rectangular in cross-section. It will be understood that other variations of the tongue-and-groove cross-sections may be used as desired.
[0037] FIG. 5 illustrates another embodiment which further enhances the fire resistance advantages of doors of the invention. A heat-expansion or intumescent strip 52 extends the full length of the door edge and is adhered in a groove 54 milled along the outer edge of replaceable stile 32 . Cover 34 may have a complementary groove along its inner surface to accommodate the strip as well. The strip 52 is covered by outer cover 34 when the latter is snapped in place. At normal room temperatures, strip 52 maintains its normal thickness. In case of fire or extreme heat adjacent the door, strip 52 expands, pushing cover 34 outwardly to tighten the seal between the edge of the door and an adjacent door or doorframe, thus increasing the fire resistance rating of the door.
[0038] A variation of the arrangement of FIG. 5 is illustrated in FIG. 6 wherein the intumescent strip 52 is adhered in a groove 34 a formed in the outer edge of cover 34 , the inward extension of the cover 34 fitting in a groove milled along the outer edge of replaceable stile 32 .
[0039] It will be understood that in the embodiments of FIGS. 5 and 6 , any of the tongue-and-groove couplings described above may be used in place of the configurations illustrated.
[0040] To improve the appearance of the door, an accent strip or reveal, of a contrasting or complementary color to the remainder of the door surface, may be incorporated in the door edge arrangements of FIGS. 3 to 6 . In the embodiment of FIG. 7A , longitudinal grooves 60 are milled along opposite sides of replaceable stile 32 , inwardly of its interior face, for receiving the flanges 34 a of cover 34 , leaving exposed narrow longitudinal surfaces 62 on opposite sides of the stile, between cover 34 and the panels 28 . These exposed surfaces 62 may be painted in any aesthetically pleasing color.
[0041] The reveal or accent strip may also be provided by insertion of a suitably colored strip of accent material in a slot provided between the stile 22 and replaceable stile 32 , as shown in FIG. 7B . As seen, stepped indents 64 are provided along each inner corner of replaceable stile 32 to receive the flanges of cover 34 and accent strips 66 . The strips 66 may be of PVC plastic, aluminum, stainless steel or other material having their outer surfaces ridged and slightly thicker than the grooves created upon joinder of replaceable stile 32 to stile 22 . The strips 66 are pressed into the grooves after cover 34 is inserted and the ridged surfaces resist any tendency of the strips to move out of the grooves.
[0042] A variation of the accent strip of FIG. 7B is illustrated in FIG. 7C . In this modification, the inside longitudinal edges of replaceable stile 32 are milled to provide both stepped indents and longitudinal grooves for receiving L-shaped accent strips 68 . One leg of each accent strip extends outwardly to just below the respective outer surface of the door with its edge exposed when replaceable stile 32 is joined to stile 22 with the accent strip in place.
[0043] In the embodiment of FIG. 7D , the accent strips comprise opposite exposed edges 70 of a strip 72 sandwiched between stile 22 and replaceable stile 32 .
[0044] The accent strips of FIGS. 7B-D may be made of any suitable material, including PVC plastic, aluminum and stainless steel.
[0045] FIGS. 8A and 8B illustrate variations of the tongue and groove arrangements of the invention shown in the previous embodiments. In both variations, the groove in the stile 22 is rectangular (as in FIG. 4C ) and lined with a U-shaped channel 80 having longitudinal ridges 82 formed along both interior sides of the channel. Channel 80 is secured in the rectangular groove milled in stile 22 by screw 84 .
[0046] Adhered along the inner surface of replaceable stile 32 is a tongue plate 86 having integral longitudinal extending flanges 88 with longitudinally extending ridges 90 formed along their outer surfaces. The pair of flanges 88 and channel 80 are dimensioned such that the flanges are snugly received within the channel and the respective ridges 82 , 90 engaged to secure replaceable stile 32 to stile 22 . Tongue plate 86 may extend the full width of stile 32 , with rounded edges extending slightly beyond the door panel as in FIG. 8A , or be narrower than the width of the stile and received in a depression milled in the inner surface of replaceable stile 32 , as in FIG. 8B . In the embodiment of FIG. 8A , the rounded extensions of the tongue plate 86 may serve as accent strips. In FIG. 8B , accent strips are provided by inserts 92 between the edges of cover 34 and stile 22 . In both embodiments, intumescent strips 52 may be provided.
[0047] Channel 80 and tongue plate 86 may be made of aluminum or other metal or plastic, as desired.
[0048] In the embodiment of FIG. 9 , a dovetail tongue and groove coupling between stile 22 and replaceable stile 32 with screw 36 , such as shown in FIG. 4A , has both tongue 94 and groove 96 covered with channels of thin aluminum, steel, or other material providing low friction slideable surfaces, 98 a and 98 b , respectively, which extend to the outer surfaces of the door. The covered channels facilitate the insertion and removal of replaceable stile 32 on stile 22 .
[0049] A variation of the embodiment of FIG. 9 is shown in FIG. 10 , in which the extents of the metal channels 100 a and 100 b are limited to the extents of the groove and tongue, respectively. This variation of the embodiment includes cover 34 and may include intumescent strip 52 . The space left between stile 22 and replaceable stile 32 is filled with tapered inserts 102 , which serve to wedge the members 22 , 32 apart and also to provide accent strips.
[0050] In FIG. 11 , a single metal channel 110 is applied to the dovetail tongue element only and in FIG. 12 , the single metal channel 112 is extended outwardly between stile 22 and replaceable stile 32 to the door faces with rounded outer edges 114 which provide accent strips.
[0051] To accommodate different door thicknesses, the adjustable width replaceable stile of FIG. 13 is advantageous. In this embodiment, the replaceable stile is made up of two separate longitudinal elements 132 a and 132 b , each having a generally L-shaped cross-section overlying and nesting with each other to be slideable away from each other between a minimum width arrangement wherein the respective longitudinal edges of elements 132 a and 132 b are in contact with each other and a maximum width configuration wherein the respective longitudinal edges are separated. Opening 134 is of greater diameter than screw 36 to allow for varying amounts of separation.
[0052] In one embodiment, as shown in FIG. 14 , a replaceable door edge construction is shown. The door edge construction is indicated at 30 ′ and comprises main body 36 ′ having first and second sidewall portions 36 a ′ extending distally therefrom. The sidewall portions are integrally connected to the main body by curved portions 36 b ′. Alternatively, however, the sidewall portions 36 a ′ can be integrally connected to the main body 36 ′ by planar portions or L-shaped portions (not shown). The door edge construction further includes first and second leg portions 38 ′ integrally connected to first and second sidewall portions 36 a ′, respectively.
[0053] The main body 36 ′ of the door edge construction is preferably formed from a resilient material and is configured to contour the vertical edge of a door. For example and not limitation, the door edge construction can be formed from a malleable metal such as aluminum or stainless steel, or alternatively from a hard yet flexible polymeric material. The main body 36 ′ has a generally bowed or curved configuration. Alternatively, however, the main body 36 ′ may have a generally planar configuration. Additionally, the first and second sidewall portions 36 a ′ may have a planar, curved or bowed shape configuration. In one embodiment, as shown in FIG. 14 , the edge construction includes planar first and second sidewall portions integrally connected by curved portions to planar main body. In this manner, the main body 36 ′ and the first and second sidewall portions 36 a ′ generally form an C-shaped member configured to contour an edge of a door.
[0054] The first and second leg portions 38 ′ are configured to engage a surface of a door. The first and second leg portions are further disengageable with the door surface. Accordingly, a readily removable and replaceable edge construction is provided. In this aspect of the invention, the edge construction can be removed from the door and replaced by a second edge construction member having a similar construction. Advantageously, a replaceable stile member is not required to provide the replaceable edge construction. Rather, the replaceable edge construction is directly engageable and disengageable with a door edge.
[0055] As shown in FIG. 14 , the first and second leg portions 38 ′ are preferably configured to form a mating relationship with groove 22 a ′ formed in door 10 . In this manner, the replaceable door edge construction 30 ′ is coupled to the edge of door. Preferably, groove 22 a ′ is a longitudinal groove milled or otherwise disposed along the full length of the front and back surfaces of the door 10 , preferably to a depth sufficient so that the groove extends through 28 b ′, 28 a ′ and 22 ′. Leg portions have a longitudinal length suitable for full engagement with the longitudinal grooves disposed in surfaces 28 a ′, 28 b ′ and vertical stile 22 ′.
[0056] In one embodiment, the first and second leg portions 38 ′ form a sliding engagement with longitudinal grooves 22 a ′ defined in and extending in the front and back surfaces 28 b ′ 28 a ′ and vertical stile 22 ′ of the door 10 . In this manner, the replaceable door edge construction 30 ′ can be slid or snap-fit into the edge of the door 10 such that the first and second leg portions 38 ′ are received in the longitudinal grooves 22 a ′ of the door. As shown in FIG. 15B , the longitudinal grooves 22 a ′ have a depth sufficient to receive the first and second leg portions 38 ′. Further, the door edge construction 30 ′ is disengageable from the door edge by sliding the replaceable edge construction upwardly to disengage the sliding engagement of the leg portions and the longitudinal grooves 22 a′.
[0057] Alternatively, however, the first and second leg portions can form a tongue and groove connection with the longitudinal grooves 22 a ′. In this regard, the longitudinal grooves 22 a ′ snugly receive the first and second leg portions when the leg portions, which are snap-fit into the longitudinal grooves. The door edge construction 30 ′ is disengaged from the door edge by prying one of the leg portions out of the groove and bending the edge construction to release the other leg portion. It should be appreciated in the art that alternative mating relationships can be formed between the edge construction and the door, if desired.
[0058] In yet another aspect of the invention, a door 10 and replaceable door edge construction 30 ′ in combination is indicated in FIG. 15C . As shown in FIG. 15A , door 10 generally comprises core 26 ′, vertical stile 22 ′ and opposing front and back surfaces 28 b ′. Vertical stile 22 ′ is disposed adjacent to core 26 ′ such that vertical stile 22 ′ and core 26 ′ are longitudinally aligned. Preferably, vertical stile 22 ′ has substantially the same length as core 26 ′. As will be recognized in the art, however, the length of the vertical stile 22 ′ can differ from core 26 ′, if desired. The front and back surfaces of door 10 is disposed proximate to sidewalls of core 26 ′ and vertical stile 22 ′.
[0059] As shown in FIG. 15B , the front and back surfaces 28 b ′ 28 a ′ and vertical stile 22 ′ of door 10 is milled to define longitudinal grooves 22 a ′ extending longitudinally along the front and back surfaces of door 10 . Additionally, the door surfaces can be further milled to define a door 10 having a first portion 10 a ′ having a first width W 1 and a second portion 10 b ′ having a second width W 2 . As illustrated in FIG. 15B , in a preferred embodiment, the first width is greater than the second width. In this manner, the door and edge in combination have a constant width, as shown in FIG. 15C .
[0060] In another embodiment, as shown in FIGS. 16 and 17 A- 17 C, door 10 and/or edge construction 30 ′ further includes a heat-expansion or an intumescent strip 52 ′. The heat expansion or intumescent strip preferably extends the full length of the door edge. As depicted in FIG. 17B , the edge of vertical stile 22 ′ is configured to include an indent 22 b ′ defined along a surface thereof. The strip of intumescent material 52 ′ is disposed in the indented surface 22 b ′, as depicted in FIG. 17C . The replaceable edge construction 30 ′, as shown in FIG. 16 , covers intumescent strip 52 ′ when engaged to the edge of door 10 . Alternatively, however, in yet another embodiment, the strip of intumescent material 52 ′ is secured to a surface of the replaceable edge construction, preferably, the main body. The intumescent material can be disposed in a indent formed in a surface of the edge construction 30 ′ such as in the outer surface of the main body. Alternatively, however, the strip of intumescent material can be secured to a planar surface of the edge construction such as the inner or outer surface of main body 36 ′ (not shown).
[0061] To improve the appearance of the door and edge construction in combination, the door may include a contrasting or complementary color relative to the color of the edge construction. In this manner, the edge construction may incorporate an aesthetically pleasing color on the main body or sidewall portions, if desired.
[0062] It will be seen from the foregoing that the present invention provides a simple, inexpensive way of repairing damaged doors by allowing replacement only of a removable door edge assembly, thereby saving the considerable exposure of replacing an entire door. Although a number of specific embodiments of the invention above have been illustrated, various modifications thereof will be apparent to those skilled in the art within the spirit of the invention. For example, replaceable stile 32 and cover 34 may be made as a single integral member and joined to stile 22 as shown. Also, the tongue-and-groove coupling between replaceable stile 32 and stile 22 may be eliminated, if desired and any of these variations may be provided with or without intumescent strips. Accordingly, it will be evident that the scope of the invention is to be limited only as set forth in the appended claims. | A door is constructed with a separate member joined to the door edge by a tongue-and-groove coupling and screws so as to be readily removable and replaceable. The separate member sustains the impacts imparted to the door by carts or wagons pushed past the door and can be readily replaced when damaged, thus avoiding replacement of the entire door. A flexible cover snaps over the outer surface of the separate member to add impact resistance and aesthetic appeal. Intumescent strips may be inserted inside or outside of the cover to enhance sealing between the door, and as adjacent door or door frame, thereby improving the fire resistance rating of the door. Accent strips or reveals of contrasting or complementary colors may be incorporated to add to the aesthetic appeal of the door. The door construction is of particular utility in schools, health care facilities and other institutions. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an enclosure which may be easily assembled and disassembled at any given site and accordingly which is effectively portable in nature such that a grown person can be positioned within the interior of the enclosure in an upstanding position for various purposes such as but not limited to changing clothes, taking a shower, etc.
2. Description of the Prior Art
In modern day society there is usually found an increasing amount of time which may be dedicated to recreational activity. Much of this time is directed to outdoor activities such as but not limited to swimming, sunbathing, camping, hunting, fishing, etc. All of these activities, after they are completed, frequently involve the participants wanting to take showers, change clothes, or the like. However enclosures specifically designed to allow such activities are not normally available except at certain permanently built publicly available sites where large numbers of people congregate.
There is therefore a need in this area for an enclosure or housing type of structure which is portable in nature at least to the extent that it may be easily assembled or disassembled at any given site utilizing a minimal amount of effort on the users part and requiring no exceptional talent, training, tools or auxiliary equipment required to assemble or disassemble such enclosures.
Numerous types of enclosures and or portable shower type housing units are well known in the prior art as evidenced by the following United States patents.
Gatley U.S. Pat. No. 3,391,409 discloses a portable shower bath apparatus which is not necessarily designed for outside use but which is certainly capable of being used in an outdoor location. This device includes a support frame formed of tubing which may be interconnected in its various segments to define an interior which may be enclosed by a drapery, curtain or like structure. This device while applicable is somewhat lightweight in overall design and construction and does require tooling and or a certain amount of expertise in its assembly and disassembly. In addition the tubular components define a frame which is meant to support a water container in an overhead location relative to the interior in which a user or participant may be positioned for showering.
Mustee discloses a free standing shower stall including a base and one or more wall panels used to impart rigidity to the stall. A drain structure is also located in the base and the wall panels are made and joined together by imperforate watertight hinges which permit the panels to be folded upon themselves for shipment when in a stored position and wherein such folding may occur in association with other parts of the stall.
The patent to Sedala U.S. Pat. No. 4,807,310 also is directed to a portable shower stall having a plurality of corner posts and upright wall elements which are removably secured to and supported by such corner posts. The outer or lower most end of the post are designed to engage and be supported on some type of surface and are particularly pointed at the ends thereof to penetrate a ground like area if such is defined as a supporting surface. Hoses, plumbing and like installations including a shower head may be mounted on the interior and communicate with an exterior source through a hose or like structure. The individual wall panels supported by the post may have a plurality of shingle type structures and may be vented to allow air flow through the interior of the stall.
The patents to Westerweller, U.S. Pat. No. 4,539,720 and Greenleaf, U.S. Pat. No. 4,453,280 are both directed to portable shower stall type structures which are capable of being folded or otherwise disposed into a stored position and carried by some type of facility such as a backpack type of arrangement (Westerweller) or in a separate compact carrying case (Greenleaf). These structures are of course portable in nature and are formed of a plurality of components which are significantly light in weight to the extent that these portable stalls or enclosures may be carried on or by the person with little problem. While such lightweight construction has certain advantages it does not add to the permanency of the structure while allowing the versatility of a knockdown device as is obviously needed in this area.
The above noted devices are considered to be operable and utilitarian for their intended function. However they do not solve the problem of establishing an enclosure or like housing structure which may be used as a shower stall or otherwise used for other activities such as changing clothes and the like whether or not a shower is attached thereto. In such a preferred device a certain permanency or feeling of structural integrity must be conveyed to the users of such a device while at the same time such a device must be capable of being easily assembled and disassembled. In addition a preferred structure of the type set forth herein should also be capable of having auxiliary or supplementary attachments made thereto such as but not limited to tables for supporting various goods and or performing other functions such as eating or the like.
SUMMARY OF THE INVENTION
The present invention relates to a portable enclosure or like housing structure which may be used by an occupant for a variety of purposes such as but not limited to taking a shower, changing clothes as well as other activities wherein privacy is desired. The enclosure assembly is portable to the extend that the various components which define the subject enclosure assembly may be removably connected to one another and thereby easily assembled and disassembled without the need of any special training or sophisticated tools or the like. Therefore the enclosure can be readily assembled at any convenient location and left standing due to the advantage of secured structural integrity. Alternately the enclosure can be readily dismantled in a short period of time and therefore only left standing for a short period such as for a days outing at the beach or the like.
The subject enclosure assembly includes a wall means. The wall means comprises a plurality of wall segments which collectively at least partially surround and thereby define a hollow interior of the enclosure. This hollow interior by virtue of the configuration and dimension of the plurality of wall segments is sufficient to enclose at least one person in a standing or upright orientation. More specifically the wall segments are arranged in a vertically stacked array so as to create sufficient height of the overall enclosure assembly as well as the interior thereof to allow a grown person to maintain a standing or upright position.
Each of the wall segments comprises a plurality of wall panels which are preferably three in number. Therefore each wall segment preferably comprises two spaced apart substantially opposed side panels and an interconnecting back panel. Each of the side panels have a free peripheral edge disposed in spaced apart relation from the corresponding side panel of the same wall segment. Since the spacings between the side panels of each wall segment are aligned, an access opening or doorway is created for the passage of occupants into and out of the interior of the enclosure.
Removable attachment of adjacently positioned ones of the wall panels of adjacent wall segments are accomplished by the formation of an attachment means along corresponding, mating peripheral edges of adjacently positioned panels. The attachment means comprises at least one but preferably a double row of alternating tongue and groove structural portions. Such tongue and groove structures are adapted such that a tongue of one wall panel removably fits into a groove or recess of an adjacent wall panel to which it is attached.
The back panels include and/or are structurally adapted to interconnect the side panels of any given wall segment. Further each of the back panels are arranged in a vertically oriented, substantially stacked array such that they are correspondingly positioned peripheral edges removably interconnect to one another in the same fashion by virtue of the tongue and groove adaptation along with corresponding peripheral edges thereof.
A roof structure is provided to overlie and substantially cover an upper opening of the upper most wall segment. Associated components of the roof portion includes means to connect and or position a supply of water such as but not limited to a garden hose which may have a shower head attached thereto. Other facilities for supplying water and mounting such water supply in an overhanging relation to the hollow interior for purposes of showering on the interior of the enclosure, may be included in the aforementioned roof portion.
Connecting means are provided in the form of upper and lower tie panels which interconnect spaced apart side panels of at least an upper most and lower most wall segment. In a preferred embodiment, to be described in greater detail hereinafter there are preferably three such wall segments arranged in a vertically stacked array such that they may be defined as a lower most wall segment, an upper most wall segment and a middle wall segment. Each of such uppermost, lowermost and middle wall segments include the same number of wall panels which, as set forth above, are defined by spaced apart side wall panels and a back or rear wall panel.
Other structural features of the present enclosure assembly include anchoring means which includes an anchor flange selectively positionable between an outwardly extending operative position or an inwardly folded position. Such anchor flanges are movably attached to certain ones of the panels of the lower most wall segment. In operation the aforementioned stored position of each of the anchor flanges is in a co-planer relation to the remainder of the panel to which it is attached. The outward extension of these anchor flanges serves to position them over and or in overlying, confronting relation to a supporting surface such as the ground or the like. Each of these flanges has an aperture through which an anchoring pin may pass so as to penetrate, at least to some extent the supporting surface which may be the ground.
Other auxiliary features of the present invention include the provision of a table like structure including a table top having a somewhat horizontal orientation and a flat planer receiving and supporting surface. One end of the table is secured by removably attached gusset members directly to an exterior surface of one of the wall segments. The table extends outwardly therefrom and is supported by a sufficient support means, including a leg type structure which is pivotal into and out of a stored position and is secured adjacent substantially one outer most end of the table.
The present invention therefore is directed to an enclosure assembly which has sufficient structural integrity to be considered and provide the "feel" of a permanent type of housing or enclosure. However the versatility of the subject enclosure assembly is such as to allow easy assembly or disassembly to facilitate at least semi permanent installation and set up of such an enclosure or alternately allowing the user to merely set up and utilize the subject enclosure for a few hours.
Another feature of the present invention is that the exterior surface of any or all of the various wall panels may have advertising or any other similar type of decorative or informative indicia printed thereon. Such printed indicia may be used for commercial purposes such as in advertising or for other purposes such as to increase the overall aesthetic appearance of the assembly or for informative or educational purposes such as identifying one such structure from another.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of the subject enclosure assembly in its assembled state.
FIG. 2 is a front view and partial cutaway of the embodiment of FIG. 1.
FIG. 3 is a detailed view and partial cutaway of an anchoring assembly associated with the subject enclosure.
FIG. 4 is a rear view of the embodiment of FIG. 2.
FIG. 5 is a side view of the embodiment of FIGS. 1, 2 and 4.
FIG. 6 is a top view and partial section and cutaway of the attachment of a roof assembly.
FIG. 7 is a view along line 7--7 of FIG. 6 in partial cutaway an exploded form of a roof component of the subject assembly.
FIG. 8 is a view along line 8--8 of FIG. 6.
FIG. 9 is a cutaway view of a lower portion of the subject assembly.
FIG. 10 is a top view and partial cutaway of a bottom portion of the device along line 10--10 thereof.
FIG. 11 is cutaway view showing an attachment structure for interconnecting panels of the present invention.
FIG. 12 is a cooperative partial cutaway view relative to FIG. 11.
FIG. 13 is a cutaway view in partial exploded form showing the connection of the panels of FIGS. 11 and 12.
FIG. 14 is a detailed view and partial cutaway and section of an auxiliary table structure associated with the subject assembly.
FIG. 15 is a side view and partial section and cutaway of the embodiment of FIG. 14.
FIG. 16 is the perspective view of the table assembly in a compact or stored or orientation.
FIG. 17 is a perspective view of the embodiment of FIG. 16 in an open and operative position.
FIG. 18 is a view and partial exploded form showing inner connection of a connecting facility for attachment of the various panels to one another.
FIG. 18A is a side view of the structure of FIG. 18 shown in exploded form.
FIG. 19 is a panel and connecting structure similar to that of FIG. 18 in exploded and partial cutaway.
FIG. 19A is a front view in part of the embodiment shown in FIG. 19 in exploded form.
FIG. 20 is a perspective view in partial form cutaway and section showing details of the support structures associated with the table of the embodiment of FIGS. 14 through 17.
FIG. 21 is a perspective view of yet another embodiment of the present invention incorporating the same structural features as the embodiments described above.
Like reference numerals refer to like part throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, the present invention is directed towards a portable enclosure assembly generally indicated as 10 which is designed to allow at least one person to enter a hollow interior of the enclosure assembly for purposes of conducting a variety of activities such as but not limited to taking a shower, changing clothes, etc. More specifically the enclosure includes a wall means which are disposed in at least partially surrounding relation to a front access opening as indicated as 12. As shown in FIG. 1 this access opening 12 extends along the entire height of the enclosure 10 and may be covered by any type of covering facility such as but not limited to a curtain, drape, foldable slat like covering or the like which is generally indicated as 14. Again with reference to the wall means, such wall means includes a plurality of wall segments generally indicated as 16, 18 and 20. These wall segments are arranged in a vertically stacked array as shown in FIGS. 1, 2 and 4 wherein each wall segment includes a plurality of panels. The panels of the lower most wall segments 16 includes two side panels 21 and 22 and a back panel 23. The middle wall segment 18 comprises two spaced apart substantially opposed side wall panels 24 and 25 and a back panel 27. The upper most wall segment 20 includes two spaced apart side panels 26 and 28 and an interconnecting back panel as at 29. Each of the spaced apart side panels of each of the various wall segments are interconnected by the corresponding back panels. Such interconnection may occur along a hinge line as at 30 and further wherein the lateral peripheral edges of each the corresponding side wall panels may be further removably connected by virtue of a tongue and groove fit as at 31.
The stacked vertical array of the various wall segments 16, 18 and 20 is accomplished through the provision of an attachment means formed along correspondingly positioned mating peripheral edges. With reference to FIGS. 11, 12 and 13 each of the mating peripheral edges of the various wall panels include a substantially double row of tongue and groove structures. More specifically a first row may include a plurality of upwardly extending tongues 32 and alternating receiving grooves 33. The next adjacent and also integrally formed row on the same peripheral edge as shown in FIGS. 11 and 12, includes upwardly extending tongues 32' and alternating recesses 33'. It can be seen from a review of FIG. 13 that the outwardly protruding tongues of one peripheral edge such as on the peripheral edge of wall panel 25 is designed to fit within the correspondingly positioned grooves of the peripheral edge of the wall panel 21. This removable attachment allows easy assembly and disassembly of the entire wall means and the correspondingly positioned and mating wall panels and also provides a secured attachment between such wall panels in order to form the vertical stacked array as set forth above. Further with regards to FIGS. 1 and 4, it should be noted that the double rows of tongue and groove structures defining the aforementioned attachment means occurs along appropriate peripheral edges of the various panels. For example each of the panels 21, 22 and 23 of the lower most wall segment 16 has the connection means formed along its upper most peripheral edge. To the contrary the upper most wall segment 20 has such connection means formed along the lower most peripheral edges of each of the panels defined thereby. The middle wall segment 18 has the attachment means defined by the double row of tongue and groove structures extending along both its upper and lower peripheral edges for reasons that are apparent.
Other features of the wall means is the structural adaptation of each of the panels of each of the wall segments such that the inner transverse dimension or transverse dimension of the interior segment about which the lower most wall segment 16 surrounds is greater than both the middle most wall segment and the upper most wall segment 18 and 20 respectively. Therefore in a preferred embodiment of the present invention there is a progressively decreasing inner transverse dimension from the lower most wall segment 16 to the upper most wall segment 20.
The distance between the outer most or free peripheral edges of each of the side panels 21, 22; 23, 24 and 26, 28 is open to define an access opening segment. The vertical stacked orientation of each of the wall segments defines the elongated access opening extending along the entire height of the enclosure 10 which is indicated as 12.
With regard to primarily FIGS. 1, 18 and 19 the subject enclosure assembly further comprises connecting means in the form of tie panels extending across and serving to interconnect spaced apart side walls of certain ones of the wall segments. In a preferred embodiment, a lower tie panel as at 35 serves to interconnect and substantially extend across the access opening segment between the outer most peripheral edges of the side panels 21 and 22 of the lower most wall segment 16. Similarly at least one upper tie panel as at 37 extends across the access opening segment between the outer or free peripheral edges of the side panels 26 and 28 of the upper most wall segment 20. The interconnection of both the lower tie panel 35 and the upper tie panel 37 is accomplished through a removable attachment wherein elongated slots as at 38 are formed in opposite ends of lower tie panel 35. These slots are designed to pass through and within the elongated slots 39 formed in correspondingly positioned ends or portions of the side panels 21 and 22. Similarly elongated slots as at 40 are formed in opposite ends of the upper tie panel 37. These slots are designed to be removably disposed to accomplish a detachable connection within the elongated slots 42 formed in the upper peripheral ends of the panels 26 and 28 of the wall segments 20.
Other features associated with the tie panels as well as the lower most peripheral edge of the panels of the wall segments 16 include penetrating spike like members as at 43 integrally formed on the lower most edges as set forth above. These penetrating spikes or like members serve to facilitate stabilization of the base or bottom of the enclosure 10 by any supporting service such as the ground or the like.
Other features of the subject enclosed assembly include a roof structure which may be formed of a variety of materials and be disposed in overlying and covering relation to an open upper end generally indicated as 44 of the enclosure. The roof structure generally indicated as 46 is sufficiently dimensioned, configured and generally adapted to be positioned in overlying relation so as to be supported at least in part above the upper peripheral edge of the upper type panel 37. An elongated supporting rod as at 47 is mounted within appropriate slots as at 48 and 49 of the upper tie panel 37 and the upper peripheral edge of the back panel 29 of the wall segment 20.
FIGS. 1 and 19 show ventilation openings as at 50 may be formed at a variety of locations in the tie panel 37 and also a plurality of such ventilation holes may also be formed in various ones of the panels of the wall means wherein such ventilation apertures or holes are indicated as 50'.
Removable attachment of the roof structure 46 is accomplished by connector elements such as but not limited to hook and loop type fastener connector strips 51 being mounted both being mounted on opposite sides of interior surface portions of the roof structure 46. These connector strips are designed to be removably connected to correspondingly positioned connector strips 53 mounted on exterior surfaces of the opposite side panels 26 and 28 of the wall segment 20.
In order to provide stabilization and secure anchoring of the enclosure 10 in the supporting surface such as the ground or the like, anchoring means are provided. Such anchoring means are disclosed in detail with reference to FIGS. 1 and 3. Such anchoring means as generally indicated as 58 include a flange as at 60 which is pivotedly mounted to a lower most wall panel as at 21, 22 and 23 by virtue of a pivot pin connection 62. By virtue of this pivotal connection, the flange or anchoring flap 60, which is centrally apertured is selectively positionable between a stored position and an operative position. The operative position is defined in FIG. 3 and in such position the flange 60 extends outwardly from the plane of the given panel to which it is attached. In the stored position the flange 60 is in a co-planer relation to the panel to which it is attached by virtue of a provision of a recess or opening as at 63. Each of the anchor flaps or flanges 60 has an opening formed therein for the passage therethrough of an anchoring stake or the like 66 as best shown in FIG. 3. The stake 66 passes through the opening 67 formed in the anchor flap 60 and may penetrate or otherwise be secured into the ground or like supporting surface 100. An auger or screw type of structure as at 69 may be formed on exterior surface portions of the anchoring stake 66 along a far end thereof as also shown in FIG. 3.
With regard primarily to FIGS. 1, 2, 4, 14 through 17 and 20, preferred embodiment of the present invention includes an auxiliary structure attachable to the portable enclosure 10. This, is in the form of a table or like supporting member generally indicated as 70. The table includes a supporting platform portion 72 being substantially horizontally oriented and having one inner most end as at 73 supported on and extending outwardly from an exterior surface of the wall means as clearly shown in FIG. 1 and 4.
The table assembly 70 includes a support means including a leg assembly 74 and one or more gusset assemblies 76 serving to support the platform 72 in its horizontal or operative position. More specifically the leg assembly 74 includes a main leg 75 having an inner most end as at 73 pivotally attached to an undersurface portion of the platform 70 as at 70'. The pivotal or hinge type connection as at 77 is defined by a structure somewhat similar to that shown in FIG. 20. A main receiving member 78 includes a central channel extending therethrough as at 79. A pivot pin or like hinge pin 80 passes through the receiving segments 82 in the object to be pivoted wherein such receiving segments 82 also include elongated central channel portions 83. These central channels 83 are aligned with the central channel 79 in the hinge support member 78. The length of the hinge pin 80 is such as to allow passage completely therethrough and thereby defining hinged connection.
It should be apparent that while with regard to FIG. 20 the pivotal connection disclosed relates to the gussets 76' rather than the main leg 75. However the pivotal connection of the main leg 75 indicated as 77 is the same.
Additional features associated with the leg assembly 74 are two end slats as at 84 pivotally secured to and extending along the length of opposite longitudinal side edges of the main leg 75. A similar hinge or pivotal type connection may be used so as to allow the positioning of the leg slat 84 into and out of co-planer relation relative to the main leg 75 as best shown in FIGS. 16 and 17. Also, by virtue of the pivotal or hinge like connection 77 the leg assembly 74 may be disposed in a stored position which is substantially parallel to the under surface 70' of the platform 70. Alternately, it may be moved into an operative position as defined and disclosed in FIGS. 1 and 17.
Other structural members of the support means for the table assembly 70 include the outwardly extending gussets as at 76'. There should be at least one gusset assembly but a plurality of gusset assembly 76 may be utilized. Each such gusset assembly includes a gusset member pivotally attached to the under surface 70' of the platform 70 and positionable between a stored position in substantially parallel relation to the under surface 70' of the support platform 72 as shown in FIG. 16. The operative position is shown in FIGS. 1 and 17 of such gusset members 76'. The gussets 76' have their inner most peripheral edge as at 79 resting on or otherwise secured in supporting engagement along the outer surface of one or more of the wall panels defining the wall means as set forth above.
With regards to FIG. 14 and 15 yet another feature of the support means associated with the table assembly 70 is a support flap as at 90 which may be selectively positionable into and out of an operative position. The operative position shows the support flap engaging the under surface 70' of the support platform 72 of the table assembly 70. The stored position, due to a pivotal connection as at 92 allows the selective positoning of the flap 90 back into a stored position which is co-planer with at least one of the side panels 21 in which the support flap is formed. A recess is formed as at 94 which is configured and otherwise adapted to receive the support flap 90 back into its co-planer relation to the panel 21 in which it is mounted. A typical hinge pin or pivot pin as at 96 may define, at least in part, the pivotal connection of the hinge type attachment 92 of the support flap 90. A V-shaped indentation 97 is formed in the upper peripheral edge of the support flap 90 and is adapted to receive a congruently shaped, depending flange 99 secured to the under surface 70' of the platform 72. This engagement between the recess 97 and the flange 99 serves to secure the support flap 90 in its operative, supporting position as best shown in FIGS. 14 and 15.
Other features of the present invention include intergrally formed strengthening ribs 101 disposed and formed to extend outwardly from the inner surfaces of each of the side and back panels of each of the wall segments 16, 18 and 20.
Also as shown in FIGS. 4 and 19 a hose bib or mounting facility 102 is secured to an upper area of the back panel 29 of the upper most wall segment 20. This bib or mounting facility 102 is designed and adapted to allow penetration of a shower head and or attachment of a garden hose or like water supply thereto so that the person can take the water within the interior of the assembly 10.
With regards to the embodiment of FIG. 21, another structural advantage further indicating the great versatility of the enclosure assembly 10 is that it may be re-oriented so as to provide a protective cover or housing for a sleeping area. Such re-orientation takes the form of orienting the assembly 10 in a somewhat horizontal position such that the open access opening 12, extending along almost the entire length of the enclosure 10 is disposed in overlying relation to a ground 110 or like supporting surface. The curtain, flap or like cover structure 14 normally used to cover the access opening 12 when in its normal upright position as shown in FIGS. 1 and 2, may be specifically structured to have some type of a cushion or other inflatable structure which allows the curtain 14 to be used as a sleeping mat thereby adding comfort to one disposed in a reclined orientation and thereby using the curtain assembly 14 as a mattress type of structure and also to protect the user from dampness or being soiled from the ground supporting surface 110. The remainder of the structure remains the same with the exception that the end most base as pictured in FIG. 21 is of course opened and the bottom tie member 35 has been removed for easy and clear access. Such end opening now indicated generally as 112 could be covered by any type of bottom or end closure (not shown for purposes of clarity) in order to facilitate privacy of the like. Similarly a roof type structure generally indicated as 46' may be used to cover the other opposite end relative to the access opening 112. The remaining wall segment 16, 18 and 20 remain the same and in place and interconnect along the tongue and groove line 31 extending between the correspondingly positioned and cooperatively structured panels 21, 25, 28 and 23, 27, 29 of the various wall segments.
Anchor means in the form of flaps 60' may be movably or removably attached to correspondingly positioned side panels 21, 25, 28 and/or 22, 24, 26. Such anchor facilities include, set forth above, the flap 60' a movable or removable connection 62' and the removable stake 66' passing through the aperture 67' into the supporting ground surface 110.
It should be clear therefore based on the detailed explanation of the structural features of the present invention that great versatility is possible through the utilization of the subject structure and its components being interconnected in an operative manner as set forth above. Further it should be emphasized that the various components as described can be easily disassembled and arranged in some type of stacked or packaged array which facilitates the transporting of the entire assembly, in its disassembled form, from one location to another. When disassembled the structural components of this invention allow minimization of volume in any type of holding package in which the various components may be placed for travel or transportation. Now that the invention has been described: | A portable enclosure designed to be mounted in any desirable location and defined by a plurality of wall segments arranged in a vertically stacked array wherein each wall segment includes a plurality of wall panels interconnected to one another so as to partially surround and thereby define a vertically oriented interior of sufficient dimension and configuration to house a person in an upstanding position. Supplementary attachments including a hose bib and water supplying hose or like water source may be attached such that the person within the interior of the enclosure may take a shower. Anchor structures are provided to secure the enclosure to the ground or other applicable supporting surface. The various components of the enclosure assembly may be easily assembled and disassembled to facilitate storage and or transport. In another embodiment the portable enclosure may be positioned in a horizontal enclosure and the position may be used as a sleeping enclosure wherein a main entrance is disposed in contiguous relation to the supporting ground and wherein one open end now defines the "crawl in" entrance for the person designed to be housed when sleeping by the portable enclosure. | 4 |
RELATED APPLICATIONS
This application is a divisional of co-pending patent application Ser. No. 12/655,939 filed 11 Jan. 2010, which claims the benefit of Provisional Patent Application Ser. No. 61/204,885, filed 12 Jan. 2008.
BACKGROUND OF THE INVENTION
Certain firearms, such as the M4, M16, SR-25, AR-10 and AR-15 weapons are fired using gas operation. The act of firing the weapon subjects certain operating mechanisms to the build up of residue due to exposure to the operating gases of the weapon. As a result, carbon residue accumulates on and around the operating mechanisms, such as the bolt and bolt carrier. Over time, the residue becomes detrimental to operational firing of the weapon. Therefore, it is important to keep operating mechanisms which are prone to residue build up clean, and to periodically remove the residue therefrom.
One of the most residue prone areas of a firearm includes the bolt and bolt carrier. However, the contours of the bolt and bolt carrier create unique difficulties in proper and complete cleaning of the relevant surfaces. Further, once the carbon residue is adhered to a surface it is difficult to remove. In view of these problems, certain tools have been improvised and developed to aid the user in cleaning a firearm, particularly the bolt and bolt carrier.
Known cleaning tools include brushes, dental tools, screwdrivers, and solvents. Use of these types of tools is ineffective at best, and sometimes damaging to the weapon. Other known tools used to remove carbon residue from the bolt and bolt carrier include those sold by NCStar, Brownells, ADCO Firearms, and AR15.com, for example. While these tools may improve the manner of carbon removal from the bolt carrier, none of them adequately addresses removal of carbon from both the bolt tail and the bolt carrier in a single tool.
SUMMARY OF THE INVENTION
The present invention is directed to a firearm maintenance tool for use in cleaning bolts and bolt carriers of certain weapons such as the AR-15, M4, M16, SR-25, or AR-10, and method of using same. A tool according to the present invention is a compact device including cutting or scraping edges to ream residue, such as carbon deposits through a scraping action, and is adapted to clean both a bolt carrier and a bolt, especially the bolt tail in a single tool. The tool preferably includes a proximal end having a scraping head provided with a scraping edge. The scraping head is preferably dimensioned to fit into the bore of a selected bolt carrier to be cleaned and is adapted to ream carbon deposits through an axial rotational scraping action. The tool further includes a distal end having pivotable scraper arm and longitudinally extending insertion pin. The pin is adapted to be inserted into the bore of the bolt tail to be cleaned, while the scraper arm is rotatable for positioning adjacent a bolt tail surface. A method of use is also contemplated.
It is an object of the present invention to provide a new and improved firearm cleaning tool which may be easily manufactured and marketed.
It is a further object of the present invention to provide a new and improved firearm cleaning tool which is of durable and reliable construction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a tool according to the present invention and used for cleaning bolts and bolt carriers of weapons.
FIG. 2 is a side elevation view of the tool shown in FIG. 1 .
FIG. 3 is a perspective view of an alternative embodiment tool according to the present invention and used for cleaning bolts and bolt carriers of weapons.
FIG. 4 is a view of a tool according to the present invention with proximal end being inserted into a bolt carrier bore to be cleaned.
FIG. 5 is a view of a tool according to the present invention with proximal end inserted in a bolt carrier bore to be cleaned.
FIG. 6 is a view of a tool according to the present invention with proximal end inserted in a bolt carrier bore to be cleaned, and showing axial movement of the tool.
FIG. 7 is a view of a tool according to the present invention and showing the distal end thereof being inserted into a bore of a bolt to be cleaned.
FIG. 8 is a view of a tool according to the present invention, with the distal end thereof inserted into a bore of a bolt tail and pivotal scraper arm moving into contact with the bolt tail.
FIG. 9 is a view of a tool according to the present invention, with the distal end thereof inserted into a bolt tail, pivotal scraper arm in contact with the bolt tail and showing axial movement of the tool.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
As seen in FIG. 1 , the present invention provides a firearm maintenance tool 10 . The tool 10 is particularly adapted for use to clean both a bolt carrier 12 (seen in FIGS. 4-6 ) and a bolt 14 , especially the bolt tail 16 (as seen in FIGS. 7-9 ), of a firearm such as large caliber AR-10, SR-25, MK-11, or M-110, (not shown in these views) by way of non-limiting example. The tool 10 of the present invention preferably includes a proximal end 18 having a scraper head 20 , wherein the scraper head 20 is preferably provided with a scraping edge 22 . As may be seen particularly in FIGS. 4-6 , the scraper head 20 is preferably dimensioned to fit into the bore 13 of a selected bolt carrier 12 to be cleaned and is adapted to ream residue (not shown) by scraping action.
As may be further seen, a tool 10 according to the present invention further includes a distal end 24 . The distal end 24 is preferably provided with a longitudinally extending insertion pin member 26 . The pin member 26 is adapted for insertion into an end of a bolt 14 to be cleaned. As seen particularly in the views of FIGS. 7-9 , the pin 26 is adapted to be inserted into the bore 15 of a bolt tail 16 of the bolt 14 to be cleaned. The distal end 24 further preferably includes a pivotable scraper arm 28 . As seen in FIGS. 7-9 , the scraper arm 28 is pivotally affixed to the distal end 24 by acceptable means, such as the screw 30 shown, although other means may be envisioned. As illustrated, the scraper arm 28 may include a relatively flat anchor portion 32 and an extending arcuate portion 34 . As will be described, the distal end 36 of the arcuate portion 34 is adapted for scraping removal of residue from the bolt 14 and bolt tail 16 .
Cleaning of the bolt 14 and bolt tail 16 may be seen particularly in the views of FIGS. 7-9 . As illustrated, the pin member 26 is inserted into the bore 15 of the tail 16 of the bolt 14 in the direction of arrow A. The scraper arm 28 is rotated in the direction of arrow B to a position in which the distal end 36 of arcuate portion 34 is in contact with the tail 16 or other portion of the bolt 14 to be cleaned. As seen in FIG. 9 , cleaning of the bolt tail 16 is accomplished as the bolt 14 and tool 10 are axially rotated relative each other in the direction of arrow C while the end 36 of arcuate portion 34 is in frictional contact with the bolt tail 16 to be cleaned. It is to be understood that the exact dimension and size of the tool 10 may be varied to accommodate cleaning weapons of different caliber, as for example the smaller caliber AR-15 or M-16, by way of non-limiting example. For example, FIG. 3 illustrates an alternative embodiment of a tool 10 A according to the present invention. As seen, the tool 10 A may be formed having various dimensions to thereby allow use with other firearms (not shown).
A method of cleaning a bolt and bolt carrier of a firearm according to the present invention may include the steps of:
providing a bolt 14 and a bolt carrier 12 to be cleaned;
providing a cleaning tool 10 , the cleaning tool 10 including a proximal end 18 and a distal end 24 , the proximal end 18 being of a predetermined size capable of being inserted into a bore 13 of the bolt carrier 12 to be cleaned;
providing the proximal end 18 with a scraper head 20 , the scraper head 20 including at least one radially extending scraping edge 22 ;
inserting the proximal end 18 into a selected bolt carrier bore 13 to be cleaned, such that the scraping edge 22 is in contact with an inner wall of the bolt carrier bore 13 ;
axially rotating the tool 10 and the bolt carrier 12 relative to one another to thereby move the scraping edge 22 relative to the bore 13 to be cleaned;
providing the distal end 24 with a longitudinally extending pin portion 26 and a radially extending pivotal arm member 28 , the arm member 28 including an arcuate member 34 having a distal end 36 ;
inserting the pin portion 26 into the bore 15 of a selected bolt 14 to be cleaned; rotating the arm member 28 until the distal end 36 contacts an outer portion of the bolt 14 ;
axially rotating the tool 10 and bolt 14 relative to one another such that the arm member distal end 36 removes residue from the bolt 14 .
The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. | A firearm cleaning tool and method of use is disclosed in which multiple firearm components may be cleaned using a single tool. The tool includes cutting or scraping edges to ream residue, such as carbon deposits through a scraping action. The proximal end includes a scraping head with a scraping edge, and the distal end includes pivotable scraper arm and longitudinally extending insertion pin. A method of use is also contemplated. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national stage application of International Patent Application No. PCT/KR2012/006380, entitled “Ring for Enhanced Male Functions,” filed on Aug. 10, 2012, which claims priority to Korean Application No. 10-2011-0079865, filed on Aug. 10, 2011, the entire contents of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
The present invention relates to a ring for enhancing male functions and, more particularly, to a ring for enhancing male functions which can rapidly fasten and release ring segment members, strengthen erection while preventing separation of the ring, and prolong a sexual act by preventing premature ejaculation.
BACKGROUND
In general, erection of a penis is brought about by collective interaction of components of the endocrine system including nerves, blood vessels, the testes, and pituitary gland hormones, and the penis has a special structure to react to this process. The penis is formed of a cavernous body tissue, such as a sponge, including a number of blood vessels. When sexual stimuli including visual, aural, and tactile stimuli are applied, the blood vessels in the penis expand, a large amount of blood flows into the penis, and then the penis expands by blood pressure to become erect. Recently, due to complexities of social environments and stress from heavy workloads, however, a number of men suffer from erectile dysfunction and premature ejaculation preventing a normal sex life.
A background technique of the present invention is disclosed in Korean Patent Publication No. 2002-0043418 (published on Jun. 10, 2002 and entitled “Male function enhancement Ring”).
Since most male function enhancement rings sold in the market do not have an opening/closing device, a user must wait until erection subsides to remove the ring, or even when there is an opening/closing device, it is very difficult to open the ring. Accordingly, it is difficult to open the ring during full erection or a user must suspend a sexual act and wait until the erection subsides to open the ring. In addition, the opening/closing device of a typical male function enhancement ring is often unintentionally opened, causing user discomfort. Further, the typical male function enhancement ring has a limit in that when the penis becomes flaccid after the ring is fitted into the penis, the ring is likely to be lost due to separation from the penis.
Therefore, there is a need to solve such problems in the art.
SUMMARY
The present invention has been made to solve such problems in the art, and an aspect of the present invention is to provide a ring for enhancing male functions, which can rapidly fasten and release ring segment members and enables erection to be strengthened and prolonged for a long period of time by constricting the penis in stages even when the penis is not fully erect.
In accordance with one aspect of the present invention, a ring for enhancing male functions includes: a first ring segment member; a second ring segment member rotatably coupled at one end thereof to one end of the first ring segment member; and a fastening member rotatably provided to the other end of the second ring segment member and removably coupled to the other end of the first ring segment member, wherein the fastening member includes: a fastening plate hingedly coupled to the other end of the second ring segment member and a latch protrusion protruding from an inner surface of the fastening plate, and the first ring segment member includes a recess formed at the other end thereof and a latch rod disposed in the recess to be latched to the latch protrusion.
The fastening plate may include a plurality of latch protrusions protruding from the inner surface thereof, and the first ring segment member may include a plurality of latch rods disposed in the recess to be latched to the latch protrusions, respectively.
The fastening plate may cover the recess such that the recess is not exposed outside when the latch protrusion is latched to the latch rod.
The recess may be formed on an outer circumferential surface of the first ring segment member, and the fastening plate may cover the recess from above the recess.
The first ring segment member may further include a guide inclined surface formed on the outer circumferential surface thereof adjoining the recess.
The first ring segment member may further include a location checking portion formed on the other end thereof for informing of a direction in which the fastening member is latched to the first ring segment member.
The location checking portion may be formed of a different material or color than that of the first ring segment member.
The first and second ring segment members may form a ring shape when the latch protrusion is latched to the latch rod.
The first ring segment member may further include a plurality of first bosses protruding inward from an inner circumferential surface thereof and a first groove formed between adjacent first bosses, and the second ring segment member may further include a plurality of second bosses protruding inward from an inner circumferential surface thereof and a second groove formed between adjacent second bosses.
Each of the first and second bosses may have a greater slope from a rear end to a highest protruding point than a slope from a front end to the highest protruding point.
In accordance with another aspect of the present invention, a ring for enhancing male functions includes: a first ring segment member; a second ring segment member rotatably coupled at one end thereof to one end of the first ring segment member; and a fastening member, one end of which is rotatably provided to the other end of the second ring segment member and the other end of which is removably coupled to the other end of the first ring segment member, wherein the other end of the fastening member is located at a central portion of a ring shape formed by the first and second ring segment members when the fastening member is coupled to the other end of the first ring segment member.
The first and second ring segment members may be coupled to each other through a hinge, and a straight line connecting the hinge to the other end of the fastening member may form a centerline of the ring shape formed by the first and second ring segment members.
The first ring segment member may further include a guide inclined surface formed on the outer circumferential surface thereof adjoining the other end of the fastening member.
The first ring segment member may further include a location checking portion formed on the other end thereof for informing of a direction in which the fastening member is latched to the first ring segment member.
The fastening member may include a fastening plate hingedly coupled to the other end of the second ring segment member and a latch protrusion protruding from an inner surface of the fastening plate, and the first ring segment member may include a recess formed at the other end thereof and a latch rod disposed in the recess to be latched to the latch protrusion.
The first ring segment member may further include a plurality of first bosses protruding inward from an inner circumferential surface thereof and a first groove formed between adjacent first bosses, and the second ring segment member may further include a plurality of second bosses protruding inward from an inner circumferential surface thereof and a second groove formed between adjacent second bosses.
Each of the first and second bosses may have a greater slope from a rear end to a highest protruding point than a slope from a front end to the highest protruding point.
In accordance with a further aspect of the present invention, a ring for enhancing male functions includes: a first ring segment member having a first boss protruding inward from an inner circumferential surface thereof; a second ring segment member rotatably coupled at one end thereof to one end of the first ring segment member and having a second boss protruding inward from an inner circumferential surface thereof; and a fastening member rotatably provided to the other end of the second ring segment member and detachably coupled to the other end of the first ring segment member.
The first ring segment member may include a plurality of first bosses formed on the inner circumferential surface thereof and a first groove formed between adjacent first bosses, and the second ring segment member may include a plurality of second bosses formed on the inner circumferential surface and a second groove formed between adjacent second bosses.
Each of the first and second bosses may have a highest protruding point that is biased from a center thereof toward a rear end thereof.
Each of the first and second bosses may have a greater slope from a rear end to the highest protruding point than a slope from a front end to the highest protruding point.
In accordance with yet another aspect of the present invention, a ring for enhancing male functions includes: a first ring segment member; a second ring segment member rotatably coupled at one end thereof to one end of the first ring segment member; and a fastening member, one end of which is rotatably provided to the other end of the second ring segment member and the other end of which is removably coupled to the other end of the first ring segment member, wherein the other end of the fastening member is located at a central portion of a ring shape formed by the first and second ring segment members when the fastening member is coupled to the other end of the first ring segment member, wherein the fastening member includes a fastening plate hingedly coupled to the other end of the second ring segment member and a latch protrusion protruding from an inner surface of the fastening plate, and the first ring segment member includes a recess formed at the other end thereof and a latch rod disposed in the recess to be latched to the latch protrusion, wherein the first ring segment member further includes a plurality of first bosses protruding inward from an inner circumferential surface thereof and a first groove formed between adjacent first bosses, and the second ring segment member further includes a plurality of second bosses protruding inward from an inner circumferential surface thereof and a second groove formed between adjacent second bosses, and wherein each of the first and second bosses may have a greater slope from a rear end to a highest protruding point than a slope from a front end to the highest protruding point.
In accordance with yet another aspect of the present invention, a ring for enhancing male functions includes: a first ring segment member; a second ring segment member rotatably coupled at one end thereof to one end of the first ring segment member; and a fastening member, one end of which is rotatably provided to the other end of the second ring segment member and the other end of which is removably coupled to the other end of the first ring segment member, wherein the first and second ring segment members are mutually asymmetrically formed when the fastening member is coupled to the other end of the first ring segment member such that the first and second ring segment members form a ring shape.
According to the present invention, a ring for enhancing male functions is mounted on the penis and may be rapidly removed so as to reduce an accident occurring in an emergency, and can reduce aching and delay ejaculation when the highest state of sexual arousal and erection are reached.
Further, according to the present invention, a ring for enhancing male functions applies continuous pressure to the penis by bosses formed on the inner perimeter of the ring, whereby erection can be strengthened through pressure from the bosses even on an initially flaccid penis, and duration of the erection can be lengthened.
Furthermore, according to the present invention, inclined slopes of bosses formed on the inner perimeter of a ring for enhancing male functions are different at the front end and the read end, so that the ring for enhancing male functions can be prevented from falling off the penis, and since the ring for enhancing male functions may only be moved toward the base of the penis, the ring can be prevented from falling off the glans.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a ring for enhancing male functions according to one embodiment of the present invention;
FIG. 2 shows a cross section of a first boss of the ring for enhancing male functions according to the embodiment of the present invention;
FIG. 3 is a perspective view of the ring for enhancing male functions according to the embodiment of the present invention before a fastening member is coupled to a first ring segment member;
FIG. 4 is an enlarged view of the fastening member and the first ring segment member shown in FIG. 3 ;
FIG. 5 is a view of the ring for enhancing male functions according to the embodiment of the present invention, showing a state in which first and second ring segment members are drawn apart from each other;
FIG. 6 is a view of the ring for enhancing male functions according to the embodiment of the present invention, showing a state in which first and second ring segment members are coupled to each other; and
FIG. 7 is a view of the ring for enhancing male functions according to the embodiment of the present invention, showing a state in which the fastening member is coupled to the first ring segment member.
DETAILED DESCRIPTION
Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.
It should be noted that the drawings are not to precise scale and may be exaggerated in thickness of lines or size of components for descriptive convenience and clarity only.
Furthermore, terms used herein are defined by taking functions of the present disclosure into account and can be changed according to the custom or intention of users or operators.
Therefore, definition of the terms should be made according to the overall disclosure set forth herein.
FIG. 1 is a perspective view of a ring for enhancing male functions according to one embodiment of the present invention; FIG. 2 shows a cross section of a first boss of the ring for enhancing male functions according to the embodiment of the present invention; FIG. 3 is a perspective view of the ring for enhancing male functions according to the embodiment of the present invention before a fastening member is coupled to a first ring segment member; FIG. 4 is an enlarged view of the fastening member and the first ring segment member shown in FIG. 3 ; FIG. 5 is a view of the ring for enhancing male functions according to the embodiment of the present invention, showing a state in which first and second ring segment members are drawn apart from each other; FIG. 6 is a view of the ring for enhancing male functions according to the embodiment of the present invention, showing a state in which first and second ring segment members are coupled to each other; and FIG. 7 is a view of the ring for enhancing male functions according to the embodiment of the present invention, showing a state in which the fastening member is coupled to the first ring segment member.
Referring to FIGS. 1 to 7 , a ring 1 for enhancing male functions according to one embodiment of the present invention includes a first ring segment member 10 , a second ring segment member 20 , and a fastening member 30 . The ring 1 has a ring shape and is divided into the first and second ring segment members 10 , 20 .
The first ring segment member 10 forms one part (a left part in FIG. 1 ) of the ring 1 , and the second ring segment member 20 forms the other part (a right part in FIG. 1 ) of the ring 1 .
The fastening member 30 is provided to the second ring segment member 20 to be removably fastened to the first ring segment member 10 . When the fastening member 30 is fastened to the first ring segment member 10 , the first and second ring segment members 10 , 20 form a ring shape.
One end 10 a of the first ring segment member 10 is hingedly coupled to one end 20 a of the second ring segment member 20 . Thus, the first and second ring segment members 10 , 20 are coupled to each other to be rotated about a hinge h 1 .
The first segmented ring portion 10 has a recess 11 formed at the other end 10 b thereof. The recess 11 is formed on an outer circumferential surface of the first ring segment member 10 . According to the present embodiment, the recess 11 is closed at both sides and at a lower side thereof, and is open at an upper side thereof to be formed in a ␣ shape.
The lower side of the recess 11 is closed. Accordingly, the penis cannot press the fastening member 30 even when the penis becomes erect with the ring 1 worn on the penis, thereby preventing the fastening member 30 from being unintentionally separated from the first ring segment member 10 .
Latch rods 12 latched to latch protrusions 32 described below are arranged in the recess 11 . The latch rods 12 are formed in a shape of a cylindrical column connecting the sidewalls of the recess 11 facing each other and are arranged to be separated from each other.
The one end 20 a of the second ring segment member 20 is coupled to the first ring segment member 10 , and the other end of 20 b of the second ring segment member 20 is hingedly coupled to one end 30 a of the fastening member 30 . Thus, the fastening member 30 is provided to be rotated about a hinge h 2 relative to the second ring segment member 20 .
When the fastening member 30 is coupled to the other end 10 b of the first ring segment member 10 while rotating about the hinge h 2 (see FIG. 7 ) in a state in which the other end 10 b of the first ring segment member 10 and the other end 20 b of the second ring segment member 20 contact each other (see FIG. 6 ), the first and second ring segment members 10 , 20 form a ring shape.
The fastening member 30 includes a fastening plate 31 and the latch protrusions 32 . The fastening plate 31 is coupled to the other end 20 b of the second ring segment member 20 through the hinge h 2 . An outer surface of the fastening plate 31 has the same smooth surface as the first and second ring segment members 10 , 20 .
The latch protrusions 32 protrude from an inner surface of the fastening plate 31 and are latched to the latch rods 12 . According to the present embodiment, the latch rods 12 are formed in the shape of a cylindrical column, whereby the latch protrusions 32 contacting the latch rods 12 have a curved shape.
A plurality of latch protrusions 32 is arranged separated from each other. The plural latch protrusions 32 are latched to the latch rods 12 while being individually inserted into spaces defined between adjacent latch rods 12 .
The fastening member 30 and the first ring segment member 10 are fastened at a plurality of locations through the plurality of latch protrusions 32 and latch rods 12 . Accordingly, when the penis becomes erect while the ring 1 is worn on the penis, or external force is applied to the ring 1 , the fastening member 30 is prevented from being unintentionally separated from the first ring segment member 10 . As described above, according to the present embodiment, the fastening member 30 is separated from the first ring segment member 10 only when the latch protrusions 32 and the latch rods 12 are all released at a plurality of locations, thereby improving coupling strength between the fastening member 30 and the first ring segment member 10 .
When the latch protrusions 32 are latched to the latch rods 12 , the fastening plate 31 covers the recess 11 such that the recess 11 is not exposed to the outside.
According to the present embodiment, since the recess 11 is formed on the outer circumferential surface of the first ring segment member 10 , the fastening plate 31 that rotates about the hinge h 2 covers the recess 11 from above the recess 11 . Thus, the fastening plate 31 may prevent foreign substances from being introduced into the recess 11 .
A guide inclined surface 13 is formed on the outer circumferential surface of the first ring segment member 10 . The guide inclined surface 13 is formed on a portion of the outer circumferential surface of the first ring segment member 10 adjoining the recess 11 and guides a user's finger nail to the other end 30 b of the fastening member 30 .
When separating the fastening member 30 from the first ring segment member 10 , a user separate the other end 30 b of the fastening member 30 from the other end 10 b of the first ring segment member 10 such that the latch protrusions 32 and the latch rods 12 are released.
The guide inclined surface 13 slopes to the recess 11 to allow a thumbnail of a user's right hand to easily reach the other end 30 b of the fastening member 30 . When the nail of the user is attached to the other end 30 b of the fastening member 30 , the user lifts the other end 30 b of the fastening member 30 using the fingernail. When the other end 30 b of the fastening member 30 is separated from the first ring segment member 10 , the fastening member 30 rotates about the hinge h 2 in the clockwise direction (see FIG. 6 ).
When the fastening member 30 and the first ring segment member 10 are released as described above, the user can easily remove the ring 1 from the penis.
The first ring segment member 10 is provided with a location checking portion 14 on the outer circumferential surface thereof. The location checking portion 14 is disposed close to the guide inclined surface 13 . A user may rapidly recognize the other end 30 b of the fastening member 30 through the location checking portion 14 .
Since a user can remove the penis confined by the first and second ring segment members 10 , 20 from the ring by separating the other end 30 b of the fastening member 30 from the first ring segment member 10 , it is very important to rapidly recognize the location of the other end 30 b of the fastening member 30 in various emergency situations.
The location checking portion 14 is formed of a different material or color than that of the first ring segment member 10 . According to the present embodiment, the first ring segment member 10 is formed of silver and thus the location checking portion 14 may be formed of cubic zirconia or plastic having the feeling of a material completely different from that of the first ring segment member 10 .
Further, the location checking portion 14 may be formed in a red or blue color different from the inherent color of silver. As the location checking portion 14 is contrasted with the first ring segment member 10 , a user can more rapidly discover the location of the other end 30 b of the fastening member 30 through the location checking portion 14 .
When the fastening member 30 is coupled to the first ring segment member 10 , the other end 30 b of the fastening member 30 is located at a central portion of the ring formed by the first and second ring segment members 10 , 20 .
When the fastening member 30 is coupled to the other end of the first ring segment member 10 such that the first and second ring segment members 10 , 20 form the ring shape, the first and second ring segment members 10 , 20 are mutually asymmetrically formed.
The hinge h 1 is located at a lower central portion of the ring formed by the first and second ring segment members 10 , 20 , and the other end 30 b of the fastening member 30 is located at an upper central portion of the ring shape formed by the first and second ring segment members 10 , 20 . In other words, a straight line C connecting the hinge h 1 and the other end 30 b of the fastening member 30 forms a centerline of the ring shape formed by the first and second ring segment members 10 , 20 , namely, the ring 1 .
Since the other end 30 b of the fastening member 30 is not biased to one side of the ring 1 and is disposed at the upper central portion of the ring, a user may easily separate the other end 30 b of the fastening member 30 from the first ring segment member 10 with weak force.
Specifically, when the other end 30 b of the fastening member 30 is located at the upper central portion as in the present embodiment, the fastening member 30 can be easily separated from the first ring segment member 10 by using the thumbnail of the right hand. However, when the other end 30 b of the fastening member 30 is biased to one side such as a left or right side instead of the central portion, there is difficulty separating the fastening member 30 from the first ring segment member 10 using the thumbnail of the right hand. That is, separation of the fastening member 30 using the thumbnail of the left hand entails awkwardness of the nail direction, and separation of the fastening member 30 using the fingernail of the left hand index finger is not performed with ease since force of the index finger is weak and the fingernail is also weak. Accordingly, separation of the fastening member 30 can be most easily performed when the other end 30 b of the fastening member 30 is located at the upper central portion of the ring.
First bosses 16 protrude inward from an inner circumferential surface of the first ring segment member 10 . In the present embodiment, the first bosses 16 protrude inward by about 2 mm to 3 mm from the inner circumferential surface. A plurality of first bosses 16 is formed on the inner circumferential surface of the first ring segment member 10 and a first groove 17 is formed between adjacent first bosses 16 .
The first boss 16 and the first groove 17 adjoin each other on the inner circumferential surface of the first ring segment member 10 to form a wave shape.
Second bosses 26 protrude inward from an inner circumferential surface of the second ring segment member 20 . In the present embodiment, the second bosses 26 protrude inward by about 2 mm to 3 mm from the inner circumferential surface. A plurality of second bosses 26 is formed on the inner circumferential surface of the second ring segment member 20 and a second groove 27 is formed between adjacent second bosses 26 .
The second boss 16 and the second groove 17 adjoin each other on the inner circumferential surface of the second ring segment member 20 to form a wave shape.
While the first and second ring segment members 10 , 20 are fitted with the penis, the fastening member 30 is coupled to the first ring segment member 10 , as shown in FIG. 7 .
As the first bosses 16 protrude from the inner circumferential surface of the first ring segment member 10 and the second bosses 26 protrude from the inner circumferential surface of the second ring segment member 20 , the penis contacts the first and second bosses 16 and 26 even in a flaccid state. Thus, the ring 1 does not separate from the penis even when the penis is completely flaccid. This means that the ring 1 does not separate from the penis even in a situation, such as walking, in which impact is not applied, and thus, the ring 1 can be previously prevented from being lost when worn on the penis.
The penis is stimulated by contact with the first and second bosses 16 and 26 , and is thus more likely to become erect as compared with when not stimulated.
As erection progresses, the penis is expanded toward the first and second grooves 17 , 27 , whereby the thickness of the penis is further increased. Thereafter, pressure on the cavernous body of the penis increases, thereby strengthening erection, so that erection of the penis is much larger and stronger as compared with when the ring 1 is not used. Further, even when erection is maintained for a long period of time, the penis will not become flaccid. These effects can be more potently realized when the ring is continuously worn even at normal times in order to increase erection strength.
A highest protruding point M where the first boss 16 most highly protrudes inward is biased from a center to a rear end A of a cross section of the first boss 16 . With reference to FIG. 2 , the highest protruding point M of the first boss 16 is located closer to the rear end A than a front end B.
For the first boss 16 , a slope from the rear end A to the highest protruding point M is greater than a slope from the front end B to the highest protruding point M. This prevents the ring 1 worn on the penis from being separated from the penis unless intended by a user.
The ring 1 for enhancing male functions is fitted with the penis such that the rear end A thereof faces towards the base of the penis and the front end B orients towards the glans.
Since the slope from the front end B to the highest protruding point M is relatively moderate in the first boss 16 , the ring 1 can be easily fitted with the penis towards the root of the penis. On the other hand, since the slope from the rear end A to the highest protruding point M is relatively steep in the first boss 16 , it is difficult for the ring 1 to move towards the glans. Accordingly, the ring 1 moves toward the glans to be prevented from separating from the penis.
In the present embodiment, the inner surface of the ring 1 is formed to be symmetric with respect to the centerline C. Accordingly, like the first boss 16 , a highest protruding point where the second boss 26 most highly protrudes inward is biased from a center to a rear end of a cross section of the second boss 26 . The highest protruding point of the second boss 26 is located closer to the rear end than a front end.
For the second boss 26 , a slope from the rear end to the highest protruding point is greater than a slope from the front end to the highest protruding point. This prevents the ring 1 worn on the penis from being separated from the penis unless intended by a user.
Since the slope from the front end to the highest protruding point is relatively moderate in the second boss 26 , the ring 1 is easily fitted with the penis towards the base of the penis. On the other hand, since the slope from the rear end to the highest protruding point is relatively steep in the second boss 26 , it is difficult for the ring 1 to move towards the glans. Accordingly, the ring 1 moves toward the glans to be prevented from separation from the penis.
A smooth surface portion P is formed on the inner surface of the ring 1 on which the first bosses 16 , the first grooves 17 , the second boss 26 , and the second grooves 27 are formed. Accordingly, even when the inner surface of the ring 1 is formed in a concave-convex pattern, the penis can be prevented from being injured by a scratch due to the ring 1 .
Although some embodiments have been described herein, it should be understood by those skilled in the art that various modifications, changes, and alterations can be made without departing from the spirit and scope of the invention.
Therefore, the scope of the invention should be limited only by the accompanying claims and equivalents thereof. | The present invention relates to a ring for enhancing male functions, and comprises: a first sectioned ring member; a second sectioned ring member having one end portion which is rotatably coupled to one end portion of the first sectioned ring member; and a coupling member, which is rotatably provided on the other end portion of the second sectioned ring member, and which couples to the other end portion of the first sectioned ring member so as to be separable, wherein the coupling member comprises a coupling plate, which is hinged-coupled to the other end of the second sectioned ring member, and a stopper protrusion portion that is protrudingly formed on the inner surface of the coupling plate, and wherein the first sectioned ring member comprises, on the other end portion thereof, a groove portion, and a hooking rod, which is provided on the groove, for coupling to the stopper protrusion by means of hooking. | 0 |
This application is a continuation of prior U.S. application Ser. No. 08/014,705 filed Feb. 8, 1993, now abandoned.
FIELD OF THE INVENTION
The present invention relates to a process for crosslinking thermoplastic olefin silane copolymers and more particularly to a process for crosslinking pipe or cable containing thermoplastic olefin silane copolymers.
BACKGROUND OF THE INVENTION
There are a variety of ways to achieve the crosslinking of polyolefins such as polyethylene. The most common way is through the use of peroxide crosslinking agents added to the resin. The peroxides provide a source of free radicals when heated above their decomposition temperatures. These free radicals are capable of extracting a hydrogen from the polyolefin backbone thus transferring the free radical site to the polyolefin. With this accomplished, two polyolefin chains can crosslink together. When this is carried out through the matrix of the resin, the molecules become tied together with covalent bonds and a crosslinked network is formed.
Peroxide crosslinking provides molded articles with excellent high temperature properties, but care must be taken during the thermoforming process. For example, extrusion temperatures must be kept quite low. If extrusion temperatures are above the peroxide decomposition temperatures, premature crosslinking (scorch) may occur. This temperature restriction limits the rates at which peroxide curable polyolefin can be extruded.
A second method of crosslinking polyolefin is through the use of irradiation. In this case, the free radical formed on the polyolefin backbone is the result of electron beam irradiation. This technique overcomes the extrusion restriction for the peroxide crosslinked systems noted above, but has restrictions of its own. Specifically, thick sections of insulation become difficult to cure uniformly and products with non uniform cross sections pose a challenging engineering problem. In addition, high energy irradiation equipment is expensive and a significant amount of safety shielding is required.
In the above two methods of crosslinking, carbon-carbon bonds are formed at the crosslink sites. This is in comparison to the siloxane bonds which form in the third type of crosslinking--moisture cure.
Moisture cure involves the crosslinking of silane modified polyolefins. The technique is dependent on modifying the polyolefins backbone with a silyl trialkoxy moiety, preferably where the alkoxy is methoxy or ethoxy. The modified polyolefin will only crosslink in the presence of water. In practice, the resin has catalyst incorporated in it to speed up the crosslinking reaction. By excluding moisture, high temperature extrusions are possible and the material can still be processed as a thermoplastic. This allows for high line rates. After the extrusion, a separate curing step is conducted by placing the extruded system into a water bath or sauna. Usually the water bath is at an elevated temperature (70°-95° C.).
There are three routes for producing the silane modified polyolefin, all of them involving the same vinyl trialkoxysilane (VTAS), but they differ in the time sequence, the complexity and the procedure for adding the silane. In one such procedure, the silane is incorporated during the reaction with an olefin to make a polyolefin addition copolymer. The resin goes directly from a reactor to the fabricator's extruder without any grafting in compounding equipment. This ensures a high degree of cleanliness and excellent control of the density and molecular weight distribution of the product. The chemical structure of the produced compound insures that the product will have at least a two year shelf stability. In order to crosslink the silane copolymer most effectively, a catalyst such as a tin catalyst is required. This is usually supplied in the form of a catalyst masterbatch prepared in a separate compounding step. For optimum performance, the catalyst masterbatch must be dried prior to use.
In a second procedure for the production of modified polyolefin, peroxide-grafting of VTAS to polyolefin is accomplished. To accomplish this, a peroxide is mixed with the silane and the polyolefin and all these components are compounded at high temperatures. During this compounding step, grafting of the VTAS occurs. In addition, some peroxide crosslinking occurs. Producers of these "Sioplas" type products must start the compounding with a polyolefin which has a melt index of about 10. After the compounding, the grafted product has a melt index of the order of one. The drop is due to the partial crosslinking (undesirable) of the peroxide acting on the polyolefin. These products have the potential disadvantages of the presence of unreacted silane and peroxide and of difficulty in controlling the grafting step, yielding a variable final melt index. Furthermore, the specific chemical structure of the graft copolymer yields a product which only has about a six month shelf stability. Similar to the thermoplastic olefin silane copolymer produced by the first technique, the fabricator of "Sioplas" resins would blend the resin with a dried catalyst masterbatch in the extruder, process the system as a thermoplastic and cure the product off-line in a water bath.
The third route for producing the silane modified polyolefin is through what is commonly called the Monosil/BICC process (see for example U.S. Pat. No. 4,117,195). In this case, a polyolefin, normally a polyethylene, a vinyl silane, a tin catalyst and a peroxide are all mixed together in an extruder/reactor at the fabricator's plant. The extruder utilizes a long extruder screw with a L/D of about 30:1. This enables the components to be mixed and reacted (grafted) during the extrusion process. As in the case with the Sioplas technology, a significant drop in melt index occurs. Great care is needed to achieve the grafting without excessive crosslinking and some unreacted silane and peroxide may pass through the system and remain in the resin. The specialized extruders are more expensive than general purpose polyethylene extruders used for thermoplastic olefin silane copolymers.
A feature common to all these processes is that in the fabrication step the silane modified resin is being processed in the presence of the silanol condensation catalyst, generally a tin catalyst. Under this condition premature crosslinking, scorch, through condensation of silane moieties may occur thereby leading to changes in melt viscosity and extrusion instability. In those cases when scorch becomes severe the process must be terminated and the equipment cleaned to removed scorched polymer before beginning again. This results in high scarp production and costly equipment outage adding to the overall cost and complexity of operation.
The present invention obviates these problems by allowing the fabrication process to occur in the absence of the condensation catalyst but permitting rapid and essentially complete crosslinking through application of the invention disclosed herein.
The present invention is primarily directed to an improvement in the crosslinking process for thermoplastic olefin silane copolymers.
It is noted that in the conventional process, the following sequences are evident.
1. The olefin silane copolymers are in contact with a catalyst such as a tin catalyst in an extruder, where unfortunately scorching can take place;
2. Catalyst masterbatch is prepared in a separate compounding step and drying before use is generally required;
3. The curing step is conducted by placing the extruded article in a steam or water bath at high temperatures.
In order to promote curing or achieve a faster curing rate and control of scorch, a carboxylic acid, such as acetic, formic, propionic, butyoic, benzoic and like acids can be compounded with the olefin silane copolymer of step 1 (see for example U.S. Pat. No. 5,047,476 issued Sep. 10, 1991 assigned to a common assignee and U.S. Pat. No. 4,680,319 issued to Gimpel).
DISCLOSURE OF THE INVENTION
An object of the invention, therefore, is to provide a process for crosslinking a thermoplastic olefin silane copolymer which eliminates scorch.
A further object is to provide a process for crosslinking a thermoplastic olefin silane copolymer with reduced process steps and wherein a catalyst such as a tin catalyst is not required.
A still further object is to produce a process for crosslinking a thermoplastic olefin silane copolymer at faster production rates and at higher molding temperatures if required.
These and other objects will become apparent from the following description of the invention.
SUMMARY OF THE INVENTION
Broadly contemplated, the present invention provides a process for crosslinking a thermoplastic olefin-silane copolymer which comprises forming a thermoplastic silane copolymer in a thermoforming operation, such as an extrusion or molding operation into a shaped article and thereafter subjecting said thermoplastic olefin-silane copolymer shaped article to a solution, preferably a saturated solution, of benzoic acid in an amount and for a time sufficient to crosslink said thermoplastic olefin silane copolymer.
DETAILED DESCRIPTION OF THE INVENTION
The term "copolymer" as used in this specification can include silane grafted olefin homopolymers and copolymers, and copolymers of one or more olefin monomers and an olefin silane monomer. The monomers on which the homopolymers and copolymers are based can be alpha-olefins or diolefins having 2 to 20 carbon atoms, particularly the lower alpha-olefins having 2 to 12 carbon atoms. Preferably, a major proportion, i.e., more than 50 percent by weight, of each copolymer is attributed to ethylene, propylene, or 1-butene. The silane monomer, which is either grafted or copolymerized, is unsaturated and has at least one hydrolyzable group.
In addition to the alpha-olefin, diolefin, and silane monomers, the balance of the copolymer can be based on one or more various olefin monomers having 2 to 20 carbon atoms. Examples of useful monomers are the vinyl esters, alkyl methacrylates, and alkyl acrylates. Examples of these compounds are 1-hexene, 4-methyl-1pentene, 1-undecene, ethylene acrylate, vinyl acetate, methyl methacrylate, 1,4-hexadiene, ethylidenenorbomene, dicyclopentadiene, methyl, ethyl or butyl acrylate.
In this copolymer, the portion attributed to the silane is present in an amount of about 0.1 percent to about 10 percent by weight based on the weight of the copolymer and is preferably incorporated into the copolymer in an amount of about 0.5 to about 4 percent by weight. The silane used to modify the copolymer can be, among others, a vinyl trialkoxy silane such as vinyl trimethoxy silane, vinyl triethoxy silane, or vinyl triisopropoxy silane. Generally speaking, any unsaturated monomeric organosilane having one or more hydrolyzable groups can be used.
A copolymer of ethylene and silane can be prepared by the process described in U.S. Pat. No. 3,225, 018 issued on Dec. 21, 1965 or U.S. Pat. No. 4,574, 133 issued on Mar. 4, 1986. The portion of the copolymer attributed to the silane is in the range of about 0.5 to about 10 percent by weight based on the weight of the copolymer and is preferably in the range of about 0.5 to about 4 percent by weight.
Processes for preparing silane grafted copolymers and numerous unsaturated silanes suitable for use in preparing these polymers and bearing hydrolyzable groups such as alkoxy, oxy aryl, oxyaliphatic, and halogen are mentioned in U.S. Pat. Nos. 3,075,948; 4,412,042; 4,413,066; and 4,593,071.
The produced silane grafted or addition copolymers which are thermoplastic ethylene silane copolymers are then introduced into a processing zone for molding operations such as rotational molding, compressed molding, injection molding or extrusion apparatus to form the desired shaped thermoplastic article.
The processing zone can be a conventional extruder, e.g., a single screw type. A typical extruder has a hopper at its upstream end and a die at its downstream end. The hopper feeds into a barrel, which contains a screw. At the downstream end, between the end of the screw and the die, is a screen pack and a breaker plate. The screw portion of the extruder is considered to be divided up into three sections, the feed section, the compression section, and the metering section, and two zones, the back heat zone and the front heat zone, the sections and zones running from upstream to downstream. If it has more than one barrel, the barrels are connected in series. The length to diameter ratio of each barrel is in the range of about 16:1 to about 30:1.
The resident time of the mixture in the processing zone is, for example, of sufficient length to complete all or part of the extrusion or injection molding. This time is in the range of about 20 to about 2000 seconds and is preferably about 60 to about 1000 seconds.
Conventional additives can be added to the mixture introduced into the processing zone. The amount of additive is usually in the range of about 0.01 to about 50 percent based on the weight of the resin. Useful additives are antioxidants, ultraviolet absorbers, such as carbon black, antistatic agents, pigments, dyes, fillers, slip agents, fire retardants, such as mineral fillers, plasticizers, processing aids, lubricants, stabilizers, and smoke inhibitors. Blends of the hydrolyzable polymer and other polymers can be prepared in the processing zone provided that the resins to be blended with the hydrolyzable copolymer will not crosslink. Examples of these resins are low density polyethylene, high density polyethylene, polypropylene, linear low density polyethylene, and very low density polyethylene (with a density equal to or less than 0.915 grams per cubic centimeter).
The thermoplastic olefin silane copolymer exiting the processing zone is then available for crosslinking. Crosslinking can be effected by subjecting the shaped article to a solution of benzoic acid in an amount and for a time sufficient to effect crosslinking.
The benzoic acid can be employed as an aqueous solution of about 0.2% to about 3% by weight based on the weight of the solution. The amount to be employed depends on the temperature of the solution which can range from about 20° C. to about 95° C. It is preferred to employ the benzoic acid solution in the range of about 2.5% to about 2.8% by weight preferably about 2.7% by weight at preferred temperatures of about 75° C. to about 85° C.
The thermoplastic shaped ethylene-silane copolymer can be contacted with the benzoic acid solution in a variety of ways. In one technique, the shaped article is finally submerged in a solution of the benzoic acid. In another technique, the thermoplastic shaped ethylene silane copolymer can be sprayed with the solution of benzoic acid. In still another technique, the solution of benzoic acid is circulated through the article such as a pipe or liner. The appropriate technique would of course depend upon the type of article.
The amount of time required to fully crosslink would range from about 1/2 hour to about 12 hours depending on the concentration and temperature of the benzoic acid solution and the type of articles to be crosslinked.
The following examples will illustrate the present invention.
An ethylene silane copolymer was prepared by the technique described in U.S. Pat. No. 3,225,018. The copolymer had a melt index of 1.5 g/10 min. and a density of 0.923 g/cc. The copolymer was an addition copolymer of ethylene and vinyltrimethoxysilane. The copolymer is available from Union Carbide Chemicals and Plastics Company Inc under the tradename designation DFDA 5451. The copolymer was produced in pelletized form and plaques were formed by compression molding at a temperature of 135° C. To simulate the extrusion process some of the pellets were first melted in a Brabender mixer at a melt temperature of 180° C. before molding into plaques of 50 mils thickness. Another set of samples (control) were molded directly from the pellets. The control and processed samples were then exposed to a solution of benzoic acid maintained at 80° C. at the concentrations indicated in Table I. The processed samples were also exposed to water at 80° C. The gel levels in the samples were analyzed by decalin extraction at 0, 1/2, 2, 3 and 12 hour exposure time. The results are indicated in Table I. Torque rheometer data was also generated to ensure that the gel was not created during the extraction process itself. The rheometer test procedure is described in U.S. Pat. No. 4,108,582 issued on Apr. 19, 1977. The rheometer reading is in pound-inches (lb-in). The results are indicated in Table II.
TABLE I______________________________________Examples 0 1/2 1 2 3 12______________________________________ Exposure Time in 1% Benzoic Acid Solution at 80° C., Hour(1) 0.8 43.7 46.0 54.8 59.0 75.1DFDA 5451 moldedfrom pellet, % gel(2) 1.0 60.3 64.7 66.6 69.2 77.9DFDA 5451 moldedafter Brabender,% gel Exposure Time in Water at 80° C., Hour(3) 0.0 0.0 0.0 0.0 0.0 0.2DFDA 5451 moldedafter Brabender,% gel______________________________________
TABLE II______________________________________ Exposure Time in Saturated Benzoic Acid Solution at 80° C., HourExamples 0 1/2 2 12______________________________________(4)DFDA 5451 moldedafter Brabender,Torque lb-in 11 15 28% Gel 0.0 2.5 50.0 62.0______________________________________
The following Examples 5-8 demonstrate the unique effectiveness of the present invention when compared to another aryl carboxylic acid. Although it has been found that arylcarboxylic acids other than benzoic acid can be employed to effect crosslinking, acceptable crosslinking however can be only accomplished at much higher concentrations which present handling and operating problems. In these examples, the same type ethylene silane copolymer and processing conditions as employed in Example I was utilized.
The results are indicated in Table III
TABLE III______________________________________ Exposure Time in Crosslinking Solution at 80° C., HourExamples 30 Min 2 Hrs 12 Hrs.______________________________________(5) 0 0 0.625% Acetic Acid, % gel(6) 0 0 4920% Acetic Acid, % gel(7) 33 56 76Concentrated AceticAcid*, % gel(8) 0.8 55-67 75-781% Benzoic Acid, % gel______________________________________ *Not practical due to handling problem.
As can be seen from the foregoing examples 1-4, after two hours of exposure to a saturated solution of benzoic acid the level of gel easily reaches 50 to 60%. Benzoic acid has been known to help promote crosslinking in silane copolymers containing a catalyst masterbatch when it is included in the formulation. This finding shows that it is also quite effective in crosslinking systems containing 100% ethylene silane copolymers when they are exposed to a solution of benzoic acid. Under the conventional procedure, catalyst, usually a tin catalyst, is required to be added to ethylene silane copolymers for their cure. In the present invention, no added catalyst is needed in addition to the benzoic acid to crosslink ethylene silane copolymers. A control experiment was also performed by exposing the plaques of DFDA 5451 in plain water. In plain water at 80° C., straight DFDA 5451 did not crosslink. In all cases the level of gel was less than 1%.
The concept of the present invention can be utilized for a wide variety of purposes particularly for the cross linking of pipe liners and wire and cable coatings.
As is known, in the current conventional relining process, thermoplastic polyethylene liners are first collapsed or folded into various shapes such as "U, S, H, Star" shapes to reduce its cross sectional area. The deformed liner is next pulled through the decayed pipe to be rehabilitated. Following the insertion of the liner, it is re-expanded against the pipeline to its circular shape by heat and pressure. The heating medium can be steam or water. In more demanding applications, thermoplastic polyethylene is replaced by crosslinked polyethylene. A similar installation procedure as described above is also applicable for crosslinked liners. The crosslinked liners offer many advantages including improved elevated temperature properties, ESCR, chemical resistance and memory. Because they can not be fused together, their lengths need to perfectly match that of the pipeline to be rehabilitated.
In the present invention, this disadvantage is eliminated. The deformed polyethylene liner stays thermoplastic up to the inflation process. Moreover the ready to be crosslinked liner can be butt fused to the desired length as needed.
The composition of the polyethylene liner is 100% ethylene silane copolymers. The liner is fabricated by extruding the resin through an annular die. The amount of crosslinking that can occur in the extruder is negligible since no catalyst is used. Furthermore, no special control of the processing temperatures or residence time in the extruder is required. Once the collapsed liner is made and pulled through the pipeline to be rehabilitated, crosslinking is achieved by mixing benzoic acid according to the teachings of the present invention with hot water used to re-inflate the deformed liner back to its circular shape. The temperatures of the hot water may range from 50° to 90° C. The pressure of the hot water may range from 5 to 20 psi. | A process for crosslinking a thermoplastic ethylene silane copolymer which comprises forming the ethylene silane copolymer in a thermoforming operation into a shaped article and thereafter subjecting the thermoplastic ethylene silane copolymer shaped article to a solution of benzoic acid in an mount and for a time sufficient to crosslink the thermoplastic ethylene silane copolymer. | 2 |
BACKGROUND OF THE INVENTION
The following U.S. Pat. Nos. comprise the closest known prior art: 1,554,589; 3,920,144; 1,568,830; 4,054,184; 1,802,426; 4,114,664; 3,410,438.
As shown in the references cited above, there is known in the prior art a plurality of receptacles and drains for flushing automotive radiators, cooling systems, and the like. These receptacles generally comprise containers having a low height profile to enable them to be placed under a vehicle to receive and retain the effluent from the vehicle cooling system. Some of these devices include interior chambers which store the liquid, as well as drain means for disposing of the liquids in a proper manner.
In many situations in which such a device is to be used, it is important to collect all of the effluent from the cooling system without spillage, spattering, and the like. For example, professional mechanics usually try to maintain their work space in a tidy condition, for safety and convenience as well as for professional pride. Likewise, do-it-yourself auto mechanics who work at home also wish to prevent spillage of cooling system effluent, due to the fact that these liquids often contain rust and anti-freeze substances which will stain driveways and garage floors. There is an apparent deficiency in the relevant prior art, that deficiency being the lack of a drain receptacle which prevents spillage and spattering yet which is sufficiently portable to be moved from an effluent-receiving position beneath a vehicle, to a disposal position some distance away.
SUMMARY OF THE PRESENT INVENTION
The present invention generallly comprises a portable drain receptacle which is particularly adapted for receiving effluent from vehicle systems such as radiators, cooling systems, or the like. Its most salient features include a low height profile and supporting wheels or casters which permit the receptacle easily to be disposed beneath a vehicle, and to be rolled to a disposal position. The invention is also particularly adapted to prevent spattering during reception of the effluent from the vehicle, and to prevent spillage of the effluent while the receptacle is being translated to a disposal site.
The drain receptacle includes a coffer formed of a generally rectangular-based panel, and side walls formed integrally therewith and extending upwardly from the perimeter thereof. The side walls include a shoulder extending inwardly into the coffer and spaced slightly above the base panel. A salient feature of the invention is the provision of a matrix of orthogonally disposed, spaced apart panels which are supported at their distal ends by the shoulders and which extend upwardly approximately to the height of the side walls. The panels define a plurality of adjacent chambers which arrest spattering when liquid is drained into the coffer. The orthogonal panels also act to attenuate wave action in the effluent contained in the coffer, so that the receptacle may be turned, translated, or otherwise manipulated while full of liquid without spilling any of the contents.
A BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the drain receptacle of the present invention.
FIG. 2 is a plan view of the drain receptacle of the present invention.
FIG. 3 is an enlarged cross-sectional elevation taken along line 3--3 of FIG. 2.
FIG. 4 is an enlarged cross-sectional elevation taken along line 4--4 of FIG. 2.
FIG. 5 is an enlarged cross-sectional elevation showing the function of the drain receptacle of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention generally comprises a drain receptacle which is particularly adapted for use in draining and flushing vehicular radiators, cooling systems, and the like. As shown in FIG. 1, the drain receptacle of the present invention comprises a generally rectangular coffer 11 which is provided with a low height profile to facilitate free access for the receptacle in the low height clearance beneath vehicles. The coffer 11 is provided with wheels or casters 12 secured in subjacently depending fashion from the corners of the rectangular coffer.
With reference to FIGS. 3, 4, and 5, the coffer 11 is formed of a base panel 13 which is provided with the desired rectangular configuration. The coffer includes two pairs of opposed side walls 14 and 16 which extend in integral fashion from the perimeter of the base panel and are continuous about the perimeter. Each of the side walls 14 and 16 includes a shoulder 17 which extends inwardly into the cavity of the coffer, and which is spaced slightly above the base panel 13. The shoulder 17 extends continuously along each side wall 14 and 16.
Each of the side walls 14 and 16 also includes a lip 18 extending outwardly from the distal edge thereof. The lip 18 includes an oblique portion 19 extending upwardly and outwardly from the distal edge of the side wall, as well as a depending portion 21 which extends generally parallel to the side wall and is spaced outwardly therefrom. The oblique portion 19 is provided to aid in catching drips, spatters, and effluent, and also act to deter spillage caused by wave motion in the liquid retained in the coffer. The depending portion 21 adds strength to the outer rim of the device 11, and also forms a convenient handhold to faciliate manipulation of the receptacle.
With reference to FIG. 5, the base panel 13 is provided with a drain hole 22, as is also shown in FIG. 2. The drain hole 22 includes a plug 23 which is selectively removable to permit disposal of effluent collected in the receptacle 11.
A salient feature of the present invention is the provision of a matrix or lattice of panels 24 and 26 disposed in orthogonal relationship and received within the cavity of the coffer. The panels 24 and 26 extend upwardly, and are supported at their distal ends by the inwardly extending shoulders 17 of the side walls 14 and 16. The height of the panels is substantially equal to the distance between the shoulder 17 and the upper extent of the lip 18 of the side wall.
It may be noted that the lattice arrangement of the orthogonally related panels 24 and 26 defines a plurality of rectangular chambers 27 which are open at their upper and lower ends. The lower ends of the chambers 27 are in open flow communication with the generally flat flow space 28 extending between the base panel 13 and the lower edge of the lattice. The flat flow space 28 permits the liquid retained in the coffer 11 to achieve a common liquid level among all of the chambers 27.
With reference to FIG. 5, the chambers 27 serve to prevent spattering which may otherwise occur when a stream of effluent 29 is directed into the coffer. The spatters and flying droplets which are created as the stream 29 strikes the base panel 13 or the liquid surface thereabove are attenuated and arrested by the upwardly extending surfaces of the panels 24 and 26. These flying droplets might otherwise attain sufficient velocity and trajectory to soil the surrounding workspace.
Another important function served by the lattice of panel 24 and 26 is the attenuation of wave motion in the liquid entrained in the coffer 11. As is known in the prior art, shallow drain pans which are substantially full of liquid are difficult to translate laterally, due to the fact that any slight motion of the drain pan will cause sufficient wave action in the liquid stored therein to cause spillage over the sides of the drain pan. However, in the present invention, any significant amount of liquid retained in the coffer 11 will have a surface level disposed between the upper and lower extents of the panels 24 and 26. Due to the fact that wave motion is substantially a surface phenomenon, any wave front established in the liquid will almost immediately impinge upon the vertical surfaces of the walls 24 and 26, and be attenuated. As a result, the lattice prevents propagation of wave fronts across the surface of the liquid retained within the receptacle of the present invention. The outstanding benefit of this feature is that the receptacle 11 may be translated laterally; for example, the receptacle may be translated from a position beneath a vehicle to a disposal site with little or no risk of creating sufficient wave motion to cause spillage from the receptacle. Of course the wheels or casters 12 aid in this effect by providing smooth lateral translation of the receptacle.
With reference to FIGS. 3 and 4, the present invention provides concave recesses at the corners of the coffer 11 in which the wheels or casters 12 are secured. A concave panel 31 extends between the converging side walls 14 and 16 adjacent to their apex at a corner of the coffer 11. The oblique portion 19 of the lip 18 of the side walls extends at a shallower angle and is broader in width at this point in the structure. In the recess formed by the concave wall 31, the broad oblique panel, and the out depending portion of the lip 21, a block 32 is secured. Screws 33 or the like are received in the block 32 to secure the wheel or caster 12.
To employ the receptacle of the present invention, it is first rolled beneath a vehicle and disposed to receive effluent from a radiator, cooling system, or the like. The vehicle system has been opened to permit drainage therefrom, and the drain receptacle fills with the effluent from the vehicle's system. When the vehicle system is completely drained, it is re-sealed, and the drain receptacle is rolled from its position beneath the vehicle. At this point the drain receptacle may be rolled or otherwise transported to a disposal site where the plug 23 is removed from the drain hole 22, and the contents of the receptacle are released. Of course, the receptacle may be reused indefinitely. | A drain pan for radiators and cooling systems includes a base panel which is molded or otherwise formed into a coffer shape defined by upstanding side walls extendings continuously about the perimeter of the base panel. The side walls include an inwardly extending shoulder spaced slightly above the base panel to support a grid formed of a plurality of upwardly extending panels. The upstanding panels are equally spaced and oriented parallel to perpendicular axes to form a rectilinear matrix. The base panel includes concave recesses at the corners of the coffer to accommodate wheels or rollers affixed thereto. | 5 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] Not Applicable.
BACKGROUND
[0002] A well capable of producing oil or gas will typically have a well structure to provide support for the borehole and isolation capabilities for different formations. Typically, the well structure includes an outer structure such as a conductor housing at the surface that is secured to conductor pipe that extends a short depth into the well. A wellhead housing is landed in the conductor housing with an outer or first string of casing extending from the wellhead and through the conductor to a deeper depth into the well. Depending on the particular conditions of the geological strata above the target zone (typically, either an oil or gas producing zone or a fluid injection zone), one or more additional casing strings will extend through the outer string of casing to increasing depths until the well is cased to its final depth. Each string of casing is supported at the upper end by a casing hanger that lands in and is supported by the wellhead housing, each set above the previous one. Between each casing hanger and the wellhead housing, a casing hanger seal assembly is set to isolate each annular space between strings of casing. The last, and innermost, string of casing extends into the well to the final depth and is referred to as the production casing. The strings of casing between the outer casing and the production casing are typically referred to as intermediate casing strings.
[0003] When drilling and running strings of casing in the well, it is critical that the operator maintain pressure control of the well. This is accomplished by establishing a column of fluid with predetermined fluid density inside the well that is circulated down into the well through the inside of the drill string and back up the annulus around the drill string to the surface. This column of density-controlled fluid balances the downhole pressure in the well. A blowout preventer system (BOP) is also used to as a safety system to ensure that the operator maintains pressure control of the well. The BOP is located above the wellhead housing and is capable of shutting in the pressure of the well, such as in an emergency pressure control situation.
[0004] After drilling and installation of the casing strings, the well is completed for production by installing a string of production tubing that extends to the producing zone within the production casing. The production tubing is supported by a tubing hanger assembly that lands and locks above the production casing hanger. Perforations are made in the production casing to allow fluids to flow from the formation into the productions casing at the producing zone. At some point above the producing zone, a packer seals the space between the production casing and the production tubing to ensure that the well fluids flow through the production tubing to the surface.
[0005] Various arrangements of production control valves are arranged at the wellhead in an assembly generally known as a tree, which is generally either a vertical tree or a horizontal tree. A horizontal tree arranges the production control valves offset from the production tubing and one type of horizontal tree is a Spool Tree™ shown and described in U.S. Pat. No. 5,544,707, hereby incorporated herein by reference for all purposes. A horizontal tree locks and seals onto the wellhead housing but instead of being located in the wellhead, the tubing hanger locks and seals in the tree bore itself. After the tree is installed, the tubing string and tubing hanger are run into the tree using a tubing hanger running tool (THRT) and a locking mechanism locks the tubing hanger in place in the tree. The production port extends through the tubing hanger and seals prevent fluid leakage as production fluid flows into the corresponding production port in the tree.
[0006] The tubing hanger typically has a plurality of auxiliary passages that surround the vertical bore associated with the production tubing. The auxiliary passages provide penetration access through the tubing hanger from outside the tree for hydraulic, optical, and electrical components located downhole. Electrical, optical, and hydraulic lines extend downhole alongside the tubing to control and/or power downhole valves such as a surface-controlled subsurface safety valve (SCSSV), temperature sensors, electric submersible pumps (ESP), downhole processors, and the like, as well as possibly provide for chemical reagent injection. Other types of lines than those listed may also be extended downhole. As the tubing hanger is landed and set in the tree, the auxiliary passages in the tubing hanger typically wet mate with auxiliary connectors located in the tree itself that may lead to a control unit mounted to the tree assembly.
[0007] A disadvantage of the conventional type of subsea wellhead assembly is that the tubing hanger must be large enough to house the number of passages extending through it. In addition to housing the passages, the tubing hanger requires a certain amount of structural integrity to support the production tubing. Thus there are only so many auxiliary passages that may be included in a given size tubing hanger before the tubing hanger needs to be enlarged. A large diameter tubing hanger also requires a large diameter drilling riser and BOP through which the tubing hanger must be run prior to installing the tree. Additionally, if the tubing hanger is made longer, the tree must also be lengthened, resulting in additional costs and weight for both items.
[0008] Another disadvantage of the auxiliary passages is that different wells may require different functions. Thus, trees must be “customized” to meet the needs of the particular well. Whereas certain downhole functionality may be common among many wells, other types of functionality may be more optional. Building a “one-size-fits-all” tubing hanger/tree thus would be inefficient because unwanted functionality built into the tree/tubing hanger adds unnecessary size, weight, and cost to the completion. Manufacturing costs alone would cause inefficiencies because of the added complexity and labor of manufacturing auxiliary ports into a solid tree body.
[0009] Another concern is that the downhole functionality needs of any given well may change over the life of the well. Specifically, a well may produce fluids at high pressure during the initial life of the well, but the pressure may taper off in the later part. With the initial higher production, the tree needs to be able to handle pressure as high as 15,000 psi. With such a high pressure, there is usually little need to install an ESP or engineer the capability of powering and controlling the ESP through the tubing hanger because the fluid pressure is adequate for fluid production. However, the pressure may taper off to as low as 5,000 psi during the life of the well and may require the use of an ESP. If so, the entire tree and completion may need to be pulled and replaced to add the ESP capability, thus costing the well operator valuable time and money. The initial tree could be designed for ESP functionality, but would result in a higher initial cost of the tree itself.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more detailed description of the embodiments, reference will now be made to the following accompanying drawings:
[0011] FIG. 1 is an embodiment of a function spool installed on a well; and
[0012] FIG. 2 shows example auxiliary port connections that may be used in the function spool.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0013] In the drawings and description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results. Any use of any form of the terms “connect,” “engage,” “couple,” “attach,” or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art upon reading the following detailed description of the embodiments, and by referring to the accompanying drawings.
[0014] FIG. 1 illustrates an embodiment of a function spool 10 mounted onto a subsea wellhead 12 . Mounted on the function spool 10 opposite the wellhead 12 , FIG. 1 also shows a horizontal tree 14 . When the well is drilled and ready for completion, the function spool 10 and the horizontal tree 14 are lowered and installed onto the wellhead 12 using hydraulically operated collet connectors 18 , with seals being formed by appropriate gaskets as shown. Although not shown, appropriate valves for controlling fluid production from the horizontal tree 14 are located in or attached to the horizontal tree 14 . Additionally, any suitable connectors may be used instead of the collet connectors 18 . For example, the function spool 10 and horizontal tree 14 may be attached using a bolted flange.
[0015] When the well is ready for completion, appropriate plugs are set downhole from the wellhead 12 to maintain fluid pressure. The blowout preventer (BOP) and riser are then removed from the wellhead 12 and the function spool 10 and horizontal tree 14 are installed either in separate sections or both sections at the same time. The BOP and riser are then reattached to the horizontal tree 14 and the plugs removed from the well using an appropriate tool run in through the riser. When installed, the function spool 10 and horizontal tree 14 may then be pressure tested to confirm pressure integrity.
[0016] A tubing hanger running tool (THRT) is then used to lower a completion, including a tubing hanger 20 and a string of production tubing 22 , through the riser and land the tubing hanger 20 in the horizontal tree 14 . When landed, the THRT actuates a lock ring 21 at the top of the tubing hanger 20 that engages the horizontal tree 14 and locks the tubing hanger 20 in place. It should be noted though that any locking assembly may be used, such as expandable dogs that engage a corresponding profile in the horizontal tree 14 . The production tubing 22 extends below the tubing hanger 20 into the well and the tubing hanger 20 includes an internal bore 24 aligned on one end with the bore of the production tubing 22 . The other end of the internal bore 24 exits the tubing hanger 20 in alignment with a master production port 26 in the horizontal tree 14 for producing well fluids to the surface. Although not shown, the completion includes a rotational alignment means that aligns the tubing hanger 20 with the horizontal tree 14 for aligning the internal bore 24 with the production port 26 as the tubing hanger 20 is lowered into the set position.
[0017] The completion also includes a function mandrel 30 extending from the production tubing 22 below the tubing hanger 20 . As shown, the function mandrel 30 surrounds the production tubing 22 and is held in place by any suitable connection with the production tubing 22 , such as a threaded connection or welding. Instead of being housed in the tubing hanger 20 , the auxiliary function passages are located in the function mandrel 30 to interact with the function spool 10 . Such auxiliary function passages may be located in any position in the function mandrel 30 and may include passages 32 for electrical, optical, and hydraulic lines that extend downhole alongside the production tubing 22 to control and/or power downhole valves such as a surface-controlled subsurface safety valve (SCSSV), temperature sensors, downhole electric submersible pumps (ESP), downhole processors, and the like, as well as possibly provide for chemical reagent injection. Other types of lines than those listed may also extend downhole from the function mandrel 30 .
[0018] Corresponding to the functional passages 32 are ports 44 in the function spool 10 that provide access to the function passages 32 from outside the tree for controlling and/or powering the components located downhole. The auxiliary passages 32 typically house connectors that passively wet mate with auxiliary port connectors located in the function spool 10 and may take any suitable form, including vertical or horizontal connectors. The ports 44 in the function spool 10 also include connectors and may also lead to a control unit located subsea or on the surface. Additionally, although the tubing hanger 20 may interact with the horizontal tree 14 to align the radial angle of the tubing hanger 20 and thus the function mandrel 30 , the connection of the function mandrel 30 to the production tubing 22 may be designed to allow a certain amount of function mandrel 30 vertical and rotational movement. The ability of the function mandrel 30 to move allows for a certain amount of tolerance should the connectors not be perfectly aligned when the tubing hanger 20 is in the set position.
[0019] As an example, the function spool 10 includes an auxiliary passage 32 for housing a hydraulic fluid line 36 that extends downhole to an SCSSV (not shown). The SCSSV controls the flow of fluid through the production tubing 22 from the producing zone. The fluid line 36 extends from the SCSSV and into the function mandrel 30 and routes into a passive coupler 40 . Corresponding with the coupler 40 in the function mandrel 30 , the function spool 10 includes a vertical coupler 42 that can extend from the function spool 10 into alignment with the function mandrel 30 coupler 40 for a vertical stab connection as shown. The stab connection forms a fluid tight connection when the tubing hanger 20 lands in the horizontal tree 14 . From the coupler 42 , a port 44 extends through the function spool 10 and is accessible from outside the function spool 10 by a hydraulic control line 46 that extends to the surface. When connected, the hydraulic control line 46 enables surface control of the SCSSV for well operations. Alternatively, line 36 may be an electrical line for powering a downhole electric submersible pump (ESP) (not shown).
[0020] Also shown in FIG.1 is an example of another auxiliary passage 32 for housing an electrical line 50 for powering an ESP (not shown). The ESP is used to increase the fluid pressure for production fluids through the production tubing 22 from the producing zone. The electrical line 50 extends from the ESP and into the function mandrel 30 and routes into a passive coupler 52 . Corresponding with the function mandrel 30 coupler 52 is a horizontal coupler 54 that can extend from the function spool 10 into engagement with the passive coupler 52 for a horizontal stabbing engagement as shown. The stab connection thus forms a fluid tight connection between the electrical line 50 and an electrical line 56 located in a port 44 that extends through the function spool 10 and is accessible from outside the function spool 10 by an electrical line 60 that extends to the surface. When connected, the electrical line 50 thus enables surface control of the ESP for well operations. Alternatively, line 50 may be a hydraulic line that extends downhole to an SCSSV (not shown).
[0021] The examples shown are simply two possible types of connections that may be made through auxiliary ports in the function mandrel 30 and accessible from the function spool 10 . It should be appreciated that other types of connections may be made as well and that the connections shown in the examples may be used for different types of communication lines, such as for example, electrical, hydraulic, or optical. Additionally, there may be as many auxiliary ports as a given function mandrel 30 may allow. Because the function mandrel 30 is not being used to support the weight of the production tubing 22 , the function mandrel 30 does not require the robust structural integrity of a support body.
[0022] With the completion set, the well is ready for production. To create a barrier to fluid from escaping the internal bore 24 through the top of the tubing hanger 20 , plugs 62 are run into the internal bore 24 and set. The BOP and riser may then be removed from the horizontal tree 14 and retrieved. Using the hydraulic control line 36 , hydraulic fluid may be used to open the downhole SCSSV and allow fluid production to flow from the production tubing 22 , and into the production port 26 for flow to the surface or any other desired location.
[0023] At different times in the life of the well, the well may need additional or different downhole functionalities. For example, as already mentioned, fluid pressure may initially be adequate for fluid production but a downhole ESP may need to be added for production in the future. Additionally, various downhole sensors or processors may need to be added for ongoing production monitoring and management. With the function spool 10 and function mandrel 30 , the horizontal tree 14 and the tubing hanger 20 need be designed for connecting and supporting the production tubing 22 . The various functional connections are no longer made in the tubing hanger 20 but are instead made using passages in the function mandrel 30 and function spool 10 . The well operators may thus change out the function mandrel 30 and function spool 10 on an as needed basis during the life of the well without having to purchase an entirely new horizontal tree 14 , resulting in considerable cost savings. In addition, the horizontal tree 14 and tubing hanger 20 may be made smaller because they no longer need to house the functional connections, resulting in lower costs. Further cost savings result from a smaller horizontal tree 14 and tubing hanger 20 because of the increased mobility in particular of the horizontal tree 14 itself. With a smaller horizontal tree 14 and separate function spool 10 , the horizontal tree 14 and function spool 10 may now be transported and installed on the wellhead 12 separately using lower capacity cranes without requiring as robust equipment as trees that house all of the functional connections. Further cost savings may also be achieved in manufacturing because instead of each horizontal tree 14 being customized for each well, one horizontal tree 14 may be made for a larger number of wells with the function spool 10 and function mandrel 30 may be customized instead.
[0024] An additional benefit also arises for wells that do not require any downhole functionality to be built into a function spool 10 during the initial production of a well. In those cases, no or minimal functionality may be built into the tubing hanger 20 , such as control for an SCSSV, and the horizontal tree 14 may be installed on the wellhead 12 directly. Later in the life of the well, should additional downhole functionality be needed, the function spool 10 and function mandrel 30 may be added at that time, resulting in cost savings for the well operator from being able to continue using the original horizontal tree 14 and not having to install a full function tree for the initial production.
[0025] Additional examples of connections through the function mandrel 30 are shown in FIG. 2 that shows the function mandrel 30 engaging a coupling collar 70 and held in place with a capture ring bolted to the bottom of the function mandrel 30 . Extending into an auxiliary passage 32 is an electrical line 76 for powering and/or communicating with a downhole sensor (not shown), such as a pressure transducer. However, any downhole sensor may be suitable. The electrical line 76 extends from the sensor into the function mandrel 30 and ends with a threaded connector 77 that threads into a connector base 78 . The connector base 78 is held in place by an insulated ring 79 and includes a pin contact 80 . Corresponding with the connector, a power connector penetrator 82 is extendable from the function spool 10 into engagement with the pin contact 80 for a horizontal stabbing engagement as shown. The stab connection forms a fluid tight connection between the electrical line 76 and an electrical line in the port 44 that extends through the function spool 10 and is accessible from outside the function spool 10 by an electrical line that extends to the surface. When connected, the electrical line 76 thus enables power of and/or communication with a downhole electronic device, such as a downhole sensor.
[0026] FIG. 2 also shows another electrical line 76 for powering and/or communicating with any type of downhole electronic device (not shown), such as a downhole processor. The electrical line 76 extends from the electronic device and into a passage 32 of the function mandrel 30 and ends in a connector base 90 . Extending from the connector base 90 is an electrical contact 92 that extends past a milled portion of the function mandrel 30 . Seals 94 are located in the function mandrel 30 to isolate the milled portion of the function mandrel 30 from fluid pressure in the function spool 10 and flushing ports 96 in the function spool 10 are used to flush the fluid trapped in the milled portion out with appropriate electrical connection fluid. The electrical contact 92 extends into the milled portion and into electrical contact with a contact ring 98 to complete the electrical connection. The contact ring 98 provides a large enough area around the electrical contact 92 that exact placement of the electrical contact 92 with respect to the contact ring 98 is not necessary. Thus, the contact ring 98 does not require exact placement of the function mandrel 30 with respect to the function spool 10 . Although not shown, an electrical line extends from the contact ring 98 in the port 44 that extends through the function spool 10 and is accessible from outside the function spool 10 by an electrical line that extends to the surface. When connected, the electrical line 76 thus enables power of and/or communication with a downhole electronic device, such as a downhole processor.
[0027] While specific embodiments have been shown and described, modifications can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments as described are exemplary only and are not limiting. Many variations and modifications are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. | A production assembly and method for controlling production from production tubing supported by a tubing hanger in a well including a wellhead. The assembly includes a function spool engaged with the wellhead and a tree engaged with the function spool. The tubing hanger is landable in the tree bore such that the production tubing is supported in the well by the tree. A function mandrel separate from the tubing hanger is engaged with the production tubing and positionable inside the function spool bore. The function mandrel includes a passage connected to a line extending into the well that is connectable with a port in the function spool such that communication with a downhole component through the line is allowable from outside the function spool. | 4 |
This is a division of application Ser. No. 017,806 filed Mar. 5, 1987 now U.S. Pat. No. 4,719,156.
BAKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for improving the efficiency of an electrical power generation system. More specifically, a power source, which includes at least one battery comprising an anode and a liquid electrolyte that contains solid particulate, is integrated with a solids separation means. The solid separation means comprises an impeller, a container having an axis and inlet and outlet means. This system provides for the highly effective continuous separation of solid particulate from the electrolyte resulting in high efficiency in electrical power generation.
2. State of the Art
The operation of certain energy or power generation systems commonly utilized a recirculating liquid. Inherent in some of these systems is the possibility of a build up of solid discharge products. Thus, in metal/air batteries, which typically use a recirculating alkaline electrolyte, a metal oxide discharge product accumulates in the electrolyte. One such system is taught in U.S. Pat. No. 4,246,324, wherein spent electrolyte containing precipitated oxides may simply be removed from the battery container through a draining nozzle.
It has been recognized, such as in U.S. Pat. No. 3,359,136, that complete energy conversion systems may employ means for separating the metal oxide from the recirculating electrolyte. As discussed in this patent, oxide removal can maintain the concentration of the oxide reaction product in the electrolyte at a sufficiently low level for recirculation of electrolyte to a power source, such as a cell stack. As also disclosed in the patent, a separator can be useful to treat a portion of recirculating electrolyte. Such separator can constitute a self-cleaning filter, although the filter may require periodic scraping.
It is disclosed in U.S. Pat. No. 3,708,345, that the mechanically separated oxide reaction product may be conveniently stored near a mechanical separator apparatus for eventual removal. As more fully discussed therein, the suspended zinc oxide reaction product which is separated, can find use as in recharging the zinc electrodes.
Impeller-fluidizers have been proposed for mixing and separating, e.g., separating at least one liquid of different densities. In U.S. Pat. No. 3,129,066 such an apParatus, containing a perforate, generally cone-shaped, solids accumulating barrier within the fluidizer container, is taught as useful for the separation of at least one solid of different density from an entraining liquid.
Also, as in U.S. patent application Ser. No. 843,055 of M. A. Petrick et al, there is described an impeller-fluidizer apparatus that can be useful for separating an entrained solid in a slurry fed to the apparatus. A product high in particulate concentration as well as one of very low particulate concentration may be produced, particularly in a cascading series of discrete fluidizer elements.
It would nevertheless be desirable if an entire power source and solids discharge separation system could be integrated to handle the continuous separation of solid particulate from the electrolyte to provide enhanced and efficient energy generation from metal/air batteries. It would also be desirable if such separator system for solids removal could operate most economically at low power requirements while integrated into such a continuous flow operation system that is operating with copious amounts of recirculating electrolyte. It would furthermore be advantageous if the system could not only operate on a continuous basis, but could do so without frequent interchange of critical elements, e.g., without interchange of used filters.
SUMMARY OF THE INVENTION
A novel method and system for improving the efficiency of electrical power generation, particularly from batteries comprising a consumable anode and a liquid electrolyte cdntaining solid particulate, has been discovered.
In accordance with the present invention, there has now been devised an efficient solids separation system useful, e.g., with metal/air batteries, which may provide for the continuous and efficient removal of solid particulate discharge products so as to maintain such products at desirably low levels in circulating electrolyte.
Further in accordance with the present invention, solids removal may be accomplished economically while providing for removal of even extremely finely divided particles.
Still further in accordance with the present invention, the system may be operated on a continuous basis while exhibiting freedom from plugging. Thus, the system does not rely on the need for interchange of critical parts, such as filters, during operation.
Still further in accordance with the present invention, the solids separation means is largely unaffected by changes in flow rate, changes in solids concentration and relatively minor changes in the specific gravity of the liquid phase.
Still further in accordance with the present invention, the solids separation means may operate with a differential pressure between the high solids concentration outlet means and the separated low solids concentration outlet means, and may further operate without a break in system pressure.
Still further in accordance with the present invention, a highly efficient electrical power generation system has been developed that is relatively small in size, light weight, operates with minimal input power requirements and is self-pumping.
Still further in accordance with the present invention, a system is provided comprising: a battery stack producing an unstable precursor material of an oxide solid in a liquid electrolyte withdrawn from the battery stack as battery effluent; an impeller-equipped container having an axis; means for conveying the battery effluent to the container; means for withdrawing solids-concentrated effluent from an annulus zone of the container; and means for withdrawing supernatant liquid from the container from a zone removed from such annulus zone, coupled with means for recycling withdrawn supernatant liquid to the battery stack.
These and other aspects of the invention will become clear to those skilled in the art upon the reading and understanding of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of an electrical power generation system according to the present invention including cell units and solids discharge removal means integrated therewith.
FIG. 2 is a side elevational view, partly in section, of a preferred apparatus useful in the invention solids separation system.
FIG. 3 is a graph illustrating how the electrolyte conductivity is reduced as a function of solids concentration.
The invention will be further described in connection with the attached drawing figures showing preferred embodiments of the invention including specific parts and arrangements of parts. It is intended that the drawings included as a part of this specification be illustrative of the preferred embodiments of the invention and should in no way be considered as a limitation on the scope of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A highly effective system has been developed that enhances electrical power generated and improves the efficiency of the operation of batteries or electrochemical cells.
The terms electrochemical cells, or batteries, as used herein, refer to those cells for generating electrical power comprising an anode, a cathode and an electrolyte. For such cells numerous anodes and cathodes have been used. An air cathode and a metal anode, however, has been found to be particularly useful for the purposes of the present invention. Thus for convenience, such cells are often referred to herein as metal/air batteries.
It is to be understood there can be used in addition to air as the cathode such alternative sources as are known to those skilled in the art, e.g., oxygen, ammonia, chlorine and carbon dioxide.
Materials useful for the anode may be any electroconductor used in such electrochemical cells which includes metals, metalloids, alloys and heavy metal salts. It is preferred for the purposes of the present invention that the anode is a consumable material. Such metals as zinc, aluminum, lead, lithium and the like are preferred. Aluminum is the most preferred for the purposes of the present invention which includes the alloys, metalloids and intermetallic mixtures thereof. During cell operation, i.e., power generation, a solids discharge product will accumulate in the electrolyte as a by-product of the electrical power generation. As used herein, the term "solids discharge product", is intended to include any such solids as will be contained in the electrolyte upon consumption of the anode. Usually this product will consist mostly of a metal oxide. Where zinc is included in the anode metal, the solids contained in the electrolyte may be referred to as zinc oxide or zinc hydroxy complex. In the case of anodes containing aluminum, the solids discharge product will contain hydrargillite, i.e., Al 2 O 3 ·3H 2 O and similar oxide complexes.
This discharge product is formed from the unstable precursor material MA1 (OH) 4 where M is usually K or Na depending on the electrolyte used. This precursor is produced by the electrochemical reaction at the anode. This anode reaction product is unstable and breaks down to the solids discharge product Al 2 O 3 .3H 2 O and the electrolyte MOH. This reaction is further illustrated below.
2 Al(OH).sub.4 →20H+Al.sub.2 O.sub.3.3H.sub.2 O
The cathode will be of a porous sheet type construction. Useful cathodes include those prepared typically as a carbon/polymeric binder matrix of a lipophobic (e.g., hydrophobic) polymer. Generally, this structure will be a catalyzed carbon matrixed with particles of halocarbon polymer binders. The hydrophobic polymer will generally contribute from about 10 to about 50 weight percent of the matrix. The carbon typically is very finely divided, e.g., particles are within the range of from about 0.01 to about 0.1 micron. The halocarbon polymer binder, i.e., a fluorocarbon polymer, may be combined with other polymeric materials which also may be finely divided. The carbon in the matrixed material may be activated such as by a platinum catalyst. Such cathodes have been disclosed for example in U.S. Pat. No. 4,354,958 which is incorporated herein by reference for such disclosure.
More specifically, the internal surface of the activated porous cathode wall, that is, the surface towards the interior of the porous sheet, is impregnated with a lipophobic resin such as a polyethylene, polypropylene, polytetrafluorethylene, polychlorofluoroethylene, various vinyl resins, and the like, in such a way as to let the resin penetrate inside the pores for a certain depth from the surface but without reaching through the entire thickness of the porous cathode. The resin partially coats the surface of the pores near the internal surface of the cathode and imparts hydrophobic properties to the gas side layer of the porous cathode.
Electrolytes that are useful in the electrochemical cells of the present invention include any material or medium capable of passing electrical current, i.e., ionically conductive, and is compatible with the respective anode and cathode materials of the present invention. In other words, the electrolyte not only must be capable of passing electrical current but also must be electrochemically reactive with the anode material while being more electropositive than the cathode.
In a preferred embodiment of the present invention, the electrolyte is an alkaline solution of an alkali or alkaline earth hydroxide. Alkali metal hydroxides are the most preferred. Although the use of a particular hydroxide or blend of hydroxides may depend upon the metal constituency of the anode if the anode contains aluminum, the hydroxide of choice making up the electrolyte is KOH or NaOH.
With respect to the solids separation means, a simple means of producing locally confined fluidized beds of fine particles is used. The particles are held dynamically within a cylindrical vessel by the interaction of centrifugal force and convection, both produced by impeller-driven swirling flow. The fluidized bed is maintained in a zone adjacent to clear fluid with or without mechanical barriers such as screens. Centrifugal force, due to swirling flow, moves particles radially outward, and secondary flow sweeps them along the walls from the impeller into a rotating, torroidal bed. Clear fluid passes through the fluidized zone. Upon leaving the fluidized zone, the fluid is stripped of particles by centrifugal force. At high impeller rotation rates, the fluidized bed becomes small and sharply defined. This phenomenon may handle, without entrainment losses, particles of at least 10 times smaller than the lower limit in conventional fluidization. Mass transfer controlled processes may possibly be reduced in volume by a factor of up to 100, the gain coming from the higher surface area of the smaller particles and their more favorable mass transfer coefficients.
A very important feature of the present invention is that the solids separation means not only serves to separate the solids discharge product but also may serve as a pump to draw electrolyte into the container for separation. Therefore, the entire system may operate without any additional pumps. This is a major advantage since pumps generally require monitoring and are obviously an additional cost factor. Furthermore, this solids separation means has the additional advantage of being substantially unaffected by changes in flow rate, changes in solids concentration and relatively minor changes in the specific gravity of the liquid phase when in operation.
FIG. 1 illustrates a flow chart of a power generation system within the scope of the present invention. Cell stack 12, which comprises at least one aluminum/air battery, has air inlet 11 and outlet 13. Cell stack 12 also has electrolyte inlet 21 and outlet 22 for the continuous circulation of electrolyte within the cell stack and to the solids separation means.
While the system is operating valve 14 is open and electrolyte liquid fills sump 15. Valve 16 is open to allow electrolyte to be drawn into solids separator 17 (e.g., as illustrated in FIG. 2). The electrolyte depleted of solids at 18 may be recirculated to cell stack 12. The solids containing liquid is taken off at 19 and fed to de-watering means 20. Fresh electrolyte may then be recirculated to cell stack 12 from outlet 23.
FIG. 2 illustrates an impeller fluidizer, shown generally at 2, has a cylindrical container or canister 3 equipped with an impeller 4 at the bottom of the canister 3. The impeller 4 is connected by a drive shaft 5 with a power source, not shown. A slurry inlet 6 feeds battery electrolyte effluent containing solids discharge product, from a battery stack, not shown (see FIG. 1). Within the canister 3 the solids entering through the slurry inlet 6 concentrate at the end of the canister 3 forming an annulus opposite from the impeller 4. The solids form a concentrated solids-containing zone 7 at such end. From this solids-containing zone 7 a concentrate product can be removed from the canister 3 through a solids product outlet 8. Nearer the impeller 4, supernatant electrolyte can be removed from an electrolyte product outlet 9. The electrolyte product from this outlet 9 can then be recycled to the battery stack, not shown.
The invention is further illustrated in the following examples. While these examples will show one skilled in the art how to operate within the scope of this invention, they are not to serve as a limitation on the scope of the invention where such scope is defined only in the claims.
EXAMPLE 1
For this Example, the electrolyte used was a five molar aqueous electrolyte of potassium hydroxide. The electrolyte was circulated in the system. Upon initiation of the test the electrolyte contained hydrargillite (Al 2 O 3 3H 2 O) particulate. This solid, in crystal form, has virtually all particles more finely divided, i.e., finer than 10 microns with the major portion of the particles, i.e., rreater than 50 weight percent, being more finely divided than 5 microns.
The separator used consisted of an 8 inch long by 2 inch diameter polysulfone cylinder with polysulfone end plates. The cylinder had two tangential outlet ports. One of these ports, located at the cylinder end opposite the impeller, was for the removal of concentrated slurry product. The other outlet port, adjacent the impeller was for removal of cleaned, supernatant liquid. The container also had an inlet port, at the container mid-section for introducing the test electrolyte to the separator. The impeller was 13/4 inch by 1/2 inch by 1/16 inch nickel 200 sheet attached to a nickel shaft using nickel pins. A Hastelloy C face seal was used to seal the shaft in the polysulfone seal housing. Such impeller-fluidizer has been more particularly described in the U.S. patent application Ser. No. 843,055.
The impeller-fluidizer was operated at 7000 rpm. Under these conditions approximately 86.4 percent by weight of the heavy particles (greater than 10 microns) and 13.6 percent by weight of the lighter particles (less than 10 microns) concentrated at the end of the fluidizer away from the impeller. The balance of the mass of particles remained fluidized throughout the electrolyte, but as such, were judged to be sufficiently suppressed for recirculation of the electrolyte for use in an aluminum/air battery cell stack.
EXAMPLE II
For this Example, the same solids-separator device as described in Example I was employed. The electrolyte employed was 5M KOH and contained over 0.7 percent by weight solids. This electrolyte was circulated at a rate of 2.5 gallons per minute with 320 ml/min. discharge of solids.
The impeller-fluidizer was operated at 5000 rpm and under such conditions approximately 0.66 percent by weight of light solid particles (less than 10 microns) and 1.48 percent by weight of heavy solid particles concentrated at the end of the fluidizer away from the impeller. The balance of the mass of particles remained fluidized throughout the electrolyte, but as such, were judged to be sufficiently suppressed for recirculation of the electrolyte for use in an aluminum/air battery cell stack.
EXAMPLE III
In this Example several trials were run with an electrolyte that contained Al 2 O 3 .3H 2 O having a particle size in the range of 44-150 microns and another set of trials were conducted with an electrolyte that contained Al 2 O 3 ·3H 2 O having an average particle size of 3.48 microns. The same solids-separato described in Example I was employed for this Example. The solids-separator device functioned as both a system pump and as a solids separation device. The results from these trials and the operation conditions are reported below in Table I. Excellent solids separation was obtained for the larger particles. Poorer separation of the smaller particles was obtained, however this may be improved by operating the device at a higher rpm.
TABLE I__________________________________________________________________________ % Solids Conc Stream Flowrate Conc StreamParticle Size Test No. % Solids Dilute Stream Flowrate Dilute Stream__________________________________________________________________________44-150 microns 1 17.9.sup.1 :1 0.36:1 1 (repeat) 16.1.sup.1 :1 0.37:144-150 microns 2 48.9.sup.1 :1 0.17:13.48 microns 3 1.7.sup.2 :1 0.41:13.48 microns 4 2.3.sup.2 :1 0.17:1__________________________________________________________________________ .sup.1 Weight % of heavier particles (i.e., larger particles) removed. .sup.2 Weight % of lighter particles (i.e., smaller particles) remaining in electrolyte after separation. The ratios shown illustrate the efficiency at which the device is separating (i.e., concentrating) the solids. The ratio of the concentrated to dilute flowrates has a large effect on the separation efficiency. At lower flowrates, the heavier particles have a longer residence time in the solids separator and, in turn, the efficiency is enhanced.
EXAMPLE IV
An aluminum/air battery was tested to illustrate the reduction in operating voltage with increasing solids content in the electrolyte. The initial trial was conducted using 5M KOH electrolyte having no dissolved aluminum or solid alumina. Solid alumina (Al 2 O 3 3H 2 O) particles of approximately 3.48 micron size were slurried with the electrolyte at 60 degrees centigrade. Conductivity measurements were taken with a Foxboro conductivity meter at different solids concentration levels. From the conductivity values, an electrolyte ir drop based on a 2 mm anode/cathode gap was calculated. The graph of FIG. 3 shows how the electrolyte conductivity is reduced as a function of solids concentration. This is represented as an electrolyte ir drop. Voltage is the sum of the cathode potential, anode potential, and electrolyte ir.
In addition to reduction of the electrolyte conductivity, some other practical problems arising from high solids content in an electrical power generation system are:
1. Scaling of the process equipment, especially the heat exchanger thus reducing heat exchanger efficiency.
2. Destruction of the valve seats, etc. by the abrasive action of the alumina.
3. Physical damage to the air cathodes due to the abrasiveness of the alumina.
4. Plugging of all the electrolyte inlet orifices.
5. Increased pumping energy required by the increased viscosity of electrolyte.
While the invention has been described and illustrated with reference to certain preferred embodiments thereof, those skilled in the art will appreciate that various changes, modifications and substitutions can be made therein without departing from the spirit of the invention. For example, the system and process may be utilized with most means that produce solid particulate in a circulating liquid medium and that requires the solid particulate be removed from the liquid medium. It is intended, therefore, that the invention be limited only by the scope of the claims which follow. | Batteries comprising an anode and liquid electrolyte produce an electrolyte effluent which may contain a solid particulate discharge. This discharge product inhibits the efficient generation of electrical power by the battery. It has been discovered that this solid particulate discharge may be effectively and economically separated from the electrolyte on a continuous basis by a solids separation means comprising a container having an axis and an impeller. This system provides for the efficient generation of electrical power. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of U.S. patent application Ser. No. 13/159,801 filed Jun. 14, 2011, which is a continuation in part of U.S. patent application Ser. No. 12/795,218 filed Jun. 7, 2010 which issued as U.S. Pat. No. 8,109,360 on Feb. 7, 2012, which is a continuation in part of U.S. patent application Ser. No. 12/355,730 filed Jan. 16, 2009 which issued as U.S. Pat. No. 7,866,438 on Jan. 11, 2011, which is a continuation-in-part of U.S. patent application Ser. No. 12/163,929 filed Jun. 27, 2008 which issued as U.S. Pat. No. 7,861,825 on Jan. 4, 2011, all of which are incorporated by reference in their entirety herein.
BACKGROUND OF THE INVENTION
[0002] (1) Field of the Invention
[0003] The present invention relates to a loudspeaker system for mounting in a suspended ceiling comprising a support frame and back box assembly and a removable speaker cartridge.
[0004] (2) Background of the Invention
[0005] Suspended ceilings, consisting of ceiling tiles supported by a grid of t-bar frames, are common in business as well as in some residential environments. It is often desired to mount loudspeakers in suspended ceilings to provide for communications and/or entertainment. Consequently, various types of loudspeaker systems have been developed for installation in suspended ceilings.
[0006] One type of prior art ceiling loudspeaker system consists of a loudspeaker mounted to a conventional ceiling tile. A hole is cut in the ceiling tile to accommodate the speaker, and the speaker is mounted to the tile over, in, or adjacent to the hole. The size of speaker that can be used in this type of loudspeaker system is limited because conventional ceiling tiles have limited structural strength and in some cases are rated by the manufacturers as having no structural strength at all. FIG. 1 shows a modification of this type of ceiling loudspeaker system that adds a support frame that provides additional support for the loudspeaker. As shown in FIG. 1 , the support frame includes support bars 105 and 110 that extend across the back of a ceiling tile 115 to t-bar frames (such as t-bar frame 120 ) that support the ceiling tile, and a support ring 125 that is mounted to support bars 105 and 110 adjacent to the hole 130 in ceiling tile 115 . The speaker is mounted on support ring 125 so that some or all of the weight of the speaker is supported by the support bars and ring and not just the speaker tile, allowing a heavier speaker to be used. The speaker can be a single speaker or can be a speaker assembly that includes multiple speakers. A further modification of this type of ceiling loudspeaker system adds a metal “can” to the back of the speaker assembly that is intended to comply with fire codes for plenum installations.
[0007] An example of a ceiling speaker assembly that includes a back can and that is intended to be mounted in a ceiling tile using a support frame like that shown in FIG. 1 is the S126CT model ceiling speaker sold by Extron Electronics, which is shown in FIG. 2 . As shown in FIG. 2 , the S126CT ceiling speaker assembly 200 includes a woofer 205 with a coaxially mounted tweeter 210 mounted to a speaker frame 215 . A metal back can 220 is mounted to the back of speaker frame 215 forming a chamber that encloses the back side of woofer 205 . A removable panel in the back of metal back can 220 (not shown) provides access for electrical connections to the speaker unit. A crossover circuit may also be mounted to the rear of woofer 205 . Internal speaker wires lead from the crossover circuit to each of woofer 205 and tweeter 210 . To improve the acoustic response, a port 225 is formed in speaker frame 215 . A plurality of mounting doglegs (sometimes referred to herein as “dogs” or “flip dogs”) 230 are attached to the rear of speaker frame 215 . To mount speaker assembly 200 onto a ceiling tile, an appropriate hole is cut into the ceiling tile. A support frame such as that shown in FIG. 1 is installed on top of the ceiling tile. The rear of speaker assembly 200 is inserted into the hole in the ceiling tile from the bottom until speaker frame 215 is flush against the bottom surface of the ceiling panel. Mounting dogs 230 are then pivoted such that the ends of their doglegs are disposed over the support ring on the back side of the ceiling tile, thereby securing speaker assembly 200 to the ceiling tile and support frame.
[0008] Another type of ceiling speaker is a “lay-in” ceiling speaker, an embodiment of which is disclosed, for example, in U.S. Pat. No. 6,944,312 issued to Mason et al. entitled “Lay-In Ceiling Speaker.” The lay-in speaker disclosed in Mason et al. is intended to replace an entire ceiling tile. It consists of a speaker mounted to a perforated metal grille, which is crimped to a fiberglass back box, forming a generally rigid loudspeaker assembly that has the same lateral dimensions as a standard ceiling tile and that can be mounted in a suspended ceiling simply by removing an existing ceiling tile and putting the “lay-in” loudspeaker assembly in its place, the edges of the “lay-in” speaker resting on the t-bar support frames of a suspended ceiling in the same manner as a ceiling tile. When installed, the visual appearance of a lay-in speaker is that of a perforated grill having the size and shape of a ceiling tile.
[0009] Although lay-in speakers are easy to install, sometimes the visual appearance of a tile-mounted ceiling speaker is preferred over the appearance of a lay-in speaker. Until now, there has been no ceiling speaker assembly that combines the ease of installation of a lay-in speaker with the aesthetics of a tile-mounted ceiling speaker.
BRIEF SUMMARY OF THE INVENTION
[0010] The present invention comprises a method and apparatus for installing a tile-mounted ceiling speaker that combines the ease of installation of a lay-in speaker system with the visual appearance of a tile-mounted speaker system. In one or more embodiments, the apparatus of the present invention includes a support frame and back box assembly configured for installation on top of a ceiling tile and a loudspeaker cartridge configured to be mounted to the support frame through an appropriately-sized hole in the ceiling tile. In one or more embodiments, the method of the present invention comprises forming an appropriately-sized hole in a ceiling tile, laying an integrated back box and support frame on top of the ceiling tile, connecting wires from an external audio source to terminals provided at the back box, connecting wires provided on the inside of the back box to a loudspeaker cartridge, inserting the loudspeaker cartridge into the hole in the ceiling tile from below, fastening the loudspeaker cartridge to the support frame, and fastening a grille to the loudspeaker cartridge. In one or more embodiments, a variety of interchangeable loudspeaker cartridges having differing loudspeaker configurations are provided. In one or more embodiments, the support frame and back box assembly is configured to allow installation of more than one loudspeaker cartridge. In one or more embodiments, the loudspeaker cartridges are configured for use both with a back box and without back box.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention may be understood and its features made apparent to those skilled in the art by referencing the accompanying drawings.
[0012] FIG. 1 is a perspective view of an embodiment of a support frame of the prior art.
[0013] FIG. 2 is a perspective view of ceiling speaker assembly of the prior art.
[0014] FIG. 3 is an exploded perspective view of an embodiment of a support frame and back box assembly of the present invention.
[0015] FIG. 4 is a rear perspective view of an embodiment of a support frame and back box assembly of the present invention.
[0016] FIG. 5 is a front perspective view of an embodiment of a support frame and back box assembly of the present invention.
[0017] FIG. 6 is an exploded perspective view of an embodiment of a speaker cartridge of the present invention.
[0018] FIG. 7 is a rear perspective view of an embodiment of a speaker cartridge of the present invention.
[0019] FIG. 8 is a front view of an embodiment of a speaker cartridge of the present invention.
[0020] FIG. 9 is a close up view showing electrical connections for an embodiment of a back box of the present invention.
[0021] FIG. 10 is a close up view showing electrical connections for an embodiment of a speaker cartridge of the present invention.
[0022] FIGS. 11A-11C show a method of mounting an embodiment of a support frame and back box assembly of the present invention.
[0023] FIGS. 12A-12C show a method of mounting an embodiment of a speaker cartridge of the present invention.
[0024] FIG. 13A is a perspective view of an embodiment of a speaker cartridge of the present invention mounted in a ceiling tile.
[0025] FIG. 13B is a cutaway perspective view of an embodiment of a speaker cartridge of the present invention mounted to an embodiment of a support frame and back box assembly of the present invention.
[0026] FIGS. 14A-14C show removable spacer tabs of one or more embodiments of the present invention.
[0027] FIG. 15 is an exploded view of a “flip dog” assembly of one or more embodiments of the present invention.
[0028] FIGS. 16A-16B show assembled “flip dog” assemblies of one or more embodiments of the present invention.
[0029] FIGS. 17A-17C illustrate a process for engaging a “flip dog” according to one or more embodiments of the present invention.
[0030] FIGS. 18A-18B show details of a screw hole of a “flip dog” of one or more embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] In the following description, numerous specific details are set forth to provide a more thorough description of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well-known features have not been described in detail so as not to obscure the invention.
[0032] FIG. 3 is an exploded view showing components of a support frame and back box assembly 375 of an embodiment of the present invention. In the embodiment of FIG. 3 , components of support frame and back box assembly 375 include a support frame 300 , a back box 305 , and an outer shield 310 .
[0033] In the embodiment of FIG. 3 , support frame 300 comprises a metal, plastic, or other material or materials formable into the desired shape and form. In one or more embodiments, support frame 300 is formed as a sheet metal stamping. In the embodiment of FIG. 3 , support frame 300 includes a planar portion 301 , an opening 304 , a plurality of stiffening ribs 303 , and a lip 302 . In one or more embodiments, lip 302 is initially formed at an approximately right angle to planar portion 301 . In one or more embodiments, support frame 300 is formed from a sheet of material. In alternative embodiments, stiffening ribs 303 and/or lip 302 may not be integrally formed with planar portion 301 , but may comprise separately formed components that are affixed to planar portion 301 to form support frame 300 . In the embodiment of FIG. 3 , support frame 300 comprises a single centrally-located round opening 304 for receiving a speaker or a speaker cartridge. In one or more other embodiments, support frame 300 may comprise two or more openings for receiving speakers or speaker cartridges. The openings may have the same or different shapes (round, rectangular or other) and sizes, and may each be located anywhere in speaker frame 300 . Further, planar portion of speaker frame 300 need not be formed from a single piece of material, but may be assembled from separately formed pieces. Further, although speaker frame 300 is shown as having a generally rectangular shape, any other desired shape can be used.
[0034] In the embodiment of FIG. 3 , back box 305 comprises a raised portion 309 and an edge portion 308 . In one or more embodiments, edge portion 308 comprises a plurality of spacer tabs 307 that allow the overall length of back box 305 to be adjusted so that support frame and back box assembly 375 can be used with a plurality of ceiling t-bar spacings. In one or more embodiments, the overall length of support frame and back box assembly 375 with spacer tabs 307 intact is approximately 2 feet, which is a standard width for ceiling tiles in the United States. In one or more embodiments, with spacer tabs 307 removed (for example by breaking off with a tool such as a pair of pliers), the overall length of support frame and back box assembly 375 is approximately 600 mm, which is a standard width for ceiling tiles in some European countries. FIGS. 14A-14C illustrate how spacer tabs 307 may be removed (for example with pliers 1401 as shown in FIG. 14B ) to create two different overall lengths for support frame and back box assembly 375 . Although spacer tabs 307 are shown as all having the same length and disposed along only one side of support frame and back box assembly 375 , in one or more alternative embodiments, spacer tabs may be included on other sides. Further, two or more sets of spacer tabs having different lengths may be used along one or more sides, providing additional discrete, selectable variations of overall lengths and/or widths for support frame and back box assembly 375 depending on which tabs are removed. In one or more embodiments, spacer tabs are scored or notched to facilitate removal of the tabs.
[0035] In one or more embodiments, back box 305 is formed from high molecular weight polyethylene (“HMWPE”), though back box 305 can be formed from any other plastic, metal, or composite material or materials. In one or more embodiments, back box 305 comprises a recessed portion 314 that is configured to accommodate a stiffening plate 320 to provide additional structural rigidity. In one or more embodiments, stiffening plate 320 is made from a relatively stiff material, such as medium density fiberboard (“MDF”). The use of stiffening plate 320 allows support frame and back box assembly 375 to have significant rigidity (which is desirable for improved acoustical response) yet be relatively light in weight. In one or more embodiments, back box 305 comprises a recessed electrical compartment 311 that includes electrical terminals 340 for making external electrical connections.
[0036] In the embodiment of FIG. 3 , outer shield 310 is configured to be mountable over back box 305 such that the inside surface of outer shield 310 conforms generally to the outside surface of back box 305 . In one or more embodiments, outer shield 310 includes a raised portion 360 and an edge portion 365 . In one or more embodiments, outer shield 310 is formed from materials as is known in the art that provide fire and heat resistance in conformity with applicable building codes. In one or more embodiments, outer shield 310 comprises a composite construction comprising an inner mineral fiber or fiberglass shell and an outer metal foil layer. In one or more embodiments, outer shield 310 conforms to the Underwriters' Laboratories UL2043 rating. In one or more embodiments, outer shield 310 includes an opening 334 that is configured to provide access to electrical compartment 311 of back box 305 when outer shield 310 is assembled to back box 305 and support frame 300 . In one or more embodiments, outer shield 310 is provided with a pair of plates 335 comprising threaded holes that can be used to mount a cover plate 350 over opening 334 using fasteners 355 .
[0037] In the embodiment of FIG. 3 , support frame 300 , back box 305 , stiffening plate 320 and outer shield 310 are assembled together to form an embodiment of a support frame and back box assembly of the invention. In one or more embodiments, stiffening plate 320 is fastened to back box 309 using a plurality of screws 330 . Back box 305 is fastened to support frame 300 and stiffening plate 345 using bolts 325 , spacers 315 and barrel nuts 345 . In one or more embodiments, when assembled, the components work together to form an assembly that has a rigidity greater than the rigidity of the individual components.
[0038] In one or more embodiments, lip 302 of support frame 300 includes openings 313 through which spacer tabs 307 of back box 305 protrude when back box 305 is mounted to support frame 300 .
[0039] In the embodiment of FIG. 3 , after back box 305 is assembled to support frame 300 , outer shield 310 is placed over back box 305 such that edge portion 365 of outer shield 310 rests on edge portion 308 of back box 305 . In one or more embodiments, lip 302 of support frame 300 is thereafter folded over edge portion 365 of outer shield 310 such that lip 302 holds outer shield 310 in place, as shown in FIG. 4 , which shows a top view of an embodiment of a resulting support frame and back box assembly 375 of the invention. A bottom view of support frame and back box assembly 375 is shown in FIG. 5 . In one or more embodiments, additional or other fastening methods and/or fasteners may be used to fasten support frame 300 and/or back box 305 to outer shield 310 as will be known to those of skill in the art. For example, in one or more embodiments, spring-loaded or folded clips may be used to hold outer shield 310 to support frame 300 and back box 305 .
[0040] An embodiment of a speaker cartridge 600 of the invention which may be used independently of or with a support frame and back box assembly such as support frame and back box assembly 375 is shown in FIGS. 6 , 7 and 8 . FIG. 6 is an exploded view showing components of an embodiment of speaker cartridge 600 . FIGS. 7 and 8 are top and bottom views, respectively, of embodiments of an assembled speaker cartridge 600 .
[0041] In the embodiment of FIG. 6 , speaker cartridge 600 comprises a cartridge frame 601 to which various components are mounted. In one or more embodiments, cartridge frame 601 is molded from a plastic, cast from a metal, or formed in any other manner as will be known by those of skill in the art. In one or more embodiments, cartridge frame 601 is molded from HMWPE. In one or more embodiments, cartridge frame 601 is formed to fit into opening 304 of support frame 300 . In one or more embodiments, cartridge frame 601 includes a flange 602 . In one or more embodiments, cartridge frame 601 provides mounting locations for components that are intended to be mounted to cartridge frame 601 . In the embodiment of FIG. 6 , components mounted to cartridge frame 601 include a speaker 610 , a tweeter 615 , a tweeter bracket 605 , a transformer 624 , a switch 614 , a crossover circuit board 624 , and a plurality of “flip dog” attachment clips each comprising a flip dog base 618 (which may, for example, be integrally formed with cartridge frame 601 ), rotatable flip dog 620 and a flip top cap 622 . In one or more embodiments, speaker 610 is a midrange speaker or a woofer. In one or more embodiments, transformer 624 is configured to match an incoming audio signal to the signal requirements of speaker 610 . In one or more embodiments, transformer 624 has multiple taps that can be selected by switch 614 so that speaker cartridge 600 can be used with a variety of input signal configurations.
[0042] In the embodiment of FIG. 6 , crossover circuit board 624 includes a conventional crossover circuit that divides the incoming audio into primarily lower frequency signals that are sent to speaker 610 and primarily higher frequency signals that are sent to tweeter 615 , as is known in the art.
[0043] FIG. 7 shows how components are assembled to cartridge frame 601 in one or more embodiments of the invention. In the embodiment shown in FIG. 7 , a portion of cartridge frame 601 that is configured to fit within opening 304 of support frame 300 has an inner perimeter 712 that has a diameter equal to or less than the diameter of opening 304 . Flange 602 extends outwards from perimeter 712 to an outer perimeter 710 that has a diameter greater than the diameter of opening 304 of support frame 300 . In the embodiment of FIG. 6 , flip dogs 620 are rotatably mounted to flip dog bases 618 such that legs 706 of flip dogs 620 can be rotated from an inward position in which they do not extend beyond inner perimeter 712 and can therefore be inserted into opening 304 of support frame 300 to an outward position in which they extend beyond inner perimeter 712 so as to extend over the perimeter of opening 304 so as to hold speaker cartridge 600 in place adjacent to support frame 300 when speaker cartridge 600 is assembled to support frame and back box assembly 375 . In one or more embodiments, flip dogs 620 and flip dog bases 618 are configured such that the rotational position of flip dogs 620 can be manipulated from the bottom side of cartridge frame 601 , for example by use of a tool such as a screwdriver. In one or more embodiments, switch 614 is also configured so as to allow operation of switch 614 from the bottom of cartridge frame 601 .
[0044] In the embodiment of FIG. 7 , cartridge frame 601 includes a port 703 , a removable port cover 612 , and a port cover storage location 702 . When mounted to a support frame and back box assembly such as support frame and back box assembly 375 , port cover 612 may be removed and stored in port cover storage location 702 so that port 703 functions like a conventional speaker port, providing a path between the outside and inside of the speaker enclosure formed by the combination of speaker cartridge 600 and support frame and back box assembly 375 . In one or more embodiments, leaving port 703 covered provides better audio response if speaker cartridge 600 is mounted in a ceiling tile or otherwise used in a manner in which the rear of speaker cartridge 600 is not enclosed by a back box or other housing.
[0045] FIG. 8 shows a bottom view of one or more embodiments of speaker cartridge 600 . In the embodiment of FIG. 8 , tweeter bracket 605 has been mounted to cartridge frame 601 , for example by engaging tabs at the ends of the legs of tweeter bracket 605 with mating slots in cartridge frame 601 . In one or more embodiments, tweeter bracket 605 allows different tweeters to be used with speaker cartridge 600 . In one or more embodiments, different tweeter brackets 605 may be interchangeably used with speaker cartridge 600 . In one or more embodiments, tweeter brackets 605 may be configured to provide various assembled locations for tweeter 615 with respect to speaker 610 , allowing the assembled location of a particular tweeter 615 to be configured to provide a desired acoustical interaction with speaker 610 . In the embodiment of FIG. 8 , cartridge frame 601 includes orifices 802 that provide access to flip dogs 620 with an appropriate tool, such as, for example, a screwdriver, that can be used to rotate flip dogs 620 from a retracted position (in which the legs 706 do not interfere with insertion of speaker cartridge 600 into opening 304 of support frame 300 ) to an extended position (in which legs 706 extend beyond opening 304 of support frame 300 ). In one or more embodiments, cartridge frame 601 also includes an opening 805 that provides access to switch 614 .
[0046] FIGS. 15 to 18 show details of a flip dog assembly 1500 of one or more embodiments of the invention. In the embodiment shown in FIG. 15 , components of flip dog assembly 1500 include bottom screw 1510 , flip dog base 618 (which may be integrally formed with cartridge frame 601 ), spring 1501 , flip dog 620 (which includes leg 706 ), flip dog cap 622 , and cap screws 1505 . Flip dog base 618 includes a bore 1511 and an inclined surface 1512 that together with inclined surface 1513 of flip dog cap 622 forms a guide passage for leg 706 of flip dog 620 as discussed in greater detail with respect to FIGS. 16A and 16B below.
[0047] In one or more embodiments, flip dog assembly 1500 may be assembled by inserting spring 1501 and flip dog 620 in bore 1511 of flip dog base 618 , placing flip dog cap 622 over flip dog 620 such that the top 1522 of flip dog 620 engages bore 1515 of flip dog cap 622 , and fastening flip dog cap 622 to flip dog base 618 using cap screws 1505 . Bottom screw 1510 can then be inserted through the bottom of flip dog base 618 through spring 1501 (which is now partially compressed) and partially screwed into the bottom of flip dog 620 , as described in greater detail below. The resulting flip dog assembly 1500 is shown in FIGS. 16A and 16B
[0048] As shown in FIGS. 16A and 16B , in one or more embodiments, flip dog cap 622 includes a notch 1517 that maintains leg 706 in its retracted position while speaker cartridge 600 is being inserted into a mounting hole (e.g. in a ceiling tile or in a support frame, such as support frame 300 of support frame and back box assembly 375 ). Leg 706 is pressed upwards into notch 1517 by the upwards bias of spring 1501 .
[0049] FIGS. 17A-17C show how leg 706 is moved from its retracted position as shown in FIGS. 16A and 16B to its engaged position as shown in FIG. 17C . The movement is accomplished by screwing bottom screw 1510 into the bottom of flip dog 620 such that flip dog 620 is pulled downwards into flip dog base 618 though guide passage 1610 formed by flip dog cap 622 and flip dog base 618 . As shown in FIGS. 17A-17C , as flip dog 620 is pulled downwards by bottom screw 1510 , the configuration of passage 1610 causes leg 706 first to disengage from notch 1517 and then to rotate outwards into its extended position as shown in FIG. 17B . Further tightening of bottom screw 1510 draws leg 706 further downwards into its fully engaged position, as shown in FIG. 17C .
[0050] FIGS. 18A and 18B show a configuration of a screw bore 1801 in flip dog 620 in one or more embodiments of the invention. As shown in FIG. 18A , screw bore 1801 includes a guide portion 1810 that has a diameter approximately the same diameter as the outside diameter of the threads of screw 1510 and a screw engagement portion 1805 that has a diameter that is less than the outside diameter of the threads of screw 1510 . Guide portion 1810 aligns bottom screw 1510 with screw engagement portion 1805 as screw 1510 is inserted into screw bore 1810 , preventing screw 1510 from becoming misaligned as screw 1510 is screwed into engagement portion 1805 .
[0051] Although cartridge frame 601 is shown in the embodiment of FIG. 8 to have a generally round shape that generally matches the shape of opening 304 in support frame 300 , in one or more embodiments, other shapes for both cartridge frame 601 and opening 304 can be used. Further, although cartridge frame 601 of FIG. 8 is configured for a single woofer or midrange speaker and a single tweeter, in one or more other embodiments, cartridge frame 601 can be configured for multiple midrange speakers/woofers and/or multiple tweeters.
[0052] FIG. 9 shows how external wiring is connected to electrical terminals 340 of support frame and back box assembly 375 in one or more embodiments of the invention. In the embodiment shown in FIG. 9 , a pair of external electrical leads 915 are fed through a conduit header 905 mounted to cover plate 350 (which has been removed to allow access) and attached to Euro-type screw electrical terminals 340 in a recessed electrical compartment 311 formed in back box 305 and accessible through opening 334 of outer shield 310 . A pair of internal electrical leads 920 lead from screw electrical terminals 340 into the interior of back box 305 .
[0053] FIG. 10 shows how internal leads 920 are connected to crossover circuit board 624 in one or more embodiments of the invention. In the embodiment of FIG. 10 , internal leads 920 (which may, for example, be connected to external leads 915 via electrical terminals 340 ) are connected to an electrical connector 1010 (for example a Molex connector) that is configured to removably mate with a mating electrical connector 624 (for example a Molex connector) connected to crossover circuit board 624 . Using removable mating connectors for connecting internal leads 920 to crossover circuit board 624 facilitates installing speaker cartridge 600 and support frame and back box assembly 375 into a suspended ceiling, as described below.
[0054] FIGS. 11A-11C illustrate steps for installing a support frame and back box assembly 375 into a suspended ceiling according to one or more embodiments of the invention. FIG. 11A shows a support frame and back box assembly 375 placed into a desired position in a grid of t-bar ceiling tile support bars 1105 . FIG. 11B shows a ceiling tile 1110 placed into the same position in grid 1105 in which support frame and back box assembly 375 is shown in FIG. 11A . In FIG. 11B , an opening 1120 has been cut in ceiling tile 1110 that corresponds to the location of opening 340 of support frame 300 of support frame and back box assembly 375 of FIG. 11A . FIG. 11C shows support frame and back box assembly 375 placed in position on top of ceiling tile 1110 .
[0055] FIGS. 12A-12C illustrate steps for installing a speaker cartridge 600 into an opening 1120 of a ceiling tile 1110 with or without a support frame and back box assembly 375 according to one or more embodiments of the invention. FIG. 12A is a bottom view of a ceiling tile 1110 with an opening 1120 . A support frame and back box assembly 375 may or may not have been placed on top of ceiling tile 1110 . If a support frame and back box assembly 375 has been placed on top of ceiling tile 1110 , opening 304 of support frame 300 will be in the same location as opening 1120 of ceiling tile 1110 .
[0056] FIG. 12B shows how electrical leads 1015 are fed through opening 1120 of ceiling tile 1110 and attached to speaker cartridge 600 , for example by using connectors such as connectors 1005 and 1010 of the embodiment of FIG. 10 . If a support frame and back box assembly 375 has been placed on top of ceiling tile 1110 , electrical leads 1015 may for example be internal electrical leads 920 of the embodiment of FIG. 9 .
[0057] FIG. 12C shows how a screwdriver 1210 may be used to secure speaker cartridge 600 to ceiling tile 1110 (if no support frame and back box assembly 375 is present) or to ceiling tile 1110 and support frame 300 of support frame and back box assembly 375 (if a support frame and back box assembly 375 is present) by tightening bottom screw 1510 , thereby moving flip dogs 620 from their retracted to engaged positions via access passages provided on the bottom side of speaker cartridge 600 such as, for example, orifices 802 of the embodiment of FIG. 8 . After speaker cartridge 600 has been secured to ceiling tile 1110 and/or support frame and back box assembly 375 , a detachable decorative grille 1310 may be attached to the bottom of speaker cartridge 600 , as shown, for example, in FIG. 13A . In FIG. 13B , ceiling tile 1110 is rendered invisible to show the assembly of speaker cartridge 600 to support frame and back box assembly 375 in one or more embodiments of the invention.
[0058] Thus one or more embodiments of a ceiling speaker system comprising a support frame and back box assembly and a mating speaker cartridge has been disclosed. An advantage of the disclosed invention is that it allows a division of labor in installing a ceiling speaker system that corresponds to a common division of labor in building trades. An example of such a division of labor is between a building contractor that installs a suspended ceiling, an electrician that installs building wires, and an audio/video system installer that installs speakers. Using one or more embodiments of the invention, a building contractor can place a support frame and back box assembly on top of a ceiling tile and cut an appropriate opening in the ceiling tile. The contractor typically would also install safety support wires (which may be required by applicable building and/or safety codes for seismic or other reasons) from the support frame and back box assembly to a support structure, such as a ceiling joist. An electrician can run external wiring to the electrical terminals of the back box of the support frame and back box assembly. After the support frame and back box assembly is in place in the ceiling and the external electrical wires have been attached, an audio/video system installer can attach the internal leads of the support frame and back box assembly to a speaker cartridge, and install the speaker cartridge into the ceiling tile and support frame and back box assembly from below.
[0059] A further advantage of the invention is that the support frame and back box assembly of the one or more embodiments of the invention forms a loudspeaker enclosure that has a relatively large volume but a low profile that allows installation in ceilings that have limited vertical clearance above the ceiling tiles. A further advantage is that in one or more embodiments, the fire-resistant back box encloses the entire rear of the speaker cartridge assembly, including its mounting hardware, which remain exposed in prior art ceiling speaker systems (such as, for instance, flip dogs 230 of the prior art ceiling speaker shown in FIG. 2 that are not enclosed by back can 230 and that could therefore be subjected directly to fire).
[0060] Although the present invention has been described with respect to certain specific embodiments, it will be clear to those skilled in the art that the inventive features of the present invention are applicable to other embodiments as well, all of which are intended to fall within the scope of the present invention. For example, although certain fastening methods and fasteners (e.g. screws) are disclosed for assembling various components of the invention, any other fastening methods and/or fasteners may be used (such as, for example, adhesives). Further, certain features of the invention can be used with other items other than a ceiling speaker. For example, the removable spacing tabs of the invention may be used with other items for which it would be useful to vary an overall dimension by discrete amounts, including items to be mounted in suspended ceilings, and elsewhere. Similarly, the flip dog assembly of the present invention can be used with other items that are intended to be mounted in holes in ceilings, walls, desktops, and elsewhere. Other variations of and uses for various aspects of the present invention will be apparent to those of skill in the art. | The present invention comprises a tile-mounted ceiling speaker that combines the ease of installation of a lay-in speaker system with the visual appearance of a tile-mounted speaker system. In one or more embodiments, the apparatus of the present invention includes a support frame and back box assembly configured for installation on top of a ceiling tile and a loudspeaker cartridge configured to be mounted to the support frame through an appropriately-sized hole in the ceiling tile. In one or more embodiments, the invention comprises a peripheral flange and a plurality of flip dogs for mounting the cartridge to the support frame that are configured to be disposed in the interior of the back box when engaged. | 7 |
FIELD OF THE INVENTION
The present invention is in the field of belt clip attachment devices for attaching personal electronic devices such as wireless mobile phones to belt clips.
BACKGROUND OF THE INVENTION
Belt clips and belt clip attachment devices have been proposed in the past for connecting a mobile phone to the belt of a user. These belt clips and attachment devices have suffered from a number drawbacks, some of which include: the belt clips are too large and bulk, making them uncomfortable and obtrusive; use of the mobile phone with the belt clip often requires extra material on the sides of the mobile phone to attach the mobile phone to the belt clip (this is fine when the mobile phone is attached to the belt clip, but when the mobile phone is being used, the extra material makes the mobile phone bulky); often the belt clip is specific for a particular type of mobile phone, making the belt clip inoperable with other mobile phones; some belt clip attachment devices are difficult to install and/or difficult to remove from the mobile phone; the design of some belt clips and belt clip attachment devices inadvertently allows the mobile phone to pop off of the belt clip.
SUMMARY OF THE INVENTION
The above drawbacks and others are addressed by the belt clip and belt clip attachment device of the present invention.
An aspect of the invention involves a belt clip attachment device that attaches to an existing battery door latch on the rear side of a mobile phone. The belt clip attachment device includes a unique design that allows it to attach and lock to the battery door latch with a unique pushing and rotating motion. The belt clip attachment device and a corresponding belt clip may have cooperative configurations that allow the belt clip attachment device and mobile phone to be connected to the belt clip at numerous possible orientations with respect to the user's belt. The belt clip attachment device may also be connected to a wide variety of generic belt clips currently on the market. The belt clip attachment device is universal in that it may be used with a variety of different mobile phones that are configured for attachment thereto.
Further objects and advantages will be apparent to those skilled in the art after a review of the drawings and the detailed description of the preferred embodiments set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a mobile phone and a belt clip attachment device constructed in accordance with an embodiment of the invention.
FIG. 1B is a front elevational view of a battery compartment door and a door latch.
FIG. 1C is a side elevational view of the battery compartment door and the door latch of FIG. 1B .
FIG. 1D is a perspective view of the belt clip attachment device illustrated in FIG. 1A .
FIGS. 1E–1G illustrate a cross-sectional view of the belt clip attachment device and a rear portion of the mobile phone illustrated in FIG. 1A , and show an exemplary method of attaching the belt clip attachment device to the door latch of the battery compartment door.
FIGS. 1H–1K illustrate a front elevational view, a side elevational view, a rear elevational view, and a perspective view of an embodiment of a belt clip that may be used with the belt clip attachment device shown in FIG. 1A .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIGS. 1A–1K , an embodiment of a universal belt clip attachment device or knob 100 used to connect a mobile phone 110 to a belt clip 120 will now be described. Although the universal belt clip attachment device 100 will be described as being used to connect a mobile phone 110 to a belt clip 120 , the universal belt clip attachment device 100 may be used to connect other personal electronic devices to the belt clip 120 . Before describing the belt clip attachment device 100 , the mobile phone 110 will first be described.
The mobile phone 110 includes a housing 130 with a rear side 140 and a substantially elliptical battery compartment door 150 detachably locked to the rear side 140 through a battery compartment door latch 160 . The battery compartment door 150 includes a top curved edge 170 and a bottom curved edge 172 . Adjacent the bottom curved edge 172 , the battery compartment door 150 may include a tang (not shown) for use in attaching the battery compartment door 150 to the housing 130 . The top curved edge 170 may include a semi-circular cut out 180 near the center of the top curved edge 170 .
As shown best in FIGS. 1C , 1 D, a substantially C-shaped latch arm 190 extends from the top curved edge 170 at the semi-circular cut out 180 . A tang 200 extends laterally from the latch arm 190 and is used to retain the battery compartment door latch 160 to the housing 130 . The latch arm 190 terminates in a circular, disc-shaped latch actuator 210 . When the battery compartment door 150 is in position in the rear side 140 of the housing 130 , a circular recess 220 is formed around the latch actuator 210 . In an alternative embodiment, the latch 160 may be connected to the housing 130 instead of the battery compartment door 150 . Two pegs 222 extend laterally from the housing 130 and are received by the belt clip attachment device 100 in a manner to be described. Alternatively, the two pegs 222 may extend from the battery compartment door 150 such as from the latch arm 190 . Further, in alternative embodiments the number of pegs 222 may be other than 2 (e.g., 1, 3, etc.). The battery compartment door 150 may be a thin member as shown, or may be part of a thicker member such as part of a rechargeable battery, fuel cell, or other renewable power source.
With reference to FIG. 1D , the belt clip attachment device, adapter, or knob 100 will now be described in more detail. The belt clip attachment device 100 includes a belt clip engagement member 240 having a starburst configuration. In alternative embodiments, the belt clip engagement member 240 may have configurations other than a starburst configuration. For example, but not by way of limitation, the belt clip engagement member 240 may have a circular configuration, an elliptical configuration, an oval configuration, a curvilinear configuration, or a rectilinear configuration. The belt clip engagement member 240 includes a central circular well 242 and a plurality of outwardly curved radiating projections 244 joined by respective inwardly curved connection portions 246 . An upper cylindrical member 248 joins the belt clip engagement member 240 to a lower cylindrical hub 250 .
Opposite C-shaped slots 260 are located in the lower cylindrical hub 250 . Although two slots 260 are described, other numbers of slots 260 may be used (e.g., 1, 3, 4, etc.). Each slot 260 may include an insertion/removal tack 262 , a rotation track 264 , and a locking track 266 . A stop or post 268 may separate the insertion/removal track 262 from the locking track 266 . A resilient member 270 (See FIGS. 1E–1G ) may be located within the upper cylindrical member 248 and the lower cylindrical hub 250 . Exemplary resilient members that may be used for the resilient member 270 include, but not by way of limitation, an elastic rubber disc and a spring.
With reference to FIGS. 1E–1G , attachment of the belt clip attachment device 100 to the mobile phone 110 will now be described. As shown in FIG. 1E , the belt clip attachment device 100 is attached to the mobile phone 110 by aligning the insertion/removal track 262 of the belt clip attachment device 100 with the lateral pegs 222 ( FIG. 1A ), and pressing and inserting the open circular end of the lower cylindrical hub 250 over the circular latch actuator 210 so that the lateral pegs 222 are slidably received into the insertion/removal track 262 . The resilient member 270 urges the belt clip attachment device 100 in the opposite direction, so an opposite pushing pressure is required to overcome the pressure exerted by the resilient member 270 . As shown in FIG. 1F , the belt clip attachment device 100 is then rotated or twisted while maintaining this pushing force so that the lateral pegs 222 are slidably received in the rotation track 264 past the stop 268 . As shown in FIG. 1G , the belt clip attachment device 100 is then released so that the resilient member 270 urges the belt clip attachment device 100 outward and the lateral pegs 222 are slidably received in the locking track 266 until the lateral pegs 222 abut the stop 268 . In the position shown in FIG. 1G , the belt clip attachment device 100 is locked in place.
To unlock the belt clip attachment device 100 from the mobile phone 110 , the belt clip attachment device 100 is pressed towards the mobile phone 110 , rotated in a direction opposite to that shown in FIG. 1F , and then released and removed from the circular latch actuator 210 .
Although the belt clip attachment device 100 is described as being attached to the battery compartment door latch 160 , in alternative embodiments, the mobile phone 110 may have an alternative configuration where the belt clip attachment device 100 attaches to the rear side 140 of the mobile phone 110 at an alternative location.
With reference to FIGS. 1H–1K , an embodiment of a belt clip 120 that the universal belt clip attachment device 100 may be used with will now be described. The belt clip 120 includes a belt attachment section 300 and an opposite-facing phone attachment section 310 .
The belt attachment section 300 includes a back plate 320 and a clip 330 pivotally attached to the back plate 320 by a pivot mechanism 340 . The pivot mechanism 340 preferably includes a spring (not shown) to urge the clip 330 in the position shown in FIGS. 1H–1K . An upper part of the clip 330 includes a pivot control member 350 and a lower part of the clip 330 includes a closed end 360 . A belt-receiving recess 370 is formed between the clip 330 , the back plate 320 , the pivot mechanism 340 and the closed end 360 .
The phone attachment section 310 includes an elongated narrow frame 380 . A rear portion 390 of the frame 380 slidably receives an actuation member or plunger 400 . The actuation member 400 includes side flanges that are slidably received by a track of the rear portion 390 of the frame 380 . An upper part of the actuation member 400 includes a broad thumb-engagement portion 410 . A lower part of the actuation member 400 include a hole that slidably receives a movable locking tang 420 . The movable locking tang 420 and the actuation member 400 preferably include respective springs (not shown) to urge the tang 420 and the actuation member 400 in the positions shown in FIG. 1K . Adjacent a bottom of the actuation member 400 , the actuation member 400 includes one or more stops (not shown) that cooperate with the projections 244 and connection portions 246 of the belt clip engagement surface 240 to maintain the belt clip attachment device 100 (and the mobile phone 110 ) in a desired orientation.
A front portion 430 of the frame 380 has a substantially C-shaped configuration with an elongated central recess 440 for slidably receiving the cylindrical hub 250 of the belt clip attachment device 100 and opposite tracks 450 for slidably receiving the belt clip engagement member 240 of the belt clip attachment device 100 .
When the belt clip attachment device 100 (with attached mobile phone 110 ) is slid to the position shown in FIGS. 1H , 1 I, the belt clip engagement member 240 contacts and urges the movable locking tang 420 rearward. Once the belt clip engagement member 240 clears the movable locking tang 420 , the movable locking tang 420 is urged by its spring to the position shown in FIG. 1K so that the movable locking tang 420 is disposed within the well 242 of the belt clip attachment device 100 . The tang 420 within the well 242 , in addition to the one or more stops of the actuation member 400 engaged with the projections 244 and connection portions 246 of the belt clip engagement surface 240 , lock the belt clip attachment device 100 (and mobile phone 110 ) in the position shown in FIGS. 1H , 1 I, or other desired orientation relative to the user's belt that the user selects.
In the embodiment of the belt clip attachment device 100 shown, the belt clip attachment device 100 includes eight projections 244 , connection portions 246 , allowing the belt clip attachment device 100 (and mobile phone 110 ) to be oriented in eight different positions relative to the users belt in 45 degree increments (i.e., 0, 45, 90, 135, 180, 225, 270, or 315 degrees relative to the user's belt). In alternative embodiments, the number of projections 244 , connection portions 246 may be a number other than eight (e.g., 0, 1, 2, 3, etc.).
To remove the belt clip attachment device 100 (and mobile phone 110 ) from the belt clip 120 , the broad thumb-engagement portion 410 is pressed with the user's thumb, causing the actuation member 400 to disengage the movable locking tang 420 . The belt clip attachment device 100 may then be slid freely upward and out of the elongated central recess 440 and tracks 450 of the belt clip 120 .
In a similar fashion, a user may change the orientation of the belt clip attachment device 100 (and mobile phone 110 ) relative to a user's belt. After disengaging the movable locking tang 420 , the belt clip attachment device 100 (and mobile phone 110 ) may be slid upward and rotated to the desired orientation relative to the user's belt, and slid downward to the position shown in FIG. 1H where the belt clip attachment device 100 (and mobile phone 110 ) are locked in the desired orientation.
The push, twist, and lock feature of the universal belt clip attachment device 100 provides an easy, convenient way to attach and secure the universal belt clip attachment device 100 to the mobile phone 100 . The universal belt clip attachment device 100 may be used with a variety of different mobile phones 110 as long as the mobile phones 110 are configured for attachment thereto with the universal belt clip attachment device 100 . As a result, the belt clip 120 may be used with a variety of different mobile phones 110 . Further, the universal belt clip attachment device 100 and belt clip 120 allow the user to easily orient one's mobile phone 110 in a variety of different orientations relative to the user's belt in addition to the standard orientation provided by existing belt clips and adapters (i.e., perpendicular and upright relative the user's belt or parallel to a user's belt). The belt clip attachment device 100 may also be connected to a wide variety of generic belt clips currently on the market.
It will be readily apparent to those skilled in the art that still further changes and modifications in the actual concepts described herein can readily be made without departing from the spirit and scope of the invention as defined by the following claims. | A method of connecting a belt clip attachment device to a personal electronic device such as a mobile phone includes providing a belt clip attachment device for connecting the mobile phone to a belt clip, the belt clip attachment device and the rear of the mobile phone constructed so that the belt clip attachment device connects to the rear side of the mobile phone through a push and twist action on the belt clip attachment device; and connecting the belt clip attachment device to the rear side of the mobile phone by pushing and twisting the belt clip attachment device relative to the rear side of the mobile phone. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. application Ser. No. 11/581,729 filed Oct. 16, 2006 which claims rights under 35 U.S.C. §119(e) from U.S. application Ser. No. 60/727,141, filed Oct. 14, 2005, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to munitions and, more particularly, to methods and apparatus for increasing the lethality of existing warheads against an array of different targets.
2. Brief Description of Prior Developments
In the use of munitions, different types of warheads are conventionally often used to attack different types of targets. This practice may impose significant logistical challenges for maintaining combat forces in the field and may increase the complexity of carrying out combat operations.
A need, therefore, exists in an improved method and apparatus for making munitions more adaptable so that they may be employed against a wide variety of targets.
There is a further need for a warhead whose output can be tailored in response to intelligence input information.
There is a further need for a warhead having an ability to reconfigure its output using an imbedded microprocessor.
There is still a further need for a warhead which produces special outputs that are both tailored to the vulnerabilities of the target being attacked and directed toward the target to dramatically increase the warhead effects on that target.
SUMMARY OF INVENTION
The present invention is a method and apparatus for initiating the high explosive in a warhead differently, the blast and fragment output of the warhead can be shaped and directed toward the target of interest. By utilizing micro-detonators and initiating them in a predetermined sequence by an on-board microprocessor, many different explosive modes can be created by the same warhead. Furthermore, the mode selection process can be integrated with other electronic targeting systems such as Automatic Target Recognition (ATR) and various smart fuse designs to produce a fully programmable weapon system.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described with reference to the accompanying drawings wherein:
FIG. 1 is a perspective view of a preferred embodiment of the munition of the present invention;
FIG. 2 is a drawing showing a perspective view of a preferred embodiment of the smart charge used in the munition of the present invention fully populated with micro detonators; and
FIG. 3 is a schematic drawing showing a preferred embodiment of the smart charge trigger command, control circuitry, and power supply.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The use of an energetic material having a controllable rate of magnitude of energy release has broad application to a number of military applications. For example, the warhead of the present application may be applied to energetic systems for mine clearing, rock penetration, and wall breaching. The warhead of the present invention is believed to control the processes of deflagration, transition, and detonation and in condensed phase explosives through the use of a smart igniter coupled with functionally graded energetic materials and specially designed charge geometries. This invention not only allows several orders of magnitude of variation in energy release rate of the warhead to be achieved, but also allows a range of effects to be produced which include enhanced blast, improved shrapnel acceleration, and a dud or incendiary, e.g. case burning mode for safe destruction or fire initiation, as well as energy focusing on the target.
The ability to fabricate charges which may deflagrate, operate entirely in transition between deflagration and detonation, or be overdriven to strong detonation is possible by a proliferation of low energy detonators distributed throughout the change, initiated in response to a microprocessor. The microprocessor is given input from any number of information systems, to include pre-launch/deployment data or on-board, real-time sensor systems and may be programmable during or immediately prior to delivery. The result is a single weapon with multi-mission functionality.
The quasi-steady deflagration and detonation process in condensed systems is a research problem that has been studied since the end of the nineteenth century. The problem is far from being completely understood, but several advances on multiple fronts, including improved understanding, dramatic reductions circuit size and energy requirements, and improved three dimensional simulation capabilities, will now allow control of this process.
Transition from deflagration to detonation is a multistage process. The idea underlying recent research interests has been to separate and study each phase of the process, i.e. deflagration and detonation. This approach has been most revealing, since in some cases, e.g. intense impact, shock, high impulse of a detonation the individual stages last a very short time and some may even appear to be absent. More recent research has lead to an increased understanding of the transition phase that separates the deflagration and detonation processes, and specifically to the development of techniques for sustaining the transition phases for extended periods. This can be accomplished by a knowledgeable choice of energetic material, grain size, surface coating, charge geometry, and most importantly-ignition parameters.
This method and apparatus of the present invention allows for an adaptive explosive composition charge which will accomplish the necessary control by employing a multiple controllable low energy detonators, functionally graded energy density explosives, and novel charge geometries to control the warhead energy release rate. These controls will be utilized to operate the charge in a deflagration, convective burning, or detonation mode and thereby vary the energy release rate. A cylindrical warhead design of this type would preferably consist of an inner cylinder of fully dense explosive surrounded by an outer annulus of porous propellant, a sheet of electrical igniters, and a case, which may break up into shrapnel.
Referring to FIG. 1 , there is a central full defragration ignitor 10 . Peripherally surrounding and positioned radially outwardly form the central defragration igniter 10 , there is a full-density explosive core 12 . Peripherally surrounding and positioned radially outwardly from the full-density explosive core 12 , there is a porous convective burning layer 14 . Peripherally surrounding and positioned radially outwardly from the porous convective burning layer 14 there is a peripheral sheet ignitor 16 . Peripherally surrounding and positioned radially outwardly from the peripheral sheet ignitor 16 there is a profragmenting pressure case 18 .
Those skilled in the are will appreciate that the munition of the present invention may be in any of the five following modes:
1. Blast and Shrapnel: The charge may be overdriven by a simultaneous initiation of the igniters, all the energetic material (EM) goes to detonation, maximum blast effect is achieved, and the case shatters and produces very small, high velocity shrapnel. 2. Fragment Acceleration: The composite charge may be driven to convective burning by a simultaneous initiation of only a few on-axis detonators. This low-rate, high-pressure rise allows the case to break along grooves designed to selectively weaken it and control fragment size. Simultaneous with this event, the inner cylinder with full density explosive is initiated and efficiently accelerates the fragments. 3. One of four off-center line of initiators may be used to cause a radially directed cylindrical blast to propel shrapnel toward the target as the warhead flies by. 4. A forward directed blast configuration may be achieved by using an inward directed cylindrical charge to confine a fast running axial directed main charge thus producing a very long duration blast at the front of the warhead. 5. Dud or Incendiary: In the event that the warhead needs to be duded, one small end igniter coupled may be used with a pyrotechnic blowout plug to produce a safe deflagration of all the chemical energy present. If the case is composed of a high density, reactive metal pair, an incendiary reaction will ensue.
If the spatial and temporal structure of explosive energy release can be controlled within a warhead, concepts such as confining the energy release in one primary direction or projecting fragment release toward the target and other energy release mechanisms are possible. FIG. 2 shows an example of a fully versatile charge design although in alternate embodiments actual warheads with only a few well defined modes of operation might appear to be simpler.
Referring to FIG. 2 , the charge is assembled from alternate layers of micro-detonator sheets as at 20 , 22 , 24 and 26 , and layers of a first explosive as at explosive 28 and a second explosive as at explosive 30 , where the first and second explosives have differing energy release rates. In this example, varying the timing of electrical impulses between sheets can cause the plane detonation wave to travel in either directions, multiple waves can be generated, or the appearance of a bulk initiation of the entire charge. For example, sheets 20 and 22 may be timed at t=0, while sheets 24 and 26 may be timed at t=t 1 >0. With additional explosively generated circumferential and end confinement, the warhead could be made to burst from one end, focusing its energy there instead of dispersing the energy over 4 π radians as in conventional warheads.
Shaping and directing energy release may be accomplished by microprocessor control. As such, a wide variety of configurations are possible, limited only by the size of the memory and the existence of the necessary micro-detonators, An example of a proposed control circuit is shown in FIG. 3 . In FIG. 3 the firing circuit includes a DC to CD converter 32 and CPU 34 that are coupled to the platform input 36 . The ignition process begins with the charging of firing capacitors (C 1 , C 2 , C 3 . . . Cn), sized from 0.1 to 10 μf, that are coupled to the DC to DC inverter 32 . The firing capacitors are then selectively switched across resistive loads (RL 1 , RL 2 , RL 3 . . . R 1 n ), namely the series circuits containing the igniter pads, by a semiconductor switching such as a SCR, FET, or gate controlled switch (in the illustrated example Q 1 , Q 2 , Q 3 . . . Qn) under control of the CPU 34 which can be programmed to provide any desired firing sequence or timing.
The circuit can be energized by an internal battery or in this case by the weapon platform itself. Energizing the power supply allows the microprocessor to receive commands from the platform's central fire control computer. A firing power supply which stores energy to drive the detonators is also energized. The firing command can come over the same two conductors as the power in the form of a pulse coded signal from on-board fusing sensors coupled with an Automatic Target Recognition (ATR) system which take full advantage of the warhead's mode selection ability. Each detonator circuit (which may contain many detonators) is switched by a separate semiconductor, time precisely by the microprocessor, and supplied from a single energy storage capacitor. The entire circuit is easily miniaturized and shock hardened for stressing applications such as gun projectile warheads.
Further information which may be useful to those skilled in the art concerning preferred methods and apparatus for practicing the method and apparatus of this invention may be disclosed in U.S. Pat. No. 6,363,853, the contents of which are incorporated herein by reference.
While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims. | A method for detonating a munition comprising the steps of providing a plurality of micro-detonators and microprocessors in said munition and initiating said micro-detonators in a predetermined sequence by means of said microprocessor. Depending on the specific predetermined sequence which is selected, one of a variety of explosive modes may be achieved. | 5 |
This application claims the benefit, under 35 U.S.C. §119 of EP Patent Application 11305853.1, filed 1 Jul. 2011.
FIELD OF THE INVENTION
The invention relates to a method and to an apparatus for data storage, and more specifically to a method and to an apparatus for data storage based on fibers.
BACKGROUND OF THE INVENTION
Especially in the media industry huge amount of digital production data are being produced. For example, every movie produced in the 4 k digital cinema format leads, conservatively calculated, to as much as at least 12.5 TByte, assuming a frame rate of 24 Hz and a color resolution of 16 bit for every of the three (RGB) color-channels. Since not only the final movie data are produced, but also some additional scenes and their variations, for the above estimation the average length of all the corresponding movie data is assumed to add up to a total duration of 180 min.
According to the Organization for Economic Co-operation and Development in the US about 700 cinema movies have been produced in 2005. Since there are 9 major studios in the US, each studio produces about 950 TByte of data each year. In this respect it needs to be emphasized that this value is based on a very conservative calculation. In praxis, there will be much more digital data generated by each of the studios, which needs to be archived.
The produced media data represent an important asset of a film studio. During the pre- and post-production phase the gathered and generated media data are generally stored on hard disk drives. Since typical hard disk drives only have a guaranteed life-span of about five years, it is not advisable to use hard disk drives for long archival of the data.
Unfortunately, there is today no really reliable long-term mass storage technology available at reasonable costs, which would allow to directly archive the produced digital data. All typically employed mass storage technologies, e.g. tapes, digital versatile disks (DVD) or Blu-ray disks (BD) as well as some less common optical storage disks, do not provide the necessary durability of several decades. As a result, these mass storage technologies require high maintenance costs since the stored data needs to be copied to new media before the end of the life-span of the storage media.
U.S. Pat. No. 6,151,287 discloses a mass optical memory having a photo-sensitive layer formed on an optical disc, which includes elementary cells distributed across its free surface, for recording data with a laser beam. For each elementary cell the optical memory comprises a light guiding rod operative as a single-mode optical fiber, made from a photo-sensitive material, the axis of which is approximately orthogonal to the free recording surface. The optical memory has an increased storage density, but is rather difficult to manufacture due to the complex structure that needs to be produced.
In the document S. Bian et al.: “Erasable holographic recording in photosensitive polymer optical fibers”, Appl. Opt. Vol. 28 (2003), pp. 929-931, it has been proposed to store data as holograms in special optical fibers. However, as the necessary polymer optical fibers, which are doped with dye material, are costly to manufacture and are only available with rather short lengths, this approach is not suitable for mass storage. Also, the holograms need to be illuminated along the fiber axis. Due to the absorption caused by the dye material, which amounts to ˜0.7 cm −1 , propagation of the reading or recording light along the fiber is confined to a couple of centimeters.
In this regard US 2011/0141871 discloses a method and an apparatus for storing data in an optical fiber. The bulk of the fiber is irradiated with a powerful irradiation beam in order to modify a characteristic of the bulk for data storage. Modification of the bulk of the fiber ensures a reliable storage of the data for a long period. However, the achievable data density is rather small.
SUMMARY OF THE INVENTION
It is thus an object of the invention to propose a reliable long-term archival technology with an increased data density.
According to one aspect of the invention, an apparatus for writing to a fiber has at least one radiation source for emitting at least one radiation beam for writing to the fiber. In order to write marks into a surface of the fiber, the surface of the fiber is irradiated with the at least one radiation beam to generate holes in the surface of the fiber or to induce changes of an optical property of the material of the fiber close to the surface of the fiber.
Similarly, a method for writing to a fiber comprises the steps of:
generating at least one radiation beam with at least one radiation source for writing to the fiber, and writing marks into a surface of the fiber by irradiating the surface of the fiber with the at least one radiation beam to generate holes in the surface of the fiber or to induce changes of an optical property of the material of the fiber close to the surface of the fiber.
According to a further aspect of the invention, an apparatus for reading from a fiber has at least one radiation source for emitting at least one radiation beam for reading from the fiber. In order to read marks from a surface of the fiber, the surface of the fiber is irradiated with the at least one radiation beam and radiation reflected by the fiber or transmitted through the fiber is detected.
Likewise, a method for reading from a fiber comprises the steps of:
generating at least one radiation beam with at least one radiation source for reading from the fiber, and reading marks from a surface of the fiber by irradiating the surface of the fiber with the at least one radiation beam and detecting radiation reflected by the fiber or transmitted through the fiber.
A main idea of the invention is to store the data to be archived on the surface or in a volume near the surface of a simple fiber, e.g. an optical fiber. Preferably a polymer fiber, e.g. a Nylon fiber or a polyamide fiber, is used for data storage. Polymer fibers are well established and easy to manufacture. Of course, other types of fibers may likewise be used. Advantageously, the radiation source is a light source, e.g. a laser diode, which emits a visible light beam or a UV or infrared light beam. Of course, other radiation sources such as X-ray sources or the like may likewise be used.
In order to read or write data, the rolled up fiber is unwound from a dispenser spindle mounted on a first mount and lead past the radiation beam. The fiber is then rolled up again by a winder spindle mounted on a second mount. When data are to be recorded, the radiation source generates a modulated radiation beam, which changes the properties of the fiber material in accordance with the modulation. In this way the data are stores while the fiber passes the radiation beam. For reading the fiber is irradiated with the radiation beam and the radiation reflected by the fiber or transmitted through the fiber is detected. As the detected radiation is modulated in accordance with the material changes of the fiber, the originally recorded data can be retrieved from the detected radiation.
The use of fibers for data storage has a plurality of advantages. For example, polymer fibers are hard-wearing. They resist water and vapor and even acid chemicals, and they are non-fading. The warehousing of polymer fibers does not require any expensive cooling, no special demands on humidity control, no unusual fire protection measures. In addition, the applied technologies are well known, while the degree of complexity is comparable low. All components are available from the shelf and will be available in the future. A further important aspect is that the technology and the fibers are very inexpensive. The total owner costs of fiber-based storage archives are thus comparably low.
Advantageously, two radiation sources are provided for emitting two radiation beams. In this case the two radiation sources are preferably arranged on opposite sides of the fiber. This solution has the advantage that an increased data rate is achieved. At the same time only part of the surface of the fiber is used for data storage. Therefore, the remaining surface can be used for the mechanical feeding of the fiber without any risk of damaging the recorded data. Alternatively, four radiation sources are provided for emitting four radiation beams. Favorably, these four radiation sources are arranged cross-wise around the fiber. This allows to further increase the achievable data rate.
Preferably, at least one actuator is provided for adjusting a position and/or an orientation of the fiber relative to the at least one radiation beam. This ensures that during recording and reading the fiber is led past the radiation beam in a well-defined manner. Alternatively or in addition, favorably a controller is provided for controlling a speed of the fiber relative to the at least one radiation beam. Advantageously, the controller evaluates calibration marks of the fiber for controlling the speed of the fiber relative to the at least one radiation beam. These calibration marks allow to easily synchronize the speed of the fiber relative to the radiation beam with the data pattern to be recorded or to be retrieved.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding the invention shall now be explained in more detail in the following description with reference to the figures. It is understood that the invention is not limited to this exemplary embodiment and that specified features can also expediently be combined and/or modified without departing from the scope of the present invention as defined in the appended claims. In the figures:
FIG. 1 schematically depicts an apparatus according to the invention,
FIG. 2 schematically illustrates a first example of an optical fiber with recorded marks,
FIG. 3 schematically depicts a second example of an optical fiber with recorded marks,
FIG. 4 shows a further apparatus according to the invention that makes use of two lasers,
FIG. 5 depicts an apparatus according to the invention that makes use of four lasers,
FIG. 6 illustrates an apparatus according to the invention that is provided with actuators for controlling the position and orientation of an optical fiber, and
FIG. 7 shows an optical fiber with calibration marks.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following the invention will be explained in more detail with reference to an optical fiber, using a laser as the source of a light beam. Of course, other types of radiation beams and radiation sources can likewise be used.
FIG. 1 schematically depicts an apparatus 1 according to the invention for optical fiber storage. An optical fiber 2 is unwind from a dispenser spindle 3 and rolled up by a winding spindle 4 . A laser 5 emits a light beam 6 , which is focused onto the optical fiber 2 by an objective lens 7 . The light beam 6 is modulated in accordance with a data signal 8 , which is received at an input 9 of the laser 5 . The modulated light beam 6 causes changes of the material of the optical fiber 2 while the optical fiber 2 passes the light beam 6 . These changes of the material of the optical fiber 2 represent data marks 20 and are used for storing the data contained in the data signal 8 .
A plurality of variants are available for implementing the invention. In the following it is assumed that the optical fiber is a polymer fiber. Of course, Nylon and polyamide fibers or other types of fibers can likewise be used as storage media. The data marks 20 may be recorded in the fiber in different ways.
A first possibility is schematically depicted in FIG. 2 , which in the left part shows a cross section and in the right part shows a top view of an optical fiber 2 , respectively. In this example pits are burned into the surface of the optical fiber 2 by the high-energy light beam 6 . Advantageously, the light beam 6 is controllable to burn pits with different extensions and/or different depths into the surface of the optical fiber 2 . In this way several levels of information can be stored. If, for instance, three different pits can be burned, then every single pit stores two bits of information.
A second possibility is illustrated in FIG. 3 , which in the left part shows a cross section and in the right part shows a top view of an optical fiber 2 , respectively. In this example the data marks 20 are formed by areas in which the optical properties of the material of the optical fiber 2 , e.g. the diffraction characteristics, are modified. Again, by generating different amounts of material changes several levels of information can be stored.
Of course, depending of the material of the optical fiber further coding principles are conceivable. For example, provided suitable material characteristics, the laser beam could curl the original smooth filament. In this case a spot that has been curled could mean a logical ‘1’, while an area of the optical fiber in its original state would indicate a logical ‘0’.
In all of the above examples the stored information can easily be retrieved by detecting the changes caused to the optical fiber 2 .
In FIG. 1 only one single laser is used for recording the information in the optical fiber. In order to increase the storage density, the operating mechanism is advantageously extended using more than just one light beam 3 for recording the information. FIG. 4 illustrates a recording apparatus that makes use of two lasers 50 , 51 , and hence of two light beams 60 , 61 and two objective lenses 70 , 71 , while FIG. 5 depicts a recording apparatus with four lasers 50 , 51 , 52 , 53 , and hence four light beams 60 , 61 , 62 , 63 and four objective lenses 70 , 71 , 72 , 73 . In the latter example preferably a diamond shaped optical fiber 2 is used. However, a normal optical fiber 2 with a circular cross section can likewise be used. In FIG. 5 each surface of the optical fiber 2 is illuminated with a single light beam 60 , 61 , 62 , 63 . Of course, provided a sufficiently large width of the optical fiber 2 , it is likewise possible illuminate one or more of the four surfaces with more than one light beam. In this case the data are preferably arranged in two or more track parallel to the axis of the optical fiber 2 .
In order to retrieve data focused laser light is directed to the optical fiber 2 . A suitably placed sensor then detects the light that is reflected by the optical fiber 2 . As during recording the optical characteristics of the optical fiber 2 are modified, the encoded data can be retrieved from the modulation of the reflected light that is caused by the modified optical characteristics.
During recording and reading the optical fiber 2 has to be led past the recording/reading laser 2 in a well-defined manner. Therefore, in practice additional means have to be provided to ensure the correct orientation and lead of the optical fiber 2 relative to the focused light beam. One possible solution is illustrated in FIG. 6 , where common actuators 10 are provided for adjusting the position and orientation of the optical fiber 2 . Apparently, adjusting the position and orientation of the optical fiber 2 is greatly facilitated when a diamond shaped optical fiber 2 is used. In any case, apart from the correct position and orientation of the optical fiber 2 , the optical fiber 2 has to be lead past the light beam 6 with the correct velocity. For this purpose the optical fiber 2 is advantageously provided with calibration marks 21 , as illustrated in FIG. 7 . These calibration marks 21 allow to easily synchronize the velocity of the optical fiber 2 relative to the focused light beam 6 with the data pattern to be recorded or to be retrieved.
The following Table 1 summarizes exemplary values for an optical fiber 2 capable of storing 12.5 TByte of data. The values are based on currently available technology, i.e. technology employed for BluRay Disks. Assuming a data rate of approximately 10 MByte per second, the time required for storing the amount of 12.5 TByte data sums up to about 15 days. The speed of the optical fiber 2 relative to the focused light beam 6 is set to 5.125 m/sec.
TABLE 1
Amount of data
12.5 TByte
Stored data per mm fiber
~2 kbit (one level coding)
Fiber length
~54 × 10 3 km
Fiber diameter
0.1 mm
Total fiber volume
0.135 m 3
Fiber spindle
30 cm × 75 cm
(cross-section × height)
Data rate
10 MByte/sec
Recording time
~365 hours, i.e. ~15 days
Fiber speed
~5.125 m/sec
The preceding figures are based on pure Pulse Coded Modulation (PCM). Applying a JPEG 2000 encoder, which shows a compression ratio of about 1 to 6 or 1 to 10, would lead to considerably smaller values. However, application of an Error Correction Code (ECC) would slightly increase the values. | A method and an apparatus for data storage based on fibers are described. Data are stored as marks in a surface of a fiber or in a volume near the surface of the fiber. Data marks are written to or read from the fiber by irradiating the surface of the fiber with at least one radiation beam. The fiber has calibration marks for controlling a speed of the fiber relative to the at least one radiation beam. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a transmission control apparatus for an automobile arranged at or near an instrument panel, and more particularly to a transmission control apparatus allowing absorption of the shock load when the shock load is applied to a control lever of the apparatus.
[0003] 2. Description of Background Art
[0004] In usual, a transmission control apparatus having a shift lever of a manually operated transmission or a selector lever of an automatic transmission (the shift lever and the selector lever will be hereinafter referred to “control lever”) is arranged at a center console between a driver's seat and a assistant driver's seat. However, it has been proposed to arrange the transmission control apparatus at or near an instrument panel of a vehicle in view of ensuring a wide space on the front floor of vehicle and improving the operability of the transmission control apparatus.
[0005] Arrangement of the transmission control apparatus at or near the instrument panel makes it possible to assure a wide space near the front seats and thus to prevent erroneous touch of a driver with the control lever. In addition, since the control lever is positioned adjacent to a steering wheel, it is possible for a driver to quickly move his hand gripping the steering wheel to the control lever.
[0006] For example, Japanese Laid-open Patent Publication No. 67245/1998 discloses a technology for absorbing the shock load applied to the control lever of the transmission control apparatus arranged at or near the instrument panel. This technology intends to absorb the shock load with a pivot portion formed on the base end of the control lever being broken when the shock load is applied to the control lever.
[0007] Other technologies for absorbing the shock load with the supporting member of the control lever being broken are disclosed in Japanese Laid-open Patent Publication Nos. 129290/1998, 138778/1998 and 278085/1999.
[0008] However all of these prior arts intend to absorb shock load only through the breakage of the supporting member of the control lever. Accordingly, although it is possible to absorb the primary shock load, the secondary shock load would be often caused after the control lever having become free.
[0009] Japanese Laid-open Patent Publication No. 278085/1999 discloses a transmission control apparatus in which provided are a plurality of means for absorbing shock load through the breakage of the supporting member of the control lever. The shock load is absorbed by this type of shock absorbing means in a discontinuous manner and thus smooth shock absorption cannot be achieved by these shock absorbing means. In addition, since all the shock absorbing steps are performed through the breakage of the supporting member of the control lever, the characteristics of the shock absorption of each shock absorbing means is identical and thus the degree of freedom in setting the shock absorbing characteristics is reduced.
[0010] In these prior arts, there is a disclosure of providing a gas layer within a gripping knob for absorbing the shock load. However the gas layer does not act as a cushion when an exceeding shock load is instantaneouly applied to the control knob and thus only the shock absorption through the breakage of the supporting member of the control lever can be achieved, which causes a same problem as that mentioned above.
[0011] In addition, it may be conceivable that a supporting member of whole the transmission control apparatus can be broken in order to absorb the shock load when the shock load is applied to the control lever. However this is undesirable in view of reducing a space for the transmission control apparatus since whole the transmission control apparatus including the control lever is displaced in this case and thus it is required to previously keep the space therefor.
SUMMARY OF THE INVENTION
[0012] It is, therefore, an object of the present invention to provide a transmission control apparatus for an automobile which can improve the space reduction and the degree of freedom in setting the shock absorbing characteristics as well as can smoothly absorb the secondary shock load following the absorption of the primary shock load.
[0013] The object of the present invention can be achieved according to the present invention of claim 1 by providing a transmission control apparatus for an automobile to be arranged on or near an instrument panel of a vehicle comprising a bracket for supporting a control lever unit for speed-change operation; a plate secured to the bracket; a shaft passed through both the bracket and the plate for rotatably supporting the control lever unit therearound; a first shock absorbing portion adapted to be broken when a shock load exceeding a predetermined value is applied to the control lever unit in order to absorb the shock load and to release the support of the shaft from the bracket or the plate; and a second shock absorbing portion adapted to be deformed by the shaft released from the bracket and displaced together with the control lever unit over a predetermined stroke in order to continuously absorb the shock load.
[0014] According to the structure of claim 1 , the applied shock load is firstly absorbed by the breakage of the first shock absorbing portion and secondly continuously absorbed by the deformation of the second shock absorbing portion. It is preferable to provide the first shock absorbing portion on either one of the bracket or the plate and the second shock absorbing portion on the other one of the bracket or the plate.
[0015] In the present invention of claim 2 , the first shock absorbing portion may comprise a supporting portion forming an aperture through which the shaft is passed; the second shock absorbing portion may comprise a deformable portion formed by a portion through which the shaft can pass and a slot extending along the displacement direction of the shaft and having a width smaller than the outer diameter of the shaft; and the supporting portion and the slot may be formed either in the bracket or in the plate respectively.
[0016] According to the structure of claim 2 , the primary shock load is firstly absorbed by the breakage of the supporting portion and then the second shock load is continuously absorbed by the deformation of the slots.
[0017] In the present invention of claim 3 , the supporting portion may be formed in the bracket, and the deformable portion may be formed in the plate.
[0018] According to the structure of claim 3 , the primary shock load is firstly absorbed by the breakage of the supporting portion formed in the bracket and then the second shock load is continuously absorbed by the deformation of the deformable portion formed in the two plate.
[0019] In the present invention of claim 4 , a second slot or a notch (recessed portion) may be additionally formed near the slot with extending substantially parallel with the slot.
[0020] According to the structure of claim 4 , the material forming the second shock absorbing portion may be deformed toward the second slot or the notch.
[0021] In the present invention of claim 6 , the bracket may be formed by molding, and the first shock absorbing portion (or portions) may be integrally formed with the bracket.
[0022] In the present invention of claim 10 , the plate may be made of metal having a predetermined ductility.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Preferred embodiments of the present invention will be described with reference to the accompanied drawings in which;
[0024] [0024]FIG. 1 is a side elevational view of a transmission control apparatus for an automobile in accordance with a preferred embodiment of the present invention;
[0025] [0025]FIG. 2 is a perspective view of the transmission control apparatus of FIG. 1;
[0026] [0026]FIG. 3 is a perspective view of a bracket in the transmission control apparatus of FIG. 1;
[0027] [0027]FIG. 4 is an exploded view of the transmission control apparatus of FIG. 1;
[0028] [0028]FIG. 5 is a front elevational view of one plate in the transmission control apparatus of FIG. 1;
[0029] [0029]FIG. 6 is a front elevational view of the other plate in the transmission control apparatus of FIG. 1; and
[0030] [0030]FIG. 7 is a perspective view of the transmission control apparatus of FIG. 1 showing its condition after having absorbed the shock load.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] A transmission control apparatus for an automobile 1 shown as a preferred embodiment of the present invention in drawings is an automatic transmission and comprises mainly a bracket 4 to be mounted in a region of an instrument panel 2 for supporting a control lever (selector lever) unit 3 ; plates 5 and 6 ; a supporting shaft 7 ; a supporting portion 8 as a first shock absorbing portion; and slots 5 a and 6 a forming a second shock absorbing portion as shown in FIG. 1.
[0032] The bracket 4 forms a main part of the transmission apparatus 1 and supports the control lever unit 3 operated by a driver of a vehicle to change the driving mode of the vehicle. The bracket 4 is formed as aluminum die casting and is integrally formed with supporting portions 8 as shown in FIG. 3. The aluminum die casting makes it possible to form the bracket having excellent resistance against the temperature and a predetermined breakage characteristics of the supporting portions 8 .
[0033] Each supporting portion 8 is formed as a substantially annular configuration having an inner diameter substantially identical to an outer diameter of the supporting shaft 7 allowing a passage of the shaft 7 through the supporting portion 8 . The supporting portion 8 is designed to be broken by the shaft 7 when a shock load exceeding a predetermined level is applied to the control lever unit 3 by adjusting the thickness of the annular portion of the supporting portion 8 . The elongation percentage of the material forming the supporting portion is preferably less than 10%.
[0034] It may be possible to form the bracket 4 and the supporting portions 8 from separate members and to secure the supporting portions 8 to the bracket 4 via bolts or rivets. In this case the connection between the bracket 4 and the supporting portions 8 should not be broken by a force less than said predetermined level.
[0035] As shown in FIG. 4, the control lever unit 3 comprises an aperture 10 into which the supporting shaft 7 inserted, a position holding portion 11 under an action of a leaf spring (not shown) arranged below to hold the control lever unit 3 at the shifted position thereof, and a link mounting portion 12 for mounting a link for transmitting the shifting motion of the control lever unit 3 to the transmission (not shown). It is preferable in view of the strength and the manufacturing cost to form these portions integrally with resin. A gripping knob 3 a is mounted on the top end of the control lever unit 3 .
[0036] Plates 5 and 6 are secured to opposite sides of the bracket 4 via screws 13 . The plate 5 having L-shaped configuration is also secured the frame of a vehicle via bolts “b” (FIG. 1) passed through apertures 5 b (FIG. 2). The plate 5 has a mounting aperture 9 a corresponding to an aperture 9 b formed in the bracket 4 . The bracket 4 is mounted on the frame of a vehicle via a steering hanger bracket (not shown) passed through the apertures 9 a and 9 b.
[0037] The plates 5 and 6 have slots 5 a and 6 a respectively extending along a direction “a” (FIG. 1) of displacement of the supporting shaft 7 during its shock absorbing stroke. As shown in FIGS. 5 and 6, each slot 5 a and 6 a has a dimension “w” at its top end substantially identical to the outer diameter of the supporting shaft 7 and a dimension “u” at its elongated portion below the top end smaller than the dimension “w” of the outer diameter of the supporting shaft 7 . The slots 5 a and 6 a deform at their edges to absorb the secondary shock load during the shock absorbing stroke.
[0038] Although the width “u” of the slots 5 a and 6 a may be constant, it is preferable to continuously reduce its width downwardly as shown in FIGS. 5 and 6. Such a design makes it possible to continuously increase the shock load to be absorbed and thus to smoothly absorb the secondary shock load. If the plates 5 and 6 are made of metal having a predetermined ductility, it is possible to attain an ideal absorption of the secondary shock load during the deformation of the slots 5 a and 6 a . Accordingly, it is preferable to make the plates 5 and 6 of SP metal such as SPCC having the ductility of elongation percentage exceeding 30%.
[0039] The plate 5 is formed with a second slot 5 c and a notch or recessed portion 5 d near the slot 5 a and extending substantially parallel therewith in order to let the material loose during the deformation of the slot 5 a . Similarly, second slots 6 b are arranged at either side of the slot 6 a of the plate 6 . It is possible to set the value of the shock load to be absorbed by the second shock absorbing portion by previously determining the distance between the slots 5 a and 6 a and the second slots 5 c and 6 b or the notch 5 .
[0040] The components mentioned above are assembled as shown in FIG. 4. Firstly plates 5 and 6 are secured to the bracket 4 via screws 13 and then the supporting shaft 7 is inserted to the slot 5 a of the plate 5 , the supporting portions 8 of the bracket 4 , the aperture 10 of the control lever unit 3 , and the slot 6 a of the plate 6 and is finally secured at its distal end by a clip 15 . Thus the control lever unit 3 is pivotably supported on the bracket 4 via the supporting shaft 7 .
[0041] The lever portion of the control lever unit is passed through a groove 14 a of a decoration panel 14 on which characters (e.g. P, R, N, D, 2, 1 etc.) are inscribed in a conventional manner. The assembly of the main components of the transmission control apparatus for an automobile 1 is accomplished by finally mounting auxiliary parts such as a solenoid valve.
[0042] The manner of shock absorption according to the transmission control apparatus 1 of the present invention will be hereinafter described.
[0043] When a shock load “F” exceeding a predetermined value is applied to the control lever unit 3 , the supporting parts 8 supporting the shaft 7 will be initially broken and thus will absorb the initial shock load. The absorption of the shock load due to the breakage can improve the static strength as compared with the absorption due to the deformation. Said predetermined value of the shock load “F” can be determined by appropriately setting the thickness of the supporting portion 8 .
[0044] Since the supporting shaft 7 is released from the support by the bracket 4 when the supporting portions 8 is broken, the supporting shaft 7 is displaced together with the control lever unit 3 along slots 5 a and 6 a (the direction “a” in FIGS. 1, 2 and 7 ). The condition after the control lever unit 3 having displaced is shown in FIG. 7. During which, the slots 5 a and 6 a are expanded by the supporting shaft 7 and thus absorb the secondary shock load after the absorption of the initial shock load due to the breakage of the supporting portions 8 . The material near the slots 5 a and 6 a can be displaced toward the second slots 5 c and 6 b and the notch 5 d . The deformed condition of the slot 6 a is shown in FIG. 6 by dotted lines. A numeral 7 ′ denotes the position of the supporting shaft 7 after having displaced.
[0045] Since the secondary shock load is absorbed by the deformation of the slots 5 a and 6 a , the secondary shock load can be smoothly absorbed by a simple structure. In addition, since the shock load F can be absorbed only by the control lever unit 3 and the shaft 7 supporting the control lever unit 3 , it is possible to substantially reduce the space to be prepared for displacement of the structural components as compared with the case in which whole transmission control apparatus should be displaced in order to absorb the shock load as in the prior art.
[0046] It is preferable to set the direction of the slots 5 a and 6 a i.e. the direction “a” at a direction of the lever of the control lever unit 3 extends while the vehicle is running forward and can be determined in consideration of positions the steering wheel or seats based on the vehicle.
[0047] According to the preferred embodiment of the present invention, since the initial shock load is absorbed by the breakage of the structural parts and the second shock load is absorbed by the deformation of the structural parts, it is possible to easily adjust the shock absorbing characteristics. Furthermore, since the secondary shock load can be absorbed continuously over a predetermined stroke, it is possible to smoothly perform the absorption of the secondary shock load.
[0048] Although preferred embodiments are illustrated and described above, it should be noted that the present invention is not limited to these embodiments. For example, it will be applied to a transmission control apparatus for a manual transmission arranged at an instrument panel of a vehicle. In addition, it is possible to arrange the first shock absorbing portion at the plates and the second shock absorbing portion at the bracket. This can be achieved by providing the supporting portion for carrying out the shock absorption due to breakage on the plates and also by providing the deformation portion for carrying out the shock absorption due to deformation on the bracket.
[0049] Furthermore, the bracket may be molded by any other suitable material (e.g. plastics) than aluminum, in such a case, glass fiber reinforced plastics having the elongation percentage less than 10% will be preferable. In addition, the bracket may be directly secured to the frame of a vehicle, in such a case, the plates are dedicated to the function of second shock absorbing members.
[0050] It is also possible to arrange the transmission control apparatus not only at a region of the instrument panel as illustrated in the preferred embodiment, but at a region near the instrument panel. | According to the present invention there is provided a transmission control apparatus for an automobile to be arranged on or near an instrument panel of a vehicle comprising: a bracket for supporting a control lever unit for speed-change operation; a plate secured to the bracket; a shaft passed through both the bracket and the plate for rotatably supporting the control lever unit therearound; a first shock absorbing portion adapted to be broken when a shock load exceeding a predetermined value is applied to the control lever unit in order to absorb the shock load and to release the support of the shaft from the bracket or the plate; and a second shock absorbing portion adapted to be deformed by the shaft released from the bracket and displaced together with the control lever unit over a predetermined stroke in order to continuously absorb the shock load. | 5 |
This is a division, of application Ser. No. 845,767 filed Oct. 26, 1977, now U.S. Pat. No. 4,208,248.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to fuel assemblies for use in nuclear reactors and, more particularly, to locking techniques for the end fittings and control rod guide tubes in a nuclear fuel assembly, and the like.
2. Description of the Prior Art
To produce useful power from a nuclear reactor it is necessary to assemble fissionable material in a concentration that is sufficient to sustain a continuous sequence of neutron-induced fissions. Frequently, this concentration is attained by sealing uranium dioxide pellets in long, slender hollow rods. These rods, when filled with a charge of nuclear fuel and sealed at the ends, are called "fuel rods".
The fuel rods are arranged in a generally cylindrical array, or reactor core, to form the required concentration of fissionable material. In order to extract the heat generated in these fuel rods through the fission process, the fuel rods usually are spaced laterally from each other and water is pumped under pressure through the reactor core. The water absorbs the fission process heat and transfers this heat to secondary cooling water. The secondary cooling water rises into steam that is used to drive power generating turbine machinery.
In the reactor core, the radiation, pressures, temperatures and cooling water flow velocities create an environment that is quite hostile to the structural integrity of the reactor core. To cope with this environment, it has been customary to arrange the fuel rods that comprise the reactor core into a number of groups each of about two hundred fuel rods. These groups are frequently called fuel assemblies.
To enhance the structural integrity of each of the fuel assemblies and to stabilize the fuel rods in the assembly, it is common to mount the fuel rods between "end fittings" and to engage the mid-portions of each of the rods in the fuel assembly by means of cellular grid structures that are positioned at predetermined intervals along the lengths of the rods.
The structure of the fuel assembly, moreover, is not restricted to fuel rods, end fittings and grids. As a general rule one or more control rod guide tubes also are accommodated in the usual fuel assembly. Typically, to control the power generated in a nuclear reactor it is customary to add neutron absorbing materials to the reactor core. These materials have the effect of decreasing the fission activity within the core and thereby decreasing the power output from the reactor. As might be expected, there are a number of ways in which these neutron absorbing materials are introduced into the reactor core. Quite frequently, for example, the neutron absorbing materials are loaded into control rods. These control rods are received in hollow metal control rod guide tubes that extend through the length of the respective fuel element. In these circumstances, the depth of the penetration of the control rods into the associated fuel element determines, to some extent, the level of neutron fission activity and associated power output from the reactor core.
Some fuel assembly designs have a further use for the control rod guide tubes beyond aligning the individual control rods within the respective fuel assembly. Typically in this regard, the control rod guide tubes are often used to space the two end fittings from each other and, essentially, to clamp the fuel rods in proper relative position between these end fittings through enabling the end fittings to engage the extreme ends of the fuel rods.
This foregoing fuel assembly construction produces a rugged, sturdy structure that is able to cope with the forces that characterize a reactor core environment. There is, however, a somewhat countervailing need to provide a fuel assembly structure that can be assembled and dismantled with ease in order to reduce manufacturing costs, improve quality assurance and facilitate inspection and replacement. If it is realized that fuel assemblies, once having been made radioactive, must subsequently be manipulated behind shielding with remote handling equipment, the importance of the need for simple disassembly techniques becomes immediately apparent.
In this respect, the typical fuel element is dismounted by unthreading nuts that connect the control rod guide tubes to the end fittings, releasing one or more springs and, in general, taking the entire fuel assembly apart piece-by-piece. Not only is this a very laborious and expensive practice but it also introduces the possibility that one or more of the smaller fittings might go astray, leading to further lost time and expense, or damage if not discovered.
Thus, there is a clear need for an improved fuel assembly that will, to a large extent, overcome many of these inadequacies that have characterized the prior art.
SUMMARY OF THE INVENTION
An improved fuel assembly in accordance with the principles of the invention is characterized by a sleeve that engages one end of a control rod guide tube, essentially fixing the guide tube to one of the fuel assembly end structures. An end of the sleeve protrudes above the surface of the end fitting. The outer surface of the sleeve has a peripheral groove that engages the resilient sides of a cellular grid or lattice shaped lock. This lock fixes the sleeve in position between the various elements that comprise the end fitting, thereby eliminating a profusion of costly and potentially troublesome nuts, threaded studs and the like that frequently are employed in the fuel assemblies that are typical of the prior art.
To dismount the end fitting from the fuel assembly in accordance with the principles of the invention, a special grapple has jaws that engage a portion of the end fitting. The jaws first clamps the upper grill that supports the ends of the control rod guide tubes and their respective sleeves. The spider which engages the control rod guide tube sleeves then is pressed against the springs that circumscribe these sleeves in order to establish some degree of longitudinal clearance between the spider and the lock mechanism. After this clearance is established individual tools are pressed into the respective open, protruding ends of each of the sleeves to engage exposed portions of the grid-shaped lock. The tools press these sides out of the groove, so engage the lock that the lock will be withdrawn from the sleeve when the grapple is withdrawn from the end of the fuel assembly. This permits the upper end fitting to be removed as a unit that captures the components which are associated with the end fitting as an assembled unit, while leaving the control rod guide tubes and the associated sleeves with the balance of the fuel assembly. In this way, end fitting components that are captured by the grapple in this manner subsequently can be replaced intact on the fuel assembly structure without indulging in the cumbersome and expensive remote manipulator detailed disassembly and assembly of scores of small parts that has characterized the prior art.
Thus, the invention provides techniques for reducing the number of parts required for fuel assembly construction, reduces manufacturing costs and simplifies quality assurance and inspection problems.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawing and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a front elevation in part section of a typical fuel assembly that embodies principles of the invention;
FIG. 2 is a front elevation in full section of a control rod guide tube structure for use in connection with the structure that is shown in FIG. 1;
FIG. 3 is a plan view in partial section of the control rod guide tube structure that is shown in FIG. 2 taken along the line 3--3 of FIG. 2;
FIG. 4 is a front elevation of a grapple and tool engaging a portion of the fuel assembly that is shown in FIG. 1;
FIG. 5 is a plan view in broken section of the grapple that is shown in FIG. 4;
FIG. 6 is a schematic drawing of a portion of the grapple in an initial operational position;
FIG. 7 is a schematic drawing of a portion of the grapple in another operational position;
FIG. 8 is a schematic drawing of a portion of the grapple in still another operational position; and
FIG. 9 is a schematic drawing of a portion of the grapple after the lock has been disengaged.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, an illustrative fuel assembly 10 comprises an array of more than two hundred fuel rods 11. It will be recalled in this respect, that the fuel rods 11 are made from long, slender, thin-walled tubes that enclose pellets of uranium dioxide or other suitable nuclear fuel, and that these fuel rods are grouped together within the fuel assembly 10 with the longitudinal axes of the fuel rods in general parallel alignment. Control rod guide tubes 12 are nested within the fuel assembly 11 amongst and in parallel with the fuel rods. The control rod guide tubes 12 each are hollow, thin-walled tubes that extend through the entire fuel assembly 10 parallel to the longitudinal axis of the fuel assembly.
A lower end support fitting 13 that is transversely disposed relative to the longitudinal axes of the fuel rods 11 engages the abutting ends of the fuel rods. As described subsequently in more complete detail, the control rod guide tubes 12 pass through the end fitting 13 in order to secure the end fitting to the fuel assembly structure.
Ends of the control rod guide tubes 12 protrude above the plane established by the sealed ends of the fuel rods 11. These protruding ends of the control rod guide tubes 12 terminate, as shown in FIG. 2, within the confines of a transversely disposed grill 14. The grill 14 is assembled from a parallel array of generally flat, slotted plates that are meshed with mating slots in a perpendicular array of essentially flat plates in order to form a cellular grill structure. The parallel grouping of the fuel rods 11 and the control rod guide tubes 12 is established and stabilized by means of transversely disposed grid structures 15, similar in construction to the grill 14 described above and through which the fuel rods and guide tubes extend. Toward the ends of the fuel rods 11 that are close to the protruding portions of the control rod guide tubes, however, a transversely disposed upper grid 16 is positioned. The upper grid 16 has a somewhat greater depth in the direction of the longitudinal axes of the fuel rods 11 than the grid structures 15 in order to enhance the structural integrity of this portion of the fuel assembly.
In accordance with a feature of the invention a parallel array of hollow cylindrical sleeves 17 telescope over the respective protruding ends of the control rod guide tubes 12 in order to extend from within the confines of the upper grid 16 through the grill 14, through a transversely disposed spider 20 and an immediately superjacent control rod guide tube assembly lock 21. Spring means, such as individual coil springs 22, each associated with a respective one of the sleeves 17 are interposed in a biasing relationship between the grill 14 and the spider 20 in order to provide some means for compensating and absorbing movement of the fuel element 10 in the direction of the longitudinal axes of the fuel rods 11. Note that in the illustrative embodiment of the invention shown in FIG. 2 that the sleeve 17 is in general axial alignment with the guide tube 12, and that the sleeve serves as a guide for the coil spring 22. The coil spring 22, moreover, also has a longitudinal axis that generally coincides with the longitudinal axis of the guide tube 12.
Attention is invited to FIG. 2 for a more detailed appreciation of the novel features of this invention that characterize the invention. More particularly, the control rod guide tube 12 is secured to a lower grid 23 by means of a bolt structure 24. The bolt structure 24 has a head 25 that is received within the adjacent open end of the control rod guide tube 12. A bolt shank 26 extends through the lower grid 23 in order to protrude from the end support fitting 13. The protruding portion of the shank 26 is threaded in order to receive a fastening nut 27. A nut retainer 30 is interposed between the end fitting and the nut 27 in order to prevent the nut from working loose and becoming disengaged from the fuel assembly.
As shown in FIG. 2, the control rod guide tube 12 extends through the main portion of the fuel assembly and through an upper grid 16. Within the upper grid 16 the guide tube 12 is telescoped within the sleeve 17, open end portion 31 of the control rod guide tube 12 abutting and bearing against a flange or shoulder 32 that is formed within the inner surface of the sleeve 17. The shoulder 32 in the sleeve 17 transfers compression loads directly to the guide tube in the manner described subsequently in more complete detail.
Through the lengths of the control rod guide tube 12 and the sleeve 17 that are coextensive protrusions or "dimples" 33 are swaged or otherwise suitably formed in the control rod guide tube 12 and the sleeve 17 in order to hold the sleeve and the guide tube together and form a tight joint. Immediately below the grill 14, circumscribing a portion of the sleeve 17 and bearing against a transverse surface of the grill 14 is a ring shaped collar 34. As shown, the collar 34 and the encircled portions of the sleeve 17 and the control rod guide tube 12 also are provided with protrusions or dimples 35, 36 that have been swaged or otherwise formed in the materials in order to position the collar 34 properly relative to the balance of the fuel assembly structure and to permit the collar to sustain loads imposed in the direction of control rod guide tube longitudinal axis 37 and to transfer these loads between the grill 14 and the combination sleeve 17 and control rod guide tube 12.
A washer 40 rests upon the transverse surface of the grill 14 that is opposite from the transverse grill surface that engages the collar 34. The coil spring 22 as illustrated in FIG. 2, is mounted on the washer 40 and encloses a portion of the sleeve 17 that protrudes above the grill 14. The longitudinal axis of the coil spring 22 generally coincides with the longitudinal axis 37 in order to press against a further washer 41. Thus, the coil spring 22 interposed between the grill 14 and the spider assembly 20, respectively biases the grill and spider assembly against the collar 34 and the lock 21.
Illustratively, the washer 41 is in engagement with the cellular spider assembly 20. As shown, the sleeve 17 is received within a cellular recess 42 in the spider 20 with sufficient clearance between the sleeve and the walls of the spider recess 42 to permit the spider and the sleeve to move relative to each other in the direction of the longitudinal axis 37.
A terminal portion 43 of the sleeve 17 protrudes above the spider 20 in order to engage the lock 21. To engage the lock 21, the outer surface of the portion 43 is provided with a circumferential groove 44 that forms a protruding shoulder 45 which serves to engage edges of the lock 21. Perhaps, as best shown in FIG. 3, the lock 21 is assembled from an array of resilient parallel plates 46, 47 that are meshed and interlock with similarly resilient plates 50, 51 that are generally perpendicular to the plates 46, 47 at the respective lines of intersection to form a cellular grid structure. As shown, the separation between the parallel plates 46, 47 is less than the maximum outside diameter of the groove 44 that is formed in the portion 43.
The plate 50 has a generally arcuate shape that conforms to and bears against a segment of the grooved surface of the terminal sleeve portion 43. The companion plate 51, however, has a plane profile that permits part of an edge of this plate to engage the shoulder 45 (FIG. 2). In this manner, all of the control rod guide tubes 12 that are shown in FIG. 1 are locked together as a single unit.
Best shown in FIGS. 2 and 3, the terminal sleeve portion 43 is provided with four longitudinal slots 52, 53, 54 and 55 that are parallel with the longitudinal axis 37. The slots 52, 53, 54 and 55 each are spaced from the next adjacent slots by about 90° and penetrate the portion 43 to a depth that is at least equal to the combined longitudinal depth of the shoulder 45 and the width of the plates 50, 51.
In accordance with an additional feature of the invention a grapple 56 is shown in FIG. 4. The grapple 56 releases the lock 21 from the control rod guide tube sleeves 17 and also provides a means for installing or removing as one entire unit the complete assembly that comprises the lock 21, the washers 40, 41 the spider 20, the coil springs 22 and the grill 14. To accomplish these results, the grapple 56 is provided with a member 57 that is movable in the direction of longitudinal axis 60. A transversely disposed linkage 61 is secured through a cross piece 62 (FIG. 5) to the vertically movable member 57. The end portions of the linkage 61 (FIG. 4) have slots 63, 64 which receive respective pins 65, 66. The pins 65, 66 are transversely movable within the respective slots in order to enable two jaws 67, 70 that are pivotally connected to a transversely disposed tool frame 71 to move in a scissors-like manner. Thus, pivot 72 joins the jaw 70 to the tool frame 71.
As shown in FIG. 4 the jaw 70 is provided at its extreme end with a clamp 73 that engages a longitudinal edge of the grill 14. In a similar manner, the extreme end of the jaw 67 also is provided with a clamp 74 that is oppositely disposed from the clamp 73 on the jaw 70.
Perhaps best shown in FIG. 4, a companion linkage 75 with pinned and pivoted jaws 76, 77 also are joined by means of the cross piece 62 to the longitudinally movable member 57. This companion structure matches and balances the structural arrangement described above with respect to the jaws 67, 70.
The transversely disposed tool frame 71 also is provided with an array of longitudinally aligned apertures 80 that each accommodate one of a group of tools 81. As illustrated in FIG. 4, the tools 81 are formed from generally cylindrical rods that are longitudinally aligned with the axis 60. Each of the tools 81 has a generally conical end portion 82. The mid-section of the tool 81 has four fins 83, of which only three of these fins are shown in the plane of the drawing. As illustrated, each of the fins 83 are spaced about 90° from the next adjacent fins. Each of the fins 83 has a tapered slope 84 in which the narrow edge of the slope is oriented toward the end portion 82. The tapered slope 84 ends in a generally flat surface 85. The width of each of the fins 83 is slightly less than the transverse width of the individual slots 52, 53, 54, 55 (FIGS. 2 and 3). The transverse depth of each of these fins, however, between the flat surface 85 (FIG. 4) and the adjacent surface of the tool 81 is greater than the corresponding wall thickness of the terminal sleeve portion 43 as shown in FIGS. 2 and 3.
An annular collar 86 is secured to the tool 81 and spaced longitudinally from the flat surfaces 85 on the fins 83 a sufficient distance to enable the fins when aligned with the respective slots in the terminal sleeve portion 43 to bear against the terminal portion and prevent the flat surfaces 85 of the fins 83 from penetrating the sleeve 17 to a depth greater than the longitudinal protrusion of the slots in the terminal sleeve portion 43 (FIG. 2) above the spider 20.
As illustrated in FIG. 4, the tool 81 has been threaded 87 at the end opposite from the end portion 82 to enable nuts 90, 91 to secure the tool 81 to a transversely disposed plate 92 that is movable in longitudinal directions as indicated by means of arrows 93, 94 under the control of spring biased pneumatic cylinders 95, 96. Thus, depending on the relative activation of the pneumatic cylinders 95, 96, the tools 81, when aligned with respective terminal sleeve portions 43 are driven into the sleeves 17 to a sufficient depth to permit the flat surfaces 85 on the fins 83 to bear against the plates 46, 47, 50, 51 (FIGS. 2 and 3). The flat surfaces 83 press these plates in a radially outward direction relative to the longitudinal axis 37 through a distance that is sufficient to permit all of the plates to clear the shoulder 45 that is formed in the terminal sleeve portion 43. In this manner the entire cellular lock 21 is released from its engagement with the sleeves 17 and fixes itself temporarily to the tools 81 in the array of tools.
In operation, and, as perhaps best understood through an examination of FIG. 6 the grapple 56 is aligned with the end fitting to permit the clamps 73 on the jaw 70 (as well as the clamps 74 on the jaws 67, and the clamps on the jaws 76, 77 on the grapple that are not shown in FIG. 6) to be spaced outwardly of the grill 14, but within the same transverse plane as the grill.
During this phase of the operation of the grapple 56, the springs associated with the springs loaded pins 97 are compressed through activation of the air cylinder 95 which moves the plate 92 in the direction of the arrow 93.
As illustrated in FIG. 7, the clamps 73, 74 on the jaws 70, 67, respectively, (as well as the changes on the comparison pair of jaws 76, 77) swing inwardly in the directions indicated by arrows 101, 102 in order to grasp firmly peripheral portions of the grill 14. This inwardly swinging movement of the clamps 73, 74 is achieved through longitudinal movement of the member 57 in the direction of arrow 103. This movement of the member 57, causes the pins 65, 66 to ride within the respective slots 63, 64 toward the longitudinal axis 60. The motion of these pins within the slots compels the jaws 67, 70 to pivot center-clockwise and clockwise, respectively, about the pivot 72 (for the jaw 70) and a similar pivot (not shown in FIG. 7) for the jaw 67.
The next illustrative step in the technique for dismounting the end fitting from the balance of the fuel assembly is shown in FIG. 8. Thus, air cylinders 96 are activated to drive piston rods 104 in the longitudinal directions indicated by means of arrow 105. The exposed ends of the piston rods 104 bear against the adjacent transverse surface of the spider 20. The force applied by the piston rods 104 to the spider 20 overcomes the oppositely directed forces established by means of the coil springs that are received on the sleeves, of which the coil spring 22 and the sleeve 17 in FIG. 8 are illustrative. In response to this new balance of forces the spider 20 also moves in the longitudinal direction of the arrow 105 in order to provide a longitudinal clearance 106 between the spider 20 and the lock 21 to relieve the force that the spider 20 applies to the lock 21.
In a typical embodiment of the invention, the next step, in the technique involves movement of the grapple 56 that is best illustrated in FIG. 9. Recall for a moment that the cellular structure of the lock 21 is so designed that the groove 44 (FIG. 2) and the shoulder 45 that is formed in the terminal sleeve portion 43 engage the plates 46, 47, 50, 51 (FIG. 3) that comprise the structure of the cells in the lock 21.
Turning now once more to FIG. 9, the air cylinders 95 are deactivated to enable the coiled springs on the spring loaded pins 97 to release and press the plate 92 in a longitudinal direction as indicated by an arrow 107. Because the recess and shoulders on the sleeves restrain the lock 21 from engaging in any longitudinal movement in the direction of the arrow 107, the tools that are fastened to the plate 92, of which the tools 81 is typical, are pressed through the individual cells in the locks 21 into the respective sleeves 17. The fins 83 that protrude radially from the tools 81 also are driven into mating slots 52, 53, 54, 55 (FIGS. 2 and 3). This longitudinal movement of the tools 81 permits the tapered slope 84 of the pins 83 (FIG. 9) to press the plates 46, 47, 50, 51 on the lock 21 in a radially outward direction in order to disengage these plates from the nested engagement within the annular groove 44 (FIGS. 2 and 3) that is formed in the terminal sleeve portion 43.
In those circumstances, further longitudinal movement of the tools 81 (FIG. 9) in the direction of the arrow 107 under the force of the released springs on the pins 97 is limited only by the braking action of the collars 86 on each of the tools. The collar 86 is so spaced relative to the lock 21 that the plates which form each of the cells in the lock 21 are forced onto the corresponding flat surface 85 of the fins 83. The effect of this engagement between the plates that form the cells on the lock 21 and the flat surfaces 85 of the fins 83 is to press the plates out of engagement with the respective annular grooves 44 (FIGS. 2 and 3) and shoulders 45.
In the next illustrative disassembly step, the entire grapple 56 is moved longitudinally in the direction of arrow 108. The grapple, withdrawn from the balance of the fuel assembly in the foregoing manner, takes with it most of the end fitting components in their proper relative position. Typically, the lock 21, the spider 20, and the grill 14 remain with the grapple 56. The coil springs 22 with their associated washers 40, 41 (FIG. 2) also are drawn away with the grapple 56 (FIG. 9). In this instance, the tools 81 serve as temporary spring guides or keepers for the coil springs 22 and the washers. The springs 22, moreover, serve to keep an approximately proper longitudinal separation between the grill 14 and the spider 20. Note in this respect that the sleeves 17 remain with the balance of the fuel assembly.
To reassemble the end fitting components on the main portion of the fuel assembly, the end portion 82 of the tools 81 on the grapple 56 are longitudinally aligned with their respective sleeves. The grapple 56 then is moved longitudinally in the direction of the arrow 107 until each of the tools 81 are fully seated in the respective sleeves 17. One or more clamps (not shown in the drawing) hold the lock 21 in suitable position relative to the grooves 44, (FIGS. 2 and 3) and shoulders 45 on the terminal sleeve portion 43. In this condition the air cylinders 95 (FIG. 9) are activated to compress the springs on the spring loaded pins 97, thereby extracting the pins 83 from engagement with the plates that form the cells in the lock 21. The disengagement of the tools 81 and the lock 21 permits the plates that form each of the lock's cells to snap back into the annular recesses 44 (FIGS. 2 and 3) and shoulders 45 in the terminal sleeve portion 43.
The spider 20 (FIG. 9) under the action of the coil springs 22 bears against the adjacent surface of the lock 21. The member 57, moreover, is moved longitudinally in the direction of the arrow 107 to permit the jaws 67, 70 to pivot in clockwise and counter-clockwise directions, respectively. This pivoting movement of the jaws 67, 70 releases the grip that the clamps 73, 74 had on the grill 14. The further clamps (not shown in the drawing) that engage the lock 21 also are removed.
The entire end fitting now is reassembled on the balance of the fuel assembly in a manner that clearly avoids the prior art requirement for tedious, detailed, piece-by-piece diassembly and reassembly. This technique that characterizes the invention also avoids the hazards that might attend the loss of one of these small end fitting components, and the like. | A typical embodiment of the invention provides a nuclear fuel assembly lock structure for control rod guide tubes. Illustratively, a sleeve telescopes over an end portion of a control rod guide tube which bears against an internal shoulder of the tube. The upper end of the sleeve protrudes beyond the control rod guide tube spider and is locked in place by means of a resilient cellular lattice or lock that is seated in a mating groove in the outer surface of the sleeve. A special tool is provided for disengaging the entire lock structure, washer, spider, spring and grill from the end of the fuel assembly in order to enable these components to be removed in an assembled state and subsequently replaced on the fuel assembly after inspection and repair. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to infusion pumps and, in particular, to a portable, programmable infusion pump wherein incremental doses of a medicant are delivered at a self-calculated rate and wherein a plurality of modes of operation may be selectively programmed to ensure that a proper total daily profile and dosage is delivered.
Infusion pumps or automatic medicant injecting mechanisms have existed in the prior art for a great many years. Such devices typically comprise a chamber for containing a medicant and means for controllably causing the evacuation of the chamber. Various and sundry control means have been employed and which most typically take the form of electro-mechanical arrangements including motor means, drive means, means for evacuating the chamber and pulse producing means for controllably operating the motor means. Some of the more recent of such systems can be found upon reference to U.S. Pat. Nos. 3,858,581; 4,150,672 and 4,191,187, and which generally show and describe infusion pumps that employ motor means, a transmission system and a lead screw for controllably causing the administration of the doses of the medicant.
In the Whitney U.S. Pat. No. 4,150,672 patent, the medicant is delivered at a rate established in response to individual, fixed width pulses that are produced by an oscillator. Wright in the U.S. Pat. No. 4,191,187 patent also delivers the medicant as per fixed width pulses in response to the actuation/deactuation of a cam and micro-switch that are operatively coupled to the lead screw assembly to control the drive/braking action of the assembly. Kamen in the U.S. Pat. No. 3,858,581 patent, on the other hand, recognizes that uniform pulses are not the same as the uniform displacement of the syringe plunger, due to the number of factors that affect the dosage delivered (i.e. variations in the work load, supply voltage and medicant). Accordingly, Kamen discloses the use of a cam/micro-switch and counter assembly for uniformly displacing the syringe plunger as each dose is delivered to the patient.
Efforts employing digital techniques can also be found upon reference to Franetzki et al in U.S. Pat. No. 4,282,872 and Ellinwood in U.S. Pat. No. 3,923,060. Franetzki generally discloses partially implantable apparatus employing preprogrammed sequences that deliver a selected amount at a rate pursuant to the programmed sequence. Ellinwood, on the other hand, discloses an implantable infusion device that employs a microcontroller that operates in response to a plurality of sensors contained within the body. The pump then dispenses the medicant in accordance with a pre-stored program that is entered either upon implant or via an external programmer.
Nowhere, however, does the prior art disclose the present apparatus and which generally comprises a portable, programmable infusion pump that acts to dispense uniform incremental doses of medicant at a rate determined by the desired dose and concentration, programmed by the patient or doctor. In its preferred embodiment, the present infusion apparatus employs a lead screw along with photo coupling means and a counter for determining the volume of each incremental dose. The number and rate of application of the doses is then determined by the microprocessor, upon entering the concentration and rate.
The above features and advantages of the present invention, as well as further objects thereof, will however become more apparent and more fully appreciated upon reference to the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an exploded view of the present apparatus wherein the syringe, plunger and lead screw are shown relative to their placement within the medicant compartment.
FIG. 2 depicts the motor means and transmission assembly for coupling the rotational movement of the motor means to the lead screw.
FIG. 3a shows another view of FIG. 2, but wherein the slotted wheel and photo-coupled encoder assembly can be seen more clearly.
FIG. 3b is a detailed view of the slotted wheel that produces the pulse train that ensures the proper volume of medicant is delivered with each incremental dose.
FIG. 4, comprised of Figures of 4a, 4b and 4c, shows a schematic diagram of the control circuitry that is employed in programming and controlling the various modes of operation of the present invention.
FIG. 5, comprised of FIGS. 5a and 5.1 through 5.66, shows the flow diagram of the micro-program that controls the operation of the present apparatus.
SUMMARY OF THE INVENTION
A portable, programmable infusion pump, wherein the infusion pump comprises a chamber for containing a medicant, means for controllably expelling the medicant from the chamber into a patient requiring the medicant and means for programmably calculating the total number and rate at which each incremental dose is delivered, upon programming the desired dosage and medicant concentration. The control means also includes a photo-coupled assembly for producing a plurality of pulses which, in turn, are counted to ensure that the proper incremental volume of medicant is delivered with each dose.
The apparatus also permits the delivery of a supplemental dose, pursuant to a programmed delay interval, a programmed supplemental dose and a programmed supplemental duration parameter. The supplemental dose thus corrects where insulin is the medicant for the hypoglycemic reaction that is often experienced after a period during which an insufficient dosage has been delivered.
The infusion pump further permits programming a manual dose, priming the means for delivering the medicant, maintaining a record of the total accumulated dose delivered between battery changes, audibly warning the user if an error condition is detected and programming a lock-out function.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, an exploded view is shown of the container 2 that contains the medication holding syringe 4 and the lead screw 6 that together generally comprise the pump of the present invention. Mounted in the upper right hand corner of the front surface of container 2 are a plurality of keys 8 that are attached to separate membrane switches and which keys collectively comprise the keyboard 10 by which the present invention is programmed.
The keyboard 10 permits an operator to address the various parameters which control the pump and to enter the specific dose data that determines the rate of delivery. The necessary numerical values for each programmable parameter are entered via the numerical keys 0 through 9. The remaining keys then control the commands corresponding to the: E(ENTER); M(MANUAL); H(HOLD); P(PRIME); S(STEP); C(CLEAR); and L(LOCK-OUT) functions.
Mounted in the upper left hand corner of container 2 is a liquid crystal display (LCD) 12 and by which the operator is able to visually confirm "what" and "if" data is entered as the keys 8 are depressed. It is to be noted the information content of the LCD display 12 is separated, via the solid slashed line so that upon programming, the function code appears to the left of the slashed line while the numerical dose data for that function appears to the right of the slashed line. During the prime and hold functions however, numerical data is not displayed, and in lieu thereof either the P or the H mnenonic is displayed, but which functions will be described in greater detail hereinafter.
The inner shape of the medicant compartment 14 can also be seen in detail, upon reference to the container 2. In particular, it is to be noted that the compartment 14 contains a plurality of support fins 16 that are used to support the syringe 4 at the appropriate height relative to the container 2, as well as limiting the travel of the plunger 18 and drive nut 24.
The medicant compartment 14 is covered, during use, by the cover 22 and which contains a viewing window 24. The medicant compartment, as mentioned, contains the disposable syringe 4, such as a CPI/Lilly Model 9110. During use, the syringe 4 can then be monitored via the viewing window 24, which permits the user to visibly monitor the contents of the syringe 4 and which window is positioned so that the markings 26 on the syringe are visible therethrough. Thus, a user, from time to time, can monitor the amount of medicant that remains within the syringe. The compartment cover 22 is also formed so that it is easily removed from the container 2 by depressing the ridged thumb latch 28.
Referring now to the more detailed view of the syringe 4, the plunger 18, lead screw 6 and drive nut 24 can be seen more clearly in their relative relationships to one another and the hexagonal drive pin 30. Generally, the displacement of the plunger 18 is controlled via the lead screw 6 and drivenut 24, which abuts the flattened end 32 of the plunger 18, and it is the linear displacement of the drivenut 24, via the turning of the lead screw 6, that causes the corresponding displacement of the plunger 18 and the delivery of a volume of medicant that is indicated by the incremental gradations 26 marked on the side of the syringe 4.
The lead screw 6 is typically fabricated so as to have a threaded portion and a non-threaded portion. The threaded portion is typically fabricated with forty threads per inch and which translates into a linear displacement of 0.025 inches per revolution of the lead screw 6. Further, the drive nut 24 is formed so as to partially support the lead screw 6 relative to the plunger 18 and thus move along an axis that is approximately coincident with the syringe 4 and the lead screw 6. The lead screw 6 also contains a hexagonal recess (not shown) within the end of the threaded end thereof for receiving the hexagonal drive pin 30, so that upon the rotation of the head screw 6, via the drive pin 30, the drive nut 24 will move linearly to the left (with respect to the drive pin 30) and thereby cause the plunger 18 to eject the medicant from the syringe 4. It should also be noted that the plunger 18 has a hollow formed through the flattened end 32 so as to receive the unthreaded portion of the lead screw 6 and maintain contact between the drive nut 24 and the plunger head 32 as the drive nut 24 moves along the lead screw 6.
From FIG. 1, it should also be noted that an opening 34 is formed in the side of the compartment cover 22 so as to permit the coupling of a tube (not shown) therethrough with the luer connector 36 of the syringe 4. The tube in turn, is coupled to a needle assembly that is affixed to the patient at most typically the thigh or abdomen so as to deliver the doses subcutaneously. The tube is also typically taped to the patient's skin and beneath the patient's clothing so as not to be visible during use.
Referring next to FIG. 2, a detailed view can be seen of the drive assembly that is contained within the container 2, beneath the keyboard 10. The drive assembly is generally comprised of a motor 50 that is attached to a gearbox 52, a pinion shaft 54, a plurality of gears 56, 58 and 60, and a drive shaft 62, all of which are mounted in a chassis 64. The pinion shaft 54 is coupled on one end to the gearbox output shaft 66 and a bearing journal 68 on the other end fits in a sintered bronze bearing 70 which is press fitted into the chassis 64. One end of the pinion shaft 56 is also machined to provide the gear teeth 56. The drive gear 60 is similarly supported by the sintered bronze bearings 78 and 80. The idler gear 58 is supported by and revolves freely on a shaft which is press fitted in the chassis 64. Thus, rotation of the output shaft 66 causes the pinion shaft 54 to rotate and, in turn, the idler gear 58 and drive gear 60. The pinion shaft 54 has 13 teeth, and the drive gear has 49 teeth, which together produce a critical gear train, that will be described in greater detail hereinafter.
The drive gear 60 assembly differs slightly in that a bushing 80 is passed through the bracket 64 so that the output shaft 62 and the hexagonal drive pin 30 can freely rotate therein. It is to be noted that the hexagonal drive pin 30 is formed from the cylindrical output shaft member 62. The hexagonal drive pin 30 thus engages the lead screw 6 within the recess formed therein (not shown) and which is of a corresponding shape, and whereby the leadscrew 6 is free to articulate about the hexagonal drive pin 30.
Thus, the motor 50 upon being subjected to appropriate electrical pulses, translates the rotary motion of its drive shaft (not shown) into a calibrated rotary motion of the lead screw 6 and which motion, in turn, is converted into a calibrated linear displacement of the plunger 18 via the drive nut 20.
The electrical signals that are employed for pulsing the motor 50 will be described in greater detail hereinafter, but generally the signals are applied so as to cause a fixed volume incremental dose of the medicant to be delivered to the patient. The specific incremental volume is determined by the number of openings on the encoder disc 82, the gear train ratio, the pitch of the leadscrew 6, and the bore of the syringe barrel. In the preferred embodiment, the encoder disc has 12 openings, the gear train ratio is 49 to 13, the leadscrew has 40 threads per inch, and the bore of the syringe is nominally 0.375 inches. Thus, the rotation of the pinion shaft 54, from one opening to the next of the encoder disc 82, causes one microliter of medicant to be dispensed.
Referring to FIG. 3a, a side view can be seen of the drive assembly and, in particular, the optical encoder disc 82 relative to a photo coupled encoder module 84. Specifically, it is to be noted that the optical encoder disc 82 revolves within a recess formed between two portions of the photo coupler module 84 that respectively contain a light emitting diode (LED) 86 and a photo detecting transistor 88. The detection of light from the LED 86, via the photo transistor 88, as the pinion shaft 54 rotates and exposes the openings of the encoder disc 82, thus causes a pulse to be produced, via the electronic circuitry, as each opening is exposed, but which will be described in detail hereinafter. Each pulse is then counted, via a digital counter, and again which will be described in detail hereinafter.
Referring next to FIG. 3b, a more detailed view of the optical encoder disc 82 is shown. From FIG. 3b, it is to be noted that a plurality of openings 90 (i.e. 12) have been formed through the optical encoder disc 82 at uniform spacings from one another. The openings 84, thus permit light to pass from the LED 86 to the photo transistor 88 as the pinion shaft 54 rotates. Therefore, as the motor 50 causes the pinion shaft 54 to rotate, each time an opening 84 is exposed to the photo coupler module 84, a pulse is produced, counted and stored within the control circuitry.
It is also to be recognized that while a particular optical encoder disc 82 and photo coupler module 84 have been shown with respect to the present embodiment, numerous other embodiments are possible, depending upon the peculiarities of the packaging arrangement. The primary concern of any assembly, however, is to create an assembly that is capable of producing electrical pulses via an efficient electro-mechanical arrangement. For instance, an alternative embodiment may comprise a pinion shaft 54 having permanent magnets affixed thereto so as to cause pulses to be produced as each magnet is coincident to a pickup coil.
Also, shown within the optical encoder disc 82 is an arrow 92 that indicates not only the direction of rotation of the pinion shaft 54, but also the leading edge of the openings 54 that are detected first and which must therefore be geometrically accurate. The center opening 94 of the encoder disc 82 is also formed so as to be compatibly mounted upon the pinion shaft 54 and attached thereto via a cyanoacrylic adhesive, thereby ensuring that the optical encoder disc 82 does not rotate independently by the pinion shaft 54. Again, however, the peculiar details of attachment are not critical and may be achievable through any number of well known mechanical arrangements.
Referring next to FIG. 4, comprised of FIGS. 4a, 4b and 4c, a detailed schematic diagram is shown of the control circuitry that is used to ensure the proper operation of the present invention. As previously mentioned, the control circuitry is programmable via the use of a microprocessor 100, an associated programmable read only memory (PROM) 102 and an associated random access memory (RAM) 104. The control circuitry is also comprised of the keyboard 10, keyboard encoder 106, display driver 108, LCD display 12, motor drive 112, audio alarm 114, one second timer 111 and low voltage detector 116. Also included are the additional power up/master clear circuitry 118, memory timer 120, address latch 122, power saver 124, time out control 126 and associated peripheral logic circuitry.
Prior to describing the operation of the control circuitry of FIG. 4, attention is directed to the flow chart of FIG. 5, comprised of FIGS. 5a and 5.1 through 5.66. The flow chart of FIG. 5 generally shows the manner of operation of the circuitry of FIG. 4, during its various modes of operation, and which will be appropriately referenced as the circuitry is described. It is to be noted, too, that the flow chart has essentially been segmented, via the various sub-figures 5.1 through 5.66, for ease of understanding. This understanding is also facilitated via FIG. 5a, wherein a key to the flow chart symbols is shown, and Table 1, below, wherein a list of the various flow chart mnemonic labels is shown relative to the figure number for the various routines and subroutines of the flow chart.
TABLE 1______________________________________INDEX TO FLOW CHART OFFIG. 5LABEL FIG. LABEL FIG.______________________________________AG 5.41 MSI 5.51Anate 5.31 MULT 5.65Back 5.37 Pause 5.63Back 1 5.15 PCLR 5.15Back 2 5.22 Prime 5.41Back 3 5.40 PUMM 5.43Back 4 5.40 PUMP 5.47Bascon 5.25 SAVP 5.8BASDF 5.61 SAVP 1 5.2BIPP 5.57 SET φ 5.64Calbi 5.23 SOSMI 5.58Calbi 1 5.22 SRT 1 5.4Check 5.28 SRT 2 5.2CK WTH 5.3 MLD Z 5.22Clear 5.15 MLDZ 1 5.26CLM DUL 5.27 MSDR 5.34CMSDF 5.54 MSDS 5.32CONBAS 5.19 MSDY 5.36DECHEX 5.66 MSYDS 5.35DIV 5.66 SRT 13 5.63DK1 5.47 SRT 19 5.40DK2 5.48 SRT 21 5.6DK3 5.48 SRT 22 5.4DOAL 1 5.21 SRT 32 5.5ETER 5.17 STAA 5.9ETER 1 5.64 STAA 13 5.32FAUL 1 5.47 STAA 42 5.10Fault 5.38 STEP 5.14Fault 1 5.38 STM 5.30FLASH 5.62 TDS 1 5.48GOUT 5.62 TDS 2 5.50HEXDEX 5.66 Time 5.53IEC 5.40 ULCT 5.54Keyloc 5.6 UNITD 5.54LOAD 5.65 UNSFIG 5.61MBTN 5.16 UNSTFG 5.61______________________________________
Returning to FIG. 4, it is to be noted that the program corresponding to the flow chart of FIG. 5 is stored in the PROM 102, which typically comprises an electrically alterable PROM of a type manufactured by Intel Corporation, Model No. 2716. In order to access this program and operate the present apparatus, however, it is necessary to first initiate the power up/master clear circuitry 118 and which occurs each time a new battery pack is inserted.
At the time of insertion of a new battery pack, the microprocessor 100 is cleared and made ready for the receipt of data from the keyboard 10. A clear function is performed via the charging of capacitor C5, via resistors R18 and diode D3, so as to cause the logic inverters 128 and 130 to produce a logic "low" output until capacitor C5 charges. The logic "high" from inverter 128 is then impressed on the chip select input (CS5) of RAM 104 so as to disable the RAM 104 during the power-up period. The inverter 130 also produces a logic "low" that is impressed on the clear (CLR) input to the microprocessor 100 and which causes the microprocessor to clear its internal registers and start at address zero.
Thus, the microprocessor 100 produces a zero address value on the 8 bit address bus 132 and which address value is transmitted to the PROM 102 so as to cause the data stored therein to be read and transmitted to the microprocessor 100, via the 8 bit data bus 134. These 8 bits then cause the microprocessor 100 to pause and begin "down loading" the "SAVP" subroutine, see FIGS. 5.8 and 5.63, into the RAM 104. After down loading the SAVP subroutine, the microprocessor 100 then begins to continuously monitor the keyboard 10 to detect "whether" and "for how long" a key 8 is depressed and "which" specific key is depressed. The down loading thus permits the circuitry to not have to initiate the PROM 102 during each keyboard scan or pause loop, until after a key 8 is pressed, and then only to perform the action required, thereby saving power.
The programming of the desired functional mode and the entry of the desired parameters is thus achieved via the depression of the necessary keys 8 on the keyboard 11. The functional mode selection is achieved via the S(STEP) key and the "STEP" subroutine, see FIG. 5.14. The operator, in order to select the proper function, repeatedly depresses the key until the desired functional code appears to the left of the slash on the LCD display 12. With each depression of the STEP key the numerical value of the function code is incremented by one and therefore the operator must strike the STEP key the appropriately desired number of times so as to produce the desired function code. Attention is directed to Table 2, below, wherein the various numerical function codes of the present invention are shown with respect to the delivery of insulin. It is to be recognized though that the present invention is adaptable to other medicants requiring the same or similar functions and dose amounts.
TABLE 2______________________________________CODE AND A RANGEFunction Code Function Range______________________________________0 PRIME, HOLD --1 CONCENTRATION 5-500 units2 BASAL RATE 1-100 units3 MANUAL DOSE 0-20 units4 SUPPLEMENTAL DOSE 0-50 units5 SUPPLEMENTAL 0-999 minutes DURATION6 SUPPLEMENTAL DELAY 0-999 minutes7 ACCUMULATED DOSE 0-999 unitsBLANK Pump has exited from "HOLD" mode, or "PRIME" has been cleared______________________________________
Upon selecting the proper function code, the operator then selects the proper numerical parameter within the various ranges provided, depending upon the selected function. Thus, if the operator is programming the CONCENTRATION, the operator may select any individual concentration of between 5 and 500 units. Similarly, the operator may select a BASAL RATE (i.e. the amount of insulin delivered in a 24 hr. period, exclusive of manual meal and supplemental doses) of between 1 and 100 units. The entry of the parameter value is achieved by depressing the desired numerical keys. It is to be noted, however, that entry of the parameter values is achieved via the depression of the numerical key for the least significant numerical position first and then successively for each of the greater value numerical positions. In other words, parameter selection proceeds from right to left; and for example, for a parameter value of 99, the operator would enter a 099. Failure to enter the 0 would also be acceptable, since the microprocessor 100 would assume this, unless otherwise indicated.
Upon entering the desired function code and parameter value, the operator then depresses the E (ENTER) key so as to cause the microprocessor 100 to act upon the entered data.
It is to be recognized that as each key is depressed an 8 bit binary code is produced that is representative of the X-Y coordinates of the depressed key (i.e. 4 bits for the X coordinate and 4 bits for the Y coordinate) relative to the keyboard 10. Each 8 bit Cartesian coordinate code is then encoded via the keyboard encoder 106 so as to produce a four bit binary code and a data available (DA) signal that is transmitted via conductor 137 to the microprocessor 100. The microprocessor 100 then, when it is ready, produces a data enable (DE) signal on conductor 140 so as to cause the keyboard encoder 106 to transmit the encoded data via the four bit bus 140 to the four least significant bit positions (D0 to D3) of the 8 bit data bus 134 and the microprocessor 100. As each encoded value is received by the microprocessor 100, it is then stored within its internal registers until either an ENTER or CLEAR code has been received. It is to be noted that the depression of the STEP key does not cause the microprocessor 100 to operate on the stored data, this occurs only with the depression of any one of the ENTER, HOLD, MANUAL, CLEAR LOCKOUT or PRIME keys.
It is also to be noted that as each parameter is received by the microprocessor 100, it is decoded into its corresponding binary coded decimal (BCD) value. The microprocessor 100 then determines which digit position the data corresponds to on the LCD display 12. The BCD data for each digit is then written by the microprocessor 100 onto the data bus 134, along with the appropriate chip select (CS) and data select (DS) signals, and transmitted to the display driver 108 so as to cause the decimal value of the BCD data to be displayed on the LCD display 12 at the proper digit position. Thus, the LCD display 12 permits the operator to visibly inspect the data that is entered, via the keyboard 10, and received by the microprocessor 100, prior to its being stored in the RAM 104.
Upon reference to Table 2 and the function code of zero, it is also to be noted that a function code of zero produces either a PRIME or HOLD function, see FIGS. 5.41 and 5.63. The specific function performed depends only upon which of the H(HOLD) or P(PRIME) keys the operator depresses after the zero function code has been selected.
Further, it is to be noted that the microprocessor 100 is able to independently display messages over and above the data which is entered via the keyboard 10. In particular and for example, a message will be displayed when the PRIME function is selected. Thus, upon selecting a function code of zero and depressing the P(PRIME) key for at least one second, reference FIGS. 5.41 through 5.43, the LCD display 12 will display O/-P-. The depression of the ENTER key then causes the microprocessor 100 to react and cause the motor 50 to begin priming the syringe 4 (i.e. moving the plunger forward until all the air has been removed from the syringe 4). It is to be noted too that during a PRIME mode, priming occurs only while the ENTER key is depressed and that the PRIME mode is cleared by pressing the C(CLEAR) key.
On the other hand, depressing the zero function code and the H (HOLD) key causes the microprocessor 100 to display a O/-H- message. Similarily too, the microprocessor 100 will cause the various other messages indicated in Table 3, below, to be displayed for the various status conditions indicated.
TABLE 3______________________________________STATUS CONDITIONSDisplay Status______________________________________O/-H- HOLDO/-P- PRIME/EEE Entry errorH/ELP Syringe empty motor fault or microcomputer fault -6 Supplemental delay operating*6/100 Supplemental dose operating* -7 Device operating*______________________________________ *Underlined digit flasing.
Likewise, the display will remain blank, reference Table 2, when the pump has exited from a HOLD or PRIME mode.
After each function is programmed, the microprocessor 100, upon detecting the function code, numerical data and ENTER code, then causes an address to be produced and whereas the microprocessor 100 reads the corresponding programmed subroutine data from the PROM 102 and writes it into the RAM 104, via the appropriate memory write (MWR) and chip select signals. Subsequently, the microprocessor 100 accesses the stored subroutine data, as needed, by generating memory read (MRD) signals, concurrently with the address signals of the memory addresses that are to be read. Thus, the microprocessor 100 is able to read and write data from and into RAM 104 as it performs the various functions of Table 2.
During the BASAL mode the present apparatus delivers incremental, one micro liter doses (i.e. basal doses) at the programmed BASAL RATE, see FIG. 5.25, after programming the CONCENTRATION, see FIG. 5.19, without requiring further operator intervention. In particular, after the CONCENTRATION is programmed in units per milliliter and the BASAL RATE is programmed in units to be delivered per 24 hours, the microprocessor 100 performs the following equation, reference FIGS. 5.23 and 5.24, while rounding to the nearest second, to determine the basal interval in seconds between the incremental doses: ##EQU1##
Thus, during the BASAL mode, the present invention delivers one microliter of medicant during each basal interval over the subsequent 24 hour period, so that the patient can be assured of obtaining the prescribed daily number of units of medicant. It is to be noted too that since the medicant, in the case of insulin, is provided in varying concentrations (i.e. U-40, U-80 and U-100), the present apparatus permits the entry of the data directly in insulin units; thus, eliminating the need to convert units to volume, according the insulin concentration used. No calculation is therefore required by the operator, since the operator need only enter the BASAL RATE (i.e. daily prescribed number of basal insulin units) and the CONCENTRATION (i.e. most typically 40, 80 or 100).
The operator therefore need only concern himself or herself with the additional dosages that are prescribed and which may be administered via the present apparatus as a MANUAL dose (i.e. a single dose of insulin delivered immediately at a rapid rate, also known as a bolus or "burst" dose) or as a SUPPLEMENTAL dose (i.e. a dose of insulin distributed over an extended time following a desired time delay) or both. The details of the delivery of the MANUAL and SUPPLEMENTAL doses, will be described in greater detail hereinafter.
In order to illustrate the above explanation of the BASAL mode and by way of some examples, assuming that a patient requires a total daily basal dosage of 12 insulin units, then depending upon the concentration of the insulin, the following basal intervals will be calculated and the following number of basal doses will be delivered:
EXAMPLE 1
If U-100 insulin is used, then the basal interval is calculated via the microprocessor 100 to be 12 minutes. Thus, the apparatus will dispense a one microliter dose of the U-100 insulin each and every twelve minutes during the 24 hour period or a total dosage of 120 one microliter basal doses.
EXAMPLE 2
If U-40 insulin is used, the basal interval is four minutes and 48 seconds. Thus, 300 one microliter basal doses will be dispensed during the 24 hour period.
EXAMPLE 3
If U-25 insulin is used, the basal interval is 3 minutes. Thus, 480 one microliter basal doses will be delivered during the 24 hour period.
It is to be recognized that because the present apparatus is programmable in whole numbers only, greater precision may be obtained by diluting the prescribed insulin concentrations so as to produce a greater degree of precision in the supply of the medicant. Also, if fractional units of medicant are prescribed, such dilution will better enable the delivery of the fractionally prescribed amount.
Returning to the description of FIG. 4 and the programming of the various other modes and parameters, it is to be noted that upon entering a desired function and parameter, and depressing the ENTER key, the apparatus, in addition to displaying the entry, confirms the entry of the data into the RAM 104 via a short audible "beep" signal. If, however, a value outside the specified range for the programmed parameter is entered, the error message (i.e./EEE) displayed on the LCD display 12, and the audible signal continues, until a new number is entered or the CLEAR key is depressed.
The audio alarm circuit 114 of the present invention is comprised transistors Q1, Q2 and Q3 and which are coupled in a self oscillating fashion so as to produce an audible warning signal of 3 Khz. The audible warning occurs when a time pulse B(TPB) and an audio enable signal from terminal N1 of microprocessor 100 initiate the alarm control circuitry 121 and cause the clocking of the D flip flop 141, via NAND gate 142. D flip flop 141 then produces a base drive signal to transistor Q2, which, in turn, causes the alarm circuit 114 to self-oscillate and produce the audible alarm signal. Similarily, if a time out condition occurs, and which can only happen during a microcomputer fault via the absence of a signal from the N2 terminal of the microprocesor 100, the time-out control circuitry 126 times out and transmits a signal from the Q terminal of one-shot 144 that causes transistor Q1 to initiate the self-oscillation.
The time-out control circuitry 126 is comprised of the retriggerable one shot multi-vibrator 144 and its associated internal NOR gate which couples the signals from conductor 148 and the N2 terminal of the microprocessor 100 to the multi-vibrator 144. It should be noted that the occurrance of a time-out condition indicates to the operator, that the microprocessor 100 is not operating properly, since the multi-vibrator 144 should be reset at regular intervals. It should also be noted that alarm signals can occur during various other conditions and which other conditions can be found upon reference to Table 4, below, and FIGS. 5.38, 5.40 and 5.48.
TABLE 4______________________________________ALARM CONDITIONSIllegal Entry. When a value outside the acceptablerange is entered, /EEE appears in the display and atone sounds. Entering a new value or depressing theC key clears the display and stops the tone.Low Battery. When the battery voltage falls belowan acceptable level, a tone sounds until the batterypack is removed. (FIGURES showing in the display arefrozen at the time the alarm sounds.) The pumpdiscontinues delivery in this condition, but, the datastored in memory is protected for at least 30minutes.Motor Fault. If the motor or any part of the drivetrain fails to operate for any reason, H/ELP appearsin the display and a tone sounds. Depressing the Ckey stops the alarm and automatically places thedevice in the HOLD. Depressing the H key until O/-H-appears reactivates the pump.Microcomputer Fault. If the microcomputer fails tosend a message to the pump's fail-safe (i.e. time outcontrol 126) circuitry at regular intervals to the inform itthat the microcomputer is operating properly, thealarm will sound and delivery will be discontinued.The alarm for this fault is similar to the LOWBATTERY alarm, with the exception that batteryreplacement may not correct the fault.Syringe Empty. If the syringe is allowed to bottomout, the pump will respond as above, with /HELPappearing in the display.______________________________________
As mentioned, the present apparatus also permits the programming of a MANUAL dose and a SUPPLEMENTAL dose over and above the BASAL dose. The dose dispensed during the MANUAL mode is essentially a single burst of insulin, delivered as the user desires, see FIGS. 5.22, 5.26, 5.27 and 5.28. The dose is programmed via the entry of a function code of 3 and the desired MANUAL DOSE (i.e. 0-20 units). The microprocessor 100, upon the entry of the dosage, then accesses the previously programmed CONCENTRATION and calculates the dose to be delivered in microliters, via the following equation, while rounding to the nearest microliter: ##EQU2##
Next, upon depressing of the M key, a beep will sound and the programmed dosage will be delivered immediately as a successive number of incremental basal doses. Upon completing the delivery of the MANUAL dose, another beep will sound and the MANUAL DOSE location in the RAM 104 will be reset to 0. It is to be noted that if the device were programmed in a HOLD mode, the thus entered MANUAL dose would not be delivered.
Furthermore, if the syringe were emptied during the delivery of the MANUAL dose, the alarm would sound and H/ELP would appear on the display 12. The operator would then have to clear the alarm and replace and PRIME the syringe 4, prior to returning to the MANUAL mode, via the depression of the M key, once again. The remainder of the MANUAL dose would then be delivered upon this subsequent depression.
The SUPPLEMENTAL dose mode of operation also permits the operator to deliver a dosage over and above the incremental basal doses, after a timed delay. This mode permits diabetics to compensate for the nocturnal glucose rise that often occurs during sleep. Thus, the SUPPLEMENTAL dose is administered during mid-sleep and accordingly requires that the patient program a SUPPLEMENTAL DOSE, SUPPLEMENTAL DURATION and SUPPLEMENTAL DELAY PARAMETER. The microprocessor 100 then computes the appropriate interval between one microliter increments, again rounding to the nearest second, but will not deliver the SUPPLEMENTAL DOSE until after the delay period has expired.
The SUPPLEMENTAL mode is selected upon programming each of the above parameters. In particular, the SUPPLEMENTAL DOSE is established via the entry of a function code of 4 and the number of units (i.e. 0-50) to be delivered, see FIG. 5.32 The SUPPLEMENTAL DURATION is established via entering a function code of 5 and the number of minutes (i.e. 0-999) over which the SUPPLEMENTAL DOSE is to be delivered, see FIG. 5.34. Finally, the SUPPLEMENTAL DELAY or period of time prior to the delivery of the SUPPLEMENTAL DOSE is established, via the entry of a function code of 6 and the desired delay period, see FIG. 5.35. It is also to be noted that each of the above supplemental parameters are entered via the depression of the E key.
The entry of the SUPPLEMENTAL DOSE, SUPPLEMENTAL DURATION AND SUPPLEMENTAL DELAY data then permits the microprocessor 100 to calculate the proper SUPPLEMENTAL INTERVAL in seconds and the appropriate total SUPPLEMENTAL DOSE in microliters. These values are calculated as per the following equations, see also FIGS. 5.32 through 5.37 and FIGS. 5.51 and 5.52. ##EQU3##
The activation of the SUPPLEMENTAL mode is then initiated upon again entering a function code of 6 and depressing the M key, which starts the timing out of the SUPPLEMENTAL DELAY period. Also, upon the depression of the M key, the function code (6) will begin to flash in the LCD display 12 as the one second counter 111 counts down at a 1 hertz rate until the delay period has expired, see FIGS. 5.54 through 5.56.
Upon the timing out of the delay interval, the microprocessor 100 will then cause the delivery of the calculated SUPPLEMENTAL DOSE in one microliter increments, one increment per each SUPPLEMENTAL INTERVAL, until the entire SUPPLEMENTAL DOSE has been delivered. Upon starting delivery, the function code (6) will also stop flashing and the first numerical digit of the programmed SUPPLEMENTAL DURATION will begin to flash and continue to do so until the entire SUPPLEMENTAL DOSE has been delivered, see FIGS. 5.58 through 5.60.
It is to be noted that the SUPPLEMENTAL mode may be deactivated at any time by depressing the C key. It is also to be noted that if the apparatus is in a HOLD mode, the microprocessor 100 will ignore the depression of the M key so that the SUPPLEMENTAL DELAY period will not be activated.
The present apparatus also maintains a record of the total ACCUMULATED DOSE delivered since the last reset, power up/master clear condition or changing of the battery pack B1. The total ACCUMULATED DOSE can be selectively monitored by the patient via the entry of a function code of 7. Upon this entry, the microprocessor 100 causes the total ACCUMULATED DOSE to be displayed on the LCD display 12. Upon reading the value, the patient can then reset the display by depressing the C key. Otherwise, the microprocessor 100 continue to maintain a record of the total ACCUMULATED DOSE. Also, upon changing the batteries or changing the concentration value, the microprocessor 100 will automatically reset the ACCUMULATED DOSE.
Referring again to FIG. 4, it is to be noted that a number of additional functional circuit elements have been included in the present apparatus, but which have not been discussed in any detail heretofore. In particular, it is to be noted that when the microprocessor 100 addresses PROM 102, which is comprised of two kilobytes of preprogrammed data, it does so in a multiplexed fashion over two clock cycles. During the first clock cycle, the three most significant bits of the address value are stored in the address latch 122. During the second clock cycle, the next eight bits of the address, along with the first three bits, are impressed on PROM 102 so as to select the desired data. It is also to be noted that the present apparatus for an additional address bit so that four kilobytes of data could be accomodated in PROM 102.
The "power saver" circuitry 124 is used in conjunction with PROM 102, via the CMOS transistors Q7 and Q8, and which transistors act as a switch, and permit the microprocessor 100 to power down PROM 102 when the microprocessor 100 is not accessing the PROM 102. Because each access to PROM 102 requires approximately 100 milliamps of current, it is desirable to have some sort of switch intermediate PROM 102 and the microprocessor 100. This switching function is achieved via transistors Q7 and Q8 and which conduct only when gate drive is present on conductor 152. It is also to be noted that transistors Q7 and Q8 have been coupled in parallel so that when the microprocessor 100 produces the gate drive, via NAND gate 150, the source to drain impedance of the transistor combination of Q7 and Q8 is reduced and the power loss due to the switching action is also minimized.
Turning now to the photo-coupled motor drive circuitry 112, it is to be noted that it is generally comprised of three transistors Q4, Q5 and Q6. The transistors, in turn, are coupled to the M+ and M- terminals of the motor 50, via conductors 154 and 156, and to the LED 74, via conductor 158. The motor drive circuitry 112 operates upon the receipt of a gate drive signal to transistors Q4 and Q6 via conductor 162 and the Q output terminal of the microprocessor 100. The gate drive, in turn, turns transistor Q4 "off" and transistor Q6 "on". The conduction of transistor Q6, in turn, energizes the windings of the motor 50 so as to cause the rotation of drive shaft 66 and the consequent delivery of the medicant to the patient. Transistor Q5 is normally "on" bus if the timeout control (144) times but, transistor Q5 is turned "off", thus preventing motor movement. Similarly the M+ windings and LED 74 are energized by the conduction of transistor Q6.
The microprocessor 100, in order to brake the motor and stop the delivery of medicant, subsequently produces braking signals via its Q terminal and conductor 162 and which drive the gates of transistors of Q4 and Q6, thereby turning transistor Q4 "on" and transistor Q6 "off" and which produces the dynamic braking of the motor 50. This dynamic braking occurs due to the shunting of the M+ and M- terminals of motor 50. It is to be noted though that the resistor R4, provides a torque limiting effect so as to produce a smooth reduction in the motor speed. The resistors R2 and R3, in turn, act to reduce any parasitic oscillations in the signals on conductors 160, 162.
It is to be noted too that as the output shaft 54 of the motor 50 turns, the LED 74 is energized, so that light pulses are generated via the passing of the optical encoder disc 82 through the infra-red beam of light produced by the LED 86. The light pulses are then converted into electrical pulses, upon detection by the photo detecting transistor 88. The pulses generated by the photo transistor 88 are then received at the PD terminal and transmitted via conductor 164 to inverter 166 and the EF 4 terminal of the microprocessor 100. The microprocessor 100 then causes the pulses, to be counted, see FIG. 5.47, until the preprogrammed number of pulses have been counted, when it next causes the dynamic braking and which count is indicative of the delivery of one microliter of medicant. The duration of the motor drive may thus vary from basal interval to basal interval, since the volume of the dose is directly related to the rotation of the motor drive shaft 66 and not the characteristics of the motor drive signals.
Next, referring to the memory timer 120, it is to be noted that it is essentially comprised of D flip flop 168. In particular, flip flop 168 operates in a strobed fashion to control the gate drive to the power saver circuitry 124 by monitoring the A4 address terminal of the microprocessor 100. Recalling that the PROM 102 is addressed in in a multiplexed fashion, a signal is present of the A4 terminal only during the second half of the clock cycle, when it is necessary to ensure that the PROM 102 is powered up. Thus, by clocking flip flop 168 at this time, the necessary gate drive is provided to the power saver circuitry 124, at the same time as the TPB signal via NAND gate 150 and conductor 152, so that PROM 102 will be powered up. At the same time, the Q1 signal ensures that RAM 104 is deselected by coupling the signal to the CS3 and CS2 terminals thereof.
D flip flop 140 of the alarm control circuitry 121, on the other hand, acts in response to the signals from the microprocessor 100 to NAND gate 142 and the presence of data on the D0 terminal of the microprocessor 100 so as to control the gate drive to the audio alarm circuitry 114.
The low voltage protection circuitry 116 is also coupled between the microprocessor 100 and the main battery pack and acts to, at all times, monitor the battery voltage. In particular, the low voltage detector 116 monitors the battery voltage as the circuitry "powers up", as well as when it "powers down". Generally, it acts to produce a threshold voltage, via resistors R14, R15 and R16 and capacitor C2, that must be exceeded before the circuitry of FIG. 4 will become active. It is to be noted though that the voltage threshold will vary depending upon whether the voltage is rising or falling and which thus reflects a hysteresis effect. In general though, so long as the voltage from the battery pack B1 exceeds the threshold voltage, a logic signal is produced on the output port of the low voltage detector 116 that enables the chip select ports CS4 and CS1 of the RAM 104. If, however, the voltage of the voltage source B1 falls below the threshold voltage, a logic signal will be produced that will disable the RAM 104, as well as force the microprocessor 100 in a "wait" condition, until the supply voltage level has again exceeded the threshold voltage.
Also, while not previously described and while not shown in detail, it is to be noted that, the present apparatus is battery powered via a rechargable battery pack (not shown) that is contained within container 10, below the keyboard 10. A battery compartment cover (not shown) is provided on the right side of the container 2 and is slidably mounted thereon and affixed thereto via a latch arrangement similar to that for the latch 28. The battery pack is designed to provide approximately 24 hours of operation, but should the battery pack fail, the emergency battery pack B1, which charges from the main battery pack, will protect the contents of RAM 104 for approximately 30 minutes. Should the charge on the main battery pack become too low, the microprocessor 100 will enter the "wait" mode, sound an alarm, freeze the characters on the LCD display 12 and stop the pump operation, until a new battery pack is inserted.
Upon inserting a new battery pack, the operator should then check the programmed parameters to determine whether data has been lost. Such a check is accomplished by successively depressing the select key so as to cause the microprocessor 100 to read the data from the RAM 104 for each function code as it is called up on the display 12. If any errors are detected, the operator need then only reprogram those individual functions. If, however, the low battery condition persisted for over 30 minutes, it is most likely that all the data will have been lost and the operator will have to reprogram all the functions.
The present apparatus also permits the operator to select a LOCK-OUT function, whereby the operator, upon depressing the L key for at least four seconds, causes the microprocessor 100 to enter the LOCK-OUT function and thereafter prevent any inadvertant re-programming from occuring. Upon the depression of the L key, a beep sounds, and upon the timing out of the four seconds a second beep sounds, confirming the entering of the LOCK-OUT mode, see FIGS. 5.6, 5.7 and 5.8. The apparatus may, however, be reactivated, by merely repeating the above operation. It is also advantagous for the operator, just prior to programming the LOCK-OUT function, to call up the function code 7 (i.e. ACCUMULATED DOSE) so that upon entering the LOCK-OUT function, the ACCUMULATED DOSE will thereafter be continuously displayed on the LCD display 12.
While the present invention has been described with particular reference to its preferred embodiment, as an insulin pump, variations thereon may suggest themselves to those of skill in the art upon a reading hereof. The following claims should therefore be interpreted as so to encompass equivalent structures within the spirit of the claimed invention. | A portable infusion pump for controllably supplying a programmed volume of medicant to a patient. The apparatus generally comprises a small, portable container having a keyboard for programming the mode of operation and operating parameters, whereby a microprocessor controls the pump in the various BASAL, SUPPLEMENTAL OR MANUAL dose delivery modes. The apparatus also contains a photo-coupler controlled driven lead screw assembly for controlling the stroke of the syringe plunger, whereby metered doses of the medicant are injected into the patient; display means for confirming programmed inputs; means for audibly warning of error conditions; and means for recording the total cummulative dosage delivered. | 8 |
FIELD OF THE INVENTION
The present invention relates to utility knives, and more particularly to a non-retractable utility knife with a durable metallic blade carrier housing halves and an integrated soft comfortable grip.
BACKGROUND OF THE INVENTION
Cutting implements, such as utility knives of the type in which the cutting blade is removable from the handle are well known, the combination of knife blade and handle being typically referred to as a utility knife. Such utility knives are normally available both with retractable blades, such as the type described in U.S. Pat. No. 3,192,624, and with non-retractable blades. Generally, such prior art utility knives comprise the type where two separate complimentary halves are secured together by a screw, such as the type of utility knife manufactured by Stanley Model No. 299, or the type disclosed in U.S. Pat. Nos. 2,376,887; 2,862,296; 2,948,961; 3,062,147; 3,107,426; or 3,192,624. Other prior art utility knives of the non-retractable type have been utilized which have a separate carrier member which pivots into and out of a handle, such as the type disclosed in U.S. Pat. No. 2,245,096. Some of the previously mentioned types of utility knives in which two separable halves are utilized provides for storage of replacement blades within the handle housing but often lack a means for securing these blades within the housing and they rattle around in the knife during storage and often get dull before these blades have had an opportunity to be utilized.
In addition, some such prior art knives are formed of metal die cast housings with a screw to hold the handle together. While the hard die cast housings serve to make the utility knife a durable work tool, the hard surface can be uncomfortable or otherwise ergonomically undesirable leading to blisters. Maintaining a good grip is also a problem with such knives. Additional problems with such knives relates to the use of the attachment screw. Generally, since the screw is centrally located to clamp the blade, a stripped thread will have a tendency to separate the halves and become a hazard. Moreover, since they require use of a screwdriver to remove the halves, the screw makes replacing the blades more difficult and potentially less safe if one slips.
Plastic injection molded utility knives have attempted to address the comfort issue by a dual molding process that combines a rigid plastic housing, typically of polypropylene, with a softer outer cover externally molded thereto, typically made from an elastomeric material such as Santoprene. The surface areas of the two materials chemically adhere due to the nature of the materials. However, these devices lack the safety, durability and feel of the heavier die cast variation as they wear quickly and the sharp blade tends to cut through. Moreover, simply molding an elastomeric material to the exterior of a metallic housing is not possible since such elastomeric material does not bond or adhere to metallic surfaces as it does with compatible plastic surfaces.
Furthermore, in several of these prior art utility knives having separate halves, the portion of the cutting blade that remains in the housing has a tendency to bear against the metal of the housing when pressure is applied to the cutting edge. This typically results in the unused edge becoming dull prior to actual use of the blade.
Accordingly, it is an objective of the invention to provide a non-retractable hardened utility knife with a soft, grippable and securely fixed outer cover.
It is an additional objective of the invention to provide such a knife with a quick and easy means for accessing the blade storage compartment or changing the blade.
It is a further objective to provide such a knife with a construction that protects the internal edge of the cutting blade from being dulled from movement when the external edge of the cutting blade is in use.
It is a still further objective to provide such a device with a frontal bridge near the cutting blade to prevent the housing halves from separation during use and causing injury.
It is another objective to provide such a knife with an economical and efficient method of manufacture.
Additional objectives will be apparent from a review of the preferred embodiment of the invention described herein.
BRIEF DESCRIPTIONS OF THE INVENTION
The present invention is a non-retractable utility knife with housing sections made of metal. These sections align together to form a handle and to hold a blade for cutting. The knife includes a means for releasably engaging the sections that, for preference, is a latch. This provides a way to install the cutting blade or access a blade storage compartment between the sections. A soft cover formed of an elastomeric material is mechanically retained on an exterior portion the housing sections. Preferably, the sections have rivet ports through which integrally formed molded rivets extend from the cover to retain the cover to the housing. The sections also have half channels at internal edges with tabs by which the cover is also retained. Optional flexible posts extend into the blade storage cavity to press against spare blades and impede movement of the spare blades during use of the utility knife. These posts bend as additional spare blades are stacked within. A blade clamp integrally formed with the cover protrudes against a side of the cutting blade to limit the blade's lateral movement. The housing sections interlock by tongue and groove near the cutting blade opposite the latch.
The invention further includes a novel method for making the utility knife housing. The method involves casting the utility knife housing in a first mold with molten metal such as zinc or aluminum. A mold in this die casting process includes mechanical or structural features to shape the housing for retaining a subsequently formed soft cover around the housing. In the subsequent injection molding process, the soft cover and its integrated features are then formed directly onto the previously die cast knife housing. The mold in this second process receives the utility knife housing and the soft cover is subsequently formed by injection molding an elastomer to and around the inner knife casting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top elevation view of a utility knife assembly of the invention;
FIG. 2 is a side elevation view of the utility knife assembly of FIG. 1 ;
FIG. 3 is an internal elevation view of a mount side of the housing of the assembly of FIG. 1 with blades and latch inserted;
FIG. 4 is an elevation view of a quick release latch from the embodiment of the invention of FIG. 1 .
FIG. 4A is a top plan view of the quick release latch of FIG. 4 .
FIG. 4B is a sectional view of the latch of FIG. 4 taken along line A-A of FIG. 4 .
FIG. 4C is a side plan view of the quick release latch of FIG. 4 .
FIG. 5 is an external elevation view of a mount side of the housing of the assembly of FIG. 1 with soft outer cover;
FIG. 6 is a top elevation of the mount side of FIG. 5 ;
FIG. 7 is an internal elevation view of the mount side of FIG. 5 ;
FIG. 8 is a sectional view of the mount side of FIG. 7 taken along line F-F of FIG. 7 .
FIG. 9 is a sectional view of the mount side of FIG. 7 taken along line D-D of FIG. 7 .
FIG. 10 is a sectional view of the mount side of FIG. 7 taken along line E-E of FIG. 7 .
FIG. 11 is a sectional view of the mount side of FIG. 7 taken along line B-B of FIG. 7 .
FIG. 12 is an elevation view of the mount side of FIG. 7 in the direction of sight of arrow G of FIG. 7 .
FIG. 13 is a sectional view of the mount side of FIG. 7 taken along line C-C of FIG. 7 .
FIG. 14 is an internal elevation view of a release side of the housing of the assembly of FIG. 1 with soft outer cover and soft inner projections;
FIG. 15 is a top elevation of the release side of FIG. 14 ;
FIG. 16 is a external elevation of the release side of FIG. 14 ;
FIG. 17 is a sectional view of the release side of FIG. 14 taken along line H-H of FIG. 14 ;
FIG. 18 is a sectional view of the release side of FIG. 14 taken along line K-K of FIG. 16 ;
FIG. 19 is a sectional view of the release side of FIG. 14 taken along line J-J of FIG. 16 ;
FIG. 20 is a sectional view of the release side of FIG. 14 taken along line I-I of FIG. 16 ;
FIG. 21 is an elevation view of the release side of FIG. 14 in the direction of sight of arrow N of FIG. 16 ;
FIG. 22 is a sectional view of the release side of FIG. 14 taken along line L-L of FIG. 16 ;
FIG. 23 is a partial sectional view of the release side of FIG. 14 taken along line M-M of FIG. 16 ;
FIG. 24 is an external elevation view of the mount side of FIG. 5 before a soft outer cover is molded to it;
FIG. 25 is a top elevation of the mount side of FIG. 24 , casting only;
FIG. 26 is an internal elevation view of the mount side of FIG. 24 ;
FIG. 27 is a sectional view of the mount side of FIG. 24 taken along line O-O of FIG. 26 ;
FIG. 28 is a sectional view of the mount side of FIG. 24 taken along line R-R of FIG. 26 ;
FIG. 29 is a sectional view of the mount side of FIG. 24 taken along line S-S of FIG. 26 ;
FIG. 30 is a sectional view of the mount side of FIG. 24 taken along line P-P of FIG. 26 ;
FIG. 31 is an elevation view of the mount side of FIG. 24 in the direction of sight of arrow T of FIG. 26 ;
FIG. 32 is a sectional view of the mount side of FIG. 24 taken along line Q-Q of FIG. 26 ;
FIG. 33 is an internal elevation view of the release side of FIG. 14 without an overmolded soft outer cover;
FIG. 34 is a top elevation of the release side of FIG. 33 , inner casting only;
FIG. 35 is an external elevation view of the release side of FIG. 33 ;
FIG. 36 is a sectional view of the release side of FIG. 33 taken along line Y-Y of FIG. 35 ;
FIG. 37 is a sectional view of the release side of FIG. 33 taken along line W-W of FIG. 35 ;
FIG. 38 is a sectional view of the release side of FIG. 33 taken along line V-V of FIG. 35 ;
FIG. 39 is a sectional view of the release side of FIG. 33 taken along line U-U of FIG. 35 ;
FIG. 40 is an elevation view of the release side of FIG. 33 in the direction of sight of arrow AA of FIG. 35 ;
FIG. 41 is a sectional view of the release side of FIG. 33 taken along line X-X of FIG. 35 ;
FIG. 42 is a partial sectional view of the release side of FIG. 33 taken along line Z-Z of FIG. 35 .
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1 and 2 , a utility knife assembly 2 of the invention includes a housing 4 , a gripping cover 5 and a quick release latch 6 . Generally, the housing 4 is configured to serve as a handle and secure a cutting blade in a cutting position extending into and from the housing 4 at a cutting portion 8 of the housing 4 . The housing 4 has two corresponding housing sections with complementing structures. When joined by the latch 6 , the two sections form the knife assembly 2 . The housing sections include a mount side 10 and a release side 12 . These housing sections are joined by interlocking structures at the cutting portion 8 of the housing 4 and by the quick release latch 6 at a latching portion 14 . The housing 2 is preferably made of a die-cast metal, such as zinc or aluminum or other moldable metal alloy, to form a hard, durable handle for the utility knife assembly 2 . The gripping cover 5 is made from a soft molded elastomer such as Santoprene. The latch 6 is a preferably firm resilient engineering plastic with some limited flexibility, e.g., Celcon acetal resin, Lexan polycarbonate or nylon.
The quick release latch 6 provides a means for releasably engaging the housing sections at the latching portion 14 . FIGS. 4 , 4 A, 4 B and 4 C depict one embodiment of the latch 6 in detail. The latch 6 is molded to complement related structural features of the housing sections. The latch 6 includes locking tabs 16 extending from the latch base 22 for fixing the latch 6 to the mount side 10 of the housing 4 . The latch 6 includes a latching tongue 18 to releasably engage with the release side 12 of the housing 2 . The latching tongue 18 is adjacent to a finger tab 20 . The latching tongue 18 has a beveled side 18 B opposite a latching side 18 L.
The finger tab 20 is incorporated to the latch base 22 by a flexing support 24 . The finger tab 20 extends from the flexing support 24 to form a lever such that when a pushing force is applied to the finger tab 20 when the latch base is fixed to the housing 4 , the flexing support 24 bends elastically in a lateral direction. With such bending, the latch 6 can release the engagement of the two sections as the latching tongue 18 moves. Similarly, the beveled side 18 B serves to convert a closing force into a lateral bending force on the flexing support 24 of the latch 6 as a housing section is forced against the bevel when the assembly 2 is manipulated from its open position to its closed position. Since the latch 6 is made from a firm material with limited flexibility, after bending of the flexing support 24 , it will return to its original molded unbent configuration to securely engage the housing sections when the assembly is in the closed position.
As previously noted, the housing 4 includes a mount side 10 . The mount side 10 is generally depicted in FIGS. 3 , 5 - 13 with the cover 5 molded thereon and in FIGS. 24-32 before molding the cover thereon. The mount side 10 includes blade ledges 26 and a blade positioning tab 28 to align a cutting blade 30 in a non-retractable position at the cutting portion 8 . The mount side 10 of the housing 4 also has a mounting aperture 32 and mounting studs 34 at the latching portion 14 . The mounting aperture 32 is sized to lock on the locking tabs 16 of the latch 6 such that ridges of the locking tabs 16 engage the external surface edges 33 of the mounting aperture 32 when the locking tabs 16 are inserted therein. The mounting studs 34 are positioned and sized to reside in corresponding holes in the latch base 22 .
The mount side 10 preferably includes a blade store cavity 36 to retain spare blades 38 . At the cutting portion 8 , the mount side 10 includes opposing grooves 40 . The grooves 40 serve to interlock the mount side 10 to the release side 12 when these housing sections are joined. The cutting blade 30 passes through the grooves 40 when installed in a non-retractable cutting position in the assembly 2 .
The mount side 10 has several features designed to mechanically secure a portion of the gripping cover 5 to the housing 4 at the mount side 10 . At a portion of the internal edges of the mount side 10 are half channels 42 with several cover holding tabs 44 . The half channels 42 serve as a mold to receive the part of the gripping cover 5 attached to the mount side. Since the half channels 42 surround the holding tabs 44 , the gripping cover 5 is retained by the cover holding tabs 44 . The mount side 10 also includes rivet ports 46 to receive molded rivets 48 that are integrally formed with the gripping cover 5 . The molded rivets 48 are formed within the housing 4 so that the head portion of each rivet within the housing 4 is larger than the rivet ports 46 and resides next to each rivet port. This serves to keep the molded rivets 48 from moving or passing out through the rivet ports 46 to thereby assist with holding the gripping cover 5 on the housing 2 .
The release side 12 of the housing 4 is depicted in FIGS. 14-23 with the cover 5 and in FIGS. 33-42 prior to the molding of the cover 5 thereon. The release side 12 has a structure to interlock with the grooves 40 of the mount side 10 and a structure to releasably engage with the latch 6 at the latching tongue 18 . At a cutting portion 8 the release side 12 has mating tongues 50 arranged to reside within the grooves 40 and interlock therewith. The release side 12 further has a latch aperture 52 to receive the finger tab 20 . A latching tongue indent 54 lies adjacent to the latch aperture 52 . The external surface of this latching tongue indent 54 engages with the latching tongue 18 at the latching side 18 L to releasably engage the housing sections when the housing sections are aligned and interlocked with the mating tongues 50 in the groves 40 and when the latch 6 is in the latch aperture 52 . This configuration corresponds with the assembly 2 being in its closed position.
The release side 12 of the housing 4 also includes a half channel 42 along a portion of its edges as well as several rivet ports 46 . The channels also include several cover holding tabs 44 to mechanically hold the portion of the gripping cover 5 on the release side 12 of the housing 4 in a similar fashion as that of the portion of the gripping cover 5 on the mount side 10 of the housing 4 . Preferably, the half channels 42 from each housing section are aligned at internal edges so that they reside between the housing sections when the assembly 2 is in its closed position. Additionally, opposing cover holding tabs 44 on the opposing housing sections may also be aligned with each other. These alignments provide for an additional mechanical hold on the gripping cover 5 by holding the edges of the gripping cover 5 between the closed housing 4 and inhibiting the gripping cover from being pulled over the cover holding tabs 44 within each half channel 42 as the opposing cover holding tabs 44 contact or otherwise reside near each other when the housing 4 is closed.
As an integral part of the portion of the gripping cover 5 on the release side 12 , flexible posts 56 protrude beyond the cavity of the release side, extending well into the blade store cavity 36 of the mount side 10 of the housing 2 . These flexible posts 56 provide a means to prevent movement of the spare blades 38 . When the assembly 2 is in its closed position with spare blades 38 enclosed in the blade store cavity 36 , the flexible posts 56 press against one or more spare blades 38 . Since they are flexible, the protruding posts will bend but still apply pressure against the spare blades 38 . As the stack reduces in height, the flexible posts 56 straighten to accommodate a varying number of spare blades. With this device, the spare blades 38 within the housing will not rattle regardless of the number of spare blades. This also serves to prevent the spare blades 38 from becoming dull as a result of being jostled against the internal structures of the housing 2 during use. To enable the flexible posts 56 to also serve a function of holding the gripping cover 5 to the housing 4 , at their base the flexible posts 56 include molded rivets 48 to impede the flexible posts 56 from passing out through the rivet ports 46 . Thus, these flexible molded rivets 48 secure the outer soft gripping cover 5 to the cast housing 4 on the release side 12 . Conversely, since the gripping cover 5 is formed integrally with the flexible posts 56 , the gripping cover 5 through one or more rivet ports 46 serves to secure the flexible posts 56 to the release side 12 .
As shown in FIGS. 14 and 17 , a flexible blade clamp 58 is another integral feature of the gripping cover 5 that extends within the release side 12 of the housing 4 . In conjunction with the blade positioning tab 28 and the blade ledges 26 , the flexible blade clamp 58 assists in securing the cutting blade 30 in a cutting position in the assembly 2 . More specifically, the blade clamp 58 provides for lateral support of the cutting blade between the housing sections. In the preferred embodiment of the blade clamp 58 , three protrusions extend toward the blade a sufficient distance to flexibly apply pressure or squeeze against the cutting blade 30 when the assembly 2 is in its closed position to limit lateral movement of the cutting blade. The flexible nature of these protrusions permits blades of varying sizes to be held firmly. Moreover, since the blade clamp 58 is integrally formed with the gripping cover 5 through one of the rivet ports 46 of the release side 12 , its location inside the housing 4 serves the further purpose of providing an additional mechanical hold on the gripping cover 5 to keep the gripping cover 5 fixed to the housing 4 . An additional hold down pin 59 formed as an integral part of the flexible blade clamp 58 resides in a pin port 60 in the release side 12 of the housing 4 .
In use the assembly 2 provides a safe, sturdy and functional utility knife. From its closed position, the assembly 2 may be opened by pressing the user's finger against the finger tab 20 , to force the latching tongue 18 away from its contact at the latching side 18 L with the latching tongue indent 54 of the release side 12 of the housing 2 . Upon release, the release side 12 may be separated from the mount side 10 by withdrawing the mating tongues 50 of the release side 12 from the grooves 40 of the mount side 10 at the cutting portion 8 of the housing 4 . A spare blade 38 can be removed from the blade store cavity 36 . The blade can then be placed on the blade ledges 26 on the blade positioning tab 28 under the grooves 40 at the cutting portion 8 of the mount side 10 of the housing 4 .
To close the assembly 2 , the mating tongues 50 of the release side 12 are inserted into the grooves 40 of the mount side 10 . The release side 12 may then be aligned so that the latch aperture 52 of the release side 12 moves over the finger tab 20 of the latch. As the release side 12 and mount side 10 are pressed together, the latching tongue 18 moves away from the latching tongue indent 54 as the release side traverses the surface of the beveled side 18 B of the latching tongue 18 on the latch 6 . Simultaneously, the flexible posts 56 from the release side 12 are forced to bend against any remaining spare blade 38 in the blade store cavity 36 of the mount side 10 of the housing 4 . Similarly, the flexible blade clamp 58 is forced against the cutting blade 30 . When the latching tongue indent 54 passes the latching side 18 L of the latching tongue 18 , the latching tongue will return to its unbent position to contact the surface of the latching tongue indent 54 , thereby engaging the release side 12 and the mount side 10 of the housing 4 .
Once locked closed, the assembly 2 may be used for cutting by grasping the assembly at the gripping cover 2 . Since the gripping cover 2 is mechanically attached to the housing 4 by (a) the flexible blade clamp 58 , (b) the molded rivets 48 , (c) edge portions of the cover residing in the interior aligned half channels 42 and looped around or otherwise surrounding the cover holding tabs 44 , the gripping cover 2 provides a firmly retained, non-slip outer skin for ergonomic comfort.
Despite the intricacies of the combined features of the assembly, a unique manufacturing process may be followed to reduce assembly of the various features during manufacture of the invention. To this end, while the gripping cover 5 , the blade clamp 58 , the flexible posts 56 and the molded rivets 48 may be manufactured as separate components and combined in a final assembly with all or some of the components, it is preferred to have some or all of these features applied to the housing sections of the housing 4 in a common process. Thus, the invention includes a methodology in which the internal and external soft structural features of the gripping cover 2 are manufactured onto either housing section in a single injection molding process.
The steps to accomplishing the method include the preparation of corresponding housing sections in a mold or molds. The molds include the reverse shapes of the separate housing sections of the utility knife particularly with the structural features for fastening or retaining the gripping cover 5 on exterior portions of the housing 4 . Thus, a mold is optionally made to include half channels 42 , cover holding tabs 44 , and/or rivet ports 46 . Those skilled in the art would understand the steps of creating such a mold. With one or more of such molds, the housing sections are cast in a first metal casting process by pressure casting molten metal into the mold.
Similarly, one or more molds are made to receive each cast metal housing section. The molds have reverse shapes to correspond with the surface of the gripping cover 2 and its integrated parts such as the interior retaining portions that hold the gripping cover 5 to the housing 4 . Thus, the preferred release side 12 mold would include structures for forming internal features including barriers for the portion of the gripping cover 5 in the half channels 42 , the interior portions of the blade clamp 58 , the interior portions of the flexible posts 56 and the interior portions of the molded rivets 48 . The preferred mount side 10 mold would include barriers for the portion of the gripping cover 5 in the half channels 42 and the interior portions of the molded rivets 48 . Of course, due to the structures of the mount side 10 and the release side 12 which will be included in the molding process, these housing sections themselves serve as an important part of the structure of the mold. In the secondary elastomer molding process, the gripping cover 5 with its incorporated features is cast by injecting an elastomer as a hot liquid into each mold with a corresponding housing section contained therein. The liquid elastomer then moves over an exterior cover portion of the housing section, through the various rivet ports 46 and into the half channels 42 of the housing section to form the gripping cover 5 with its integrated features. The latch 6 formed from another mold may then be installed in the cooled housing sections by attaching one to a mount side 10 and a release side 12 .
Basically, the tool ends up being an extremely simple and safe two-piece knife with a soft and comfortable grip. It is safe as the user's hand does not slip. It is convenient as the cutting blade can be changed readily without the use of a screwdriver or other tool. It is accurate since the blade is clamped during use and cuts straight. It is strong since the blade will not move during cutting. Its razor sharp spare blades do not shake or dull during use or transport, thereby promoting safety. A sharp blade is a safe blade. In its preferred form, it is the only two-piece non-retractable utility knife without loose or moving parts.
Although the invention is described in terms of a particular embodiment, it is to be understood that the embodiment is merely illustrative of an application of the principles of the invention. Numerous modifications may be made and other arrangements may be devised without departing from the spirit and scope of the invention as defined by the claims. For example, although a latch is the preferred means for releasably engaging the other housing sections, alternatives might be used for example, a screw. | A metallic housing utility knife and method for making the device with a soft over molded elastomeric cover to provide blister free comfort and slip proof safety. The cover or skin is molded into the unique structure of the housing in a fashion that results in mechanical bonds that embrace the cover on the housing. The knife includes flexible posts from the cover that project into the blade storage compartment of the housing to prevent internally stored spare blades from moving within the storage compartment. An elastomeric blade clamp integrally formed with the cover serves to restrict lateral movement of blades of varying sizes when installed in a cutting position within the knife assembly. A rear quick release latch and interlocking housing sections provide a convenient way to open and close the knife and assure that it is also secure and firmly held when locked in a safe cutting position. | 1 |
This is a continuation of application Ser. No. 254,502, filed Oct. 6, 1988, now abandoned, which is a continuation of application Ser. No. 932,811, filed Nov. 19, 1986, now U.S. Pat. No. 4,798,803, which is a continuation-in-part of application Ser. No. 512,797, filed July 11, 1983, now abandoned which is a continuation-in-part of Ser. No. 753,750 filed 7/10/85, abandoned.
FIELD OF THE INVENTION
This invention relates to a new apparatus and method for improved flow injection titrimetry analysis.
BACKGROUND OF THE INVENTION
The need for repeatable accurate chemical analysis methods and apparatus is ever increasing. In response to this need, a variety of analyzers have been built. With each new analyzer, the focus has consistently been on the construction of analysis apparatus which increases analysis apparatus capacity and reduces the number of required steps in the analysis process. Flow injection analyzers have been built to meet these needs.
Flow injection analyzers are instruments capable of detecting features of a sample injected into a continuously flowing solution. Flow injection analysis is based on an analysis system capable of forming a reproducible gradient of sample in a reagent flow, detectable as a gradient curve. Measurements carried out on the resultant gradient curve are used to determine the characteristics and components of the sample.
A new area in the field of flow injection analysis is flow injection titrimetry (F.I.T.) which combines the best features of flow injection analysis with titrimetry techniques.
Flow injection titrimetry is derived from titration which is the volumetric determination of a constituent in a known volume of a solution by the slow addition of a standard reacting solution of a known strength until the reaction is completed. Completion of the reaction is frequently indicated by a color change (indicator) or electrochemical change in the solution.
Flow injection titrimetry (F.I.T.) has been developed to produce rapid, simple, reliable, versatile and accurate analysis systems for process control applications. Different from other flow injection analysis techniques, flow injection titrimetry is based on the measurements of peak width rather than peak height. The width of this peak is proportional to the log of the sample concentration. Contrary to other flow injection analysis techniques, flow injection titrimetry makes use of a large sample dispersion to create a concentration gradient over time. This concentration gradient is known as the "exponential concentration gradient". The exponential concentration gradient is the concentration gradient within the mixing cell during flow injection analysis.
The concept of single point titration using flow injection analysis techniques has been described for acid/base systems by Ove Åstrm's article, "Single-Point Titrations" found in Analytica Chimica Acta, 105 (1979) 67-75. The Åstrom method for a single-point titrimetric system for acids and bases utilizes a reaction cell consisting of a reference electrode, a glass electrode, a mixing coil 300 cm long, and teflon injection tubing. Only one analysis can be performed using the reaction cell with detection electrodes. A need has long been felt for a dual analysis system.
Multielement trace analyzers using nonsegmented continuous flow analysis have been described in "Correspondence", Analytical Chemistry, Vol. 50, No. 4. (1978) 654-656. However, this analysis technique is taught in only a very general way. The multielement trace analysis using nonsegmented continuous flow for the compounds 4-(2-pyridylazo) resorcinol (PAR), lead (II) and vanadium (V) is colorimetric rather than titrimetric. No specific teaching of multielement trace analysis using flow injection titrimetry has been found, particularly for caustic/carbonate systems.
The apparatus used in multielement trace analysis, generally has included a reaction cell, a measuring instrument, and a recorder or data processing unit, see, "Injection Technique In Dynamic Flow-Through Anaylsis With Electroanalytical Sensors" by Pungor, Feher, Nagy, Toth, Horvai and Gratzl, appearing in Analytica Chemica Acta, 109 (1979), 1-24. This apparatus has not been capable of both acting as a reaction cell and a detection cell for multiple endpoint flow injection titrimetry. The present invention seeks to provide such an instrument and an accompanying flow injection titrimetry technique.
Known analysis methods have utilized batch analysis methods for detecting endpoints of independently titratable species in caustic/carbonate reactions. One batch technique, as described in Scotts', Standard Methods of Chemical Analysis (5th Ed., p. 2256) describes a double-endpoint determination of sodium hydroxide and sodium carbonate in a mixture thereof by (a) titrating with sulfuric acid to the phenolphthalein endpoint (NaOH converted to NaHSO 4 and H 2 O; Na 2 CO 3 converted to NaHCO 3 ) and (b) titrating further with sulfuric acid to the methyl-orange endpoint (NaHCO 3 converted to NaHSO 4 , CO 2 and H 2 O). However, batch techniques have numerous drawbacks since they are not capable of continuous quantitative measurements nor continuous titration analysis. The batch titrations must be periodically stopped and the reactors must be cleaned after each reaction is completed. This known technique has required abundant analysis time to obtain the necessary results. A need has existed for determining multiple end points of independently titratable species in a continuous flow, nonbatch type of titration system.
Known continuous flow injection analysis techniques have been developed for continuous flow acid-base titration as described in J. Ruzicka, and E. H. Hansen, Flow Injection Analysis, Wiley-Interscience Publication, (Chemical Analysis, Vol. 62), 1981. With the batch tank model developed by Ruzicka et al., the time span between these two observed equivalence points, t eq , may be expressed by the following equation: ##EQU1## where V m is the mixing cell volume which is much larger than the sample volume, V s , C so is the concentration of S in the mixing cell at t=0, Q s is the sample flow rate, and Q t is the titrant flow rate and thus ##EQU2## where C s @ is the initial concentration of S. With a single channel manifold as used in this work,
Q.sub.s =Q.sub.t =Q (3)
and the above equation reduces to ##EQU3## where C t is the concentration of the titrant. Therefore, for the titration of base with an acid ##EQU4## where n is the number of equivalents weight of the acid. Rearranging this equation and substituting the equation for C so , a linear equation is obtained with the form of
ln.sub.e C.sub.base =K.sub.1 t.sub.eq +k.sub.2. (6)
The slope of the response curve is affected by V m and Q. The intercept, and thus the lower limit of detection, is affected by V s , V m , and C acid . Thus if V s and V m are kept constant, the sensitivity of the method can be changed by varying Q; and the lower limit of detection can be changed by varying C acid . Flow injection titrimetry methods are capable of providing detection limit sensitivities which can be chosen to fit the needs of the analyst.
A problem with the above described single channel system is that the results were limited to the analysis of one component, that is, where C s is the molar concentration of species to be titrated; K is the constant related to the apparatus including cell volume and flow rate; t eq is the time to an equivalence point, i.e., t i ; C is the constant relating concentration of the titrant; V m is the volume in the mixing cell; and Q is the flow rate then:
ln.sub.e C.sub.s =Kt.sub.eq +C (7)
C.sub.s =ln.sub.e.sup.-1 (Kt.sub.eq +C) (8)
ln.sub.e C.sub.s =Q/V.sub.m t.sub.eq +ln.sub.e C (9)
Ruzicka and Hansen also developed another titration system, described in "Recent Developments in Flow Injection Analysis: Gradient Techniques and Hydrodynamic Injection", Analytica Chimica Acta, 145 (1983), 1-15. However, this continuous flow multiple endpoint titration system is limited to a teaching for a single component acid-base titration. In particular, the authors focus on the titration of phosphoric acid by 1×10 -3 M sodium hydroxide, and do not address a multiple component flow injection analysis multiple endpoint system.
Yet another flow injection titrimetry technique was taught in U.S. Pat. No. 4,283,201 to DeFord et al. In that reference, a titrant is supplied to two parallel fluidly communicating circuits. The first circuit involved a pressure regulator means and a flow restricting means terminating in a first electrical conductivity detection cell means having a vent means. The second circuit involved a flow rate controller means, a sample valve means and a chromatograph column or equivalent means terminating in a second electrical conductivity detection cell means also having a vent means. The electrical output signals representing the electrical conductivity of the fluid conducted through the first cell means and the second cell means were combined in an electrical difference detection means. The electrical output signal generated within the detection means and representative of the difference in the two fluid conductivities was passed to one channel of a dual channel strip chart recording means and additionally passed to an electrical signal derivative detection means. The electrical output signal, representative of the derivative of said difference signal, was then passed to a digital clock and counter means and then to a recording means. The material or sample to be reacted or titrated was supplied to the two parallel fluidly communicating circuits from a third conduit.
The DeFord teaching provided a method and apparatus for flow injection titrimetry which used a plurality of reactant streams, analyzers, and detection apparatus to detect a plurality of end points of a complex sample. This teaching has not satisfied all the needs of the medical, pharmaceutical and argicultural fields in regard to analysis apparatus. A need exists for a flow injection method of analysis which provides data regarding a plurality of end points requiring less equipment and less time than the DeFord teaching. A method and device have long been needed for performing multiple endpoint titrations in a single analysis. The present invention seeks to go beyond these teachings and present a method of nonlinear multiple endpoint flow injection titrimetry for several species of sample.
One problem with prior mixing cells for titration flow injection analysis is entrapment of bubbles in the mixing cell. This problem is related to the mixing action of the stirrer in the mixing cell. Bubbles tend to collect on cell walls and to remain in the vortex of the stirred contents of the cell and interfere with analytical accuracy. Special stirrers such as the Fisher Scientific stir bar for spectrophotometer cells, Catalog No. 14-511-72, are designed to minimize aeration and are effective in spectrophotometric cuvettes. They are, however, inadequate in Flow Injection titration analysis because of a demonstrated tendency to form and trap bubbles on the stirrer itself and on the tip of the detector probe. The trapped bubbles interfere with the analytical accuracy. The stirrer of the present invention results in helical flow of the carrier from the inlet to the outlet of the mixing cell with a minimum of vertical mixing (assuming vertical progression of helical flow in the mixing cell). This helical flow, preferably in combination with a chamber which is narrowed near the outlet of the chamber to allow bubble coalescing which facilitates bubble removal from the cell and effectively solves the above mentioned bubble problem.
SUMMARY OF THE INVENTION
The present invention provides a method for determining the titration endpoints of at least two independent titratable species by flow injection analysis of a single sample, comprising the steps of: providing a stream of carrier; introducing a multicomponent sample into the carrier stream; flowing the sample into a mixing and detection cell at a defined carrier flow rate; forming an exponential dilution gradient within the mixing and detection cell; titrating with a reactant, each species of the sample mixture, in the mixing cell, to a plurality of end points; determining the concentration of each species of the sample in the mixing cell by forming a relationship between the time of titrating each species to an equivalence point using the multicomponent system relationship expressed as:
Tln(RF.sub.i)=t.sub.i +TlnC.sub.t, (10)
developed from the equations:
t.sub.i =Vm/Qln(Vs/Vm)-ln C.sub.t ]+Vm/Qln(Sn.sub.i C.sub.i)(11)
wherein:
t i are the times to titration endpoints;
V s is the volume of the sample;
V m is the mixed cell volume;
Q is the flow rate;
C i are the molar concentrations of each titratable species in the sample;
n i are the number of equivalents of each titratable species in the sample;
R is the ratio of sample volume to cell volume;
T is the average cell residence time of titrant;
F i are the sample concentration functions corresponding to the relationships between the concentrations of C i , as controlled by the stoichiometry of the species/titrant reactions; and
C t is the molar concentration of titrant.
The invention method further comprises the step of using at least two acid base neutralization reactions which occur during the same time interval, during titration of each species of the sample mixture to obtain a plurality of endpoints.
The method invention can be used for the multiple-endpoint titration of the following caustic/carbonate system:
n.sub.1 NaOH+n.sub.1 HCL→n.sub.1 NaCl+n.sub.1 H.sub.2 O(12)
n.sub.2 Na.sub.2 CO.sub.3 +n.sub.2 HCl→n.sub.2 NaHCO.sub.3 +n.sub.2 NaCl (13)
wherein at t 1 :
n 1 moles of NaOH=C 1 , and
n 2 moles of Na 2 CO 3 =C 2
such that:
F 1 =C 1 +C 2 .
n.sub.2 NaHCO.sub.3 +n.sub.2 HCl→n.sub.2 NaCl+n.sub.2 CO.sub.2 +n.sub.2 H.sub.2 O (14)
wherein at t 2 :
n 1 moles of NaOH=C 1
n 2 moles of Na 2 CO 3 =C 2 , and
n 2 moles of NaHCO 3 is equivalent to the concentration of C 2 such that:
F 2 =C 1 +2C 2
to simultaneously determine a plurality of end points.
Alternatively, the method of the invention may further comprise the step of using at least two reduction or oxidation reactions which occur during the same time interval, during titration of each species of the sample mixture to obtain a plurality of endpoints.
The invention yet further involves a mixing cell for titration flow injection analysis, comprising:
a body defining a chamber having a lower inlet port to said chamber and an upper outlet port from said chamber; a sensing means within said chamber placed between said inlet and outlet ports; a stirring means effective to generate helical flow of a liquid flowing into said inlet port to said outlet port in said chamber so that bubbles in said liquid are not retained in said chamber at said detection means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of the preferred embodiment of the apparatus invention.
FIG. 2 is a cross section of the embodiment shown in FIG. 1, taken along the cutting line 2--2.
FIG. 3 is a graphic representation of data obtained by the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
More particularly, the invention achieves a reaction between a sample and a titrant wherein equivalence points are reached such that
t.sub.1 =Vm/Q[ln(Vs/Vm)-ln C.sub.t ]+Vm/Q ln (C.sub.1 +C.sub.2)(15)
and
t.sub.2 =Vm/Q[ln(Vs/Vm)-ln C.sub.t ]+Vm/Q ln (C.sub.1 +2C.sub.2)(16)
wherein:
t 1 is the time to the equivalence point of the first species;
t 2 is the time to the equivalence point of the second species;
V s is the volume of the sample;
V m is the mixed cell volume;
Q is the flow rate;
C 1 is the molar concentration of the first species; and
C 2 is the molar concentration of the second species.
If a sample plug with concentration C s is injected into a flowing stream of titrant with concentration C t and then passed into a mixing cell, and if the mixing and chemical reactions are instantaneous, an exponential concentration gradient is formed. The exponential concentration gradient of the sample and titrant mixture is then passed in the cell to a detector where two or more signal transitions are obtained. These signal transitions are the points at which there is a significant change in the concentration of a monitored species such as pH. The first signal change marks the effective start of the titration. Other signal changes mark the passage of titration equivalent points described by a sudden change in, for example, the carrier pH; and in the case of a single titration species, the end of the titration. Changes in pH may be easily detected with a pH electrode. Other titratable species may be detected using similar sensors (e.g. ion-selective electrodes or amperometric means).
One embodiment of the apparatus invention is shown in FIGS. 1 and 2. The apparatus includes a mixing cell having a body 12 defining a chamber 14. Disposed within the chamber 14 is a stirrer 16. The stirrer 16 serves a dual function within the chamber 14; (1) by mixing the reagent fluid with the sample to promote a reaction and (2) by forcing the fluid to flow in a helical manner upwards through the chamber with a maximum of rotational mixing but with a minimum of up and down mixing so that bubbles do not remain in the chamber 14. A preferred stirrer 16 is a Spinfin type, sold by Ace Scientific, of East Brunswick, N.J., which has been modified by removal of the top fins and addition of side slots 17 (one of which is shown in FIG. 1). Other stirring means, such as devices including stirrers mounted on rotating shafts, may be used as long as they provide for helical flow, and do not trap bubbles.
The body 12 has a lower inlet port 18 and an upper outlet port 20. A sensing means 22 is disposed within the chamber 14. The sensing means can be a pH electrode, an ion specific electrode, or generally any amperometric or potentiometric sensing electrode. A narrowing of the chamber 14 near the outlet port 20 results in a gas trap 24 for trapping bubbles formed during the multiple endpoint titration in the chamber 14. The chamber 14 is designed to provide helical flow between the inlet port 18 and the sensing means 22 whereas the gas trap 24 is designed to provide laminar flow, and collect and dispose of any gas bubbles formed during the reaction. The trap 24 is positioned at the top of chamber 14 near the outlet port 20 to prevent gas bubbles disrupting the titrametric measurements being taken. The outlet port 20 may be positioned from the bottom to the top of the gas trap 24, but is preferably positioned at the top as shown in FIG. 1.
Typical results for caustic/carbonate systems using the inventive method and apparatus are depicted in the Table I and in FIG. 3 for the following multicomponent system wherein:
C s =Sample Concentration
C t =Titrant Concentration
R=Sample Volume/Cell Volume Ratio
T=Average Cell Residence Time of Titrant
and
Tln(RF.sub.i)=t.sub.i +Tln C.sub.t (17)
where:
t i =Time to equivalence Point i
F i =Sample Concentration Function
Corresponding to Point i then, for the caustic/carbonate system: ##STR1##
n.sub.2 NaHCO.sub.3 +n.sub.2 HCl→n.sub.2 NaCl+n.sub.2 CO.sub.2 +n.sub.2 H.sub.2 O}t.sub.2 (20)
and for:
Titrated species at time t 1 :
n 1 moles of NaOH (Concentration=C 1 ) and
n 2 moles of Na 2 CO 3 (Concentration=C 2 )
for a concentration function at t 1 of F 1 =C 1 +C 2 ;
and for:
Titrated species at time t 2 :
n 1 moles of NaOH (Concentration=C 1 ) and
n 2 moles of Na 2 CO 3 (Concentration=C 2 )
for a concentration at t 2 of F 2 =C 1 +2C 2 ;
Equation (17) is rearranged as follows:
Tln R+TlnF.sub.i =t.sub.i +Tln C.sub.t (21)
t.sub.i =T(1n R-1n C.sub.t)+Tln F.sub.i =a+b 1n F.sub.i (22)
t.sub.1 =a+b ln(C.sub.1 +C.sub.2) (23)
t.sub.2 =a+b ln(C.sub.1 +2C.sub.2) (24)
C.sub.1 +C.sub.2 =ln.sup.-1 (t.sub.1 /b-a/b)=K.sub.1 (25)
C.sub.1 +2C.sub.2 =ln.sup.-1 (t.sub.2 /b-a/b)=K.sub.2 (26)
C.sub.2 =K.sub.2 -K.sub.1 (27)
C.sub.1 =K.sub.1 -C.sub.2 =K.sub.1 -(K.sub.2 -K.sub.1)=2K.sub.1 -K.sub.2(28)
and using system constants which are:
C t =0.001 mole/liter
R=0.0816
Estimated from measurements
T=4.57 min.
R=ln -1 (a/b+ln C t )=0.0945
Calculated from experimental data,
T=b=4.71 min.
The following example of data was obtained in Table I.
TABLE I__________________________________________________________________________ Calculated100 C.sub.1 100 C.sub.2 -1n F.sub.1 -1n F.sub.2 t.sub.1 t.sub.2 100 C.sub.1 100 C.sub.2__________________________________________________________________________1.2 0.3962 4.1375 3.9158 1.875 3.063 1.124 0.4531.2 0.7925 3.9158 3.5809 3.075 4.713 1.188 0.8471.5 1.3019 3.5749 3.1933 4.730 6.470 1.598 1.2952.6 0.3962 3.5078 3.3836 4.563 5.375 2.266 0.5262.4 0.7925 3.4444 3.2226 5.117 6.217 2.314 0.8272.1 1.9057 3.2175 2.8283 6.063 7.713 2.227 1.6138.8 0.6038 2.3641 2.3018 10.016 10.392 8.157 0.7408.7 0.8962 2.3438 2.2545 10.225 10.706 8.300 1.0019.0 1.8019 2.2254 2.0712 10.983 11.683 9.175 1.7533.6 4.3962 2.5262 2.0881 9.767 11.650 4.286 4.1534.6 0.8019 2.9184 2.7800 7.750 8.467 4.592 0.9054.4 2.0000 2.7489 2.4769 8.763 10.050 4.672 2.145__________________________________________________________________________
Where concentration C i is mole/liter and time t i is minutes.
The linear relationship of this multiple endpoint system is graphically depicted in FIG. 3.
Statement of Intent
The inventor hereby states his intent to rely on the Doctrine of Equivalents to determine and assess the fair scope of his invention as set out and defined in the following claims. | A method for titration flow injection analysis by introducing a multicomponent sample into a carrier stream which flows into a mixing/sensing cell and titrating with a reactant more than one component of the sample by sensing a plurality of endpoints. The apparatus of the invention includes a stirring means within the mixing/sensing cell which generates helical flow within the cell so that bubbles are not retained in the cell. | 6 |
DESCRIPTION
Size recovery is becoming more and more important for economic and environmental reasons. However, from singeing and the natural impurities in cotton, the cloth contains a large number of impurities which, in the course of size washoff, pass from the fabric into the resulting regenerated size and impart to the latter a dark self-color. This self-color makes it impossible to size white or colored yarns with regenerated size without affecting the appearance of the yarns. This is important in particular when the size is not removed but is left as a finish in the fabric, as for example in the case of mattress duck and fashionable sportswear or with any fabric dyed in white, pastel-colored and bright shades. It is therefore an object of the present invention to work up the regenerated sizes in such a way that all or substantially all the dark color disappears.
This object is achieved by adding oxidative, chlorine-containing compounds, preferably sodium chlorite, to the regenerated sizes.
The amount of sodium chlorite is about 0.1 to 3% by weight per liter of regenerated size. These regenerated sizes contain in general from 1 to 12% by weight of solid sizing agent. Possible sizing agents of this type here are for example polyvinyl alcohol, carboxymethylcellulose, polyacrylates, carboxymethyl starch, guar derivatives, polyester resins or vinyl acetate/acrylate copolymers.
If sodium chlorite is used as the chlorine-containing compound, the otherwise customary activation with an acid or an acidic salt can be dispensed with, since the oxidation takes place close to neutral without significant quantities of chlorine dioxide being detected. The oxidation can be further enhanced by adding to the regenerated size, shortly before the bleaching process has ended, small amounts of active chlorine in the form of sodium hypochlorite. The ratio of sodium hypochlorite:sodium chlorite can be between 1:1 and 1:10.
The process according to the invention it possible not only to brighten the very dark impurities in the regenerated size but also to destroy the color of the marking dyes which are used in sizing to identify fiber blends and to distinguish right-hand and left-hand twisted yarns. It is consequently possible to color the recovered size once again. Nor is there any need to add preservatives, such as formaldehyde, since in the process according to the invention the regenerated size keeps for a prolonged period even at room temperature although no residues of sodium chlorite or chlorine dioxide are detectable. The regenerated size treated according to the invention is as usual returned to the required concentration by renewed addition of solid sizing agent and used for a new sizing process. The film-forming and sizing properties of the sizing agent are not impaired by the process according to the invention.
EXAMPLE
To 10,000 liters of regenerated size containing 4% by weight of sizing agent for 52 kg of sodium chlorite (30%) and the regenerated size was then pumped round at 80° C. for 14 hours. The sizing agent was two thirds polyvinyl alcohol and one third carboxymethyl cellulose. The process of oxidation took place without the addition of acid donors, since the liquor is self-activating despite a pH of 6.5. At the end of the stated period all the sodium chlorite had been consumed, as indicated by an iodine/potassium iodide paper.
To 400 liters of this regenerated size was then added 12 kg of hydroxypropyl starch and 1 kg of Na-alkane sulfonate.
This size was then used to size a pure cotton yarn of the following type:
Yarn count: tex 36/36; total number of ends: 7780 ends/200 cm; weft density: 16 picks/cm.
Sizing took place on a drum sizing machine containing medium high pressure squeeze rollers (2500 kg). The sizing temperature was 90° C., the drying temperature 140°/120° C. and the size wet pickup 120%.
This warp yarn was woven on a gripper machine with high efficiency. A reflectance measurement showed that 90% of the coloring substances had been removed from the regenerated size. | Process for working up regenerated sizes by adding oxidative chlorine-containing compounds, in particular sodium chlorite. These compounds have the effect in the regenerated size of oxidatively brightening the interfering dark-colored impurities. | 3 |
This application is a continuation of application Ser. No. 477,064 filed Mar. 21, 1983, now abandoned.
BACKGROUND OF THE INVENTION
The field of the present invention is vibratory separating equipment and more particularly equipment suited for the screening of course material from liquid borne solids.
Certain screening operations, particularly those involving liquid borne materials, are best conducted with a partially submerged screen. On the submerged portion of the screen, blinding and clumping are generally avoided. Furthermore, the suspended material generally cannot dry out or otherwise be separated from the carrying liquid. By employing a partially submerged screen, and by employing vibratory motion of that screen, the oversized material which is screened from the liquid-solid mixture is slowly moved from the submerged portion of the screen and discharged without loss of suspended material or liquid.
The foregoing principles have been employed in the paper industry for the screening of water borne pulp. One such early device employed in this industry includes a rectangular, vibrated open vat having a curved screen extending through a portion of its length beneath a water level maintained in the vat. Translational vibration moves the material screened from the pulp mixture up the incline of the screen from the water to an outlet. The water borne pulp is discharged from the vat below the screen.
The operation of such screening systems has been found generally acceptable. However, heretofore such partially submerged screening systems have not incorporated the more modern, efficient and versatile screening devices employing rotational and radial motion rather than simple translation. The modern screening device generally includes a horizontal screen mounted in a sprung frame. Eccentric weights are arranged to induce vibrational motion which in turn causes the material on the screen to move in an outward spiral. Such motion gives an extended path of travel and allows for easy collection of the oversized material. Furthermore, the path of motion may be easily varied to increase or decrease residence time. Such modern devices are also more amenable to advantageous material feed and cleaning spray arrangements.
Vibratory separators of a type similar in overall arrangement to the present invention but lacking the partially submerged feature are shown in the series of Miller et al, U.S. Pat. Nos. 2,696,302; 2,753,999; 2,777,578; and 2,714,961, the McCausland, U.S. Pat. No. 3,035,700, and the Wright, Jr., et al, U.S. Pat. No. 3,029,946. See also Miller et al, U.S. Pat. No. 3,616,906. The foregoing patents are incorporated herein by reference.
SUMMARY OF THE INVENTION
The present invention is directed to an improved screening system employing a partially submerged screening device. The present system employs a horizontally disposed, downwardly concaved screen mounted in a vibratory separator. A chamber extends upwardly around the lower central portion of the screen and during operation is filled with the liquid and liquid borne solid material to partially submerge the screen. A peripheral area around the lower central portion remains above the liquid level in the chamber to receive and dewater oversized material removed from the flow by the screen. The partial submersion of the screen makes the present mechanism useful for water borne solids such as wood pulp in the paper industry.
The advantageous arrangement of the present invention in combination with the modern vibratory screen structure provides substantial advantage both in operation and in permitting the addition of other features. The vibratory separator allows spiral movement of the oversized material from the liquid-solid mixture such that it may be collected about the outer periphery of the device and removed. At the same time, properly sized pulp which is conveyed above the liquid level may still pass through the screen.
To enhance the clearing of the properly sized material through the screen above the water level and to wash adhering properly sized material from the oversized material prior to discharge of the oversized material, a spray manifold and nozzles may be employed. These nozzles may be directed to advantageously work with the vibratory motion to move material on the surface of the screen in the same rotational direction or to partially impede flow for further cleaning. At the same time, the nozzles do not either retard or accellerate movement of material in a radial path.
The device of the present invention may also be advantageously employed to distribute in a central location liquid-solid flow. A mechanism has been devised to reduce the velocity of this flow so as not to adversely affect the operation of the screen.
Accordingly, it is an object of the present invention to provide an improved screening mechanism for liquid borne solids. Other and further objects and advantages will appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a cross-sectional elevation taken through the center of a preferred embodiment of the present invention.
FIG. 2 is a plan view of the mechanism of FIG. 1.
FIG. 3 is a cross-sectional elevation taken through the center of a second preferred embodiment of the present invention.
FIG. 4 is a plan view of the mechanism of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning in detail to the drawings, a first preferred embodiment of the present invention is illustrated in FIGS. 1 and 2. The device includes a frame, generally designated 10. This frame includes a cylindrical wall 12, a rigidifying upper flange 14 and a base plate 16. The base plate 16 extends outwardly to the cylindrical wall 12 and has a circular hole located centrally therethrough. The frame 10 is sprung by means of a plurality of springs 18. The springs are in turn positioned on a base 20.
To provide means for inducing vibration of a predetermined nature, a motor 22 with eccentric weights 24 and 26 is mounted to the frame 10. To provide adequate mounting supports, a cylindrical mounting structure 28 is fixed to the base 20 both at the intersection thereof and by means of gussets 30.
Mounted horizontally in the frame 10 on annular mounting flange 32 is a screen 34. The screen 34 is shown to be a perforated plate which is downwardly concaved and circular in plan. The phrase "downardly concaved" is employed to denote a surface, or assembly of surfaces, which is lower in the middle than about the outside. Thus, dished, conical, truncated conical and other, less regular surfaces are contemplated. The screen has been arbitrarily divided for purposes of clarity in the present description into a central lower portion defined as being inwardly of the chamber described below and a peripheral elevated portion outwardly of the chamber. As the screen is all one plate, in the embodiment illustrated, there is surface continuity between portions which is preferable for smooth flow of material from the central portion of the screen. The peripheral elevated portion includes a planar annular segment most adjacent the cylindrical wall 12 and a truncated dished segment defined between the planar annular segment and the central lower portion. Again, a smooth transition between portions provides unimpeded material flow to the outer periphery of the screen.
Located horizontally across the frame 10 beneath the screen 34 is an upwardly convex plate 36. As with "downwardly concaved", "upwardly convex" is intended to encompass a variety of surfaces having the middle thereof higher than the outside. This plate 36 defines the lowermost portion of the screening cavity in the frame 10. By virtue of the position of the plate 36, all flow through the screen 34 is collected and eventually conveyed to outlet 38. Similarly, oversized material on the screen 34 eventually is conveyed to outlet 40. Associated equipment may convey the effluent from each of these outlets 38 and 40 to further processing or disposal.
To retain the screen 34 in position, a tie-down 42 is fixed to the plate 36 and to the screen 34 at its mid point. The tie-down 42 may then be drawn down to fix the screen 34 in position.
Located between the screen 34 and the plate 36 circumferentially about the central lower portion of the screen 34 is an upstanding or cylindrical peripheral wall 44, circular in plan. This wall extends upwardly from the plate 36 to the screen 34 and defines a chamber therein. As the peripheral wall 44 extends upwardly to a position above the central lower portion of the screen 34, a liquid level may be defined above this lowermost portion of the screen. To maintain the liquid level at the top of the chamber and possibly flowing over, chamber outlet means is provided for exhausting the liquid-solid material. In order that the chamber will fill, the outlet means is to be restricted, either on a fixed or variable basis, such that the flow rate therethrough will be less than the flow rate which is capable of entering the chamber through the portion of the screen 34 immediately above the chamber. To this end, small ports 46 have been shown in the preferred embodiment. Other baffle arrangements and the like may be otherwise employed to the same end.
To provide material to the system, an inlet manifold is centrally positioned above the screen 34. This inlet manifold 48 is specifically designed to condition the flow to the screen such that the incoming material will not adversely effect the operation thereof. To this end, the manifold includes an inlet port 50, an outlet port 52 and baffles 54. The outlet port 52 is directly facing the upper surface of the screen 34 in the area where the screen is submerged. The baffles 54 prevent any straight flow between the inlet 50 and the outlet 52 to condition the flow, particularly by reducing its velocity. The cross-sectional open area at the outlet 52 around the lowest baffle is preferably larger than the cross-sectional area of the inlet 50 in order that the velocity may be reduced at the lower point.
Outwardly of the inlet manifold 48 is a spray manifold 56. The spray manifold 56 consists of an annular tube concentrically placed about the center line of the separator above the screen 34. An inlet 58 is provided to receive fresh water, in the case of pulp screening, or other processing liquid. Located about the underside of the spray manifold 56, uniformly spaced, are spray nozzles 60. These spray nozzles are particularly aimed at the edge of the submerged portion of the screen and outwardly therefrom for some distance.
The nozzles 60 are biased, in the embodiment best seen in FIG. 2, in one circular direction at the surface of the screen 34. This direction is preferably in the same circular direction as the induced movement of particles moving in a spiral path both about the screen 34 and outwardly toward the cylindrical wall 12 of the frame 10. However, if additional washing of the fines from the larger separated particles is desired, the nozzles 60 may be biased in the opposite direction. Such a reverse bias may require some attention to the amount and force of the spray such that the spiral motion of the material on the screen, albeit impeded, will not be stopped or reversed.
In operation, the vibratory separator is vibrated by means of the motor 22 and eccentric weights 24 and 26 preferably to provide a spiral flow of material on the surface of the screen 34. In the present embodiment, this flow would be in the counterclockwise direction as seen in FIG. 2. Inlet flow of, for example, water and pulp is passed through the manifold 48 and distributed into the body of liquid and material above the screen 34 where the screen is submerged. The flow is preferably conditioned such that it will not cause undue splashing and other displacement of the liquid maintained in that area.
The liquid and solid material flowing from the manifold 48 is then primarily collected within the confines of the peripheral wall 44. The primary flow is downwardly through the screen 34 such that oversized pieces will be left behind. The rate of flow into the device is preferably such that there will be some overflow over the top of the peripheral wall 44 and through the screen 34 outwardly of that wall. The material passing through the screen 34 inwardly of the peripheral wall 44 is then discharged through ports 46 into the annular space above the plate 36. Eventually, this material is conveyed to the outlet 38 where it is collected for further operation. As this screening takes place, the induced vibration is tending to move all material in a counterclockwise outward spiral. The vibration also helps to prevent binding of the screen 34 by the material which would otherwise pass therethrough.
As the oversized material cannot pass through the screen 34, it eventually moves outwardly to the edge of the central lower portion of the screen. At this point, the oversized material is substantially dewatered. Certain of the acceptable material is also moved by the vibrations outwardly from the central lower portion of the screen. This material moves either independently of the oversized material or is associated with it. The nozzles 60 on the spray manifold 56 act to convey the acceptable material through the screen 34 and to also wash it from the oversized particles and then through the screen. Because of the direction the spray is biased, in the embodiment of FIG. 2, the spray does not impede travel of the oversized particles. These particles eventually move outwardly in a spiral direction to the outer cylindrical wall 12 of the device and then are collected and discharged through the outlet 40.
Looking to the second preferred embodiment of the present invention illustrated as FIGS. 3 and 4, the same reference numbers as employed for FIGS. 1 and 2 will be used for identical or substantial identical parts. Reference is made to the earlier description corresponding to such numbers.
Generally speaking, the variation in the two embodiments is presented in the chamber beneath the screen 34. In the embodiment of FIGS. 3 and 4, the chamber beneath the screen is formed by a dished plate 62. The dished plate 62 is circular in plan with an outer rim 64 extending upwardly to a position above the central lower portion of the screen 34. An upstanding cylindrical wall 66 is fixed to the plate 36 and forms a rigid support for the dished plate 62. This cylindrical wall conveniently includes an attachment flange 68 which is secured to the plate 36. Additionally, the lip 64 is shown to be formed as a flange on the upper end of the cylindrical wall 66.
The placement of the dished plate 62 with the outer rim 64 is such that the chamber formed is circumferentially disposed about the lower portion of the screen 34. To provide outlet means for the chamber such that the carrying liquid and suspended material may exit from the chamber and flow to the outlet 38, the plate 62 at the rim 64 is spaced below the most adjacent portion of the screen 34. Thus, an annular outlet is formed between the screen 34 and the outer rim 64. The plate 62 is also configured to assume a concavity similar to that of the screen 34. In this way, a minimum amount of retained mass is achieved without restriction to the flow of material to the rim 64 for discharge.
Thus, a continuous processing of liquid borne solids to remove course material may be effected in the most efficient and advantageous manner by the disclosed system. While embodiments and applications of this application have been shown and described, it would be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except by the spirit of the appended claims. | Separating equipment having a partially submerged vibratory screen in a screening device wherein oversized particles are induced to flow in a spiral direction outwardly from a central submerged area of the screen. A low velocity inlet manifold is employed centrally above the screen and a spray mechanism directs clearing spray to a peripheral area outwardly of the submerged portion of the screen. The screen is submerged by means of a chamber which extends outwardly above the lower most portion of the concaved partially submerged screen. The preferred embodiments specifically contemplates the screening of water borne wood pulp for the paper industry. | 1 |
RELATED APPLICATIONS
This application is a continuation of U.S. app. Ser. No. 10/322,681, filed Dec. 17, 2002 now U.S. Pat. No. 6,674,680; which is a divisional of U.S. app. Ser. No. 09/954,600, filed Sep. 11, 2001 now U.S. Pat. No. 6,525,982.
TECHNICAL FIELD
The present invention relates generally to the computer memory field and, more specifically, to methods and circuitry concerning programming elements of memory devices.
BACKGROUND
The fabrication and operation of electronic circuitry on a die often involves allowing for voltages or electronic signals to be received from sources external to the die by way of terminals on the die such as contact pads—electrically conductive areas that are relatively large in relation to a conductive line coupled thereto. The relatively large area of such pads allows them to receive voltages and signals from nodes such as bond wires or probe tips.
Concerning Dynamic Random Access Memory (DRAM) devices, for example, it is often desired to provide a pad that receives a voltage designated as “DVC 2 .” In normal operation, the DVC 2 voltage is ideally half of the full voltage (Vcc) under which the memory device operates and which corresponds to a logic “1” value that may be stored in memory. The DVC 2 voltage is applied to the DRAM's digit lines, including the main digit lines as well as the complementary digit lines, before reading from or writing to a memory cell.
Writing to a memory cell further involves transmitting at least one command, such as a “write enable” (WE) signal, to the DRAM's control circuitry. It is often desirable to provide a pad configured to receive the WE signal.
Moreover, operation of a DRAM may involve blowing an anti-fuse. Doing so may reroute a signal to or from a device other than the one originally configured to be associated with that signal. For example, in the event a defective memory cell is detected, an appropriate anti-fuse may be blown so that the relevant signals are associated with a redundant cell. Blowing an anti-fuse often involves generating enough of a voltage difference between the opposing plates of a capacitor to break down the dielectric between those plates. For instance, one plate may be coupled to a voltage source, herein referred to as CGND (also known as Vpop), while the other plate may be coupled to ground through a transistor. Thus, when CGND is applied to one plate and the transistor allows the other plate to be grounded for a sufficient time, a short is created between CGND and a node coupled to the other plate. Subsequently, the voltage of CGND is lowered and the transistor isolates the pathway to ground. As with the DVC 2 voltage and the WE signal, a pad may be used to provide the CGND voltages. However, to provide yet another pad—one dedicated to this purpose—would require more die space and go against the desire in the industry to use as little space as possible per die in order fabricate more die on each silicon wafer. Further, providing such a pad would require more test resources per die, which decreases the ability to test in parallel and increases test time and cost. As a result, a pad that serves another function may be chosen to transmit the CGND voltage as well. Which pad is chosen depends on several factors.
Two factors to be considered in choosing the pad for CGND involve the notions that (1) blowing anti-fuses may be desired at several stages in the process of fabricating a memory device; and (2) some contact pads may not be available later in the process. The pad receiving DVC 2 , for example, is accessible for anti-fuse blowing that may occur during a production stage known as “probe.” At that stage, testing an unpackaged die may occur by applying voltages directly to the die's pads using conductive pins from a test device. However, at some point after probe, the die is packaged. As a non-limiting example of packaging, some of the contact pads may be bonded to wires leading to conductive fingers of a lead frame. The die is then encapsulated with a protective material, with the far ends of the fingers projecting from the encapsulant. Some of the contact pads, however, may not be bonded to wires and are therefore inaccessible after packaging. Nevertheless, additional testing, repairing, or reconfiguring of the die may be desirable at this stage, known as “backend.” The DVC 2 pad is a contact pad that is not bonded to a wire and is therefore inaccessible after packaging. As a result, one of ordinary skill in the art is encouraged to choose another pad to provide CGND.
A pad receiving the WE signal may be available during both probe and backend; but if a pad is accessible by a tester at backend in testing/reconfiguration modes, it may also be accessible by a post-production user during non-test/non-reconfiguration/standard operation modes. Because it is not desirable to allow such a user to affect CGND, the conductive path from the write pad to the anti-fuse must be regulated, such as with a transistor. However, in order to ensure that sufficient voltage passes through the transistor during an anti-fuse blowing mode at backend, self-booting circuitry is included. As discussed in greater detail below, such circuitry is not foolproof, and additional delays may be introduced into the anti-fuse blowing process.
As a result, there is a need in the art to address the time, methods and circuitry of blowing an anti-fuse.
SUMMARY
Accordingly, exemplary embodiments of the current invention concern a direct connection between a die's anti-fuse and a die terminal configured to receive an external voltage. In a preferred embodiment, the terminal is also configured to provide voltage to another device. When a voltage is being supplied to that other device, and that voltage would affect the ability of circuitry to properly determine the status of the anti-fuse, preferred embodiments of the current invention isolate the anti-fuse from such circuitry. In a more preferred embodiment, access to the terminal is eventually prevented, but access to the anti-fuse by way of a still-accessible second terminal is allowed, wherein the connection between the anti-fuse and the second terminal is regulated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an anti-fuse circuit and a latch circuit known in the prior art.
FIG. 2 depicts an anti-fuse circuit and related circuitry known in the prior art.
FIG. 3 depicts the voltages at various nodes of a regulation transistor known in the prior art.
FIG. 4 depicts an exemplary embodiment of the current invention.
FIG. 5 depicts memory circuitry known in the prior art.
FIG. 6 depicts another exemplary embodiment of the current invention.
FIG. 7 depicts yet another exemplary embodiment of the current invention.
FIG. 8 depicts still another exemplary embodiment of the current invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows prior art circuitry 10 comprising an anti-fuse circuit 11 and a latch circuit 18 . The anti-fuse circuit 11 comprises a capacitor—the anti-fuse 12 —wherein one plate of the capacitor is configured to couple to a voltage source CGND and the other is configured to couple to ground through node 14 and a transistor 16 . Before blowing, the dielectric between the plates of anti-fuse 12 is intact, thereby electrically isolating node 14 from CGND. In a non-limiting example of blowing the anti-fuse, CGND is established to be ten volts and the gate of transistor 16 is driven for at least 2 milliseconds. As a result, the dielectric between the plates of anti-fuse 12 breaks down, and a conductive path from CGND to node 14 is established. Subsequently, the voltage of CGND is lowered, preferably to less than Vcc.
While CGND is high, however, there is a risk of damaging the latch circuitry 18 . In order to prevent such damage, a voltage regulation transistor 17 is electrically interposed between the anti-fuse circuit 11 and the latch circuit 18 . In the prior art, this voltage regulation transistor 17 is turned off only during the anti-fuse blowing mode. Any other time, a voltage that is slightly less than Vcc is applied to the gate of voltage regulation transistor 17 by way of signal FLTV (Fuse Latch Transistor Voltage). For instance, 200 millivolts less than Vcc may be applied. As a result, the maximum voltage that could be applied from the anti-fuse circuit 11 to the source of voltage regulation transistor 17 is Vcc minus 200 millivolts and minus the threshold voltage of voltage regulation transistor 17 . Such a voltage provides enough electrical communication for reading the state of the anti-fuse 12 using latch circuit 18 while protecting it from excess voltages. Prior artisans are taught to maintain this sub-Vcc voltage to the gate of voltage regulation transistor 17 at all times other than during an anti-fuse-blowing mode. This is due at least in part to the fact that prior art already provides other protection circuitry between the pad receiving the voltage and the CGND node (such as the pass gate 42 described below) that is to be used in times other than the anti-fuse-blowing mode. Thus, to shut off regulation transistor 17 outside of that mode would result in unnecessary redundancy.
As mentioned above, latch circuitry 18 is used to determine the state of the anti-fuse 12 . An example of such circuitry includes an inverter 20 with an input coupled to node 14 (through voltage regulation transistor 17 ) and an output node OUT that drives a p-channel transistor 22 and an n-channel transistor 24 . The p-channel transistor 22 has a source coupled to Vcc (assumed to be 3 volts) through a current-limiting p-channel transistor 23 . The drain of p-channel transistor 22 is coupled to the input of inverter 20 . The n-channel transistor 24 has a source coupled to ground. A second p-channel transistor 26 has its source coupled to Vcc (through p-channel transistor 23 ) and its drain coupled to the input of inverter 20 . A second n-channel transistor 28 has its drain coupled to the input of inverter 20 and its source coupled to the drain of n-channel transistor 24 . The gates of second n-channel transistor 28 and second p-channel transistor 26 are coupled and driven by a signal RDFUS that is transmitted when one desires to read whether the anti-fuse has been blown.
The results of such reading depend on whether the anti-fuse 12 is blown and whether CGND represents a low enough voltage. In any case, the status of the anti-fuse 12 is read when RDFUS represents a low voltage or “logic 0” signal. Such a signal turns on the second p-channel transistor 26 and turns off the second n-channel transistor 28 . As a result, the transistors 26 and 28 in this state attempt to raise the voltage of node 14 and the input of the inverter 20 to Vcc. If the anti-fuse 12 is unblown, node 14 is isolated from the low CGND voltage (and it is assumed that transistor 16 is off as well). Because the input of inverter 20 has a high voltage, its output OUT is a low voltage or “logic 0” signal, which represents the fact that the anti-fuse is unblown. If the anti-fuse is blown, however, then there is a path from node 14 and the input of inverter 20 to a voltage lower than Vcc (CGND). The resulting discharge results in a low voltage or logic 0 signal input to inverter 20 . Accordingly, the output OUT of inverter 20 is a high voltage or logic 1 signal, which represents the fact that the anti-fuse is blown. This second example assumes that CGND is low enough below Vcc such that a logic 0 is recognized at the input of inverter 20 . Typically, CGND is held at ground during modes that do not involve blowing an anti-fuse. However, if for some reason CGND is not low enough, the input of inverter 20 may not sufficiently discharge through the anti-fuse 12 . As a result, a logic 1 may be recognized at the input of inverter 20 , and the output OUT will be a logic 0, signifying an unblown anti-fuse when in fact the anti-fuse is blown.
Even if the low voltage RDFUS command is not given, the output node OUT will still reflect the status of the anti-fuse 12 , and the latch circuit 18 may suffer the same problem discussed above if the CGND is too high at the wrong time. If RDFUS has a high voltage representing a “logic 1,” the second p-channel transistor 26 is turned off and the second n-channel transistor 28 is turned on. If the anti-fuse 12 is blown, the input to inverter 20 should have a low voltage. As a result, the output node OUT will have a high voltage that turns off p-channel transistor 22 and turns on n-channel transistor 24 . Thus, the input of inverter 20 will be isolated from Vcc and grounded, thereby maintaining the high voltage signal at OUT, which signifies a blown anti-fuse. However, if the anti-fuse is blown but CGND is too high, then there is a risk that the input node of inverter 20 may have a high enough voltage for long enough to result in a low voltage signal at the output node OUT. When that voltage is applied to the gates of transistors 22 and 24 , it isolates the input of inverter 20 from ground and allows the Vcc source to electrically communicate with the input of inverter 20 , thereby maintaining a low voltage signal at OUT, which incorrectly signifies an unblown anti-fuse.
Thus, regardless of the state of RDFUS, if for some reason CGND is not low enough, the latch circuit 18 may indicate that the anti-fuse 12 is unblown when in fact it is blown. This could reverse the effect of any changes that the blown anti-fuse 12 is supposed to govern. One reason that CGND may not be low enough is if the contact pad used to carry the CGND voltage serves another function involving increased voltages. Although using one contact pad for multiple functions may create the potential for certain problems to arise, one of ordinary skill in the art is nevertheless encouraged to share such resources in order to conserve die space. For reasons discussed in the Background section, one of ordinary skill is further encouraged to share the CGND function with a pad that can be accessed at backend as well as probe, such as the WE pad 38 depicted in FIG. 2 . FIG. 2 shows that, in addition to transmitting the CGND voltage to anti-fuse 12 , the WE pad 38 is coupled to memory control circuitry 39 . It should be noted, however, that the WE pad 38 is not directly connected to the anti-fuse 12 . Rather, any signal from the WE pad 38 must first pass through the drain 44 , channel 45 , and source 46 of a transistor identified as a pass gate 42 , which is part of a larger self-booting pass gate circuit 40 .
Such regulation of the signal stems from another issue raised by the fact that the WE pad may be accessed after packaging. Specifically, if a tester can transmit a high voltage during testing through a lead finger, bond wire, and pad 38 to CGND node 52 , so too can a customer/end-user transmit a high voltage to that same destination during non-anti-fuse-blowing modes of operation. As described above, the result could be that the voltage output from the anti-fuse circuit 11 would indicate that the anti-fuse is unblown when, in fact, it has been blown. This may reconfigure the die's circuitry and interfere with its operation. As a result, pass gate 42 is provided and is turned off during non-fuse-blowing modes of operation in order to prevent electrical communication between pad 38 and the CGND node 52 .
Only when an anti-fuse-blowing mode is desired is the gate 48 of pass gate 42 driven. Further, the voltage required for such a mode encourages the use of capacitor 50 as illustrated in FIG. 2 . Capacitor 50 is coupled to both the source 46 and gate 48 of the pass gate 42 . When the time comes to blow an anti-fuse, prior art teaches providing ten volts at the CGND node 52 using the WE pad 38 . Thus, ten volts is applied to the WE pad 38 , and the pass gate circuitry ideally operates to transmit that voltage to the CGND node 52 in the manner described below.
Regardless of the voltage applied to drain 44 , the maximum voltage that can be generated at the source 46 is equal to the voltage applied to the gate 48 minus the threshold voltage of pass gate 42 . Hence, it is desired to apply a voltage to gate 48 that is high enough above the voltage applied to the drain 44 so that the drain 44 voltage may generate the same voltage at the source 46 . Thus, before the anti-fuse blowing process begins, the drain 44 , gate 48 , and source 46 are at zero volts, as illustrated in FIG. 3 at time to. In anticipation of the anti-fuse blowing process, three volts are applied to gate 48 before a voltage is applied to the drain 44 at time t 1 . At that time t 1 , the voltage of the drain 44 is gradually raised from zero volts. When the drain 44 reaches one volt, the gate (already at three volts) allows that one volt to be applied to the source 46 . Given the configuration of the pass gate circuitry, that one volt is also applied to the capacitor 50 which, in turn, causes the voltage at the gate 48 to increase to four volts. As a result, at a time within the range t x , the gate 48 voltage stays higher than the drain 44 voltage, and the full voltage at the drain 44 is applied to the source 46 and the CGND node 52 .
The paragraph above describes the ideal operation of the pass gate circuitry 40 . In reality, however, the capacitor 50 leaks charge. As a result, the ability of the capacitor to keep the gate 48 voltage above the drain 44 voltage decreases over time. Eventually, the gate 48 voltage is lower than the drain voltage 44 , as depicted in FIG. 4 after time t 2 . Even before t 2 , the source 46 voltage begins to lower, as its maximum may only be V gate −V threshold ). Thus, at some point, the voltage at the source 46 is not sufficient for a reliable anti-fuse blow. In addition, it should be appreciated that the CGND node 52 may be coupled to more than one anti-fuse 12 and that blowing multiple anti-fuses in parallel further lowers the source 46 voltage. In practice, the source 46 voltage is sufficient for blowing ten anti-fuses in series. Additional blows will be increasingly uncertain. As a result, after ten anti-fuse blows in series, prior art teaches carrying out a “boot-up” process, wherein the drain 44 , gate 48 , and source 46 are grounded; and the voltages are increased again as described in the above paragraph. During probe, this boot-up process represents about 20% of the test time it takes to blow all fuses and repair.
At least one exemplary embodiment of the current invention addresses this problem by providing a direct connection between a contact pad and the CGND node, as seen in FIG. 4 . Illustrated therein is an electrically continuous conductive line leading from contact pad 30 to the anti-fuse 12 . In this exemplary embodiment, the contact pad 30 is also used to transmit a voltage DVC 2 for the benefit of equilibration circuitry 36 . FIG. 5 illustrates the equilibration circuitry 36 . Equilibration circuitry 36 will short digit lines D and D* in response to a signal EQ. In further response to signal EQ, a voltage of DVC 2 is established at both D and D*, which is encouraged before attempting to read from or write to memory cell 34 . In normal operations, DVC 2 is half of Vcc. During certain test modes, however, DVC 2 may be higher in order to test the margin of a sense amp 32 . The contact pad 30 is used to initially provide the DVC 2 voltage for equilibration circuitry 36 ; thereafter, the DVC 2 voltage is generated internally and the contact pad 30 is isolated from equilibration circuitry 36 unless it is needed to provide a different voltage for that circuitry 36 , such as for margin testing.
Such differing voltages are one factor that discourages one of ordinary skill in the art from using such a pad for CGND. As mentioned above, a high voltage at CGND in the prior art risks having the latch circuitry 18 mistakenly indicate that a blown anti-fuse is unblown. At least one exemplary embodiment of the current invention addresses this issue by countering another teaching in the art. Specifically, such an embodiment proposes turning off regulation transistor 17 during at least one mode other than the one in which anti-fuses are blown—preferably including the testing mode in which DVC 2 is raised. Thus, although node 14 may reflect a logic 1 value in the event anti-fuse 12 is blown and CGND is high enough, the lack of drive to the gate of transistor 17 prevents that value from being input to inverter 20 and signifying an unblown anti-fuse at the output node OUT.
Another factor that would discourage one of ordinary skill in the art from using a contact pad such as the DVC 2 pad 30 is that, sometime after probe and before backend, access to the DVC 2 pad 30 by external devices is denied. Specifically, the die undergoes the packaging process without a wire being bonded to that pad 30 . Moreover, access to the FLTV signal is denied as well. Accordingly, it is preferred under at least some of the exemplary embodiments of the current invention to maintain the regulated connection between CGND node 52 and the WE pad 38 . A great benefit is still realized under exemplary embodiments of this type, as it has been found that only one or two anti-fuses per die are blown at backend, whereas probe generally involves blowing two to ten thousand anti-fuses per die, and this number should increase as density increases in terms of devices per unit area of the die. Thus, with the direct connection eliminating the need for a self-booting pass gate circuit and the problems related to it, the 20% of anti-fuse blowing time devoted to reboot at probe is saved.
Exemplary embodiments of this type also allow for blowing several anti-fuses in parallel without comprising the voltage of CGND. In fact, given the direct connection to CGND, the only limitation on the voltage of CGND is the current supply from the tester.
It should be noted that in the exemplary embodiments described above, the regulation transistor 17 is illustrated as an n-channel transistor. However this particular type of transistor is not relevant to all embodiments. In fact, providing a p-channel transistor for regulation transistor 17 offers certain benefits. As shown in the exemplary embodiment of FIG. 6, a p-channel regulation transistor 17 may be driven by the same DVC 2 pad 30 used to provide CGND to node 52 . When the voltage of the DVC 2 pad 30 is at ground, regulation transistor 17 is turned on, and the latch circuit 18 may determine the status of the anti-fuse 12 . Should the voltage of DVC 2 pad 30 increase, either due to margin testing, an anti-fuse blowing mode, or another reason, that voltage will serve to further turn off the regulation transistor 17 , thereby further protecting the latch circuit 18 from that very voltage. In yet another embodiment seen in FIG. 7, FLTV may still be used to drive regulation transistor 17 (provided the logic generating that signal is configured to accommodate a p-channel transistor rather than an n-channel transistor), and a multiplexer 54 is used to switch between the two inputs.
Further, exemplary embodiments of the current invention may be used to accommodate systems using memory, wherein the memory may include nonvolatile, static, or dynamic memory, and wherein the memory may be a discrete device, embedded in a chip with logic, or combined with other components to form a system on a chip. Further, such configurations represent exemplary embodiments of the current invention themselves. For example, the embodiment in FIG. 8 illustrates a computer system 232 , wherein a microprocessor 234 transmits address, data, and control signals to a memory-containing device 236 such as one including but not limited to those described above. A system clock circuit 238 provides timing signals for the microprocessor 234 .
One skilled in the art can appreciate that, although specific embodiments of this invention have been described above for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. For example, while exemplary embodiments addressed above address directly connecting the CGND node 52 to a contact pad that 30 that will not receive a wire bond by the end of the die packaging process, the current invention includes within its scope exemplary embodiments that do not involve any wire bonding of the die. For instance, at least one exemplary embodiment concerns communicating with at most some of the die's bond pads using a ball grid array (BGA), wherein traces leading from the balls to the pads avoid at least one contact pad that may be used to provide a high CGND voltage for blowing an anti-fuse at probe. Moreover, DVC 2 is not the only pad that may be used to provide the CGND voltage. For instance, at the time of filing this application, Micron Technology is experimenting with a part that transfers data at a Double Data Rate (DDR—both on the rising and the falling edge of a clock pulse). This part uses a pad designated as “QFC” to provide high CGND voltage for blowing an anti-fuse. Alternatively, any pad designated as a “no connect” pad could be used. Moreover, the current invention is not limited in scope to methods and circuitry involving anti-fuses. Rather, fuses and other programmable elements are included within the scope as well. Moreover, the current invention includes embodiments involving any circuit device wherein a first voltage is used in a first mode of that device and a second voltage is used in a second mode of that device, and the first and second voltages are provided to the die at a shared terminal. Accordingly, the invention is not limited except as stated in the claims. | As part of anti-fuse circuitry for a memory device, a preferred exemplary embodiment of the current invention provides a direct connection between an anti-fuse and a contact pad used to provide voltage to that anti-fuse. The contact pad also serves as a voltage source for at least one other part of the memory device. At least one circuit coupled to the anti-fuse is temporarily isolated from it in the event that a voltage present at the pad would damage the circuit or cause the circuit to improperly read the status of the anti-fuse. The contact pad is available during a probe stage of the in-process memory device, but once the device is packaged, access to that contact pad is prevented. At the back end of the production process, the anti-fuse may be accessed through a second pad, whose electrical communication with the anti-fuse is regulated. | 6 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to the field of semiconductor diodes. It relates, in particular, to a freewheeling diode for converter circuit arrangements.
Discussion of Background
The article entitled "Comparison of High Voltage Power Rectifier Structures" by M. Mehrotra and B. J. Baliga, Proceedings of the ISPSD, pages 199-204, IEEE 1993 discusses various structures of high-voltage diodes. Diodes according to the PiN, P-iN, MPS, SSD, SPEED and SFD designs are compared. In particular, the reverse-current problems during the commutation of a current are investigated.
Such diodes comprise, between a cathode-side and an anode-side principal surface, an n-doped semiconductor substrate into which a heavily p-doped anode emitter is diffused from the anode-side principal surface and a heavily n-doped cathode emitter is diffused from the cathode-side principal surface. Anode and cathode are formed by the metal layers covering the corresponding principal surface.
In modern converters, the freewheeling diodes frequently cause faults, in particular at high rates of change of current and voltage during the commutation of a current. In the case of contemporary freewheeling diodes, this results in not only the semiconductor switch, but also the freewheeling diode having to be heavily protected with passive protective circuits. This is due to the stored charge of the diode which, during turn-off (commutation of the current), results in the known reverse-current peak. In the case of contemporary freewheeling diodes for GTOs, the current change must not exceed approximately 300 A/s.
In the case of future MOS-controlled semiconductor switches (for example, high-voltage IGBTs having blocking voltages of 2.5 kV to 4.5 V), which are faster than the GTOs, these problems become still more critical. The IGBT is a comparatively fast switch which is able to handle reliably even very high dI/dt values. However, this also increases the loading of the freewheeling diodes. In addition, it would be desirable for cost reasons if the freewheeling diode could also be operated without protective circuit (snubber). This has resulted, inter alia, in optimized diode designs (see, for example, the SPEED design in the abovementioned article), which are tailored to operation with fast IGBTs having blocking voltages up to 1600 V.
Minimization of the stored charge, for example by short carrier lifetimes, generally results in a reduction of the reverse-current peak. A fast voltage rise and consequently a short duration of the commutation process can be achieved by means of the flat plasma profiles which are made possible, for example, by the SPEED design. But even if all the possibilities of minimizing the stored charge and of limiting the reverse-current peak are utilized, the power loss in the case of such optimized diodes rises to such high values that avalanche breakdown of the diode becomes probable.
SUMMARY OF THE INVENTION
Accordingly, one object of the invention is to provide a novel diode with which high dI/dt values and high voltages can be handled without difficulty, in particular without the danger of an avalanche breakdown increasing.
This object is achieved in the case of a diode of the type mentioned at the outset by the features of the first claim.
The essence of the invention is therefore that there are provided on the anode-side principal surface electron injection means which are so designed that they make possible an injection of electrons during the commutation of a current.
The design according to the invention is based on the following physical facts and considerations:
Studies on diodes have shown that the maximum in the power loss is not at the highest current densities, but, on the contrary, in the region of low values. Since the reverse-current peak does not depend very greatly on the forward-current density, the stored charge is reduced more rapidly at low forward-current densities. This results in a faster voltage increase. The fact that the reverse-current peak and the power loss peak do not take place at the same point in time, but with a short delay, is remarkable. The power loss peak occurs in the region of positive values of dI/dt. After the reversal of the polarity of the diode voltage, the holes drain via the anode through the space-charge zone, while the electrons return to cathode via the n + -type emitter. Consequently, the dynamic field overshoot at the anode caused by the holes is responsible for the breakdown of the diode (this phenomenon is known by the term "dynamic avalanche"). The dynamic breakdown takes place at peak power losses of approximately 300 to 500 kW/cm 2 .
Consequently, a diode structure is desirable in which further electrons can be injected in a controlled manner from the anode side during the turn-off or commutation of the current. The negative charge of the electrons compensates for part of the positive charge of the holes. The dynamic field overshoot can consequently be substantially reduced so that essentially only the doping level governs the electric field level.
Preferably, this electron donor is controlled by means of a MOS control electrode (gate). A preferred structure which comprises controllable electron injection means on the anode-side principal surface has at that point, according to the invention, at least one n-channel MOS cell.
Said MOS cell can be integrated into the heavily p-doped anode emitter of the diode by designing the anode emitters as well-like regions, the semiconductor substrate penetrating to the anode-side principal surface between two adjacent anode emitter regions. The MOS cells are then formed by heavily n-doped short-circuit regions which are disposed at the two peripheries of the anode emitter regions. Disposed on top thereof is a control electrode which extends in each case from one short-circuit region of an anode emitter region to the short-circuit region of the adjacent anode emitter region via the semiconductor substrate which penetrates to the principal surface.
To reduce the field overshoot caused by the holes, the n-channel of the MOS cells is now opened, for example, a few fractions of a μs after the reverse-current peak. This can be achieved by applying a voltage of approximately 15 V which is positive with respect to the anode to the control electrode. Since the cathode of the diode is positive with respect to the anode under reverse conditions, the electrons drain in the direction of the cathode and consequently in opposition to the holes flowing towards the anode. The required neutralization of the positive hole charge is consequently achieved and a reduction in the electric field can be obtained.
A freewheeling diode in accordance with the invention is preferably used as freewheeling diode in converter circuit arrangements containing semiconductor switches. A freewheeling diode is disposed in antiparallel to the semiconductor switch and takes over a current flowing in the reverse direction of the semiconductor switch. A separate control unit which generates the required control voltage of approximately 15 V and applies it at the correct point in time to the control electrode can be provided for operating and driving the diode according to the invention. Obviously, the control unit for the diode may also be integrated into one which is in any case already present for the semiconductor switches.
A particularly inexpensive variant is one wherein, instead of a separate control unit for the diode, an inductance is connected in the anode current path. Said inductance, which is already provided in the ideal case by the inductance of the bonding wires, generates a voltage which is proportional to the rate of current change dI/dt. The polarity of said voltage with respect to the anode is such that the control electrode of the diode according to the invention is negatively polarized in the region of decreasing diode current, i.e. up to the point in time where the reverse-current peak is reached. After the reverse-current peak has been traversed, the polarity of the induced voltage changes, with the result that a positive voltage is applied to the control electrode. Said positive voltage is established approximately at the point in time of the maximum power loss. Consequently, said voltage results in the desired injection of electrons which counteract the field overshoot due to holes (dynamic avalanche).
Further exemplary embodiments emerge from the corresponding dependent claims.
All in all, the diode according to the invention makes it possible to handle high dI/dt values and voltages without there being the danger of an avalanche breakdown.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein
FIG. 1 shows a portion of a diode according to the invention in section;
FIG. 2 shows a circuit arrangement in which the diode in accordance with the invention can be used;
FIG. 3 shows a further circuit arrangement for which the diode according to the invention is suitable.
The reference symbols used in the drawings and their meaning are listed in the list of designations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 1 shows a portion of a diode in accordance with the invention in section. Such a diode 1 comprises, between a first principal surface 2 and a second principal surface 3, an n-doped semiconductor substrate 4. In the figure, n-doped regions are shaded from the top left to the bottom right, p-doped regions are shaded with double lines and metallizations are shaded with lines extending from the top right to the bottom left. In the semiconductor regions, the density of the shading corresponds approximately to the doping concentration.
An n + -doped cathode emitter 8 is diffused into the semiconductor substrate 4 from the first principal surface 2 and a p + -doped anode emitter 9 is diffused into the substrate 4 from the principal surface 3. The corresponding electrodes, cathode 7 and anode 6 are formed by metal layers 5 covering the associated emitters 8 and 9, respectively.
According to the invention, the anode emitter 9 comprises at least one well-like region which is contacted by the metallization 5 of the anode electrode 6. The semiconductor substrate 4 penetrates to the second principal surface 3 between two adjacent anode emitter regions 9. Essential to the invention are the n + -doped short-circuit regions 10 which are disposed on both sides of the well-like anode emitter regions 9. The short-circuit regions 10 and the semiconductor substrate 4 which penetrates to the second principal surface 3 between two adjacent anode emitter regions 9 are spanned by a control electrode 11 which is disposed in an insulated manner. The insulation 15 (dotted region in FIG. 1) may be composed, for example, of SiO 2 and the control electrode, for example, of polysilicon. That part of the anode emitter 9 which extends from the periphery to the short-circuit regions and is spanned by the control electrode 11 is denoted below as channel region. If a voltage which is positive with respect to the anode is now applied to the control electrode, an n-channel forms in the channel regions. Electrons are thereby injected. The structure according to the invention of the anode emitter therefore functions like an MOS-controlled electron injection source.
The p + -doped anode emitter 9 of the diode 1 in accordance with the invention has, in contrast to the SPEED design mentioned at the outset, a very high injection efficiency. With a carrier lifetime of only 4 μs for electrons and 1 ks for holes, a forward voltage of only 2 V results for a current density of 100 A/cm 2 .
The diode 1 according to the invention is advantageously used as freewheeling diode in a converter circuit arrangement containing at least one semiconductor switch 12. FIGS. 2 and 3 show such circuit arrangements. The semiconductor switch 12 forms, for example, a part of a polyphase converter. As depicted, it may be an IGBT, but other types of semiconductor switches are also possible.
A functionally separate drive unit 14 may be provided to drive the diode 1 in accordance with the invention (FIG. 2). At the same time, it is immaterial whether said drive unit is physically integrated into a possibly already present drive unit 14 of a semiconductor switch 12. If the semiconductor switch is, for example, an IGBT module, an integration is expedient since, under some circumstances, the diode is already integrated in the IGBT module. The control function of the diode could be combined, for example in an expanded ASIC, with the control function of the IGBT.
Regardless of where the drive unit-for the diode is provided, its function must in any case be such that a voltage which is positive with respect to the anode potential (approximately 15 V) is applied to the control electrode of the diode a short time after the reverse-current peak. As a result, a conducting n-channel which provides the desired injection of electrons during the commutation of a current is formed in the channel regions.
The time for applying the positive voltage depends on the reverse-current peak. The full voltage is generally already present 50 ns to 100 ns after the reverse-current peak has been traversed. The voltage should be applied at this point in time at the latest.
A more inexpensive variant and one which is simpler in relation to the circuit complexity consists in only an inductance 13 being connected in the anode path instead of a separate drive unit 14 for the diode 1 (FIG. 3). A voltage proportional to the current change dI/dt is induced across said inductance 13. If the diode 1 is integrated into a module housing, the bonding wires which connect the diode electrodes to the leads of the module present precisely the necessary inductance. In this case, a separate inductance may even be dispensed with. The polarity of the induced voltage is such that the control electrode is negatively polarized in the region of decreasing diode current, i.e. up to the point in time where the reverse-current peak is reached. As soon as the current direction changes after the reverse-current peak has been traversed, the polarity of the induced voltage changes and a positive voltage is applied to the control electrode of the diode. Because of the normal finite rate of voltage increase, this takes place, in particular, approximately at the point in time of the power loss maximum. The desired electron injection is consequently triggered automatically at the optimum point in time.
FIG. 1 shows only a portion of a diode 1 in accordance with the invention. A plurality of the cells shown are, however, necessary for a serviceable diode. Since high hole-current densities have to be collected by the p + -type anode emitter 9 during commutation, there is the danger of triggering the parasitic n-p-n structure formed by the semiconductor substrate 4, the anode emitter 9 and the short-circuit regions 10, as in the case of a power MOSFET. For this reason, the chosen cell spacing, i.e. the spacing of two well-like anode emitter regions 9, must be markedly less than in the IGBT. Very small cell spacings are, however, also to be avoided since the electron emission is made more difficult and even completely prevented as a consequence of the JFET effect. In connection with a tested diode, a cell spacing of approximately 50 m has proved optimum.
Since the diode in accordance with the invention is to be suitable, in particular, for high voltages (from approximately 1200 V upwards), a typical thickness of >100 μm results for the semiconductor substrate 4 with a doping of approximately 1-2·10 14 cm -3 . The cathode emitter 8 then has a typical doping of >10 17 cm -3 . The insulating layer 15 on the anode side has an oxide thickness of approximately 100 μm. Typical values for the well-like anode emitter regions 9 are: peripheral concentration approximately 10 19 cm -3 , depth approximately 5 μm. The short-circuit regions 10 are preferably doped with 10 19 cm -3 . The window opening for the metallization 5 in the region of the anode emitter 9 is typically 10-20 μm.
A diode in accordance with the invention therefore has a structure with which high voltages and dI/dt values can be handled safely.
Obviously, numerous 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 herein. | A diode (1) is specified which has electron injection means on the anode-side principal surface (3). After the reverse-current peak has been traversed, said means inject electrons into the anode emitter. This compensates for holes and the danger of a dynamic field overshoot, which may result in an avalanche breakdown, is reduced. The electron injection means preferably comprise an n-channel MOS cell. High voltages and high dI/dt values can be safely handled with a diode according to the invention. A diode in accordance with the invention is preferably used as freewheeling diode in a converter circuit arrangement. | 7 |
RELATED APPLICATIONS
The present application is a divisional of U.S. application Ser. No. 12/683,842, filed on Jan. 7, 2010, which was based on, and claims priority from, Taiwan Patent Application Serial Number 98108983, filed Mar. 19, 2009, the disclosure of which is hereby incorporated by reference herein in its entirely.
BACKGROUND
1. Field of Invention
The present invention relates to a display apparatus. More particularly, the present invention relates to a liquid crystal display (LCD).
2. Description of Related Art
With respect to a LCD, a pixel aperture ratio directly affects the utilization rate of a backlight source, and also affects the display brightness of the LCD. One of the major factors affecting the pixel aperture ratio is the area of a contact hole disposed on a thin film transistor (TFT) array substrate. Generally speaking, if the area of the contact hole is smaller, the area of a pixel region will be larger, and also the pixel aspect ratio will be larger.
However, due to the limitation of the current etching technique, if the area of the contact hole is too small, the contact hole in general cannot pass through an insulation layer smoothly. Particularly, with respect to a COA (Color Filter On Array) structure or an UHA (Ultra High Aperture) structure, since it is very difficult for the current etching technique to fabricate a contact hole having a high aspect ratio on a color resist, the contact hole has to be designed to have a sufficiently large area so as to ensure a certain yield level. However, this design will definitely affect the pixel aperture ratio. Hence, a designer is usually trapped in this dilemma and cannot have a breakthrough.
SUMMARY
An aspect of the present invention is to provide a TFT array substrate in which a stack structure is used to raise an extended electrode of a drain electrode of a TFT, and thus a contact hole does not need to be very deep for exposing the extended electrode of the drain electrode to contact a pixel electrode.
According to an embodiment of the present invention, a TFT array substrate includes a substrate, a first patterned conductive layer, a first insulation layer, a semiconductor layer, a second patterned conductive layer, a second insulation layer, a contact hole, and a pixel electrode. The first patterned conductive layer is disposed on the substrate, and includes a scan line, a gate electrode, and a float electrode, wherein the gate electrode is electrically connected to the scan line. The first insulation layer is disposed on the first patterned conductive layer. The semiconductor layer is disposed on the first insulation layer, and includes a channel area. The second patterned conductive layer is disposed on the first insulation layer, and includes a source electrode, a drain electrode, a data line crossing the scan line, and an extended electrode of the drain electrode. The gate electrode, the source electrode, the drain electrode, and the channel area constructs a TFT, wherein the source electrode is electrically connected to the data line, and the extended electrode of the drain electrode is partially overlapped with the float electrode. The second insulation layer is disposed on the second patterned conductive layer. The contact hole passes through the second insulation layer and exposes a portion of the extended electrode of the drain electrode. The pixel electrode is electrically connected to the extended electrode of the drain electrode through the contact hole.
According to another embodiment of the present invention, a TFT array substrate includes a substrate, a first patterned conductive layer, a first insulation layer, a semiconductor layer, a second patterned conductive layer, a second insulation layer, a contact hole, and a pixel electrode. The first patterned conductive layer is disposed on the substrate, and includes a scan line and a gate electrode, wherein the gate electrode is electrically connected to the scan line. The first insulation layer is disposed on the first patterned conductive layer. The semiconductor layer is disposed on the first insulation layer, and includes a channel area and a first semiconductor area. The second patterned conductive layer is disposed on the first insulation layer, and includes a source electrode, a drain electrode, a data line crossing the scan line, and an extended electrode of the drain electrode. The gate electrode, the source electrode, the drain electrode, and the channel area constructs a TFT, wherein the source electrode is electrically connected to the data line, and the extended electrode of the drain electrode is partially overlapped with the first semiconductor area. The second insulation layer is disposed on the second patterned conductive layer. The contact hole passes through the second insulation layer and exposes a portion of the extended electrode of the drain electrode. The pixel electrode is electrically connected to the extended electrode of the drain electrode through the contact hole.
It is to be understood that both the foregoing general description and the following detailed description are examples, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
FIG. 1 is a schematic top view showing a TFT array substrate according to an embodiment of the present invention;
FIG. 2 is a schematic cross-sectional diagram viewed along line 2 - 2 in FIG. 1 ;
FIG. 3 is a schematic cross-sectional diagram showing a TFT array substrate according to another embodiment of the present invention, wherein the cutting position thereof is similar to that of FIG. 2 ;
FIG. 4 is a schematic cross-sectional diagram showing a TFT array substrate according to another embodiment of the present invention, wherein the cutting position thereof is similar to that of FIG. 2 ;
FIG. 5 is a schematic cross-sectional diagram showing a TFT array substrate according to another embodiment of the present invention, wherein the cutting position thereof is similar to that of FIG. 2 ;
FIG. 6 is a schematic cross-sectional diagram showing a TFT array substrate according to another embodiment of the present invention, wherein the cutting position thereof is similar to that of FIG. 2 ;
FIG. 7 is a schematic top view showing a TFT array substrate according to another embodiment of the present invention;
FIG. 8 is a schematic top view showing a TFT array substrate according to another embodiment of the present invention; and
FIG. 9 is a schematic top view showing a TFT array substrate according to another embodiment of the present invention;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
FIG. 1 is a schematic top view showing a TFT array substrate according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional diagram viewed along line 2 - 2 in FIG. 1 . As shown in FIG. 1 and FIG. 2 , the TFT array substrate includes a substrate 110 , a first patterned conductive layer 120 , a first insulation layer 130 , a semiconductor layer 140 , a second patterned conductive layer 150 , a second insulation layer 160 , a contact hole 170 , and a pixel electrode 180 .
The first patterned conductive layer 120 is disposed on the substrate 110 , and includes a scan line 122 (as shown in FIG. 1 ), a gate electrode 124 , and a float electrode 126 , wherein the gate electrode 124 is electrically connected to the scan line 122 (as shown in FIG. 1 ). The material forming the substrate 110 can be such as glass or plastic. The material forming the first patterned conductive layer 120 can be metal such as aluminum, copper, silver, gold, or any combination thereof, or alloy thereof.
The first insulation layer 130 is disposed on the first patterned conductive layer 120 . Concretely speaking, the first insulation layer 130 can at least cover the gate electrode 124 as a gate dielectric layer of a TFT 200 . The material forming the first insulation layer 130 can be one of various dielectric materials such as silicon dioxide, silicon nitride, and silicon oxynitride, or any combination thereof.
The semiconductor layer 140 is disposed on the first insulation layer 130 , and includes a channel area 142 . Concretely speaking, the channel 142 can be disposed above the gate electrode 124 , and opposite to the gate electrode 124 with the first insulation layer 130 sandwiched therebetween.
The second patterned conductive layer 150 is disposed on the first insulation layer 130 , and includes a source electrode 152 , a drain electrode 154 , a data line 156 crossing the scan line 122 (as shown in FIG. 1 ), and an extended electrode 158 of the drain electrode 154 . The gate electrode 124 , the source electrode 152 , the drain electrode 154 , and the channel area 142 constructs the TFT 200 , wherein the source electrode 152 is electrically connected to the data line 156 (as shown in FIG. 1 ), and the extended electrode 158 of the drain electrode 154 is partially overlapped with the float electrode 126 . Detailedly speaking, at least one portion of the extended electrode 158 of the drain electrode 154 is stacked above the float electrode 126 , i.e. a portion of the extended electrode 158 of the drain electrode 154 overlaps the float electrode 126 with the first insulation 130 sandwiched between the extended electrode 158 and the float electrode 126 , so that when viewed from the top, the extended electrode 158 of the drain electrode 154 is at least partially overlapped with the float electrode 126 . The material forming the second patterned conductive layer 150 can be metal such as aluminum, copper, silver, gold, or any combination thereof, or alloy thereof.
The second insulation layer 160 is disposed on the second patterned conductive layer 150 , and can be formed from an organic or inorganic material. Further, when the TFT array substrate has a COA or UHA structure, a third insulation layer (not shown) also can be optionally formed on the second insulation layer 160 , and can be formed from an organic material layer 205 such as a color resist or a color filter layer; or formed from an inorganic material. The second insulation layer 160 and the third insulation layer (not shown) can be used to planarize the TFT array substrate, and in another embodiment, also can provide the required filtering function, wherein the second insulation 160 and the third insulation layer (not shown) can be formed from the same material, such as a color filter layer.
In order to electrically contact the extended electrode 158 of the drain electrode 154 , the contact hole 170 is generally formed on the second insulation layer 160 and the organic material layer 205 , and passes through the second insulation layer 160 and the organic material layer 205 to expose a portion of the extended electrode 158 of the drain electrode 154 , so that the pixel electrode 180 can be electrically connected to the extended electrode 158 of the drain electrode 154 through the contact hole 170 . For example, the pixel electrode 180 is formed on the portion of the organic material layer 205 and is electrically connected to the extended electrode 158 of the drain electrode 154 through the contact hole 170 .
In this embodiment, since the extended electrode 158 of the drain electrode 154 has the float electrode 126 formed thereunder, and thus the extended electrode 158 can be effectively raised. That is, the contact hole 170 does not need to be very deep to expose the extended electrode 158 of the drain electrode 154 . Consequently, even though the current etching technique fails to fabricate the contact hole 170 having a high aspect ratio on the color resist, yet since the contract hole 170 does not require a deep depth, the area of the contact hole 170 still can be relatively small, thereby promoting the pixel aperture ratio.
In detail, the float electrode 126 is an electrode which is not electrically connected to any elements. Since the float electrode 126 is not electrically connected to any elements (directly or indirectly), the potential of the float electrode 126 is generally equal or close to the ground potential. Also, since the potential of the float electrode 126 is equal or close to the ground potential, no noticeable capacitance effect between the float electrode 126 and there will be the extended electrode 158 of the drain electrode 154 and the operation of the TFT array substrate will not be affected.
Further, the aforementioned semiconductor layer 140 can further include a first semiconductor area 144 disposed between the first insulation layer 130 and the extended electrode 158 of the drain electrode 154 , i.e. the extended electrode 158 of the drain electrode 154 can be partially overlapped with the first semiconductor area 144 . In other words, at least one portion of the extended electrode 158 of the drain electrode 154 is stacked on the first semiconductor area 144 . Detailedly speaking, a portion of the extended electrode 158 of the drain electrode 154 overlaps the float electrode 126 with the first insulation 130 and the first semiconductor area 144 sandwiched between the extended electrode 158 and the float electrode 126 , so that when viewed from the top, the extended electrode 158 of the drain electrode 154 at least partially cover the first semiconductor area 144 and the float electrode 126 , thereby further raising the extended electrode 158 of the drain electrode 154 .
Concretely speaking, in this embodiment, a height HT between a surface of the substrate 110 and a top surface of the extended electrode 158 exposed through the contact hole 170 is ranged between about 3700 Å and about 14000 Å, a height HP between the surface of the substrate 110 and a bottom surface of the extended electrode 158 contacting the first semiconductor area 144 is ranged between about 1500 Å and about 10000 Å. It should be understood that the aforementioned size is merely stated as an example for explanation, and is not used to limit the embodiments of the present invention. One of ordinary skill in the art may flexibly adjust the height of the extended electrode 158 of the drain electrode 154 in accordance with actual needs.
FIG. 3 is a schematic cross-sectional diagram showing a TFT array substrate according to another embodiment of the present invention, wherein the cutting position thereof is similar to that of FIG. 2 . The difference between this embodiment and the previous embodiment is that: in the previous embodiment, the channel 142 is separated from the first semiconductor area 144 ; but in this embodiment, the channel 142 and the first semiconductor area 144 are connected to each other. One of ordinary skill in the art may flexibly choose the method for implementing the channel 142 and the first semiconductor area 144 in accordance with actual needs.
Also, in the embodiment shown in FIG. 3 , an edge of the extended electrode 158 of the drain electrode 154 is substantially aligned with an edge of the float electrode 126 . However, the present invention is not limited thereto. One of ordinary skill in the art may flexibly choose the relative position between the float electrode 126 and the extended electrode 158 of the drain electrode 154 in accordance with actual needs.
For example, in another embodiment, a projection position of an edge of the extended electrode 158 located away from the drain electrode 154 protrudes a distance R from an edge of the float electrode 126 located away from the gate electrode 124 , wherein the distance R is ranged between about 0 μm and about 10 μm, as shown in FIG. 4 . Alternatively, a projection position of an edge of the extended electrode 158 located away from the drain electrode 154 shrinks a distance P from an edge of the float electrode 126 located away from the gate electrode 124 , and the distance P is ranged between about 0 μm and about 10 μm, as shown in FIG. 5 .
Besides using the float electrode 126 to raise the extended electrode 158 of the drain electrode 154 , one of ordinary skill in the art may optionally omit the float electrode 126 , and merely use the first semiconductor area 144 to raise the extended electrode 158 of the drain electrode 154 . In the below, FIG. 6 is used as an example to concretely explaining the aforementioned technical contents.
FIG. 6 is a schematic cross-sectional diagram showing a TFT array substrate according to another embodiment of the present invention, wherein the cutting position thereof is similar to that of FIG. 2 . The difference between this embodiment and the previous embodiments is that: this embodiment does not dispose the float electrode on the substrate, but merely disposes the first semiconductor area 144 between the first insulation layer 130 and the extended electrode 158 of the drain electrode 154 . Detailedly speaking, a height HT between a surface of the substrate 110 and a top surface of the extended electrode 158 exposed through the contact hole 170 is ranged between about 3200 Å and about 13500 Å, and a height HP between a surface of the substrate 110 and a bottom surface of the extended electrode 158 contacting the first semiconductor area 144 is ranged between about 1000 Å and about 9500 Å.
In other words, one of ordinary skill in the art should flexibly choose the structure stacked under the extended electrode 158 of the drain electrode 154 in accordance with actual needs, and it is not necessary to choose the float electrode 126 . Concretely speaking, one of ordinary skill in the art may choose only using the float electrode 126 ; only using the first semiconductor area 144 ; or simultaneously using both of the float electrode 126 and the first semiconductor area 144 to raise the extended electrode 158 of the drain electrode 154 .
Further, although the shape of the float 126 depicted in FIG. 1 substantially is a square, yet the embodiments of the present invention are not limited thereto. The shape of the float electrode 126 also can be a polygon as shown in FIG. 7 ; an ellipse as shown in FIG. 8 ; or a circle. One of ordinary skill in the art may flexibly choose the appropriate shape in accordance with actual needs.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. For example, one of ordinary skill in the art also can integrate a common electrode 210 into the TFT array substrate as shown in FIG. 9 without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents. | A thin film transistor (TFT) array substrate includes a stack structure disposed to raise an extended electrode of a drain electrode of a thin film transistor. Therefore, a contact hole does need to be very deep to expose the extended electrode of the drain electrode. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
(Not Applicable)
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
(Not Applicable)
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates generally to e-commerce systems, and more particularly to monitoring online transaction processing and validation systems.
2. Description of the Related Art
E-commerce systems typically include one or more back-end systems for facilitating the completion of an online transaction. Such back-end systems can include systems for performing credit card clearance, or systems for performing order fulfillment. Examples of order fulfillment systems can include shipping and handling coordination systems, external inventory management systems, tariff determination systems, and the like. Because such back-end transaction processing can be complex, many e-commerce systems rely upon one or more third-party service providers to perform certain back-end transaction processing tasks. In particular, portions of an e-commerce system which are controlled locally can be communicatively linked to those external back-end systems which are controlled by third party providers.
By way of example, many e-commerce systems presently are available which can process retail sales transactions. Typically, these online retail systems can include an interface through which a range of inventory items available for retail sale can be presented to online shoppers. In addition, these online retail systems can include local logic for grouping inventory items selected for purchase by an online shopper, for instance an electronic shopping basket. Finally, these online retail systems can include local logic for performing a “check-out” operation so that when an online shopper chooses to “check-out” of the store, credit card information and shipping information can be collected and accounting can be performed as would be the case when an in-store shopper “checks-out” of a brick-and-mortar retail establishment.
In a typical online retail system, when a shopper selects a check-out operation, product and payment information collected by the online retail system can be forwarded to both a third-party, back-end credit card validation system, and where appropriate, a third-party, back-end shipping system, respectively. Using the forwarded information, these third party systems can perform back-end transaction processing, such as credit card clearing and shipping and handling processing, which would otherwise have to be handled by the online retail establishment. In this way, burdensome back-end processing tasks can be out-sourced to third parties while online retail stores can focus on the marketing and sales aspects of their respective e-commerce systems.
As will be apparent to one skilled in the art, the success of an e-commerce system, particularly an e-commerce system having an online sales aspect, can be dependent on the availability and response time of third-party systems relied upon to provide back-end validation and transaction processing. Specifically, without the availability and rapid response of a third party credit card validation system, e-commerce systems can be unable to process purchase requests. Similarly, without the availability and rapid response of a third party shipping system, e-commerce systems can be unable to coordinate the shipment of requested goods. In the best case scenario, customers are forced to wait for the back-end transaction processing to complete. In the worst case scenario, the transaction cannot be completed due to the complete unavailability of the third-party back-end system. In either case, sales can be lost for circumstances beyond the control of the operator of the e-commerce system.
Importantly, since these third-party validation and transaction processing systems are external to the e-commerce system, it is not possible for the e-commerce system to directly diagnose third-party back-end system failures. Furthermore, it is not possible for the e-commerce system to correct third-party back-end system failures. Rather, the state of health of these third-party back-end systems often cannot be determined by local e-commerce systems. Still, although the operator of an e-commerce system can neither diagnose nor remediate a failure in a third-party back-end system upon which the e-commerce system relies, the mere detection of a fault in a third-party back-end system can be helpful in as much as the e-commerce system can take measures to circumvent the problem. For example, if an e-commerce system detects a failure in one third-party credit card validation system, the e-commerce system can either notify potential customers of anticipated delays, or the e-commerce system can request transaction processing from an alternative third-party source.
SUMMARY OF THE INVENTION
The present invention can include both a monitoring tool for detecting an unreliable response condition in a back-end transaction processing system associated with an e-commerce system, as well as a method for detecting an unreliable response condition in a back-end transaction processing system associated with an e-commerce system. In a first aspect of the invention, the monitoring tool can detect unreliable response conditions not only in the back-end processing system, but also in each network component which communicatively links the back-end processing system to the e-commerce system. Hence, in the first aspect of the invention, the monitoring tool can include a placebo transaction dispatcher for dispatching placebo transactions to a subscribing e-commerce system and not to associated back-end processing systems.
The monitoring tool also can include a response collector for collecting responses to dispatched placebo transactions; a logger for computing transaction latency data based upon when a placebo transaction is dispatched to the subscribing e-commerce system, and when a response is received in the collector; and, an alerter for alerting the subscribing e-commerce system when computed transaction latency data indicates an unreliable response condition in an associated back-end transaction processing system. The monitoring tool can also include a user interface through which a user can monitor the transaction latency data. Notably, the monitoring tool further can include a list of references to a plurality of subscribing e-commerce systems. In that case, the dispatcher can dispatch placebo transactions to each e-commerce system in the list. Conversely, the collector can collect responses to the dispatched placebo transactions.
The logger can compute transaction latency data based upon when each placebo transaction is dispatched to a subscribing e-commerce system, and when a corresponding response is received in the collector. Finally, the alerter can alert individual subscribing e-commerce systems when computed transaction latency data for the individual subscribing e-commerce systems indicates an unreliable response condition in an associated back-end transaction processing system.
Notably, though the monitoring tool can dispatch placebo transactions to the e-commerce system which can forward a transaction to the associated back-end processing system, in a second aspect of the invention, the monitoring tool can dispatch placebo transactions directly to the back-end transaction procession system. In this case, only the reliability of the back-end transaction processing system is determined and not intermediate components which communicatively link the back-end transaction processing system to the e-commerce system. Hence, in the second aspect of the present invention, the monitoring tool can include a placebo transaction dispatcher for dispatching placebo transactions to a back-end transaction processing system associated with a subscribing e-commerce system.
A method for detecting an unreliable response condition in a back-end transaction processing system associated with an e-commerce system can include the steps of: generating a placebo transaction; dispatching the placebo transaction to the e-commerce system; and determining if a response to the placebo transaction is received. If no response to the placebo transaction is received prior to detecting a time-out condition, the e-commerce system can be notified that an unreliable response condition exists in the back-end transaction processing system. Similarly, if a response to the placebo transaction is received after period of time has elapsed from the dispatching of the placebo transaction which exceeds a latency threshold, the e-commerce system can be notified that an unreliable response condition exists in the back-end transaction processing system.
A method for detecting an unreliable response condition in a back-end transaction processing system associated with an e-commerce system alternatively can include the steps of: generating a placebo transaction; dispatching the placebo transaction to the back-end transaction processing system; and, determining if a response to the placebo transaction is received. If no response to the placebo transaction is received prior to detecting a time-out condition, the e-commerce system can be notified that an unreliable response condition exists in the back-end transaction processing system. Additionally, if a response to the placebo transaction is received after period of time has elapsed from the dispatching of the placebo transaction which exceeds a latency threshold, the e-commerce system can be notified that an unreliable response condition exists in the back-end transaction processing system.
A method for detecting unreliable response conditions in a plurality of back-end transaction processing systems also can include the steps of: reading a list of references to a plurality of subscribing e-commerce systems; generating and dispatching placebo transactions to each e-commerce system in the list; receiving responses to the dispatched placebo transactions; computing transaction latency data based upon when each placebo transaction is dispatched to a subscribing e-commerce system, and when a corresponding response is received; and, notifying individual subscribing e-commerce systems when computed transaction latency data for the individual subscribing e-commerce systems indicates an unreliable response condition in an associated back-end transaction processing system.
BRIEF DESCRIPTION OF THE DRAWINGS
There are shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein:
FIG. 1 is a schematic illustration of an e-commerce system communicatively linked to user nodes, a back-end transaction processing system and a monitoring tool which has been configured in accordance with the inventive arrangements.
FIG. 2 is a block diagram illustrating one preferred configuration of the monitoring tool of FIG. 1 .
FIG. 3 is a block diagram illustrating a second preferred configuration of the monitoring tool of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a monitoring tool that provides a method for empirically validating the on-going availability of one or more back-end systems for verifying and clearing online transactions. Online transactions can include, but are not limited to credit card clearing, shipping and handling, tariff computing, and the like. In operation, the monitoring tool of the present invention can generate placebo transactions which can be submitted to corresponding back-end systems either directly, or via a subscribing e-commerce system. Concurrently, the monitoring tool can collect responses to the placebo transactions from the corresponding back-end systems either directly, or via the subscribing e-commerce system as the case may be. Transaction latency metrics can be computed for each monitored back-end system based on the time when a placebo transaction is submitted and when a corresponding response is received. If the latency metrics for a particular monitored back-end system exceed a specified threshold, the subscribing e-commerce system can be alerted and pro-active measures can be undertaken.
FIG. 1 is a schematic illustration of an e-commerce system 102 communicatively linked to user nodes 106 , a back-end transaction processing system 108 and a monitoring tool 200 which has been configured in accordance with the inventive arrangements. Each of the e-commerce system 102 , user nodes 106 , back-end transaction processing system 108 and monitoring tool 200 can be communicatively linked via a computer communications network 104 , for instance the Internet. The e-commerce system 102 can be any online transactional system, for example online retail systems, online pay-for-service systems, reservation systems, and the like.
Each user node 106 can be any suitable computing having a user interface through which corresponding users can interact with the e-commerce system 102 . Notably, while each of the e-commerce system 102 , user nodes 106 , back-end transaction processing system 108 and monitoring tool 200 can communicate with one another via the public interface to the Internet, the invention is not so limited. Rather, any of the e-commerce system 102 , user nodes 106 , back-end transaction processing system 108 and monitoring tool 200 can communicate privately through a separate network such as a LAN or WAN, or tthe monitoring tool 200 can communicate privately through a public network such as the Internet using such technologies as virtual private networking (VPN).
Importantly, the e-commerce system can rely upon one or more third-party back-end transaction processing systems 108 , for example credit card clearing systems, external inventory management systems, external customer service systems, shipping and handling systems, and other such back-end processing systems. In paticular, in order to complete an online transaction between a user node 106 and the e-commerce system 102 , transactional processing must also complete in the back-end transaction processing system. For example, to consummate the online purchase of a book from an online book retailer, the purchaser's credit card must be validated by a third-party credit card validation system.
As one skilled in the art will recognize, if the back-end transaction processing system 108 becomes unavailable, or if the response time of the back-end transaction processing system 108 becomes too great, a user interacting with the e-commerce system 102 via a user node 106 may become impatient and may abandon the transaction without having fully completed the transaction. Accordingly, the monitoring tool 200 of the present invention can monitor the status of the one or more back-end transaction processing systems 108 in order to detect when the back-end transaction processing system 108 becomes unavailable, or if the response time of the back-end transaction processing system 108 becomes too great.
To effectively monitor the back-end transaction processing system 108 , the monitoring tool 200 periodically can formulate and submit placebo transactions to selected back-end transaction processing systems 108 , optionally via the e-commerce system 102 . Each time the monitoring tool 200 submits a placebo transaction to a back-end transaction processing system, the submission time can be recorded. Subsequently, as the monitoring tool 200 receives responses back from the selected back-end transaction processing systems 108 , the time of receipt can be recorded and a latency metric can be determined. From the latency metric, the monitoring tool 200 can determine whether the response time of a selected back-end processing system exceeds and acceptable threshold. Of course, where no response is received which corresponds to a placebo transaction submitted to a particular back-end transaction processing system, the monitoring tool 200 can conclude that the particular back-end transaction processing system has become inaccessible.
Once an unacceptable response time or unavailability determination has been made, the monitoring tool can alert subscribing e-commerce systems 102 of the inaccessibility of the monitored back-end data processing system 108 . While the subscribing e-commerce systems 102 may not be able to remediate the fault in the back-end data processing system, the subscribing e-commerce system 102 at least can notify the various user via user nodes 106 of the temporary inability of the e-commerce system 102 to accept online transactions. Alternatively, the e-commerce system 102 can fail-over to an alternate back-end processing system, be it a local or outsourced system.
FIG. 2 is a block diagram illustrating one configuration of the monitoring tool 200 of FIG. 1 . In the present configuration, the monitoring tool 200 can include a dispatcher 210 and a collector 212 . The dispatcher 210 can be used to submit placebo transactions to third-party back-end transaction processing systema 108 utilized by subscribing e-commerce systems 102 . Conversely, the collector 212 can be used to receive responses to submitted placebo transactions from corresponding third-party back-end transaction processing systems 108 . Notably, the dispatcher 210 can identify subscribing e-commerce systems 102 from a subscription list 220 , for example a list of URLs for associated e-commerce systems. In this way, placebo transactions can be periodically submitted to each e-commerce system 102 associated with a URL included in the list 220 .
As illustrated in FIG. 2 , in the present configuration, placebo transactions can be submitted to the third-party back-end system 108 via the e-commerce system 102 . Specifically, the dispatcher 210 can spoof the e-commerce system 102 into believing that an actual online transaction has occurred which requires the e-commerce system 102 to request back-end transaction processing from the third-party back-end system 108 . In this way, all data metrics which are collected in association with the monitoring of the back-end processing system 108 can appear as it would from the perspective of a user of the e-commerce system 102 .
Notwithstanding, the invention is not limited in regard to the network entity which initially receives the placebo submission. In fact, in one aspect of the invention, illustrated in FIG. 3 , the dispatcher 310 can bypass the e-commerce system 102 and can submit placebo transactions directly to the back-end system 108 from which the collector 312 can receive responses. In any case, the invention is only limited in as much as ultimately, the third-party back-end server must receive a request for back-end transaction processing based upon a placebo transaction. Thus, if the placebo transaction is first directed towards the e-commerce system 102 , then the e-commerce system 102 can forward a request for back-end transaction processing through the ISP 204 of the e-commerce site 102 , onto the Internet 206 , through the ISP 208 of the third-party back-end system, and finally to the third-party back-end system 108 .
Returning now to FIG. 2 , each time the dispatcher 210 submits a placebo transaction, associated data can be recorded in both a persistent log 222 and a status array 224 via the logger 214 . Concurrently, while the dispatcher 210 transmits placebo transactions to the e-commerce system 102 , the collector 212 can receive responses to submitted placebo transactions. As in the case of the dispatcher 210 , each time the collector 212 receives a response to a placebo transaction, associated data can be recorded in a persistent log 222 and in a status array 224 . More particularly, in response to a submission, the URL of the subscribing e-commerce system 102 can be recorded in addition to the targeted back-end processing system and the time of submission. Similarly, upon receiving a response, the collector 212 can request that the logger 214 record the time the response had been received.
Notably, the status array 224 is a two-dimensional array indexed by the URL and the sample size for each subscribing e-commerce system 102 . Each element in the status array 224 can include an indication that a placebo transaction has been submitted and whether a response has been received. Each element in the status array 224 also can include the latency between the submission and response time. Metrics can be recorded in the status array 224 for each subscribing e-commerce system 102 . When the number of entries for a subscribing e-commerce system 102 exceeds a pre-specified sample size, older entries can be discarded in favor of newer entries. Based on the data in the status array 224 , an average response time can be computed for each subscribing e-commerce system 102 . Additionally, non-responsive back-end transaction processing systems can be identified from the status array 224 .
The user interface 216 can continuously monitor the data written to the status array 224 . In addition to providing a graphical summary of the computed latencies, the user interface 216 can detect latency measurements which fall below a pre-determined threshold. Similarly, when a response has not been received within a pre-specified timeout value, the user interface 216 can conclude that the back-end data processing system 108 is not accessible. In either case, the user interface 216 can notify an alerter 218 which can provide pro-active feedback users. Examples of pro-active feedback can range from a textual or audible alarm provided to a network node or personal device such as a cellular phone or pager, to pre-programmed failover operations.
Importantly, by continuously monitoring third-party back-end transactional processing systems, the monitoring tool of the present invention can detect non-responsive conditions. In consequence, subscribing e-commerce systems can be alerted so that pro-active measures can be undertaken. For example, where the monitoring tool detects longer than acceptable response times in a third-party credit card validation system, subscribing e-commerce systems either can inform online customers that delays can be expected. Alternatively, subscribing e-commerce systems can request credit card clearance from an alternative source of credit card validation.
Notably, the present invention can be realized in hardware, software, or a combination of hardware and software. The method of the present invention performed by the monitoring tool can 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 could 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 can also 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 means or 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.
While the foregoing specification illustrates and describes the preferred embodiments of this invention, it is to be understood that the invention is not limited to the precise construction herein disclosed. The invention can be embodied in other specific forms without departing from the spirit or essential attributes. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope of the invention. | A method for detecting unreliable response conditions in a plurality of back-end transaction processing systems also can include the steps of: reading a list of references to a plurality of subscribing e-commerce systems; generating and dispatching placebo transactions to each e-commerce system in the list; receiving responses to the dispatched placebo transactions; computing transaction latency data based upon when each placebo transaction is dispatched to a subscribing e-commerce system, and when a corresponding response is received; and, notifying individual subscribing e-commerce systems when computed transaction latency data for the individual subscribing e-commerce systems indicates an unreliable response condition in an associated back-end transaction processing system. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application is a division of application Ser. No. 10/103, 910, filed Mar. 25, 2002, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to solar cells for use in space comprising compound semiconductors. More specifically, the invention relates to the improvement in performance and reduction in manufacturing cost for such solar cells.
[0004] 2. Prior Art
[0005] A solar cell or solar array has commonly been used as the main power source in a man-made satellite in space. The solar cell dedicated for use in space is produced using compound semiconductors of Group III-V compounds, for example, GaAs. For such solar cells, a crystalline thin film formed on a single-crystalline semiconductor substrate such as GaAs using a metal organic vapor phase deposition system is commonly used. Furthermore, in order to suppress any degradation in performance of the solar cell due to the presence of high energy cosmic rays such as electrons, protons, etc., in space, a high energy particle protection plate of glass, called “a cover glass”, is usually attached to a surface of the solar cells with an adhesive for improving the radiation tolerance of the solar cells.
[0006] In such compound semiconductor type solar cells the single-crystalline semiconductor substrate occupies the major part of the weight of the solar cells, but it does not contribute to photovoltaic conversion performance of the solar cells because of the high absorption coefficient of III-V materials. In such sense, the semiconductor substrate in the prior art solar cell is functionally useless, which is a major factor to impede realization of thinner and lighter solar cells. On the other hand, the single-crystalline semiconductor substrate is expensive, which adds to manufacturing cost of the solar cells. In addition, because of a step for attaching the cover glass involved in the assembly process for the solar cell arrays, such step obstructs reduction in manufacturing cost of the solar cell arrays. Furthermore, the adhesive for the cover glass is defective in that it increases the weight of the solar cell arrays.
[0007] In view of the above, an object of the present invention is to provide a compound semiconductor solar cells for space that has lighter weight, requires lower manufacturing cost and improves the radiation tolerance.
SUMMARY OF THE INVENTION
[0008] To attain such object the present invention provides a compound semiconductor type solar cell for use in space, comprising a cover glass used as a substrate, and crystalline thin films of compound semiconductor directly formed on a cover glass.
[0009] In one embodiment of the present invention said crystalline thin film of a compound semiconductor is formed using a metal organic chemical vapor deposition system. The term “crystalline” is used herein to mean either “single-crystal” or “polycrystalline”.
[0010] Preferably said crystalline thin film of compound semiconductors is formed from Group III-V elements using a metal organic chemical vapor deposition system.
[0011] In another embodiment said crystalline thin films of the compound semiconductor is formed at the temperature range of approx. 400° C. to 600° C.
[0012] Preferably said crystalline thin films of the compound semiconductor are formed at the temperature range of approx. 450° C. to 550° C.
[0013] In the manufacturing process of the solar cell according to the present invention a cover glass is provided, instead of the conventional semiconductor substrate. Then, a thin film of semiconductor acting as a photovoltaic conversion element is formed on a surface of the cover glass using a metal organic chemical vapor deposition system (MOCVD). In this connection the cover glass acting as the substrate is required to be heated for thermally decomposable thin film growth materials of semiconductors. To avoid deterioration or softening of the glass occurred if the temperature is too high it is necessary to precisely control the substrate temperature in a MOCVD system. In general the glass starts to soften when the temperature exceeds approx. 600° C., therefore, the temperature of the substrate in a MOCVD system is required to be kept less than approx. 600° C., and more preferably, less than approx. 550° C. On the other hand, if the temperature is too low, decomposition of the semiconductor crystal growth material is impeded, therefore, the substrate temperature is required to be kept over at least approx. 400° C., and more preferably, over 450° C. This temperature range is relatively lower, as compared to the conventional process where the thin film is formed on the semiconductor substrate at the temperature ranging from approx. 600° C. to approx. 800° C.
[0014] In such manner, the cover glass is used, in place of the conventional semiconductor substrate, which can dispense with the single-crystal semiconductor substrate and the adhesive for the cover glass used in the prior art. Accordingly the weight and manufacturing cost of the solar cell can be significantly reduced. According to the present invention the semiconductor thin film is formed with the cover glass, which completely eliminates the step for attaching cover glass in the prior art. This can further reduce the manufacturing cost of the solar cell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention is better understood by reading the following Detailed Description of the Preferred Embodiments with reference to the accompanying drawing figures, in which like reference numerals refer to like elements throughout, and in which:
[0016] [0016]FIG. 1 is a cross section view illustrating the construction of a compound semiconductor type solar cell for use in space constructed according to one embodiment of the present invention;
[0017] [0017]FIG. 2 is a graph showing an X-ray diffraction spectrum measured on a multi-layered film of crystalline compound semiconductors used for manufacturing the compound semiconductor type solar cell in FIG. 1;
[0018] [0018]FIG. 3 is a graph showing the relation between light absorption coefficient and photon energy measured on the multi-layered film of the crystalline compound semiconductor used for manufacturing the compound semiconductor type solar cell in FIG. 1;
[0019] [0019]FIG. 4 is a graph showing a current-voltage characteristic for the compound semiconductor type solar cell according to one embodiment of the present invention; and
[0020] [0020]FIG. 5 is a graph showing a radiation degradation characteristic for the compound semiconductor type solar cell when it is irradiated with 1 MeV electrons.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] [0021]FIG. 1 is a cross section view illustrating the structure of a compound semiconductor type solar cell for use in space constructed according to one embodiment of the present invention. Instead of using conventional semiconductor substrates, the solar cell in this embodiment includes a cover glass 01 used as a substrate, that is in the form of a square plate having the dimension of 2 cm×2 cm and the thickness of 150 μm. The cover glass 01 is one that is available from Pilkington PLC in United Kingdom under the model name of “CMG” and that has the same thermal expansion coefficient as GaAs. The composition of the cover glass typically includes boron in 5.2%; oxygen in 51%; sodium in 3.7%; aluminum in 1.4%; and silicon in 38.8%. In addition, the cover glass has physical characteristics including distorting point of approx. 510° C. (that means the maximum temperature in normal usage over which any deterioration starts) and softening point of approx. 720° C. (over which any deformation starts).
[0022] One side of the cover glass 01 on which the thin film compound semiconductors is formed has already been provided with an electrically conductive and transparent layer 02 of zinc oxide used as an electrode of the solar cell. On such transparent conductive layer 02 of the cover glass 01 the following layers are sequentially formed: n+-AlGaAs crystalline semiconductor layer 03 ; n+-GaAs crystalline semiconductor layer 04 ; p-GaAs crystalline semiconductor layer 05 ; and p+-GaAs crystalline semiconductor layer 06 (“+” means that the carrier density is higher), thereby configuring the solar cell. The n+-AlGaAs crystalline semiconductor layer 03 has the thickness of approx. 0.1 μm and the carrier density of approx. 2×10 19 cm −3 . The n+-GaAs crystalline semiconductor layer 04 has the thickness of approx. 0.3 μm and the carrier density of approx. 5×10 18 cm −3 . The p-GaAs crystalline semiconductor layer 05 has the thickness of approx. 2.0 m and the carrier density of approx. 2×10 16 cm −3 . The p+-GaAs crystalline semiconductor layer 06 has the thickness of approx. 0.2 μm and the carrier density of approx. 2×10 19 cm −3 . A p-side metal electrode 07 of Au—Ge/Ni/Au is formed entirely on the p+-GaAs crystalline semiconductor layer 06 . The metal electrode 07 also acts as a reflection layer for the light that is not absorbed, but is transmitted thereto. In addition, a-side metal electrode 08 of Au is formed on the zinc oxide layer 02 at the end portion thereof. A solar cell having the configuration as above is used is called “a superstrate type” in which the light is incident on the front surface of the cover glass. It is noted that the thickness of each of the semiconductor layers in FIG. 1 is not illustrated in the real scale.
[0023] Process for manufacturing the compound semiconductor type solar cell for use in space will be described in more detail hereafter.
[0024] First of all the cover glass 01 having one side dimension of 2 inch in diameter and thickness of 150 μm and having a zinc oxide layer 02 formed on one side thereof is degreased by washing it with solutions including an organic solvent such as acetone and then sulfuric acid added with hydrogen peroxide. Thereafter, both surfaces of the cover glass are etched using a hydrogen fluoride solution.
[0025] After the washing for degreasing and the etching, the cover glass 01 is placed on a graphite susceptor in a reactor of a metal organic chemical vapor deposition system (MOCVD) with the zinc oxide layer 02 faced upwardly. Then a radio frequency heating system is operated to heat the susceptor for increasing the temperature of the cover glass to the desired substrate temperature. Next, the sequential growth of n + -AlGaAs crystalline semiconductor layer 03 ; n + -GaAs crystalline semiconductor layer 04 ; p-GaAs crystalline semiconductor layer 05 ; and p+-GaAs crystalline semiconductor layer 06 is performed. The n-type and p-type dopants are Se and Zn, respectively, and the time period required for growth of the layers is determined depending on the thickness of the layers. After completion of growth of the layers, the reactor is cooled down to the ambient temperature and the resultant product is removed from the MOCVD system. It is desired that the substrate temperature is set at some temperature that is lower than the distorting temperature over which the physical characteristics of the cover glass such as light transmittivity starts to change. In this example the substrate temperature is set at 500° C.
[0026] [0026]FIG. 2 is a graph showing an X-ray diffraction spectrum measured on the semiconductor multi-layered film produced by the MOCVD system, as described above. As can be seen in the graph, a diffraction line (111) is shown as having higher strength. This is due to the polycrystalline film mainly oriented to (111) direction rather than (220) or (311) orientations. Therefore, the semiconductor multi-layered film has the crystalline characteristic, instead of amorphous characteristic.
[0027] [0027]FIG. 3 is a graph showing the relation between light absorption coefficient (squared value) and optical band gap derived from the wavelength dependency of light reflection and light transmission measured on the multi-layered film. Because of the very thin n + -AlGaAs crystalline semiconductor layer 03 it may be considered that the graph in FIG. 3 substantially shows the relation between light absorption coefficient and the optical band gap for the GaAs layers 04 to 06 . The value of the optical band gap estimated from the threshold of the light absorption coefficient (squared value) is approx. 1.35 eV, which is considered preferable for solar cell material.
[0028] Thereafter, the p-side metal electrode 07 having Au/Ni/Au—Ge construction is formed entirely on the surface of the p + -GaAs crystalline semiconductor layer 06 using the vacuum evaporation system. Then, an annealing process is conducted at the temperature of approx. 400° C. for a period of approx. 15 min. to reduce contact resistance between metal and semiconductor. Next, a pattern is produced for forming the electrodes on the front side by a conventional photolithography. Then, an end portion of the crystalline semiconductor multi-layered film is partially etched using an etching solution including the mixture of phosphoric acid, hydrogen peroxide, and pure water. Evaporation process is then used to produce the n-side electrode 08 made from Au. FIG. 4 is a graph showing a current-voltage characteristic for the compound semiconductor type solar cell according to the present invention, as measured under such condition that it is irradiated with “AMO simulated sunlight” (of 136.7 mW/cm 2 ) at the cell temperature of 28° C. The data such as the open-circuit voltage of 931 mV, the short-circuit current density of 27.9 mA/cm 2 and the fill factor of 78.2% are derived, which provides a conversion efficiency of approx. 15.0%.
[0029] [0029]FIG. 5 is a graph showing the remaining factor of the maximum output power (or the ratio of deteriorated value to the initial value) for the compound semiconductor type solar cell according to the present invention, as measured after irradiated with an electron ray of 1 MeV. The remaining factor at the irradiation dose of 1×10 15 cm −2 is 95%, and the output power at that time is equal to that of the conventional single-crystalline GaAs solar cell at the irradiation dose of 1×10 15 cm −2 .
[0030] Thus, one embodiment of the present invention has been described in detail with reference to the drawings. The present invention is, however, not limited to such embodiment, but it may be implemented in several other ways.
[0031] For instance, the present invention has been described with respect to the solar cell formed from the compound semiconductors such as GaAs and AlGaAs. However, the present invention may additionally be applied to the solar cell formed from another compound semiconductors such as InP, InGaP, InGaAs, GaN, ZnSe, etc.
[0032] In the embodiment as above, the “MOCVD” system has been used to produce the multi-layered film of the crystalline compound semiconductors of the solar cell. Of course, other thin film growth process such as a molecular beam epitaxial growth system may be used. Furthermore, the structure of the multi-layered film of the compound semiconductors on the solar cell may be modified to have another structure such as that for so called tandem type solar cell where there is two or more p-n junctions provided therein.
[0033] It will be understood that the present invention may be embodied in other specific forms without departing from the spirit or scope thereof. The present example and embodiment, therefore, are to be considered in all respect as illustrative and not restrictive, and the present invention is not to be limited to the details given herein. | Disclosed is a solar cell for use in space, comprising compound semiconductors used as photovoltaic conversion material. The solar cell comprises a cover glass used for improving the radiation tolerance as a substrate for thin film deposition. The solar cell further comprises a crystalline thin film of the compound semiconductors directly formed on a surface of the cover glass for acting as the photovoltaic conversion material. The crystalline thin film of compound semiconductors is formed using a metal organic chemical vapor deposition system. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from German Patent Application No. 103 18 968.8 dated 26 Apr. 2003, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an apparatus at a carding machine, wherein at least one stationary carding segment comprising a carrier together with at least one carding elements is associated with a roller, for example a cylinder.
[0003] In a known apparatus at least two carding elements are arranged behind one another in the direction of rotation of the roller, and the clothings of the carding elements and the roller clothing are located opposite one another. According to EP 0 431 482, a plurality of stationary carding segments, each comprising three fixed carding elements, are associated with the cylinder of the carding machine, each of them being fastened by means of end parts to the associated side frame of the carding machine. The mounting surfaces for the three fixed carding elements on a carrier are so matched to the curvature of the cylinder that, when the carding segment has been optimally set, the width of each carding element extends perpendicular to a respective radius of the cylinder. The carding surfaces of the carding elements are accordingly, in each case, oriented parallel to a corresponding tangent at the clothing of the cylinder. Re-setting can be so performed, for example with the aid of a suitable gauge, that the clothing of one of the carding elements has a desired spacing from the clothing of the cylinder. However, in all probability, the clothings of the other two carding elements will not then have the desired spacing from the cylinder clothing. The desired setting is achieved by means of a pivoting movement of the carding segment about a predetermined axis. During that pivoting movement, all three inter-connected carding elements are displaced until the desired setting has been achieved, at which setting the width of all the carding elements extends perpendicular to a respective radius of the cylinder. The complexity of the construction for pivoting and fixing the carding segment is disadvantageous. It is also disadvantageous that orientation of the carding elements parallel to a respective tangent at the roller results in increased fibre damage and nep formation. Finally, the clothings of the carding elements are subject to considerable wear in operation.
[0004] It is an aim of the invention to provide an apparatus of the kind described at the beginning which avoids or mitigates the mentioned disadvantages and which especially is simple in terms of construction and installation, enables individual setting of the carding intensity and makes possible a reduction in wear on the clothings of the carding elements.
SUMMARY OF THE INVENTION
[0005] The invention provides a carding machine having:
[0006] a roller which has a direction of rotation;
[0007] a carding segment opposing said roller and comprising a carrier and first and second carding elements arranged one behind the other in the direction of rotation of the roller;
[0008] wherein:
[0009] said first carding element has a first carding surface;
[0010] said second carding element has a second carding surface; and
[0011] at least one of said carding surfaces is inclined with respect to a tangent at the opposed roller surface.
[0012] The measures according to the invention make it possible for the angle between the clothing surface of each carding element and the cylinder clothing—the so-called “offset angle”—to be selected individually. It is especially advantageous that, as a result of specifically or individually orienting the clothing surfaces of the carding elements in relation to one another, the ratio of fibre damage to nep formation is very considerably improved. In addition, the lasting technical improvement is achieved in especially simple manner in terms of construction. As a result of the stationary arrangement of the carding elements there is no need for additional devices for pivoting the carding segments. According to a further advantage, the wear on the clothings of the carding elements is considerably reduced as a result of the individual inclination of the carding surfaces.
[0013] The carding elements may be non-movable. The carding elements may be movable.
[0014] The term “stationary” is used herein in relation to one or more carding elements as meaning that the carding element or elements maintain their position as such in the carrier and also with respect to the roller. The term “movable” is used herein in relation to one or more carding elements as meaning that the orientation of the carding element or elements relative to the carrier and/or roller can be changed, for example, by rotation of the element or elements. The carding elements are advantageously rotatable about an axis parallel to the roller. Advantageously, the angles are the same. Advantageously, the angles are not the same. The angle may be acute. The angle may be obtuse. One of said first and second elements may advantageously be inclined at an acute angle and the other at an obtuse angle, said acute and obtuse angles advantageously being complementary. Advantageously, the carding surface of at least one carding element forms an angle with a respective radius of the roller. Advantageously, the roller is the cylinder of the carding machine. Advantageously, the carding elements are arranged to be rotatable about an axis of rotation parallel to the roller axis, the spacing between the clothings of the carding elements and the roller clothing being adjustable. Advantageously, the carding elements are arranged to be individually rotatable in the carrier. Advantageously, the carding elements are arranged to be rotatable in relation to a fastening surface. Advantageously, the axis of rotation is, in each case, arranged in the middle of a carding element. Advantageously, the axis of rotation is, in each case, associated with the end region of a carding element. Advantageously, an adjusting device for the rotation is provided. The adjusting device preferably has at least one adjusting screw or the like. Advantageously, a rotary connection is associated with each carding element. Advantageously, the carrier is attached at both ends to a stationary support by means of a fastening element, for example a fastening bolt. Advantageously, the carding elements are arranged to be detectable. Advantageously, at least one apparatus is arranged in the preliminary carding zone between a licker-in and the rear card-top-deflecting roller of the revolving card top. Advantageously, at least one apparatus is arranged in the after-carding zone between a doffer and the front card-top-deflecting roller of the revolving card top. Advantageously, at least one apparatus is arrange din the underneath carding zone between the doffer and the licker-in. Advantageously, only stationary card top elements are associated with the cylinder of the carding machine, and a plurality of apparatuses are provided at the cylinder. Advantageously, a carding segment has two carding elements. Advantageously, the angle can be changed in operation and out of operation of the carding machine. Advantageously, the angle for two carding elements can be changed simultaneously, the angular position settings of the carding elements being coupled to one another. Advantageously, when the angles are changed, the transmission ratio (angular change) of each carding element is different. Advantageously, a central adjusting device is provided for changing the angles of all the carding elements. Advantageously, the adjusting device comprises a drive motor, for example a step motor. Advantageously, the angles are arranged to be adjusted in stepped manner from carding segment to carding segment, for example to be changed centrally by 0.5°. Advantageously, the spacing between the carding segment and cylinder remains constant. Advantageously, the angular position between the licker-in and the rear card-top-deflecting roller and the angular position between the doffer and the front card-top-deflecting roller are different. Advantageously, the adjusting device, for example the step motor, is connected to an electronic control and regulation device.
[0015] Advantageously, the carrier is an extruded profile, for example aluminium. Advantageously, a deflecting element or the like, for example a spoiler or similar, is provided at the entry region of the carding segment, seen in the direction of rotation of the cylinder. Advantageously, the deflecting element or the like is arranged upstream of the carding segment. Advantageously, the deflecting element or the like shields the tips of the carding elements.
[0016] Advantageously, an angle display, for example an angle scale or the like, is provided. Advantageously, the angle is arranged to be changed starting from a tangential position of the carding surface of the carding element (zero point). Advantageously, in a carding segment, the carding nip becomes smaller at the first carding element and larger at the second carding element, seen in the direction of rotation of the cylinder. Advantageously, each carding element is arranged to be rotated in the carrier with two degrees of freedom. Advantageously, the rotation of each carding element takes place about a stationary axis (longitudinal axis) in the carrier. Advantageously, the spacings at the narrowest locations of the carding nips are the same or substantially the same.
[0017] The invention also provides an apparatus at a carding machine, wherein at least one stationary carding segment comprising a carrier and one carding element is associated with a roller, for example a cylinder, and wherein the clothing of the carding element and the roller clothing are located opposite one another, in which the carding surface of the carding element forms an angle to a tangent at the clothing of the roller, and the carding element is arranged in stationary manner with respect to the roller. Advantageously, a plurality of carding segments are arranged behind one another in the work direction. Advantageously, the carding element is stationary and non-movable. Advantageously, the carding element is stationary and rotatable about its longitudinal axis.
[0018] The invention also provides an apparatus at a carding machine, wherein at least one stationary carding segment comprising a carrier together with at least two carding elements is associated with a roller, for example a cylinder, which carding elements are arranged behind one another in the direction of rotation of the roller, and wherein the clothings of the carding elements and the roller clothing are located opposite one another, characterised in that the carding surface of at least one carding element forms an angle with a respective tangent at the clothing of the roller, and the carding elements are arranged in stationary manner with respect to the roller.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 shows, in a diagrammatic side view, a carding machine according to the invention;
[0020] [0020]FIG. 2 shows, in a side view and in section, a fixed carding segment having two non-movable carding elements, the carding surfaces of which are arranged at an angle to the cylinder clothing;
[0021] [0021]FIG. 2 a shows a carding element having a sawtooth clothing;
[0022] [0022]FIG. 3 a shows three fixed carding segments according to the invention in the preliminary carding zone of a revolving card top carding machine;
[0023] [0023]FIG. 3 b is a top view of the fastening at both ends of a carding segment;
[0024] [0024]FIG. 4 shows spacings between the clothings of two carding elements and the cylinder clothing;
[0025] [0025]FIG. 5 shows two carding elements, the carding surfaces of which form an angle with a respective radius of the cylinder;
[0026] [0026]FIG. 6 shows two carding elements, which are rotatable about axes parallel to the cylinder axis;
[0027] [0027]FIG. 7 shows two manually rotatable carding elements together with a display device;
[0028] [0028]FIG. 8 shows two motor-rotatable carding elements, each having a deflection element;
[0029] [0029]FIG. 9 shows three carding segments, each comprising two carding elements exhibiting—seen in the direction of rotation of the cylinder—an offset angle, no offset angle and a counter-offset angle;
[0030] [0030]FIG. 10 shows three carding segments, each comprising one non-movable carding element;
[0031] [0031]FIG. 11 shows three carding segments, each comprising one rotatable carding element; and
[0032] [0032]FIG. 12 is a generalised circuit diagram having an electronic control and regulation device together with two motor-driven actuating members for rotation of the carding elements, two angle-measuring devices and a display device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] With reference to FIG. 1 a carding machine, for example a DK 903 high-performance carding machine made by Trutzschler GmbH & Co. KG of Monchengladbach, Germany, has a feed roller 1 , feed table 2, lickers-in 3 a , 3 b , 3 c , cylinder 4 , doffer 5 , stripper roller 6 , nip rollers 7 , 8 , web-guiding element 9 , web funnel 10 , draw-off rollers 11 , 12 , revolving card top 13 having card-top-deflecting rollers 13 a , 13 b and card top bars 14 , can 15 , can coiler 16 and fixed carding segments 17 ′, 17 ″ according to the invention each having carding elements. Reference numeral 4 a denotes the direction of rotation of the cylinder 4 , reference numeral 4 b denotes the clothing of the cylinder 4 , and reference numeral 4 c denotes the central axis of the cylinder 4 . Reference letter G denotes the work direction.
[0034] The carding segment 17 according to FIG. 2 consists of a carrier 18 and two carding elements 19 a , 19 b , which are arranged behind one another in the direction of rotation (arrow 4 a ) of the cylinder 4 , the clothings 20 a , 20 b (FIG. 2 a ) of the carding elements 19 a and 19 b , respectively, lying opposite the clothing 4 b of the cylinder 4 . The carding elements 19 a , 19 b are stationary and arranged in movable manner. The carding surfaces of the sawtooth-shaped clothings 20 a , 20 b (see FIG. 2 a ) of the carding elements 19 a , 19 b form an acute angle α and β, respectively, with a respective tangent 21 a and 21 b , respectively, at the clothing 4 b of the cylinder 4 . It will be appreciated that reference to a respective tangent is to a tangent at a location on the roller corresponding to the nip defined between the respective carding element and the roller. In the embodiment of FIG. 3 a , fixed carding segments 17 a , 17 b and 17 c , at least one and advantageously each of which is as described with reference to FIG. 2, are arranged in the preliminary carding zone between the licker-in 3 c and the rear card-top-deflecting roller 13 a of the revolving card top 13 . As FIG. 3 b shows, the carrier 18 of each carding segment 17 is fastened to two fastening plates 27 a , 27 b . The fastening plates 27 a , 27 b are attached, by means of bolts 28 a , 28 b , to extension bends 29 a and 29 b , respectively (FIG. 3 a shows only the extension bend 29 a on one side of the carding machine), which are in turn fastened to the card plates 30 a and 30 b , respectively, on each side of the carding machine (only 30 a is shown in FIG. 3 a ).
[0035] In the embodiment of FIG. 4, the clothing 20 a of the carding element 19 a forms an acute angle α with the tangent at the cylinder clothing 4 b (cf. FIG. 2), as a result of which the carding nip becomes narrower in the direction of rotation 4 a of the cylinder 4 . The angle of inclination α is designated the so-called “offset angle”. The spacing between the clothing 20 a and the cylinder clothing 4 b is denoted by reference letter a at the entrance to the carding nip and by reference letter b at the exit from the carding nip, a being greater than b. The clothing 20 b of the carding element 19 b forms an acute angle β with the tangent at the cylinder clothing 4 b (cf. FIG. 2), as a result of which the carding nip opens out in the direction of rotation 4 a of the cylinder 4 . The angle of inclination β is designated the so-called “counter-offset angle”. The angles α and β may be, for example, about 1°. The spacing between the clothing 20 b and the cylinder clothing 4 b is denoted by reference letter c at the entrance to the carding nip and by reference letter d at the exit from the carding nip, c being less than d. The spacings b and c, that is to say at the narrowest positions of the carding nip, are preferably the same or substantially the same, for example {fraction (3/1000)}″.
[0036] As FIG. 5 shows, the carding surface 20 a of the carding element 19 a forms an acute angle γ with a radius r 1 of the cylinder 4 , and the carding surface 20 b of the carding element 19 b forms an acute angle δ with a radius r 2 of the cylinder 4 .
[0037] In the embodiment of FIG. 6, the carding elements 19 a , 19 b are arranged to rotate at a rotary connection about a respective axis of rotation 22 a and 22 b , which is oriented parallel to the roller axis 4 c (see FIG. 1). The axes of rotation 22 a , 22 b are located in a radial direction in relation to the cylinder 4 , in the middle of the respective carding element 19 a and 19 b . As a result, the angles α, β (see FIG. 2) between the clothings 20 a , 20 b of the carding elements 19 a , 19 b and the cylinder clothing 4 b are adjustable individually (that is to say, independently of one another) and by simple means. When there is a change in the angles α, β, the spacings b and c (see FIG. 4) preferably do not change. The carding elements 19 a , 19 b are stationary and arranged in movable manner in the carding segment 17 a . “Stationary” means that the carding elements 19 a , 19 b maintain their position as such in the carding segment 17 a and also with respect to the cylinder 4 without change. “Movable” means that the carding elements 19 a , 19 b are, for example, rotatable, by means of which the described angles of inclination α, β and spacings can be changed.
[0038] In the embodiment of FIG. 7, one end of a lever 23 a , 23 b acts on a respective point of rotation 22 a and 22 b of the carding elements 19 a , 19 b . At the start, the lever 23 b is in position no. 5 on the display device 24 (zero position). Associated with the lever 23 a is a further display device (not shown). The starting position corresponds to an angle α=0° and β=0°. Moving the levers 23 a , 23 b in the direction of arrows E, F causes the associated carding element 19 a and 19 b , respectively, to rotate about the respective point of rotation 22 a and 22 b . The positions of the levers 23 a , 23 b can be fixed by means of a latching device (not shown) or the like.
[0039] In the embodiment of FIG. 8, adjustable drive motors 25 a and 25 b , for example step motors, act on the rotary connections 22 a , 22 b and set the angles of inclination α, β of the carding elements 19 a , 19 b in the manner shown in FIG. 7. At the intake into the carding elements 19 a , 19 b there is arranged, upstream of the clothings 20 a , 20 b of the carding elements 19 a and 19 b , respectively, seen in the direction of rotation 4 a of the cylinder 4 , a respective deflecting element 26 a and 26 b (spoiler). The deflecting element 26 a , 26 b may be longer than, as long as or shorter than the tips of the clothings 20 a , 20 b.
[0040] In the embodiment of FIG. 9, three fixed carding segments 17 a , 17 b and 17 c are provided opposite the clothing 4 b of the cylinder 4 (cf. FIG. 3 a in that regard). The fixed carding segments 17 a to 17 c each comprise two carding elements 19 a , 19 b and 19 c , 19 d and 19 e , 19 f , respectively. Seen in the direction of rotation 4 a of the cylinder 4 , the carding elements 19 a , 19 b arranged at the fibre intake exhibit an offset angle, the carding elements 19 c , 19 d arranged in the central region exhibit no offset angle, and the carding elements 19 e , 19 f arranged at the fibre exit exhibit a counter-offset angle, by means of which optimum carding action is brought about, together with a considerable reduction in wear on the carding clothings 20 .
[0041] [0041]FIGS. 10 and 11 show two arrangements, wherein one carding element 19 ′, 19 ″ and 19 ′″ is associated with each of the fixed carding segments 17 a , 17 b and 17 c , respectively. In accordance with FIG. 10, the carding elements 19 ′, 19 ″, 19 ′″ are stationary and arranged in non-movable manner. The carding element 19 ′ forms an offset angle, the carding element 19 ″ forms no offset angle, and the carding element 19 ′″ forms a counter-offset angle. In accordance with FIG. 11, the carding elements 19 ′, 19 ″, 19 ′″ are mounted so as to be rotatable about a respective axis of rotation 22 ′, 22 ″ and 22 ′″. All three carding elements 19 ′, 19 ″ and 19 ′″ form an offset angle, the respective carding nips and angles of rotation becoming smaller in the direction of rotation 4 a of the cylinder 4 .
[0042] In accordance with FIG. 12, the step motors 25 a , 25 b (FIG. 8), two angle-measuring devices 32 a , 32 b and a display device 33 , for example a display monitor or the like, are connected to an electronic control and regulation device 31 , for example a microcomputer machine control, by means of which the angles of inclination α β of the carding elements 19 a , 19 b can be adjusted either manually by means of an input device (not shown) or automatically by means of a memory (not shown).
[0043] Although the foregoing invention has been described in detail by way of illustration and example for purposes of clarity and understanding, it will be obvious that changes and modifications may be practised within the scope of the appended claims. | In an apparatus at a carding machine, wherein at least one stationary carding segment comprising a carrier together with at least two carding elements is associated with a roller, for example a cylinder, which carding elements are arranged behind one another in the direction of rotation of the roller, the clothings of the carding elements and the roller clothing are located opposite one another.
In order, by means that are simple in terms of construction and installation, to make possible individual setting of the carding intensity and a reduction in wear on the clothings of the carding elements, the carding surface of at least one carding element forms an angle with a respective tangent at the clothing of the roller 4 and the carding elements are arranged in stationary manner with respect to the roller. | 3 |
FIELD OF THE INVENTION
The invention relates to circular knitting machines and their sinkers. In particular, the invention relates to controlling the vertical motion of radially reciprocating sinkers of circular knitting machines.
BACKGROUND OF THE INVENTION
Circular knitting machines are widely used to produce knitted fabric, such as knitted fabric that is tubular. A conventional circular knitting machine includes a vertically extending cylinder, and multiple sinkers and latch needles that extend around and move relative to the upper end of the cylinder. The sinkers reciprocate radially and the latch needles reciprocate vertically in a cooperative fashion to produce knitted fabric. For example, U.S. Pat. Nos. 4,459,830; 4,765,155; 5,182,927; 5,477,707; 5,577,401 and 5,609,044 disclose circular knitting machines, and each of those patents is incorporated herein by reference.
It is important to control accurately the vertical movement of the sinkers of a circular knitting machine. For example, U.S. Pat. Nos. 1,684,682; 2,120,796; 3,230,742; 3,377,823; 4,519,221; 4,665,718 and 5,564,291 discloses circular knitting machine cylinders having annular ledges that at least partially define the paths of associated sinkers. The sinkers have upper and lower arms that bear upon opposite surfaces of the ledges.
Notwithstanding past improvements to circular knitting machines, at least some modern circular knitting machines experience problems when sinkers encounter deposits of lint, dirt, or the like, on an upper surface of the circular knitting machine cylinder upon which the sinkers slide. Accumulations on the cylinder upper surface can cause the sinkers to ride upward, resulting in “sinker lines” in the knitted fabric. The presence of sinker lines is a defect that knitters wish to avoid. Efforts have been made to avoid this problem by trying to keep the upper regions of the cylinder clean by forcing air in and around the vertically and radially extending slots in which the sinkers at least partially reside. Whereas this approach works fairly well, it is not an infallible solution, and this approach requires extra parts such as fans, compressors, ducting, filters and so forth.
Downward motion of the sinkers is also undesirable because it may lead to sinker lines or problems such as smashing of sinker parts and other parts of the circular knitting machine. In machines that have been run for some time, downward motion of the sinkers can occur due to wear between the sinkers and the cylinder upper surface. Over time, this wear causes grooves to form in the upper surface of the cylinder, and the sinkers may ride downwardly into grooves. Whereas it is known in the art to harden the upper surface of the cylinder, or a portion thereof, so as to reduce the wearing and resulting grooves, such hardening can be expensive, and can in some cases cause warping and tolerance problems.
Accordingly, there is a need for an improved mechanism for restricting vertical movement of sinkers.
SUMMARY OF THE INVENTION
The present invention restricts undesirable vertical movement of sinkers, and provides other advantages, while simultaneously avoiding problems with binding or excessive friction. More specifically, at least one readily replaceable restricting member is carried by a cylindrical portion of a circular knitting machine and is operative to restrict at least upward or downward movement of the sinkers. For a circular knitting machine having a cylinder with a cylinder top ring, the cylindrical portion to which the restricting member is mounted is preferably the cylinder top ring. For a circular knitting machine in which the cylinder is not equipped with a cylinder top ring, the cylindrical portion to which the restricting member is mounted is preferably the upper portion of the cylinder.
In accordance with one aspect of the present invention, the restricting member is biasingly engaged to the cylindrical portion such that the biased restricting member extends at least partially around the cylindrical axis of the cylindrical portion. The sinkers are operative for reciprocating radially relative to the cylindrical portion and the biased restricting member such that sliding contact is defined between the sinkers and one or more bearing-like surfaces of the biased restricting member.
In accordance with one aspect of the present invention, the biased restricting member is manually bent and thereafter released so that the bias of the biased restricting member causes it to become biasingly engaged to the cylindrical portion. Most preferably, the biased restricting member is released so that the biased restricting member becomes biasingly engaged within a receiving channel that is defined by the cylindrical portion and encircles the cylindrical axis of the cylindrical portion. It is preferable for the biased restricting member to remain stationary within the receiving channel during the reciprocating of the sinkers.
In accordance with one aspect of the present invention, the cylindrical portion comprises a plurality of spaced-apart, radially extending protrusions, and a plurality of radially extending slots are defined between the protrusions. The slots are operative for at least partially receiving the reciprocating sinkers, and the protrusions at least partially define the receiving channel such that the receiving channel and the biased restricting member at least partially bisect the slots.
In accordance with some of the embodiments of the present invention, an interior surface of the cylindrical portion defines an opening to the receiving channel. In accordance with other embodiments of the present invention, an exterior surface of the cylindrical portion defines an opening to the receiving channel. Both types of openings to the receiving channel extend at least partially around the cylindrical axis of the cylindrical portion so that the biased restricting member can be readily introduced into and removed from the receiving channel, whereby the biased restricting member is readily replaceable.
In accordance with one aspect of the present invention, the biased restricting member may be biased toward a substantially straight configuration, in which case the biased restricting member has opposite ends. The opposite ends of the biased restricting member may abut in an end-to-end manner when the biased restricting member is properly positioned within the receiving channel. Alternatively, the opposite ends of the biased restricting member may not abut in an end-to-end manner when the biased restricting member is properly positioned within the receiving channel, in which case the biased restricting member can be characterized as having a discontinuous circumference.
In accordance with another aspect of the present invention, the biased restricting member defines a relaxed diameter while the biased restricting member is separate from the cylindrical portion. As one example, the biased restricting member may be in the form of a hoop. Such a hoop may be formed, for example, by joining the opposite ends of a biased restricting member, such that the opposite ends define an end-to-end arrangement. As another example, the opposite ends of a biased restricting member are not joined, but the biased restricting member at least partially defines an arcuate configuration while separate from the cylindrical portion and relaxed, and the arcuate configuration defines the relaxed diameter. When the receiving channel has an outwardly facing opening, the relaxed diameter is preferably smaller than the diameter of the receiving channel. When the receiving channel has an inwardly facing opening, the relaxed diameter is preferably larger than the diameter of the channel.
When the biased restricting member is not in the form of a hoop, or the like, it may be preferred for the length of the biased restricting member to be greater than the circumference of the receiving channel, so as to maximize the overlapping of the biased restricting member within the receiving channel. Further, it may be preferred to have two or more separate biased restricting members in the receiving channel so as to provide at least a doubled configuration. The overlapping or doubled configurations increase the area of contact between the sinkers and the biased restricting member or members, so as to prolong the life of, and increase the effectiveness of, the biased restricting member or members.
In accordance with one aspect of the present invention, upper surfaces of the sinkers contact bearing-like surfaces of at least one biased restricting member so that upward movement of the sinkers is restricted. In accordance with another aspect of the present invention, lower surfaces of the sinkers contact the bearing-like surfaces of at least one biased restricting member so that downward movement of the sinkers is restricted. In accordance with another aspect of the present invention, upper and lower surfaces of the sinkers contact the bearing-like surfaces of one or more biased restricting members so that both upward and downward movement of the sinkers is restricted.
In accordance with another aspect of the present invention, each of the sinkers comprises an upper nib and a lower nib, a radially extending slot is defined between the upper nib and the lower nib, and the slot is open at the leading edge of the sinker. At least one biased restricting member is in the travel paths of the sinkers so that the biased restricting member is at least partially received within the radially extending slots in response to the radial reciprocating of the sinkers. In one embodiment of the present invention, upper surfaces of the lower nibs of the sinkers contact bearing-like surfaces of at least one biased restricting member so that upward movement of the sinkers is restricted. In accordance with another embodiment of the present invention, lower surfaces of the upper nibs of the sinkers contact bearing-like surfaces of at least one biased restricting member so that downward movement of the sinkers is restricted. In accordance with another embodiment of the present invention, upper surfaces of the lower nibs and lower surfaces of the upper nibs of the sinkers contact bearing-like surfaces of at least one biased restricting member so that both upward and downward movement of the sinkers is restricted.
In accordance with another aspect of the present invention, lower surfaces of the lower nibs of the sinkers contact bearing-like surfaces of at least one restricting member so that downward movement of the sinkers is restricted. In accordance with this aspect of the present invention, the slots in the sinkers are optional. Further, the restricting member may or may not be biased, and the restricting member may be positioned as described above, or the restricting member may be positioned differently. As one specific example, the restricting member may be positioned in a channel having an annular opening that is defined by a surface around and from which the above-mentioned plurality of spaced-apart, radically extending protrusions extend. It is within the scope of the present invention for a circular knitting machine to include a combination of different types of restricting members and/or a combination of differently positioned restricting members.
A restricting member may include one or more springs or pieces of wire. A significant advantage of the use of wires and/or springs as the restricting member is that the wires and springs are relatively inexpensive and easy to replace when worn. Ideally the wires or springs would last as long as possible, but as a minimum they only need to last as long as the sinkers, which are consumable elements that must be replaced every few months.
The present invention provides numerous other advantages. For example, in accordance with some of the embodiments of the present invention a biased restricting member restrains the sinkers from moving upwardly, which prevents the formation of sinker lines in the knitted fabric. Further, because the biased restricting member restrains the sinkers from moving upwardly, the need for trying to keep the upper regions of the cylindrical portion clean by means of fans and compressed air is at least partly reduced.
As an additional example of an advantage, in accordance with some of the embodiments of the present invention a restricting member restrains the sinkers from moving downwardly, thus bearing the weight of the sinkers and any downward forces imposed by knitted fabrics and yarn so as to prevent undesired wearing and groove formation in the upper surface of the cylindrical portion. Thus, the restricting member can eliminate or reduce the need to replace the cylindrical portion, and further eliminates or reduces the need for hardening an upper portion of the cylindrical portion, which is expensive and can sometimes cause warping and tolerance problems.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other advantages and features of the invention, and manners in which the same are accomplished, will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings which illustrate preferred and exemplary embodiments, wherein:
FIG. 1 is a sectional perspective view of a portion of a cylinder assembly of a circular knitting machine, with a portion of a representative sinker exploded therefrom, in accordance with a first embodiment of the present invention;
FIG. 2 is a sectional view of a portion of the cylinder assembly of FIG. 1, wherein two positions of the sinker are shown in broken lines, in accordance with the first embodiment of the present invention;
FIG. 3 is a sectional view of a portion of a cylinder assembly in accordance with a second embodiment of the present invention, wherein a sinker is shown in broken lines;
FIG. 4 is a sectional view of a portion of a cylinder assembly in accordance with a third embodiment of the present invention, wherein a sinker is shown in broken lines;
FIG. 5 is a sectional view of a portion of a cylinder assembly in accordance with a fourth embodiment of the present invention, wherein a sinker is shown in broken lines;
FIG. 6 is a sectional view of a portion of a biased restricting member of a cylinder assembly in accordance with a fifth embodiment of the present invention, wherein a sinker is shown in broken lines;
FIG. 7 is a sectional view of a portion of a cylinder assembly in accordance with a sixth embodiment of the present invention, wherein a sinker is shown in broken lines; and
FIG. 8 is a sectional view of a portion of a cylinder assembly in accordance with a seventh embodiment of the present invention, wherein a sinker is shown in broken lines.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; 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. Like numbers refer to like elements throughout.
First Embodiment
FIG. 1 is a sectional perspective view of a portion of a cylinder assembly 10 of a circular knitting machine (not shown), with a portion of a sinker 12 exploded therefrom, in accordance with the first embodiment of the present invention. The cylinder assembly 10 includes a cylindrical portion 14 that extends around a cylindrical axis, which is the axis about which the cylindrical portion is defined. For circular knitting machines that have a cylinder top ring at the top of the cylinder of the circular knitting machine, the cylindrical portion 14 is preferably the cylinder top ring. For circular knitting machines in which the cylinder is not equipped with a cylinder top ring, the cylindrical portion 14 is preferably the upper portion of the cylinder.
The cylindrical portion 14 includes multiple upwardly extending protrusions 16 , which also extend radially. The upwardly extending protrusions 16 , only a few of which are shown or identified with a reference numeral in FIG. 1, together encircle the cylindrical axis of the cylindrical portion 14 . Multiple upwardly extending slots 18 , which also extend radially, are defined between the upwardly extending protrusions 16 . The multiple upwardly extending slots 18 , only several of which are shown or identified with a reference numeral in FIG. 1, together encircle the cylindrical axis of the cylindrical portion 14 . Each slot 18 has, or is defined between, opposite and parallel side walls of adjacent upwardly extending protrusions 16 . The parallel side walls of the slots 18 extend upwardly and radially. For each upwardly extending slot 18 , the parallel side walls thereof extend upward from opposite ends of a generally horizontal base wall that provides the base of the slot. The cylindrical portion 14 further includes an upper face 19 that encircles the cylindrical axis of the cylindrical portion and is coplanar with the base walls of the slots 18 . The upwardly extending protrusions 16 encircle the upper face 19 . Whereas only a single sinker 12 is shown in FIG. 1, each of the upwardly extending slots 18 receives a different sinker, such that multiple sinkers encircle the cylindrical axis of the cylindrical portion 14 .
Each of the upwardly extending protrusions 16 has an interior surface 20 that faces the cylindrical axis of the cylindrical portion 14 . The interior surfaces 20 , only a few of which are shown or identified with a reference numeral in FIG. 1, together encircle the cylindrical axis of the cylindrical portion 14 . Whereas the interior surfaces 20 are separated by the upwardly extending slots 18 , the interior surfaces 20 can be characterized as together providing a composite interior surface 20 that generally faces and encircles the cylindrical axis of the cylindrical portion 14 , and that extends upward from the upper face 19 .
Each of the upwardly extending protrusions 16 further has an exterior surface 22 . The exterior surfaces 22 , only a few of which are shown or identified with a reference numeral in FIG. 1, together encircle the cylindrical axis of the cylindrical portion 14 . Whereas the exterior surfaces 22 are separated by the upwardly extending slots 18 , the multiple exterior surfaces 22 can be characterized as together providing a composite exterior surface 22 that generally faces away from and encircles the cylindrical axis of the cylindrical portion 14 .
Each of the upwardly extending protrusions 16 defines a receiving channel 24 that can be characterized as being in the form of a horizontally or sideways oriented U-shaped channel. Each receiving channel 24 has an opening that is defined by the respective interior surface 20 and oriented toward the cylindrical axis of the cylindrical portion 14 . As best be seen in FIG. 2, each receiving channel 24 has, or is defined by, opposite and parallel upper and lower interior walls of the respective upwardly extending protrusion 16 . The parallel walls of the receiving channels 24 extend horizontally. The parallel walls of each receiving channel 24 extend from opposite ends of an arcuate wall, which is an interior wall of the respective upwardly extending protrusion 16 and provides the base of the receiving channel. The receiving channels 24 , only a few of which are shown or identified with a reference numeral in FIG. 1, together encircle the cylindrical axis of the cylindrical portion 14 . The multiple receiving channels 24 can be characterized as together providing a composite receiving channel 24 that encircles the cylindrical axis of the cylindrical portion 14 .
The cylinder assembly 10 further includes a biased restricting member 26 , which is preferably a biased elongate, arcuate, or hoop-like member, such as a spring or a spring-like piece of wire, or the like. The biased restricting member 26 is positioned in the composite receiving channel 24 and functions to provide bearing-like surfaces that are engaged by the sinkers 12 and restrict undesired vertical movement of the sinkers, as will be discussed in greater detail below. One example of an acceptable biased restricting member 26 is a length of wire having opposite ends. In accordance with one version of the first embodiment of the present invention, the piece of wire is biased toward a straight configuration, such that when the wire is free from the composite receiving channel 24 the wire extends substantially straight. As a result, when the wire is manually placed in the composite receiving channel 24 , the wire seeks to return to its straight configuration, which causes the wire to become biasedly engaged to the arcuate walls that define the base of the composite receiving channel, whereby the wire is engaged to the cylindrical portion 14 . Stated more generally, a somewhat straight section of wire is bent around the inside periphery of the cylindrical portion 14 so that the wire is biased into place.
In accordance with another version of the first embodiment of the present invention, the wire is biased toward a configuration in which the wire defines an arcuate or somewhat circular configuration, or the like. The relaxed diameter of the arcuate or somewhat circular wire is preferably larger than the diameter of the composite receiving channel 24 , so that the wire becomes biasedly engaged to the arcuate walls that define the base of the composite receiving channel when the wire is inserted into the composite receiving channel. The opposite ends of any such piece of wire may not be joined to one another, so that the wire has a discontinuous circumference. Alternatively, they can be joined such as by brazing or welding the ends together. The diameter of the composite receiving channel 24 can be characterized as being approximately the diameter defined by the arcuate walls that define the base of the composite receiving channel.
In accordance with another version of the first embodiment of the present invention, the biased restricting member 26 is an elongate helical spring that is wound so that it is in the form of an elongate, somewhat tube-like member which may be biased toward any of the configurations described above with respect to the pieces of wire. Additionally, the opposite ends of the tube-like member may be attached to one another, such as by welding, so that the helical spring is in the form of a hoop or circle, or the like. In accordance with the first embodiment of the present invention, it is preferred for the relaxed diameter of the hoop or circle to be greater than the diameter of the receiving channel 24 , so that the hoop or circle becomes biasedly engaged to the arcuate walls that define the base of the composite receiving channel 24 when the helical spring is introduced into the composite receiving channel.
When the biased restricting member 26 is an elongate member having opposite ends that are not joined to one another, the length of the biased restricting member may be greater than the circumference of the composite receiving channel 24 , so that at least a portion of the biased restricting member overlaps itself to provide a doubled configuration, as illustrated in FIG. 2 . The circumference of the composite receiving channel 24 can be characterized as being approximately the circumference defined by the arcuate walls that define the base of the composite receiving channel.
It may be preferred for the length of the biased restricting member 26 to be at least two to three, or more times greater than the circumference of the composite receiving channel 24 , so as to maximize the overlapping of the biased restricting member 26 within the composite receiving channel. Further, it may be preferred to have two or more separate biased restricting members 26 in the receiving channel to provided at least a doubled configuration in which an inner of the biased restricting members is biasedly engaged to the arcuate walls that define the base of the composite receiving channel 24 as described above, and an outer of the biased restricting members is biasedly engaged to the inner of the biased restricting members.
Throughout this Detailed Description of the Invention section of this disclosure, unless expressly stated otherwise or understood otherwise by those skilled in the art, reference to a biased restricting member 26 within the composite receiving channel 24 is to be considered to alternatively include all of the variations of biased restricting members discussed above, including, but not limited to, a single biased restricting member that does not overlap itself within the composite receiving channel, a biased restricting member that overlaps itself within the composite receiving channel, and two or more biased restricting members contemporaneously within the composite receiving channel and providing a doubled configuration, such as that illustrated in FIG. 2 .
As best seen in FIG. 2, in accordance with the present invention it is preferred for there to be little, if any, clearance between the biased restricting member 26 and the parallel walls of the composite receiving channel 24 . Thus, the upper walls of the composite receiving channel 24 restrict upward movement of the biased restricting member 26 and the lower walls of the composite receiving channel restrict downward movement of the biased restricting member. Therefore, the biased restricting member 26 remains substantially stationary while within the composite receiving channel 24 , even while the sinkers 12 are in motion, as will be discussed in greater detail below. Whereas the members 26 are shown as have substantially circular cross-sectional configurations in FIG. 2, it is also within the scope of the present invention for biased restricting members to have other cross-sectional configurations, such as rectangular, or the like.
The sinker 12 illustrated in FIG. 1 is representative of multiple sinkers, each of which is individually received by a respective upwardly extending slot 18 . As best seen in FIG. 1, the sinker 12 includes a lower nib 30 having a top surface 32 , a bottom surface 34 and a leading edge 36 . The sinker 12 further includes an upper nib 38 having a top surface 40 , a bottom surface 42 and a leading edge 44 . A nib slot 46 is defined between the top surface 32 of the lower nib 30 and the bottom surface 42 of the upper nib 38 . The sinker 12 further includes a catch 48 .
As mentioned above, the cylinder assembly 10 includes a separate sinker 12 extending at least partially into each of the upwardly extending slots 18 . Each of the sinkers 12 is radially reciprocated within its respective upwardly extending slot 18 in response to the action of a cam (not shown). Two positions of a sinker 12 along the reciprocative travel path thereof are represented by the two broken-lined illustrations of a sinker in FIG. 2 . Latch needles (not shown) reciprocate vertically and cooperate with the reciprocating sinkers 12 to produce knitted fabric (not shown) in a manner understood by those skilled in the art. Whereas only a single sinker 12 may be referred to in the following disclosure, the information provided with respect to that one sinker is representative of the other sinkers.
As best seen in FIG. 2, in accordance with the first embodiment of the present invention the composite receiving channel 24 is positioned so that the biased restricting member 26 therein closely overlies the lower nib 30 of the sinker 12 so as to prevent the sinker from riding upwardly due to lint or dirt accumulations on the upper face 19 of the cylindrical portion 14 or within the respective upwardly extending slot 18 (FIG. 1 ). More specifically, and with reference to FIGS. 1 and 2, as a sinker 12 reciprocates in its respective upwardly extending slot 18 , the top surface 32 of the lower nib 30 slides across a bottom surface of the biased restricting member 26 in a bearing-like fashion such that the biased restricting member restricts upward movement of the sinker.
When there are two or more biased restricting members 26 within the composite receiving channel 24 , or a single overlapping biased restricting member within the composite receiving channel, the surface or surfaces of the sinker 12 that contact the restricting member or members slide across multiple bearing-like surfaces of the biased restricting member or members, such that the biased restricting member or members provide a composite bearing-like surface that enhances and prolongs the optimal operation of the cylinder assembly 10 .
As best seen in FIG. 1, in accordance with the first embodiment of the present invention the upper nib 38 does not come into contact with the biased restricting member 26 . Thus, it is preferable for the bottom surface 34 of the sinker 12 to slide across the base wall of the respective upwardly extending slot 18 (FIG. 1) and the upper face 19 in a bearing-like fashion while the sinker reciprocates, so that the downward motion of the sinker is restricted.
In accordance with the first embodiment of the present invention, the biased restricting member 26 restrains the sinkers 12 from moving upwardly, so as to prevent the formation of “sinker lines” in the knitted fabric. Consequently, the need for trying to keep the upper regions of the cylindrical portion 14 clean, such as by means of forcing air into and near the slots 18 , is at least partly reduced.
A significant advantage of the use of wires and/or springs as biased restricting members 26 is that the wires and springs are relatively inexpensive and easy to replace when worn. Ideally the wires or springs would last as long as possible, but as a minimum they only need to last as long as the sinkers 12 , which are typically consumable elements that must be replaced every few months.
Second Embodiment
FIG. 3 illustrates portions of a cylinder assembly 10 and a portion of a sinker 12 , which is shown by dashed lines, in accordance with a second embodiment of the present invention. The cylinder assembly 10 of the second embodiment of the present invention is identical to the cylinder assembly of the first embodiment of the present invention, except for variations that are noted and variations apparent to those skilled in the art.
In accordance with the second embodiment of the present invention, the receiving channel 24 and the biased restricting member 26 therein are positioned so that the upper nib 38 of the sinker 12 closely overlies the biased restricting member, so as to prevent the sinker from pivoting downward. More specifically, in accordance with the second embodiment of the present invention, the bottom surface 42 of the upper nib 38 slides across the top surface of the biased restricting member 26 in a bearing-like fashion so as to restrict downward movement of the sinker, while the sinker 12 reciprocates radially in its upwardly extending slot 18 (FIG. 1 ).
In accordance with a first version of the cylinder assembly 10 of the second embodiment of the present invention, the bottom surface 34 of the lower nib 30 slides across the base wall of the respective upwardly extending slot 18 (FIG. 1) and the upper face 19 in a bearing-like fashion as the sinker 12 reciprocates in its upwardly extending slot 18 . However, it is preferred for the biased restricting member 26 to bear the brunt of the downward forces applied by the sinker 12 with respect to the cylindrical portion 14 , so that any forces applied by the sinker against the base wall of the respective upwardly extending slot 18 and the upper face 19 are relatively small and cause a minimal amount of wear.
In accordance with a second version of the cylinder assembly 10 of the second embodiment, the receiving channel 24 and the biased restricting member 26 are positioned so that the biased restricting member bears all of the downward forces applied by the sinker with respect to the cylindrical portion 14 . That is, the bottom surface 34 of the lower nib 30 of the sinker 12 preferably does not come into contact with the base wall of the respective upwardly extending slot 18 (FIG. 1) or the upper face 19 .
In accordance with the second embodiment of the present invention, the biased restricting member 26 restrains the sinker 12 from moving downward, so as to prevent the formation of sinker lines in the fabric, to prevent problems such as smashing of the reciprocating needles and sinker parts, and to prevent wear to the base wall of the respective upwardly extending slot 18 (FIG. 1) and the upper face 19 .
Third Embodiment
FIG. 4 illustrates portions of a cylinder assembly 10 and a portion of a sinker 12 , which is shown by dashed lines, in accordance with a third embodiment of the present invention. The cylinder assembly 10 of the third embodiment of the present invention is identical to the cylinder assembly of the first embodiment of the present invention, except for variations that are noted and variations apparent to one skilled in the art. In accordance with the third embodiment of the present invention, the receiving channel 24 and the biased restricting member 26 therein are sized and positioned so that the top surface 32 of the lower nib 30 interacts with the biased restricting member as described for the first embodiment of the present invention, the bottom surface 42 of the upper nib 38 interacts with the biased restricting member as described for the second embodiment of the present invention, and the bottom surface 34 of the lower nib interacts with the base wall of the respective upwardly extending slot 18 (FIG. 1) and the upper face 19 as described for the second embodiment of the present invention.
Fourth Embodiment
FIG. 5 illustrates portions of a cylinder assembly 10 and a portion of a sinker 12 , which is shown by dashed lines, in accordance with a fourth embodiment of the present invention. The cylinder assembly 10 of the fourth embodiment of the present invention is identical to the cylinder assembly of the third embodiment of the present invention, except for variations that are noted in this disclosure and variations apparent to those skilled in the art.
In accordance with the fourth embodiment of the present invention, the composite receiving channel 24 defined by the upwardly extending protrusions 16 is oriented oppositely from the configuration illustrated in FIGS. 1 - 4 . That is, in accordance with the fourth embodiment of the present invention, the opening of the horizontally or sideways oriented U-shaped receiving channel 24 is defined by the exterior surfaces 22 (also see FIG. 1) of the upwardly extending protrusions 16 , such that the opening of the composite receiving channel encircles and is oriented away from the cylindrical axis of the cylindrical portion 14 .
In accordance with the fourth embodiment of the present invention, the biased restricting member 26 is preferably circular or at least biased toward an arcuate or circular configuration. The relaxed diameter of the arc or circle defined by the biased restricting member 26 is preferably smaller than the diameter of the composite receiving channel 24 , so that the biased restricting member becomes biasedly engaged to the arcuate wall that defines the base of the composite receiving channel. For example, when the biased restricting member 26 is a segment of wire, the wire is bent so that it is biased to a configuration having a diameter smaller than the diameter of the composite receiving channel 24 , and then the wire is placed in the composite receiving channel, so that the wire becomes latchedly biased into the composite receiving channel.
It is within the scope of each of the embodiments of the present invention for the composite receiving channel 24 to be outwardly oriented, as in FIG. 5 .
Fifth Embodiment
FIG. 6 illustrates portions of a cylinder assembly 10 and a portion of a sinker 12 , which is shown by dashed lines, in accordance with a fifth embodiment of the present invention. The cylinder assembly 10 in accordance with a first version of the fifth embodiment of the present invention is identical to the cylinder assembly of the third embodiment of the present invention, and the cylinder assembly in accordance with a second version of the fifth embodiment of the present invention is identical to the cylinder assembly of the fourth embodiment of the present invention, except for variations that are noted and variations apparent to those skilled in the art.
In accordance with the fifth embodiment of the present invention, the lower nib 30 of the sinker 12 closely overlies the composite receiving channel 24 (FIGS. 1 - 5 ) and the biased restricting member 26 therein, so that the sinker is prevented from pivoting downward. More specifically, in accordance with the fifth embodiment of the present invention, the bottom surface 34 of the lower nib 30 of a sinker 12 slides across a top surface or surfaces of the biased restricting member 26 in a bearing-like fashion so as to restrict downward movement of the sinker, while the sinker 12 reciprocates in its upwardly extending slot 18 (FIG. 1 ).
In accordance with the fifth embodiment of the present invention, the composite receiving channel 24 and the biased restricting member 26 are positioned so that the biased restricting member bears all of the downward forces applied by the sinker 12 with respect to the cylindrical portion 14 (FIGS. 1 - 5 ). That is, the bottom surface 34 of the lower nib 30 does not come into contact with the base wall of the respective upwardly extending slot 18 (FIG. 1) or the upper face 19 (FIG. 1 ). Thus, the advantages provided by the fifth embodiment of the present invention correspond to the advantages provided by the second embodiment of the present invention.
In accordance with other embodiments of the present invention, advantages like those provided by the fifth embodiment of the present invention are achieved with a receiving channel and a restricting member positioned at or proximate to the upper face 19 of the cylindrical portion 14 , as will be discussed in greater detail below.
Sixth Embodiment
FIG. 7 illustrates portions of a cylinder assembly 10 and a portion of a sinker 12 , which is shown by dashed lines, in accordance with a sixth embodiment of the present invention. The cylinder assembly 10 of the sixth embodiment of the present invention may be identical to the cylinder assembly of any of the first, second, third or fourth embodiments of the present invention (that is, in accordance with the sixth embodiment the cylinder assembly may include the receiving channel 24 (FIGS. 1 - 5 ) and the biased restricting member 26 (FIGS. 1 - 5 )), except that in accordance with the sixth embodiment of the present invention the cylinder assembly further includes a receiving channel 50 and a restricting member 52 . More specifically, in accordance with the sixth embodiment of the present invention, the cylindrical portion 14 defines the receiving channel 50 , which is in receipt of the restricting member 52 . Further, it is also within the scope of the sixth embodiment of the present invention for the cylinder assembly 10 not to include the receiving channel 24 and the restricting member 26 .
More specifically, the receiving channel 50 can be characterized as a somewhat U-shaped channel that encircles the cylindrical axis of the cylindrical portion 14 and has an opening that is defined by the upper face 19 (also see FIG. 1) of cylindrical portion. The receiving channel 50 has, or is defined by, opposite and vertically extending inner and outer walls of the cylindrical portion 14 that extend upward from opposite sides of a base wall of the cylindrical portion, which provides the base of the receiving channel 50 .
The restricting member 52 , which may or may not be biased, is preferably an elongate, arcuate, or hoop-like member, such as a piece of wire, a spring or a spring-like piece of wire, or the like. The restricting member 52 is positioned in the receiving channel 50 and functions to provide a bearing-like surface that is engaged by the bottom surfaces 34 of the sinkers 12 and restricts undesired downward movement of the sinkers.
One example of an acceptable restricting member 52 is a length of wire having opposite ends. In accordance with one version of the sixth embodiment of the present invention, the piece of wire defines a circular shape having a diameter that corresponds to the diameter of the receiving channel 50 , and the piece of wire is placed into the receiving channel 50 . The force of gravity may maintain the piece of wire in the receiving channel 50 , or, alternatively, the piece of wire may be press-fit into the receiving channel or secured in the receiving channel by other conventional means.
In accordance with another version of the sixth embodiment of the present invention, the piece of wire is biased toward a straight configuration such that when the wire is free from the receiving channel 50 the wire extends substantially or somewhat straight, or the piece of wire is biased toward an arcuate or somewhat circular configuration having a relaxed diameter that is larger than the diameter of the receiving channel 50 . As a result, when the wire is manually placed in the receiving channel 50 , the wire seeks to return to its relaxed configuration, which causes the wire to become biasedly engaged to the outer wall of the cylindrical portion 14 that defines the receiving channel, whereby the wire is engaged to the cylindrical portion 14 . As shown by dashed lines in FIG. 8, the outer wall of the cylindrical portion 14 that defines the receiving channel 50 may be angled, so that a biased piece of wire is biased into an angled crotch defined between the outer and base walls of the cylindrical portion that define the receiving channel.
In accordance with another version of the sixth embodiment of the present invention, the piece of wire is biased toward an arcuate or somewhat circular configuration having a relaxed diameter that is smaller than the diameter of the receiving channel 50 . As a result, when the wire is manually placed in the receiving channel 50 , the wire seeks to return to its relaxed configuration, which causes the wire to become biasedly engaged to the inner wall of the cylindrical portion 14 that defines the receiving channel, whereby the wire is engaged to the cylindrical portion 14 . As shown by dashed lines in FIG. 8, the inner wall of the cylindrical portion 14 that defines the receiving channel 50 may be angled, so that a biased piece of wire is biased into an angled crotch defined between the inner and base walls of the cylindrical portion that define the receiving channel.
The opposite ends of any somewhat circular or hoop-like piece of wire used in the receiving channel 50 may not be joined to one another, so that the wire has a discontinuous circumference. Alternatively, the opposite ends of such a piece of wire can be joined, such as by brazing or welding the ends together.
In accordance with another version of the sixth embodiment of the present invention, the restricting member 52 is an elongate helical spring that is wound so that it is in the form of an elongate, somewhat tube-like member which may be unbiased or biased toward any of the configurations described above with respect to the pieces of wire. Additionally, the opposite ends of the tube-like member may be attached to one another, such as by brazing or welding, so that the helical spring is in the form of a hoop or circle, or the like.
In accordance with another version of the sixth embodiment of the present invention, the restricting member is a hardened circular band having a substantially constant cross-sectional configuration, such as a substantially rectangular cross-sectional configuration, or a substantially circular cross-sectional configuration or other cross-sectional configurations. A suitable hardened circular band is disclosed in U.S. Pat. No. 5,577,401, which has previously been incorporated herein by reference.
Throughout this Detailed Description of the Invention section of this disclosure, unless expressly stated otherwise or understood otherwise by those skilled in the art, reference to a restricting member 52 within the receiving channel 50 is to be considered to alternatively include all of the variations of restricting members discussed above.
In accordance with the sixth embodiment of the present invention, the bottom surface 34 of the sinker 12 closely overlies the receiving channel 50 and the restricting member 52 therein, so that the sinker is prevented from pivoting downward. More specifically, in accordance with the sixth embodiment of the present invention, the bottom surface 34 of the sinker 12 slides across a top surface of the restricting member 26 in a bearing-like fashion so as to restrict downward movement of the sinker, while the sinker 12 reciprocates in its upwardly extending slot 18 (FIG. 1 ).
As mentioned above, the upper face 19 (also see FIG. 1) is preferably coplanar with the base walls of the slots 18 (FIG. 1 ), so as to define a first plane. In accordance with the sixth embodiment of the present invention, the receiving channel 50 and the restricting member 52 are positioned and sized so that the uppermost surface of the restricting member 52 is coplanar with the first plane, or most preferably the uppermost surface of the restricting member is at an elevation that is slightly above the first plane. That is, in accordance with the sixth embodiment of the present invention, the receiving channel 50 and the restricting member 52 are arranged so that the restricting member bears all of the downward forces applied by the sinker 12 with respect to the cylindrical portion 14 that would otherwise be born by the upper face 19 or the base walls of the slots 18 . That is, in accordance with the sixth embodiment, the bottom surface 34 of the sinker 12 preferably does not come into contact with the base wall of the respective upwardly extending slot 18 or the upper face 19 . Thus, the advantages provided by the sixth embodiment of the present invention correspond to the advantages provided by the second embodiment of the present invention.
Seventh Embodiment
FIG. 8 illustrates portions of a cylinder assembly 10 and a portion of a sinker 12 , which is shown by dashed lines, in accordance with a seventh embodiment of the present invention. The cylinder assembly 10 of the seventh embodiment of the present invention is identical to the cylinder assembly of the sixth embodiment of the present invention, except for variations that are noted in this disclosure and variations apparent to those skilled in the art.
In accordance with the seventh embodiment of the present invention, the upper and lower surfaces of the restricting member 52 are broad and flat in cross-sections of the restricting member. The broad and flat upper surface of the restricting member 52 provides an enlarged bearing-like surface that slidingly receives the bottom surface 34 of the sinker 12 , and that enlarged bearing-like surface enhances and prolongs the optimal operation of the cylinder assembly 10 . The broad and flat upper and lower surfaces of the restricting member 52 may be formed by forcing a restricting member having a round cross-section through a nip defined between shaping rollers, or similar conventional means, so that the restricting member becomes shaped as illustrated in FIG. 8 . Alternatively, the broad and flat upper and lower surfaces of the restricting member 50 may be formed by machining material away from the upper and lower surfaces of a restricting member originally having a round cross-section.
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | A readily replaceable restricting member is within an annular receiving channel that is defined by a cylindrical portion of a circular knitting machine, and the restricting member is operative to restrict at least upward or downward movement of the sinkers of the circular knitting machine. The sinkers are operative for reciprocating radially relative to the cylindrical portion and the restricting member such that sliding contact is defined between the sinkers and the biased restricting member. In accordance with several of the embodiments of the present invention, each of the sinkers comprises an upper nib and a lower nib, a radially extending slot is defined between the upper nib and the lower nib, and the slot is open at the leading edge of the sinker. In accordance with several embodiments of the present invention, the restricting member is in the travel paths of the sinkers so that the biased restricting member is at least partially received within the radially extending slots in response to the radial reciprocating of the sinkers. In various combinations, upper surfaces of the lower nibs contact the restricting member, lower surfaces of the upper nibs contact the restricting member, and lower surfaces of the sinkers contact the restricting member, so that movement of the sinkers is restricted. In accordance with several embodiments of the present invention, the restricting member is biasedly engaged within the receiving channel. | 3 |
This application is a continuation-in-part of Ser. No. 08/650153, filed Feb. 20, 1996.
FIELD OF THE INVENTION
This invention relates generally to an automated stitching or suturing device. More particularly, this invention relates to an automated stitching or suturing device which can be used advantageously in surgical procedures such as coronary artery bypass grafting (CABG) surgery, laparoscopic procedures, and various less invasive surgical procedures.
BACKGROUND OF THE INVENTION
Suturing by surgeons is currently generally accomplished by manual suturing of tissues, whereby the surgeon uses a fine pair of pliers to grab and hold a suture needle, pierce the tissue with the needle, let go of the needle, and regrab the needle to pull the needle and accompanying suture thread through the tissues to be sutured. Such needles may be curved or "C"-shaped, with the suture thread attached to the back end of the needle.
Automated suturing devices, including devices described as suitable for microsurgery, are known. For example, U.S. Pat. No. 4,557,265 to Andersson describes a suturing instrument for joining two edges of biological tissue, such as blood vessels, using an arcuate suture needle which is driven and rotated by friction rollers via a cylindrical fly-wheel and plunger rod arrangement with a pneumatic or other drive source, so that the suture thread forms a continuous suture looped through the two tissue edges. U.S. Pat. No. 4,899,746 to Brunk describes a suturing apparatus in which an electric motor drives a curved needle around in a circular path of travel by means of a gear arrangement connecting to a plurality of drive rollers in supporting and driving arrangement with the needle. U.S. Pat. No. 5,308,353 to Beurrier describes a surgical suturing device in which an arcuate needle having outward projecting angled barbs positively engages and is rotated by a continuous loop drive belt.
However, such known automated suturing devices have not found wide use due to the inherent deficiencies of their design and operation, including needle slippage, inefficient transfer of drive motion to the advancement of the needle, inefficient and impractical drive mechanisms, and generally poor performance of the devices, particularly for microsurgical applications where a very small size for the device is required. Accordingly, there is a need for an improved suturing device which overcomes these deficiencies.
SUMMARY OF THE INVENTION
The stitcher device of the present invention is an automated stitching or suturing device in which a "C"-shaped arcuate suturing needle is positively driven in a circular path to suture tissues, including blood vessels. The "C"-shaped arcuate needle is held and advanced in increments by clutches and by a drive plate and toggle mechanism, which converts rotary motion to oscillating motion, and is powered via a drive shaft connected to an electric motor. The "C"-shaped needle and drive plate are positioned at the end of an elongated shaft. The stitcher is particularly adapted for use in microsurgery and/or in interior body spaces. For example, in coronary bypass surgery, the stitcher device of the present invention is able to precisely and rapidly place stitches to join grafts to coronary arteries and to seal leaks in the grafted vessels.
In general, it is an object of the present invention to provide an automated stitcher device which can be used for surgical and other applications. A further object of the invention is to provide a suturing instrument which can be used for microsurgical applications, including the suturing of blood vessels, and preferably which can be operated by a surgeon using one hand.
Additional objects and features of the invention will appear from the following description in which preferred embodiments are set forth in detail in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut-away top view of the distal portion of one embodiment of the stitcher.
FIG. 1A is an enlarged view of the distal extremity of FIG. 1.
FIG. 2 is a side view in cross-section of FIG. 1.
FIG. 2A is an enlarged view of the distal extremity of FIG. 2.
FIG. 3 is a cross-sectional end view of the distal nose tip of the stitcher.
FIG. 4 is a cut-away top view of the full length of the stitcher.
FIG. 5 is a side view of the main portion of FIG. 4.
FIG. 6 is a side view of FIG. 4 showing three positions for the stitcher distal nose tip.
FIG. 7 is an enlarged cut-away top view of the embodiment of the nose tip of the stitcher in FIGS. 1 and 1A.
FIG. 7A is a further enlargement of a portion of FIG. 7 depicting engagement of a needle with the clutch components of the stitcher.
FIG. 8 is a cut-away top view of the distal portion of another embodiment of the stitcher.
FIG. 9 is a side view in cross-section of FIG. 8.
FIG. 10 a perspective view of the crank-toggle configuration of the embodiment of FIGS. 8 and 9.
FIG. 11 is a cut-away portion of another embodiment of the nose tip and clutch components of the stitcher.
FIG. 12 is a cut-away portion of another embodiment of the nose tip and clutch components of the stitcher.
DETAILED DESCRIPTION OF THE INVENTION
Turning in detail to the drawings, with like reference numbers referencing like components, FIG. 1 shows the distal portion of a stitcher 10 incorporating a preferred embodiment of the present invention generally comprising an elongated tubular body or housing member 30, a head assembly 21, and a nose tip 20 having a "C"-shaped arcuate needle 12 slidably mounted therein for 360° rotation within nose tip 20. Housed within head assembly 21 and tubular body 30, from the distal end or nose tip 20 to the proximal end, are a drive plate 16, a diamond-shaped toggle 18, a crank pin 32, crank shaft 38, drive shaft 40 (FIGS. 1 and 2), and a nose tip articulation mechanism 51 (FIGS. 4-6). At the proximal end of stitcher 10 is an electric motor 56 coupled to the stitcher base 42 (FIG. 4).
Stitcher 10 is preferably made of medical grade stainless steel, and is designed to be held in the hand, similar to the way a pencil or pen is held. The length of stitcher 10 from nose tip 20 to stitcher base 42 is approximately between 15 and 20 cm but may be more or less depending on the application. Tubular housing 30 has a diameter more or less equal to the diameter of the arc of needle 12. Preferably, the length and diameter of stitcher 10 are configured for use in conventional open surgeries as well as minimally invasive surgeries.
As is more clearly shown in FIGS. 1A and 7, needle 12 has an arc preferably in the range between about 200° and 300°, and more preferably has an arc about 270°. Needle 12 has a sharp point 13 at one end and a suturing thread 14 attached to the other end thereof. The diameter of needle 12 is approximately 0.23 mm (0.011 inches), a typical diameter for surgical needles, and the outer diameter of the arc of needle 12 is preferably about 6-7 mm (0.25 inches). Needle 12 is preferably made of stainless steel; however, other surgical grade materials are suitable, as will be appreciated by those skilled in the art.
Needle 12 is engaged and held at nose tip 20 within an arcuate guide, track, groove, or channel 41 which extends around an arc of more than about 180° and has the same radius of curvature as needle 12. Arcuate guide 41 is defined by a static guide or clutch body 22 and also by a dynamic guide or clutch body 24, as well as by a drive plate 16. Because needle 12 extends along an arc greater than 180°, at least a portion of needle 12 is always in positive engagement within guide 41. During operation of stitcher 10, needle 12 is caused to travel about guide 41 by actuation of dynamic clutch body 24, about rivet 15. The function of static and dynamic clutch bodies 22 and 24 is described in more detail below.
Static clutch body 22 has one or more clutch components or engaging units 23, and dynamic clutch body 24 has one or more clutch components or engaging units 25. Each clutch component 23, 25 is comprised of a plurality of clutch fingers 26 extending radially outward at a slight arc from clutch bodies 22 and 24 which engage the inner curved surface of the needle 12. For example, the clutch component may be composed of a stack or fan configuration of bendable or flexible leaf springs or reeds, each having a length of about 2 mm (0.07 inches) and a width of about 0.5 mm (0.02 inches). These fingers 26 are preferably made of hardenable 17-7 stainless steel. Although static clutch body 22 and dynamic clutch body 24, as shown in FIGS. 1, 1A, and 7, each have two clutch components 23, 25 each having four clutch fingers 26, more or fewer clutch components and/or fingers may be used for each clutch body. For example, dynamic clutch body 24 may have multiple engaging units spaced along its arcuate guide 41 an arcuate distance preferably greater than about 90°. Additionally, solid sprags could be used in place of the flexible clutch fingers.
In a preferred embodiment, as shown in FIG. 7A, needle 12 has a series of radially inward projecting protuberances or protrusions 17 on its inner curved surface for engaging one or more clutch components or engaging units 23 of static clutch body 22 and one or more clutch components or engaging units 25 of dynamic clutch body 24. More specifically, protuberances 17 and clutch components 23, 25 are designed and have dimensions which allow a clutch component to frictionally engage the needle within the valleys or spaces between the protuberances. The peak-to-peak distance of the protuberances is approximately 0.20 to 0.25 mm and preferably about 0.22 mm (0.0087 inches), and the height of protuberances 17 from the inner diameter of needle 12 to the peak of protuberances 17 is approximately 0.03 to 0.05 mm and preferably about 0.04 mm (0.0015 inches).
The operation of stitcher 10 is as follows. A crank shaft 38 is driven by the rotational movement of elongated drive tube shaft 40 which is, in a preferred embodiment, powered by electric motor 56 (see FIG. 4). Motor 56 is of a type commonly known, for example having a gear head 59 which rotates drive shaft 40 when motor 56 is operably coupled to a power supply (not shown) via associated electric cable 58. Alternately, a pneumatic or hand-driven, rather than an electric, motor drive could be used. Crank shaft 38 and drive shaft 40 are coaxially provided and rotationally moveable within a bearing sleeve 34 (FIG. 2). Bearing sleeve 34 is fixed to tubular housing 30 by means of keys 36, and allow crank shaft 38 and drive shaft 40 to rotate independently of tubular body 30.
As can be seen in FIG. 1, crank shaft 38 has a crank pin 32 extending from its distal end at an acute angle α from the longitudinal axis of crank shaft 38, and resides within a slot 31 that extends through the diameter in the proximal end of a diamond-shaped toggle 18. A pin 73 extends through the longitudinal center of toggle 18 and serves to maintain alignment of the toggle 18 as well as crank shaft 38 and drive shaft 40 within tubular housing 30. In order for crank pin 32 to maintain continuous alignment within slot 31 as crank shaft 38 rotates, angle α is such that the longitudinal axis of crank pin 32 passes through the center of pin 73. Accordingly, α is between about 5° and 10°, and closer to 7°.
FIG. 2 provides a side cross-sectional view of the distal portion of the stitcher 10, showing the crank pin 32 and its engagement with toggle 18, wherein crank pin 32 has been rotated and toggle 18 has been oscillated 90° from their respective positions in FIG. 1. The distal end of toggle 18 tapers to a spherically shaped tip 27 which mates with the slotted configuration of the proximal end of drive plate 16.
The crank-toggle configuration described converts the rotary motion of drive shaft 40 and crank shaft 38 to the oscillating motion of toggle 18, which, in turn, moves drive plate 16 back and forth (which is up and down as viewed in FIG. 1). In addition, alternate crank-toggle configurations, such as that depicted in FIGS. 8-10, may also be used to effect the translation of rotary to oscillating motion.
FIGS. 8 and 9 illustrate cut-away views of the distal portion of a stitcher having a crank shaft 80 with a distal end in the form of a swash plate 81. The face 85 of swash plate 81 extends forward at a slight angle β from the vertical axis 82 and abuts toggle 83 at its proximal end 84, which is in the form of a triangular wedge, as is more clearly seen in FIG. 10. Angle β is such that face 85 is perpendicular to the central axis of toggle 83 when proximal end 84 is in its extreme positions. Here, β is between about 5° and 10°, and closer to 7°. FIG. 9 shows a cross-sectional side view of crank shaft 80 and toggle 83 when toggle 83 is in a centered position, or otherwise described as half-way between its extreme positions.
Referring again to FIGS. 1, 1A, 2A, and 7, at the distal end of drive plate 16 is formed the dynamic clutch body 24. The oscillating movement of drive plate 16 rocks the dynamic clutch body 24 back and forth in an arcuate path, which incrementally and non-continuously advances the arcuate needle 12 in a circular path within guide 41 and about an axis, defined by a rivet 15, which is perpendicular to the longitudinal axis of tubular housing 30. Needle 12 is advanced in less than about 180° increments, and preferably less than about 30° increments, and more preferably about 15° increments.
In a preferred embodiment, clutch bodies 22, 24 are one-way or uni-directional clutches. As shown in FIG. 7, the sets of clutch fingers 26 are slightly arced in the direction that needle 12 is advanced, here, in a clockwise direction. Each set of clutch fingers 26 occupies at least a substantial portion of the space between two consecutive protuberances 17. When dynamic clutch body 24 is caused to rotate in the clockwise direction, its associated clutch components 25 grip needle 12 and advance it in the clockwise direction. However, when dynamic clutch body 24 is caused to rotate in the counter-clockwise direction (opposite the direction in which fingers 26 are pointing), the flexible arced clutch components 25 are able to freely slide over protuberances and, thus, release needle 12. Simultaneously, arced clutch components 23 of static clutch body 22 grip and hold needle 12, and ensure that needle 12 is held in place until the next incremental, clockwise advancement of dynamic clutch body 24 by drive plate 16. The slight forward arcing of clutch fingers 26 prevents needle 12 from sliding backwards or in the counter-clockwise direction when dynamic clutch body 24 is rotated in a forward or clockwise direction. In another embodiment, clutch fingers 26 may be arced in a counter-clockwise direction which would act to advance needle 12 in a counterclockwise direction upon the oscillation of drive plate 16 and dynamic clutch body 24.
In other embodiments, the inner curved surface of the needle 12 may be smooth or roughened, or contain gears, ratchet teeth, or like protrusions to aid in gripping of the clutch elements, or the clutch bodies 22, 24, may be bi-directional clutches.
Other clutch mechanisms may also be utilized with the stitcher of the present invention to hold and facilitate incremental advancement of arcuate needle 12 by drive plate 16. For example, one-way bearings or rollers may be used, positioned along the inner curved side (FIG. 11) or the outer curved side (FIG. 12) of arcuate needle 12, and such bearings or roller clutches serve to engage, hold, or secure the needle while permitting its incremental advancement.
FIGS. 11 and 12 show cut-away portions of the nose tip 100 of a stitcher having a needle 102 held within a channel 101 defined by respective static and dynamic clutch bodies and drive plates 104. The roller or bearing clutches 106 of FIG. 11, two associated with each of static clutch body 108 and dynamic clutch body 110, are positioned on the inside curved side of needle 102. In FIG. 12, the roller or bearing clutches 120, two associated with static clutch body 122 and dynamic clutch body 124, respectively, are positioned on the outside curved side of needle 102. As with embodiments discussed previously, the dynamic clutch bodies of the embodiments of FIGS. 11 and 12 are integral with their respective drive plates 104 and rotate about a rivet 112 when the drive plate 104 is rotated, while static clutch body 108 remains in a fixed position.
Each roller clutch 106 (FIG. 11) and 120 (FIG. 12) comprises a roller or bearing 107 which resides within a curved bearing slot having a tapered rearward section 109 and a forward section occupied by a spring 111 which is biased against bearing 107. The width of tapered rearward section 109 is less than the diameter of bearing 107 such that the spring bias causes bearing 107 to be frictionally engaged within rearward section 109. Accordingly, when drive plate 104 and dynamic clutch body 110 of FIG. 11 are rotated in a forward or clockwise direction, bearings 107 of both the dynamic and static clutch bodies 110 and 108 are caused to sufficiently overcome the spring bias and roll clockwise, allowing needle 102 to advance in a forward or clockwise direction within channel 101. However, when dynamic clutch body 110 is caused to rotate in a backward or counter-clockwise direction, bearings 107 of FIG. 11 are, in turn, caused to become frictionally engaged within tapered end 109 of the bearing slot and are unable to roll. The bearings 107 of static clutch body 108 exert a sufficient force on needle 112 to hold it in its advanced position while dynamic clutch body 110 is rotated backward or counter-clockwise. The bearing 107 of dynamic clutch body 110 slide along needle 112 but do not overcome the force exerted on needle 112 by the now static bearings of static clutch body 108. In this way, needle 112 can be incrementally advanced in an arcuate path. The operation of static and dynamic clutch bodies 122 and 124 of FIG. 12 is similar to that of FIG. 11 with the exception that bearings 107 of roller clutches 120 roll counter-clockwise when dynamic clutch body 124 is rotated in a forward or clockwise direction.
With the various embodiments of the present invention, the sequential steps of gripping, incrementally advancing, and then releasing of a surgical needle by the dynamic clutch body are repeated as needed for driving the needle to form the desired suture.
Returning to a description of the other stitcher components, FIGS. 1A, 2A, and 3 show the details of nose tip 20 at the distal extremity of stitcher 10. FIG. 2A shows a circular assembly cap plate 19 with a rivet 15 at stitcher nose tip 20. Cap plate 19 serves to hold in place and cover static clutch body 22 and dynamic clutch body 24 to prevent blood, tissue particles, dust, and other undesirable elements from interfering with these components.
As shown in FIGS. 1A and 3, thread 14, being attached to the back end of the needle 12, will follow the rotation of the needle 12, but may be offset from the path of the needle 12. As discussed above, the components of the nose tip 20 may form an arcuate guide or a circular groove or track 41 within which the arcuate needle 12 is disposed.
FIG. 4 provides a view of the full length (with a cut-away section) of stitcher 10, having motor 56 with gear head 59 coupled to the stitcher base 42 by means of threaded motor mount 54. Seal 57 and coupling 55 provide the connection between drive shaft 40 and motor 56. Extending from the back end of motor 56 is an electric cable 58 for connection to a power supply. A hand-held control mechanism or foot pedal mechanism may be used for regulating the speed of motor 56 and for optimizing the speed or rate of rotation of needle 12. For example, the speed of motor 56 may be increased so as to provide a very rapid rotation of needle 12 wherein the incremental advancement of needle 12 appears to approach a "continuous" rotation. Conversely, the motor speed may be reduced such that the incremental advancement of needle 12 is intermittent.
Stitcher 10 is also provided with a nose tip articulation means 51 which includes a handle or lever 46 (FIG. 5), two cables 50 each having a ball fitting 61 (FIG. 2), a cable anchor 52, a spring 44, and a brake shoe 48 (FIG. 6). Nose tip 20 is hinged and can be articulated about pivot point 49 at various angles, as shown in FIG. 6, by adjusting the position of handle or lever 46. Lever 46 is pivotally mounted at base 42 and is preferably located on stitcher 10 so as to be easily manipulated by the user's thumb or finger of the hand in which stitcher 10 is held. Lever 46 may be configured to be moveable along the length of the stitcher 10 for accommodating various surgical applications. Alternatively, the nose tip articulation mechanism of the present invention may include a low-profile finger tip lever or actuator located just proximal to head assembly 21.
Articulation means 51 further includes two cables 50 each extending substantially within and along the length of tubular body 30 from nose tip 20 to lever 46. Two ball fittings, one at the distal end of each cable 50, are held in respective sockets 61 located distally of the center of rotation or pivot point 49. The proximal ends of cables 50 are held by a cable anchor 52 mounted to lever 46. The cable anchor 52 provides the mechanism for adjusting the length of cables 50. Tension on cables 50 is provided by a spring 44 which is biased against a brake shoe 48 abutting the distal side of lever 46.
Thus, as shown in FIG. 6, clockwise pivoting of lever 46 causes the associated cable 50 to pull up on nose tip 20 and rotate it upward (designated in phantom at 70) about the center of rotation of point 49. Similarly, counter-clockwise pivoting of lever 46 causes the other associated cable 50 to pull upon on nose tip 20 and rotate it downward (designated in phantom at 71). Nose tip articulation means 51 allows nose tip 20 to be rotated within a total range of approximately 180°, more or less, or about 90°, more or less, left and right of a centered position. The force exerted by spring 44 maintains tension on cables 50 and applies a braking force on lever 46, and thus, serves to hold nose tip 20 in the selected articulated position.
The entire nose tip 20, including needle 12 and drive plate 16, may be pivoted while maintaining engagement between drive plate 16 and toggle 18. The spherical end of toggle 18, which engages drive plate 16, permits nose tip 20 to pivot and yet maintains the oscillating motion of drive plate 16 necessary to drive needle 12. By manually rotating stitcher 10 about its longitudinal axis and simultaneously articulating nose tip 20, the position of nose tip 20 and needle 12 therein can be varied to accommodate almost any suturing angle.
The way in which "C"-shaped needle 12 is engaged or held and advanced by drive plate 16 and toggle 18 combination, as disclosed, permits stitcher 10 to have a tip whose dimensions are not much larger than the width and height of needle 12 itself. The resulting small tip and profile of stitcher 10 provides good site access and visibility to the surgeon. Some or all of the distal portion of the stitcher 10 may comprise a removable cartridge containing at least needle 12 and attached thread 14 and which may be disposable.
It is further contemplated that the disclosed clutch mechanism may be utilized to engage, hold, and facilitate advancement of an arcuate needle by various other drive means, including drive means which provide continuous, rather than incremental, advancement of the arcuate needle.
Although stitcher 10 of the present invention has been described principally in conjunction with surgical suturing applications, it should be appreciated that it is not limited to surgical uses, and can also be used for any sewing or stitching application. Further, while embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art that many other and further embodiments of the invention are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims. | An automated stitching device having a "C"-shaped arcuate needle which is incrementally advanced in a circular path. A toggle and drive plate arrangement is used to drive the needle, and a one-way clutch mechanism is used to engage and permit incremental advancement of the needle along its circular path. The "C"-shaped arcuate needle is mounted and driven at the distal end of an elongated shaft. The stitching device is particularly suited for microsurgery, laparoscopic surgery, and various less invasive surgical procedures, and particularly for the suturing of blood vessels including during cardiac bypass surgery. | 3 |
FIELD OF THE INVENTION
[0001] The present invention is directed towards a cylinder former having a variable hydraulic pulse whilst drainage, for use in papermaking.
BACKGROUND OF THE INVENTION
[0002] Today there are numerous ways of forming continuously a sheet of paper or paperboard, for example the use of a number of separate forming sections. The capital cost required to install one of the multifoudrinier is high and sometimes the change is not feasible because of the total capital required. Accordingly, in certain applications, the use of a cylinder mould in formation is desirable.
[0003] The principle of sheet formation on a cylinder mould is as follows. A horizontal cylinder (cylinder mould) having a wire cloth surface is arranged to rotate approximately three quarters submerged in a container (vat) of paper stock so that a small arc of its circumference is above stock level. Water associated with the fibrous suspension drains through the wire cloth with the result that a layer of fibers is deposited on the surface. Drainage take place because of a difference in level between the stock in the vat and the back water inside the mould.
[0004] A moving felt (mould felt/making felt) is then pressed by means of a roll (couch roll) into a contact with the cylinder at approximately the top position. By doing this the layer of fibers that has formed on the wire screen is transferred to the mould felt which moves away from the forming screen with it. Once the web has been transferred, the wire of the cylinder mould is washed by sprays and re-enters into the fiber stock where a new web is going to be formed.
[0005] If a number of these units are placed in series, then a multi-ply web or sheet of paper is produced continuously. Each forming unit typically has its own supply of paper stock and a method of removing the drainage water from its interior so that, in effect, each cylinder mould is a separated web forming machine in itself.
[0006] Various types of cylinder mould or vat arrangements currently exist. In this regard, a typical cylinder mould is constructed around a cast iron core upon that are secured bronze supporting spokes known as spiders. The spiders support concentric rims, the outside peripherals of which are grooved in order to carry rods that are approximately 1 centimeter in diameter and approximately 3.5 centimeters apart parallel with the axis of the central shaft. A continuous wire is wound round the cylinder.
[0007] On this skeleton is commonly sewn a bronze or stainless steel backing wire. It is over this backing wire that the forming wire is stretched and secured.
[0008] Another type of arrangement is what is known as contraflow vat where the stock flows opposite to that of the rotation of the mould. In this regard, the stock from the flow distribution arrangement enters the side at the bottom of the vat, passes over a weir and then over a baffle, rising again to be fed into the vat circle via wing boards (butterfly) and a making board. The purpose of the wing board is to help to correct the basis weight levels, when they have the tendency to be lighter or heavier on one side or the other.
[0009] In a uniflow vat, the basic components are essentially the same as for a contraflow vat, but the stock flows with the direction of the mould rotation.
[0010] In a dry vat situation, the dry vat has a seal introduced into the vat circle so that the fiber suspension is confined to a shorted section of a vat circle. Because the forming length has been reduced in size, the degree of uncontrolled turbulence is decreased.
[0011] In a restricted flow vat or half vat, it is essentially a dry vat with the unused half removed.
[0012] In the case of the contraflow vat, the stock enters the vat at considerable turbulence but in a short time becomes less turbulent and moves slowly through the vat towards the opposite side. This is the point where the forming surface of the mould enters the stock and where the major portion of the web formation is taking place. It is found that, in this zone, suspension is practically stationary and the stock is in an extremely flocculated state. Adjacent to the rotating mould surface a boundary layer is formed which moves rapidly in the direction of the cylinder rotation. The thickness of this layer depends on the consistency of the stock, its freeness and machine speed. Continued drainage without a corresponding fiber deposition leads to the consistency in this layer increasing to become substantially higher than that of the inlet stock. This stream of high consistency stock follows the cylinder surface to the point where the mould surface emerges. Here it mixes with the incoming stock and is recirculated to the other side of the cylinder thus increasing the consistency.
[0013] Between the two streams of stock mentioned above, an unstable layer is formed and localized differences in velocities are created which lead to a continuous exchange of stock between the two streams. This in turn leads to a non-uniform flow velocity and a non-uniform consistency across the machine that gives uneven conditions influencing both the web formation and the stock wash-off at the line of emergence.
[0014] In the case of the uniflow vat, at its inlet there is a turbulent flow that extends over the entire vat section, but this turbulence diminishes as the stock flows downward towards the center of the vat. It is during this first phase at the inlet that the rapid preliminary formation takes place. Some time later, when the flow velocity through the wire has decreased to a certain level, a boundary layer is formed that travels with and approximately at the velocity of the mould surface. This layer transports to the side of the vat a sufficiently large volume of stock to cause stagnation of other layers close to the walls of the vat. As in the case of the previously mentioned contraflow vat, wash-off takes place and results in the elevated consistency of the boundary layer. Where the mould surface leaves the stock, some thickened stock separates from the cylinder, some of this being discharged at the overflow while the remainder flows back downwards into the vat. The consistency of this stock is higher than that at the boundary layer. Counterflow and boundary layer are separated by an unstable intermediate layer through which thickened stock from the counterflow stream is fed back irregularly onto the boundary layer stream. This has a negative effect on web formation. The level differences between the vat and the inside cylinder level, the freeness, the machine speed and the amount of overflow control the intensity of the counterflow.
[0015] A rotoformer or sandy hill former consists of an open-ended perforated suction cylinder that is covered by a coarse backing wire and a fine face wire. Inside the cylinder are adjustable compartmented boxes into which drainage takes place under controlled conditions. There is also an initial draining zone at the beginning of web formation where draining is by means of gravity. The pond regulator can have its position adjusted in order to change the stock velocity and pressure applied at the initial forming zone.
[0016] The forming length is very short, 10 to 25 centimeters, while the drainage flow rate in the forming zone is very high limiting the basis weight and consistency that this former can handle.
[0017] A cylinder suction former consists essentially of a tapered stock inlet system from which tubes feed the stock to a dispersion chamber, followed by a top lid which can be adjusted on the run. Web formation takes place between the top lid and surface of the mould. The position of the suction box can be adjusted on the run. The forming length is very short, 10 to 25 centimeters, while the drainage flow rate in the forming zone is very high limiting the basis weight and consistency that this former can handle.
[0018] A short pressure former is a combination of a well-designed stock inlet with an explosion chamber feeding directly into a forming zone. The fiber suspension passes from a tapered inlet through a series of shear pipes into a small compartment, known as the explosion chamber, where the fiber dispersion takes place. Finally, the dispersed fibrous suspension passes to the forming zone where it is confined between a hinged lid and the mould surface. In this case, formation takes place under pressure. The forming length is very short, 10 to 25 centimeters. The drainage flow rate in the forming zone is very high limiting the basis weight and consistency that this former can handle.
[0019] Examples of some of the foregoing with modifications can be found in the following patents:
[0020] U.S. Pat. Nos. 1,801,238 1,870,971 3,021,899 3,091,563 3,111,454 3,272,692 4,543,159
[0021] While the types of cylinder mould arrangements as aforenoted have particular advantages, they also have attendant disadvantages some of which have certain been mentioned.
SUMMARY OF THE INVENTION
[0022] It is therefor a principal object of the invention to overcome the shortcomings of the devices heretofore mentioned.
[0023] It is a further object of the invention to provide for a hydraulic pulsing of the stock that is going to form the sheet to enhance stock distribution whilst also providing for drainage.
[0024] The formation of the sheet is the result of physical interaction during the forming process. There are three important hydrodynamic processes during the sheet formation. These processes are drainage, shear and turbulence.
[0025] The drainage process has two stages, one is filtration and other is thickening. Filtration is obtained when in the early part of the forming zone a high rate of water removal is achieved, the fines retention is high but shear is not present during this process. Thickening is obtained when small amounts of water are removed. During this process, fines retention is low.
[0026] The shear process is the result of controlling the differential speed between the stock flow and the forming (mould) machine. This process has to be controlled accurately or the final sheet will not have the desired properties.
[0027] The turbulence is present when the fibers in the stock flow are well dispersed at any consistency and the two hydrodynamic processes above described are present at the same time.
[0028] An additional objective of the invention is to provide the combination of the three aforementioned hydrodynamic processes in one forming zone and all of them interacting at the same time, the design of the forming zone will vary depending upon the particular operation.
[0029] In this regard, the present invention provides for a cylinder mould former which utilizes an adjustable contoured section in its forming zone. The contoured section provides for control over the ratio between the fiber suspension velocity and the cylinder mould velocity. The MD/CD ratio of the paper improves and becomes lower which is similar to that of a fourdrinier paper machine. At any given position of the contoured section, the fiber suspension flow is subject to continuous hydraulic pulses so the water is forced to pass in and out of the mould. The contoured section is graduated so as to eliminate flow separation due to shear at the boundary layers. The sheet formation occurs as a result of the gently pulsation of the stock slurry and the gradual removal of water as the water/fiber mixture moves towards the discharge lip near the top of the cylinder. This process will decrease or eliminate the filtration process, thus uniformly distributing fines across the thickness of the newly formed sheet. In addition, a baffle arrangement is provided to avoid stock build-up at the bottom of the former.
BRIEF DESCRIPTION OF DRAWINGS
[0030] [0030]FIG. 1 shows a cross sectional view of the inventive former.
[0031] [0031]FIG. 2 shows an enlarged cross sectional view of the forming zone of the inventive former of FIG. 1.
[0032] [0032]FIG. 3 shows an enlarged cross sectional view of the adjustable contoured section of the inventive former of FIG. 1.
[0033] [0033]FIGS. 4 a and 4 b show a schematic of the principle of operation of the former.
[0034] [0034]FIG. 5 shows an alternative embodiment of the present former.
[0035] [0035]FIG. 6 shows an alternative embodiment of the present former.
DETAILED DESCRIPTION OF THE INVENTION
[0036] [0036]FIG. 1 shows a cross sectional view of a preferred embodiment of the former. Former 10 includes a cylinder mould 12 which is coupled with a drainage outlet 14 which includes a fan pump (unseen) which sends the stock to the former and receives the entrained liquid from the cylinder mould 12 . The general generic operation of the former 10 is along the lines of those previously discussed. A paper stock inlet 16 is provided and may comprise a series of shear hoses in the cross machine direction which feeds paper stock 20 from a distributor (unseen). The paper stock 20 fed through shear hoses 17 is subject to an explosion chamber 18 . The former 10 further comprises a baffle 24 and a seal 26 to prevent the water drained through mould 12 from entering the forming zone 32 . When paper stock 20 encounters baffle 24 and seal 26 , the water 28 is separated from paper stock 20 to form a fiber suspension 30 . Fiber suspension 30 is then passed to a forming zone 32 (FIG. 2) which further comprises an adjustable contoured section lip 34 adjacent to the cylinder mould surface 12 . Adjustable contoured section lip 34 has one hinged side 36 to allow for adjustment of distances from the cylinder mould 12 and the other side an adjustable sliding mechanism 38 for rush/drag adjustment producing a paper web with MD/CD ratio control similar to a fourdrinier paper machine. In this regard, the sliding mechanism 38 allows the contour section lip 34 to be adjusted in an angular basis from the pivot point 36 , by doing this operation the contour section lip 34 will be adjusted at various distances from the cylinder mould 12 because of the radial distances from the hinge point 36 and the seal mechanism 38 as well as the angular movements of the contour section lip 34 . The distance from the contour section lip 34 to the cylinder former 12 will change (increase) because of the radial distance from the hinge point 36 . This operation will allow to control in a very precise manner the rush drag ratio and drainage of the stock, controlling the hydraulic pulses.
[0037] Also, adjusting the contour section 34 provides control over the ratio between the fiber suspension velocity and the cylinder mould 12 velocity. This allows one to control the amount of water remaining in the fiber suspension 30 .
[0038] The drain water 28 will flow through the cylinder mould 12 , and out of the cylinder mould 12 towards a baffle 39 located on the discharge side. Baffle 39 is curved and extends in the cross-machine direction substantially co-extensive with the width of the cylinder mould 12 . Drain water 28 will follow the cylinder mould 12 rotation, as shown by the arrows in FIG. 3. The excess water will exit at the port between the baffle 39 and the seal 26 - 24 . This process avoids the stock from build up at the bottom of the former eliminating the possibility of any plug or cylinder mould 12 jam by providing a scouring effect.
[0039] Turning now more specifically to FIG. 2, it shows forming zone 32 in greater detail. At any given position on the adjustable contoured section lip 34 , the fiber suspension 30 is subject to continuous hydraulic pulses forcing the water to pass in and out of the mould 12 through the series of hills and valleys. The remaining water is drained from the contour section 34 to a flat section 40 to form a sheet of paper 42 . This flat section can also be a curved lip which follows the shape of the cylinder.
[0040] In FIG. 1, a felt 44 is then pressed by means of a couch roll 46 into a contact with the cylinder mould 12 at approximately the top position. By doing this the layer of fibers forming the sheet of paper 42 that has formed on the wire screen is transferred to the felt 44 which moves away from the forming screen with it.
[0041] [0041]FIG. 3 shows in detail the dilution zone 48 where fiber dispersions takes place and the drainage zone 49 where shear effect in boundary layers is generated. The combination of these two processes will produce a sheet of paper well-formed, free of flocks and will allow higher stock loading per former.
[0042] The principle of operation of the improved former is that in the area between the contoured section lip 34 and the cylinder mould 12 , the large distances B 1 , B 2 , . . . B n therebetween is in continuous reduction as well as to the distances A 1 , A 2 , . . . A n as shown in FIGS. 4 a and 4 b . The pressure differential forces water 28 back to the cylinder mould 12 and forces fiber suspension 30 through the system as shown in FIG. 4 b . The shape of the adjustable contoured section lip is designed in such a manner that flow separation at the boundary layers between the adjustable contoured section lip 34 is minimized or otherwise eliminated.
[0043] Such design considerations may be in accordance with the following:
[0044] Let C be the cord from 0 to 1
[0045] Angular Increments every 5 degrees
[0046] θ=0 . . . 180
[0047] Equation to find x every 5 degrees increments
X = [ c 2 * ( 1 - cos ( θ * Π 180 ) ) ]
[0048] Equation Yt evaluated
Yt= 1.4845. t. SQRT[ 0.437* c *(1−cos(θ*π/180))−8.79*10 −2 *c 2 *(1−cos(θ*π/180)) 2 +3.55375*10 −2 *c 3 *(1−cos(θ*π/180)) 3 −6.34375*10 −3 *c 4 *(1−cos(θ*π/180)) 4 ] Yc = [ m p 2 * [ 2 * p * [ c 2 * ( 1 - cos ( θ * Π 180 ) ) ] - [ c 2 * ( 1 - cos ( θ * Π 180 ) ) ] 2 ]
[0049] m=Maximum ordinate
[0050] p=Cordwise position of maximum ordinate
[0051] Xc value is calculated as follows
Xc = [ c 2 * ( 1 - cos ( θ * Π 180 ) ) ] - Yt * sin ( θ )
[0052] Y1 value is calculated as follows
Y 1 =Yc+Yt *cos(θ)
[0053] One section of the contour lip profile is the result of plotting Xc vs. Y1
[0054] The stream line that defines the contour lip is depending on the specific speed of the application and is as follows:
ψ = U * y = q * θ 2 Π Y = U * [ c 2 * ( 1 - cos ( θ * Π 180 ) ) ] * sin ( θ * Π 180 )
[0055] U is the velocity at any given point
[0056] q is the mean velocity of the media
[0057] Accordingly, sheet formation occurs as a result of the gentle pulsation of the stock slurry and the gradual removal of water as the water/fiber mixture moves towards the discharge lip near the top of the cylinder mould 12 . The process decreases the speed of the filtration, thus uniformly distributing fines across the thickness of the newly formed sheet. The advantages of the improved former results in paper having an MD/CD ratio similar to any fourdrinier machine. There is also an increase in the basis weight capacity over that of prior formers; improvement in the paper formation at any capacity thus improving quality; increase in production capacity; in addition to a lower capital investment in comparison to prior art formers.
[0058] The operation of the above embodiment may be enhanced by the use of an alternative embodiment shown in FIG. 5 which further comprises a forming wire 50 , vacuum flat boxes 52 , pick up roll 54 and transfer felt 56 . The water remaining in the fiber sheet 58 is further drained by way of vacuum boxes 52 , to reach a desired dryness. After the formed sheet 58 is fed over vacuum boxes 52 , the felt 56 is fed through pick up roll 54 which will remove the formed sheet 58 for further processing. The alternative embodiment has the benefit of being able to increase the load of the former 10 without loss of paper quality or additional energy consumption.
[0059] An second alternate embodiment is shown in FIG. 6. The former 10 further comprises a mixing roll 60 near the baffle 24 and at a point where a high consistency stock flows from the stock inlet 16 . This rotating mixing roll 60 disperses the stock and so that the former 10 may use high consistency stock (2 to 4%) from the distributor. The mixing roll 60 disperses the fibers reusing the water that is presently inside the cylinder mould. The additional benefit of this embodiment is the reduction of the energy and size of the fan pump used to feed stock to the former 10 .
[0060] Thus by the present invention its advantages will be realized and although preferred embodiments have been disclosed and described in detail herein, its scope should not be limited thereby rather its scope should be determined by that of the appended claims. | A cylinder former having a variable hydraulic pulse whilst drainage, for use in papermaking comprising a drainage means comprising a cylinder mould and a contoured member adjacent the cylinder mould having a plurality of hills and valleys which force entrained liquid through the fiber suspension forming on the cylinder mould so as to improve sheet formation. A baffle is provided in the discharge portion of the former to prevent stock build-up therein. | 3 |
TECHNICAL FIELD OF INVENTION
[0001] The invention relates to the asymmetric synthesis of (−)-venlafaxine using an organo catalyst. Particularly, the invention relates to the selective synthesis of one enantiomer of venlafaxine using the organocatalyst.
BACKGROUND AND PRIOR ART
[0002] Venlafaxine is a new generation antidepression drug, first introduced in 1993. It is used for the treatment of major depressive disorder (MDD), as a treatment for generalized anxiety disorder, and co-morbid indications in certain anxiety disorders with depression. In 2007, venlafaxine was the sixth most commonly prescribed antidepressant on the U.S. retail market, with 17.2 million prescriptions. Although venlafaxine is sold as a racemate, (−)-venlafaxine is a more potent inhibitor of norepinephrine synaptosomal uptake while (+)-venlafaxine is more selective in serotonin uptake. It is different from other antidepressants in that it has no or little activity on a variety of neuroreceptors. (e.g. α OR β-adrenergic receptors, muscarinic receptors, cholinergic receptors, histaminic receptors etc.).
[0003] There are number of racemic syntheses reported for venlafaxine, including those by the inventors. These synthetic routes for racemic venlafaxine mainly involve the condensation of cyclohexanones with 4-methoxyphenyl acetic acids or 4-methoxyphenyl acetonitriles followed by functional group manipulation.
[0004] As both enantiomers possess different biological activities, therefore asymmetric synthesis of Venlafaxine is a subject matter of interest.
[0005] Nanda et al in Tetrahedron Letters 53 (2012) 1990-1992 reported an enzyme based resolution for asymmetric synthesis of venlafaxine. Their strategy included (S)-HNL catalyzed synthesis of cyanohydrins from cyclic ketones and lipase-PS catalyzed kinetic resolution for creation of the stereocenter.
[0006] Chem. Commun., 2006, 3110-3112 disclose β-Amino esters which are readily formed from rhodium(II) prolinate-catalyzed intermolecular C—H insertion between methyl aryldiazoacetates and a bis-silyl protected methylamine. This was applied for effective synthesis of venlafaxine with enantiomers obtained with moderate yields moderate % ee.
[0007] But prior art methods suffer from the main drawback of having to resolve the enantiomers in a separate dedicated step, and yet result in only moderate yield. Also, these processes employ hazardous and potentially explosive reagents. They need dry, inert conditions during use of Grignard's reagent and many processes need cryogenic conditions. Also, these prior art processes use metal based catalyst which are not environmentally friendly.
OBJECTS OF INVENTION
[0008] The main object of the invention is to provide a process for asymmetric synthesis of (−)-venlafaxine, wherein one enantiomer is obtained in high enantiomeric purity.
[0009] Another object of the invention is to provide a process to those results selectively in one enantiomer of venlafaxine, without the need for a step of resolution.
SUMMARY OF INVENTION
[0010] Accordingly, the present invention provides a process for asymmetric synthesis of enantiomerically pure venlafaxine with ee≧99% comprising the steps of:
a. reacting anisaldehyde with nitromethane in mole ratio 1:11.8 in presence of ammonium acetate in acetic acid under sonication condition at room temperature ranging between 25-35° C. for a period ranging between 2-4 hrs to obtain nitro styrene; b. michael addition of nitrostyrene as obtained in step (a) with cyclohexanone in mole ratio 1:5 in presence of proline based organocatalyst under stirring at room temperature ranging between 25-35° C. for a period ranging between 23-25 hrs in the presence of p-toluene sulphonic acid to obtain nitro ketone; c. reducing nitro ketone of step (b) using NaBH 4 in THF:H2O (9:1) to obtain crude alcohol (2S)-2-((R)-1-(4-methoxyphenyl)-2-nitroethyl)cyclohexan-1-ol which on subjecting to nitro reduction by NiCl 2 .6H 2 O and sodium borohydride in MeOH as a solvent, afforded the resultant amine (2S)-2-((R)-2-amino-1-(4-methoxyphenyl)ethyl)cyclohexan-1-ol which on in situ protection by benzylchloroformate in presence of Et 3 N as a base furnished Cbz protected amino alcohol benzyl ((2R)-2-((1S)-2-hydroxycyclohexyl)-2-(4-methoxyphenyl)ethyl)carbamate; d. treating amino alcohol of step (c) with mesyl chloride in presence of Et 3 N as a base in DCM solvent under reflux condition at temperature ranging between 40-45° C. for a period ranging 14-25 hrs to give the crude mesylated reaction mixture which further on treatment with DBU in acetonitrile solvent furnished selectively more substituted double bond product benzyl (R)-(2-(cyclohex-1-en-1-yl)-2-(4-methoxyphenyl)ethyl)carbamate; e. subjecting compound (R)-(2-(cyclohex-1-en-1-yl)-2-(4-methoxyphenyl)ethyl)carbamate of step (d) with NaH and MeI in dry THF to obtain benzyl (R)-(2-(cyclohex-1-en-1-yl)-2-(4-methoxyphenyl)ethyl)(methyl)carbamate; f. epoxidation of benzyl (R)-(2-cyclohex-1-en-1-yl)-2-(4-methoxyphenyl)ethyl)(methyl)carbamate of step (e) by treating with m-CPBA in presence of NaHCO 3 in DCM under stirring at temperature ranging between 25-35° C. for a period ranging between 1-3 hrs to afford crude epoxide benzyl ((2R)-2-(7-oxabicyclo[4.1.0]heptan-1-yl)-2-(4-methoxyphenyl)ethyl)(methyl)carbamate; g. subjecting the crude epoxide of step (f) to selective epoxide opening as well as carbamate reduction in one pot using lithium aluminum hydride at reflux condition at temperature ranging between 65-70° C. for a period ranging 4-5 hrs in THF to afford (−)-venlafaxine.
[0018] In one embodiment of the present invention the overall yield of enantiomerically pure (−)-venlafaxine is in the range of 21-22%.
[0019] In an embodiment of the present invention the enantioselectivity of (−)-venlafaxine is in the range of 99-99.9%.
[0020] In another embodiment of the present invention proline based organocatalyst used in step (b) is (S)-N1,N1-dimethyl-N2-(pyrrolidin-2-ylmethyl)ethane-1,2-diamine
BRIEF DESCRIPTION OF FIGURES
[0021] FIG. 1 : Chromatogram for racemic venlafaxine
[0022] FIG. 2 : Chromatogram for optically pure venlafaxine
[0023] FIG. 3 Scheme I indicates Retrosynthetic analysis of (−)-venlafaxine.
[0024] FIG. 4 : Scheme 2 indicates synthesis of venlafaxine
DETAILED DESCRIPTION OF INVENTION
[0025] Abbreviations used:
PTSA: para-Toluene sulphonic acid. THF: Tetrahydrofuran. Cbz: Carbobenzyloxy. Ms: Methanesulphonyl DBU: 1,8-Diazabicyclo[5.4.0]undec-7-ene. m-CPBA: meta-Chloroperoxybenzoic acid. DCM: Dichloromethane LAH: Lithium aluminium hydride.
[0034] The process of the invention is outlined in Scheme 1.
[0035] According to retrosynthetic analysis, synthesis of (−)-venlafaxine began with Henry reaction of commercially cheap, easily available starting material anisaldehyde 6 with nitromethane in presence of ammonium acetate in acetic acid under sonication condition at room temperature to furnish nitro styrene 5 in 95% yield. Michael addition of nitro styrene 5 with cyclohexanone in presence of proline based organocatalyst 11 gives nitro keto compound 4 in 79% with ≧99% ee after stirring 24 hours at room temperature in presence of p-toluene sulphonic acid (PTSA) as an additive in DMF solvent. Selective reduction of keto 4 using NaBH 4 in THF:H 2 O (9:1) as solvent system afforded alcohol. The crude alcohol was subjected to nitro reduction by NiCl 2 .6H 2 O and sodium borohydride in MeOH as a solvent, then the resultant amine was in situ protected by benzylchloroformate in presence Et 3 N as a base to furnish Cbz protected amino alcohol 7 in 75% yield.
[0036] Scheme 2. Reagents and conditions: a) Nitromethane, NH 4 OAc, glacial acetic acid, ))), 3 hrs, 95%; b) Cyclohexanone, 11, PTSA, DMF, 24 hrs, 79%, ≧99% ee; c) i) NaBH 4 , THF:H 2 O (9:1), 2 hrs.; ii) NiCl 2 .6H 2 O, NaBH 4 , MeOH, 1.5 hrs., 0° C. then CbzCl, Et 3 N, rt, overnight, 75% (over two steps); d) i) MSCI, Et 3 N, reflux, 14 hrs; ii) DBU, CH 3 CN, 24 hrs, reflux, 68% (over two steps); e) MeI, NaH, THF, overnight, rt, 92%; f) i) m-CPBA, NaHCO 3 , DCM, 2 hrs., rt. LiAlH 4 , THF, 5 hrs, reflux, 60% , ≧99% ee.
[0037] The hydroxyl group of compound 7 was converted into corresponding mesyl derivative by using mesyl chloride in presence of Et 3 N as a base in DCM solvent under reflux condition. The crude mesylated reaction mixture on treatment with DBU in acetonitrile solvent furnished selectively more substituted double bond product 8 in 68% yield. After introduction of double bond dihydroxylation reaction condition was tried for installation of tertiary hydroxyl group. After successful installation of diol through dihydroxylation (OSO 4 , NMO), selective removal of secondary hydroxyl group failed. So it was decided to install tertiary hydroxyl group through epoxidation and followed by epoxide opening. Thus the compound 8 was subjected with NaH and MeI in dry THF to afford compound 9 in 92%- yield. For epoxidation compound 9 was treated with m-CPBA in presence of NaHCO 3 in DCM to afford epoxide. The crude epoxide 10 was subjected to selective epoxide opening as well as carbamate reduction in one pot using lithium aluminum hydride at reflux condition in THF to afford (−)-venlafaxine 1 in 60% yield with ≧99% ee. Spectral data and optical rotation for (−)-Venlafaxine 1 is provided herein in the form of examples.
[0038] This strategy of asymmetric synthesis of venlafaxine 1 by using organocatalyst can be extended to the synthesis of both enantiomers by switching the stereocentre of the catalyst with no loss in the optical activity of desired product. Derivatives of venlafaxine can be prepared in the same manner.
[0039] The invention is now explained with reference to embodiments and preferred embodiments, which in no way should be construed to be restrictive.
EXAMPLES
Example 1
Synthesis of (−)-Venlafaxine
[0040] Reacting anisaldehyde (20 gm, 0.147 mol) with nitromethane (94 mL, 1.741 mol) in presence of ammonium acetate in acetic acid (24 mL, 0.419 mol) under sonication condition at room temperature (25° C.) for a period of 3 hrs to furnish 24.7 gm nitro styrene 5 in 95% yield. Michael addition of nitro styrene 5 (3 gm, 16.8 mmol) with cyclohexanone (8.2 gm, 84 mmol) in presence of proline based organocatalyst (S)-N1,N1-dimethyl-N2-(pyrrolidin-2-ylmethyl)ethane-1,2-diamine (115 mg, 0.67 mmol) gives 6.1 gm of (S)-2-((R)-1-(4-methoxyphenyl)-2-nitroethyl)cyclohexan-1-one 4 in 79% with ≧99% ee after stirring 24 hours at room temperature (25° C.) in presence of pr-toluene sulphonic acid (PTSA) (127 mg, 0.67 mmol) as an additive in DMF solvent. Selective reduction of keto 4 (2 gm, 7.2 mmol)using NaBH 4 (0.816 gm, 21.6 mmol) in THF:H 2 O (9:1) (20 ml), as solvent system afforded (2.5)-2-((R)-1-(4-methoxyphenyl)-2-nitroethyl)cyclohexan-1-ol. The crude alcohol (2.06 gm, 7.4 mmol) was subjected to nitro reduction by NiCl 2 .6H 2 O (4.4 gm, 18.5 mmol) and sodium borohydride (7.03 gm, 0.185 mol) in MeOH (20 mL) as a solvent, then the resultant amine was in situ protected by benzylchloroformate (3.7 ml, 22.2 mmol) in presence Et 3 N (4 mL, 29.6 mmol) as a base to furnish 2.07 gm Cbz protected amino alcohol benzyl ((2R)-2-((1S)-2-hydroxycyclohexyl)-2-(4-methoxyphenyl)carbamate in 75% yield. The hydroxyl group of Cbz protected amino alcohol (100 mg, 0.26 mmol) was converted into corresponding mesyl derivative by using mesyl chloride (0.06 mL, 0.78 mmol) in presence of Et 3 N (0.22 mL, 1.56 mmol) as a base in DCM solvent under reflux condition (40° C.) for 14 hrs The crude mesylated reaction mixture (120 mg) on treatment with DBU (1 mL) in acetonitrile solvent (3 mL) furnished 64.6 mg of selectively more substituted double bond product 8 benzyl (R)-(2-(cyclohex-1-en-1-yl)-2-(4-methoxyphenyl)ethyl)carbamate in 68% yield. After introduction of double bond dihydroxylation reaction condition was tried for installation of tertiary hydroxyl group.
[0041] After successful installation of diol through dihydroxylation (OsO 4 , NMO), selective removal of secondary hydroxyl group failed. So it was decided to install tertiary hydroxyl group through epoxidation and followed by epoxide opening. Thus the compound 8 (100 Mg, 0.274 mmol) was subjected with NaH (22 mg, 0.55 mmol, 60%) and MeI (0.034 mL, 0.55 mmol) in dry THF (5 mL) to afford 95 mg compound 9 benzyl (R)-(2-(cyclohex-1-en-1-yl)-2-(4-methoxyphenyl)ethyl)(methyl)carbamate in 92% yield. To a cold (0° C.), magnetically stirred solution of N-methylCbz compound 9 (235 mg, 0.6 mmol) in distilled DCM (5 ml), NaHCO 3 (126 mg, 1.5 mmol) was added followed by 60% mCPBA (348 mg, 1.2 mmol) was added portion wise and stirred for 2 hrs at rt (25° C. ) The reaction was quenched with solid NaHCO 3 (300 mg) and stirred for further 15 min. The reaction mixture was extracted with DCM (3×5 ml) and the combined organic layer was washed with brine (7 mL) and dried over anhydrous Na 2 SO 4 , filtered and concentrated under reduced pressure. The crude reaction mixture was used as such in the next reaction without further purification.
[0042] To a cold (0° C.), magnetically stirred solution of lithium aluminum hydride (100 mg, 2.5 mmol) in dry THF (5 ml), crude epoxide 10 (100 mg, 0.25 mmol) was added dropwise and refluxed (66° C.) for 5 hrs. The reaction mixture was cooled to 0° C. and excess LAH was quenched with ethyl acetate and then by addition of water, stirred for 2 hrs. Evaporation of the solvent furnished a residue which was extracted with ethyl acetate (3×20 mL). The combined organic layer was washed with brine (20 mL) and dried over anhydrous Na 2 SO 4 , filtered and concentrated under reduced pressure. Purification of the residue on a silica gel column using ethyl acetate as eluent furnished the (−)-venlafaxine 1 (103 mg, 60%) as a white solid.
Example 2
Characterization Data of (−)-Venlafaxine
[0043] The product of the process enlisted in example 1 was characterized by IR and 1 H and 13 C NMR and results are as follows:
[0044] R f (100% EtOAc) 0.2 (long tail); IR (CHCl 3 ): 3164, 2982, 2938, 2860, 2782, 1610, 1512 cm −1 ;
[0045] 1 H NMR (200 MHz, CDCl 3 +CCL 4 ): 1 H NMR (200 MHz, CDCl 3 +CCl 4 ): 0.83-1.00 (m, 2H), 1.23-1.76 (m, 8H), 2.28 (dd, J12.2, 2.9 Hz, 1H), 2.33 (s, 6H), 2.93 (dd, J=12.2, 2.9 Hz, 1H), 3.28 (t, J=12.2 Hz, 1H), 3.79 (s, 3H), 6.79 (d, J8.8 Hz, 2H), 7.03 (d, j=8.79 Hz, 2H). 13 C NMR (50 MHz, CDCl 3 +CCl 4 ): 20.70, 21.05, 25.55, 30.72, 37.53, 44.89, 51.20, 54.36, 60.74, 73.48, 112.75, 129.43, 132.00, 157.72.
Example 3
Optical Purity of (−)-Vanlafaxine
[0046] (R)-venlafaxine [α]=−24.285 (c=1.04, EtOH).
[0047] Column: Kromasil 5-Amy Coat (250×4.6 mm)
[0048] Mobile Phase:EtOH:Pet ether: Diethylamine (05:95:0.5)
[0049] Wave length: 254 nm
[0000]
Racemic:
Chiral
Retention time Area %
Retention time Area %
12.075
47.587
15.158
100.000
15.283
52.413
ADVANTAGES OF INVENTION
[0000]
1. Use of cheap and easily available raw materials
2. Use of cheap and environmentally friendly catalyst
3. Avoidance of expensive and metal based catalyst
4. Avoidance of additional steps involving resolution of enantiomers
5. High % ee purity of product obtained | The patent discloses an asymmetric synthesis of (−)-venlafaxine using an organocatalyst via a unified strategy employing organcatalytic Michael addition, regio-selective dehydration and selective epoxide ring opening. | 2 |
BACKGROUND OF THE INVENTION
Cotton and cotton blend knit goods are commonly bleached with an alkaline hydrogen peroxide solution in a range which first saturates the goods with bleaching liquor, then heating the saturated goods by steaming and transiently storing the goods in a J-box while retaining the heat applied by steaming for a sufficient bleaching period. Prior U.S. Pats. No. 2,334,066 and No. 2,858,184 contain representative disclosures of such processing.
More recently systems have been developed in which the bleaching liquor was applied in the heel of the J-box while steaming in the straight leg of J-box below the piling level therein. Both of these systems, however, have involved troublesome disadvantages. Where the goods are saturated first and then steamed it has not been possible to stop the process without emptying the J-box because tendering of the goods results if this is not done, while when the bleaching liquor is applied at the heel of the J-box a constant poundage of throughput must be maintained in order to keep the J-box piling high enough in the straight leg of the J-box for steaming and steaming of the J-box pile has tended to yield non-uniform results.
The present invention eliminates these disadvantages.
SUMMARY OF THE INVENTION
According to the present invention the goods are first saturated with bleaching liquor and then fed to the J-box for steaming prior to piling therein, while additional heated bleaching liquor is maintained flowing through the heel of the J-box during processing, but means is provided whenever the feed of goods is to be interrupted to stop the steaming and redirecting the heel flow of bleaching liquor for unheated flow throughout the J-box pile of goods so that the bleaching action is discontinued, as described further below in connection with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevation of a bleaching range embodying the present invention; and
FIG. 2 is a perspective illustration of the J-box arrangement.
DETAILED DESCRIPTION OF THE INVENTION
Referring just to FIG. 1 of the drawings, the illustrated bleaching range is seen a cradle 10 from which a roll of greige goods to be bleached is fed to a dry scray 12 through a poteye 14 to rope the goods and through a pair of draw rolls 16 for accumulation ahead of a saturator 18. The roped goods enters the saturator through another poteye 20 and over driven reel 22 to an entering J-chute 24. Adjacent the top of the J-cute 24 a spray ring at 26 is fed from a recirculating system 28 running from the bottom of a bleaching liquor tub 30 to provide thorough penetration of the goods being treated as they enter the J-chute 24. The goods emerge from the J-chute 24 under an immersion roll 32 from which it is directed upwardly through a pair of squeeze rolls 34 and over an unloading doffer 36 to a wet scray 38 which accumulates the saturated goods for feed through the J-box 40.
The J-box includes a downwardly extending entry leg 42 having a poteye 42' at its bottom and at the top of which a three-roll cluster is arranged for pulling the goods upwardly and transferring them into the adjacent straight leg 44 of the J-box proper in which the goods are piled for progress ultimately through the curved bottom heel portion 46 from which the goods are led to a SLACK LOOP WASHER 48 and exits over a doffing roll 50 to a suitable truck or other receptacle to be conveyed for further processing.
The arrangement of the J-box 40 is indicated best in FIG. 2 of the drawings in which an inlet pipe is shown at 52 adjacent the top of the straight J-box leg for introducing steam above the piling point of the goods therein for heating the goods in the range of 140° to 212° F. during travel upwardly in the entry leg 42 and prior to piling in the straight leg storage portion. The steam enters the J-box 40 at the inlet 52 and flows counter-currently to the goods through the entry leg 42 and exits at a poteye at the bottom of this entry leg 42 through which the entering goods are trained.
The heated goods then progress downwardly in piled form through a major portion of the straight J-box leg 44 to the curved bottom heel portion at which further bleaching liquor is added through an inlet at 54 and exits through an outlet at 56 just before the goods are lifted out of the J-box 40 through a discharge poteye 60 for transfer to a SLACK LOOP WASHER 48. The further bleaching liquor is recirculated from a tank at 46' which incorporates a steam panel for indirect heating for the heel recirculation.
In operation, the goods pass through the range so as to leave with a 100% pick-up of bleaching liquor at the saturator squeeze rolls 34 and are pulled into the entry leg 42 of J-box 40 for uniform steaming that brings the goods up to bleaching temperature before being piled in the straight J-box leg 44 and this temperature is maintained by the recirculation provided in the J-box heel portion 46. Whenever the operation must be interrupted, however, as at the end of a shift the heel recirculation is redirected to the steaming point 52 and the liquor heat is shut off as well as the steaming so that the bleaching liquor is circulated throughout the J-box piled storage but at a temperature below that at which bleaching takes place so that tendering of the goods standing in the J-box 40 is avoided. As the J-box 40 is sized to contain 3,000 pounds or more of goods a good deal of time is saved in being able simply to shut it down whenever necessary without having to remove the goods first. With the arrangement of the present invention it is only necessary to begin preliminary steaming again and heated heel recirculation in order to start up the range again.
The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise to exclude any variation or equivalent arrangement that would be apparent from, or reasonably suggested by, the foregoing disclosure to the skill of the art. | An improved arrangement and method for bleaching textile goods is provided wherein a J-box is employed for storing the goods transiently for the bleach while allowing the travel of the stored goods to shut down whenever desired while leaving the goods in place without damage. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to relay circuits and, more particularly, to methods and apparatus for compensating for temperature changes affecting the overload trip level in such circuits.
2. History of the Prior Art
A great variety of solid state relays circuits have been devised which use a power semiconductor as the output switching device and use a silicon controlled rectifier or similar latching circuit to sense a current overload or short circuit condition. For example, U.S. Pat. No. 4,581,540 discloses such a circuit.
Although the circuit disclosed in the prior art patent application accomplishes its purpose well to limit overload current in normal operating conditions, the circuit does have a relatively high trip voltage of approximately 450 millivolts at room temperature of 25 degrees C., and that trip voltage is sensitive to changes in temperature in the operating environment. For example, when the circuit is used in environments in which the temperature varies from -55 degrees C. to 115 degrees C. (a relatively normal range for aircraft operation, for example), the trigger level at which the current protection trips the cutoff of the switching device varies by approximately 400% from 150 to 600 millivolts.
Although the objectives can be met by using operational amplifiers and comparators circuitry, such arrangements require the use of additional power supplies, eliminate the ability to provide optical isolation of the input, and often incur large increases in input current. These changes increase the cost, complexity, and size of the circuitry while decreasing its reliability.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an improved solid state relay with current overload protection which has a lower trip voltage level for triggering the overload protection.
It is another more specific object of the present invention to reduce the temperature variation of the trip voltage level for triggering current overload protection in a solid state relay circuit.
It is another object of the present invention to provide higher input impedance and lower power dissipation in solid state relay with current overload protection.
These and other objects of the present invention are realized in a solid state relay circuit comprising a metal oxide field effect transitor connected for switching current to a load circuit, a latch circuit including first and second transistors connected to monitor a voltage caused by current in the load circuit and to shunt current away from the field effect transistor in response to current overload in the load circuit, the first and second transistors having temperature characteristics such that they turn on in response to different voltages at different temperatures, the improvement comprising second means for turning on the latch to shunt current away from the field effect transistor in response to the voltage caused by current in the load circuit, the second means comprising temperature compensating means for matching the temperature characteristics of the first and second transitors of the latch circuit whereby the latch turns on at the same voltage in the load circuit over the typical operating range of the device.
These and other objects and features of the invention will be better understood by reference to the detailed description which follows taken together with the drawings in which like elements are referred to by like designations throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a solid state relay circuit of the prior art.
FIG. 2 is a schematic diagram of a switching circuit in accordance with the invention.
FIG. 3 is a modification to the circuit of FIG. 2.
FIG. 4 is a modification to the circuit of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a solid state relay circuit 10 of the prior art. The circuit 10 includes an input portion 11 including a current limiter 12 and a pair of light emitting diodes 13 and 14. A switching portion 15 includes a detector array 17 which is arranged to sense light generated by the light emitting diodes 13 and 14 and thereby provide the desired circuit isolation of the input circuitry. The detector array 17 is connected to the gate of a switching device 18 (which may preferably be a metal oxide field effect transistor) through a current limiting resistor 19. The detector array 17 is also connected to the source terminal of the switching device 18 through a resistor 21. A load circuit 22 and a voltage source 23 are arranged in series connecting the drain terminal of the switching device 18 and the resistor 21. Another resistor 24 is connected across the detector array 17.
In the normal operation of the switching relay, the provision of an input signal in the input portion of the circuit 10 (exemplified by the closing of a switch 25 to connect a battery 26 into the circuit) causes the light emitting diodes 13 and 14 to provide a light output which is detected by the detector array 17. The detector array 17 provides a signal between the gate and the source terminals of the switching device 18 which, when sufficient, turns on the switching device 18 and provides current to the load 22. When the input signal is removed from the input portion 11, the detector array 17 no longer generates a signal sufficient to operate the switching device 18; and that device 18 turns off, removing current from the load 22.
There are different conditions which may generate an overload current in the load 22 and such an overload current may damage or destroy the switching device 18 or the load 22. To limit the range of currents which may be furnished to the load 22 through the switching device 18, the circuit 10 is provided and arrangement for turning off the switching device in the presence of overload currents. The particular arrangement illustrated in FIG. 1 includes a first PNP transistor 28 and a second NPN transistor 29 connected to form a latch to short current away from the switching device 18. A resistor 31 joins the detector array 17 to the base of the transistor 28 and the collector of the transistor 29. The emitter of the transistor 28 is connected to the upper terminal of the detector array 17, and the emitter of the transistor 29 is connected to the lower terminal of the detector array 17. A resistor 32 is connected between the source terminal of the switching device 18 and the resistor 21 to provide a measure of the voltage across the resistor 21 to the collector of the transistor 28 and the base of the transistor 29 during operation of the switching device 18.
The latch arrangement effectively provides a pair of input terminals, one which measures the voltage across the resistor 21 and a second which measures a current to the collector of the transistor 29. The value of the resistor 21 is selected so that if the current through the load 22 becomes too large, the voltage across the resistor 21 (which is a measure of this current) increases to the point at which the latch is enabled, shorting the input across the source and drain terminals of the switching device 18. The voltage difference between the base and emitter junction of the transistor 29 turns that transistor on and causes current to be drawn through the emitter-base junction on the transistor 28. The transistor 28 turns on and locks the latch in the ON state. This causes the switching device 18 to be disabled, removing current from the load 22.
A major problem of the circuit 10 illustrated in FIG. 1 is that the voltage required to trigger the latch comprising the transistors 28 and 29 into operation changes drastically with temperature. Since this voltage is determined by measuring across the resistor 21, it is, in effect, a measure of the current through the switching device 18 and the load 22; and this value is allowed to vary drastically with temperature. More particularly, in a particular arrangement 10, the value of current through the load required to operate the latch varies from 1.3 amperes at -55 degrees C. through 1 ampere at 25 degrees C. to 0.33 amperes at 115 degrees C. Moreover, since the trip voltage necessarily varies in the same degree, the nominal trip voltage must be kept much higher than would be necessary were the value more stable. Coupled with the lower trip voltage would come lower overall power dissipation for the circuitry.
FIG. 2 illustrates a switching circuit 40 designed in accordance with the present invention. The circuit 40 includes elements of an input portion 11 essentially identical to the circuit 10 of FIG. 1 for energizing a pair of light emitting diodes 13 and 14 to provide an electrically isolated input. The switching circuit 40 also includes an output portion 15 which includes all of the elements of the output portion 15 of the circuit 10, all of which are identified by identical numbers in the figures. To the output portion of FIG. 2 are added a number of elements which cooperate with those the operation of which has already been explained to provide temperature compensation to the circuit 40.
These elements include a light emitting diode 42 arranged in parallel with a silicon diode 43. The light emitting diode 42 is optically coupled to one or both of the light emitting diodes 13 and 14 to sense the presence of an input signal in the input portion 11. The parallel arrangement of the silicon diode 43 and the light emitting diode 42 is connected to the emitter terminal of an NPN transistor 44 which has its collector connected to the base of the transistor 28 and the collector of the transistor 29. The base of the transistor 44 is connected by a resistor 46 between the switching device 18 and the resistor 21. A capacitor 47 is connected between the base of the transistor 44 and the negative side of the source voltage 23.
When input is applied as by closing the switch 25 in the input portion 11, the light emitting diodes 13 and 14 furnish detectable light to the detector array 17 and to the light emitting diode 42. The light emitting diode 42 is selected to generate about 1.1 volts when an open circuit and provides approximately 20 microamperes current in the short circuit condition. However, the light emitting diode 42 is connected in parallel with the silicon diode 43; consequently, the voltage across the light emitting diode 42 is constrained to be that across the diode 43. The voltage of the diode 43 varies with temperature from approximately 0.5 volts at -55 degrees C. through 0.350 volts at 25 degrees C. to 0.05 volts at 115 degrees C.
Since the transistor 44 is connected to the input at the base of the transistor 28 of the latch, when the transistor 44 turns on it will trigger the operation of the latch to short circuit the switching device 18 and turn off the circuit 40. The transistor 44 is turned on when the voltage applied across the resistor 21 becomes large enough that the voltage applied between the base and the emitter terminals of the transistor 44 becomes sufficiently great. The value of resistor 46 is chosen to provide little voltage drop so that biasing of the base-emitter terminals of the transistor 44 is essentially the difference created by the voltage across the resistor 21 and the voltage across the diode 43. As pointed out above, the voltages required to turn on a transistor (such as the latch transistors 28 and 29) and the voltage across the diode 43 vary with temperature. Consequently, by selecting a transistor 44 having a turn on voltage which varies across the expected temperature range in a manner which matches the variation of voltage across the silicon diode 43, a constant turn on voltage across the resistor 21 may be attained. This, in turn, translates into a relatively constant tripping of the latch comprising the two transistors 28 and 29 because the trip occurs at the current sink terminal of the latch rather than the voltage sensitive input terminal. Ultimately this translates into a relatively constant trip current through the switching device 18.
Using typical numerical values of emitter-base trip voltage of 0.450 volts for the transistor 44, a value of 0.350 volts across the diode 43 gives a voltage across the resistor 21 of 0.10 volts to trip the transistor 44 at 25 degrees C. At -55 degrees C., the transistor 44 requires 0.6 volts, the diode 43 drops 0.50 volts so the voltage across the resistor 21 is again 0.10 volts. At 115 degrees C., the voltage across the transistor 44 is 0.15, across diode 43 is 0.05, and across resistor 21 is 0.10.
Thus, it may be seen that the trip current through the switching device 18 is held constant with a wide variation in temperature by the circuit 40. Moreover, the relatively constant value of trip current allows a much lower value to be used to trigger the operation of the latch and, consequently, allows overall lower power dissipation. It should be noted that the combination of the resistor 46 and the capacitor 47 are selected to provide a timing circuit either a slight delay which eliminates nuisance tripping of the transistor 44 by fast current transients.
It will be recognized by those skilled in the art that other methods of implementing the invention are possible. For example, the parallel arrangement of the silicon diode 43 and light emitting diode 42 might be replaced by an NPN transistor with the same voltage-current characteristic of the silicon diode 43 and light emitting diode 42. A light sensitive transistor would provide the desired variation with temperature to compensate for the variation of the trip voltage of the latch with temperature. FIG. 3 illustrates such a circuit. An additional possibility would be to replace the light emitting diode 42 with a constant current diode or similar constant current device arranged in parallel with the silicon diode 43. FIG. 4 illustrates such a circuit.
Although the present invention has been described in terms of a preferred embodiment, it will be appreciated that various modifications and alterations might be made by those skilled in the art without departing from the spirit and scope of the invention. The invention should therefore be measured in terms of the claims which follow. | In solid state relay circuit including a metal oxide field effect transistor connected for switching current to a load circuit, a latch circuit including first and second transistors connected to monitor a voltage caused by current in the load circuit and to shunt current away from the field effect transistor in response to current overload in the load circuit, the first and second transistors having temperature characteristics such that they turn on in response to different voltages at different temperatures, the improvement including a second means for turning on the latch to shunt current away from the field effect transistor in response to the voltage caused by current in the load circuit, the second apparatus including temperature compensating apparatus for matching the temperature characteristics of the first and second transistors of the latch circuit whereby the latch turns on at the same voltage in the load circuit over the typical operating range of the device. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to circuit guarding and particularly to circuit guarding to protect circuits associated with integrated circuits operational amplifiers from internal (self-generated) leakage currents.
Techniques for shielding or guarding circuits or networks from the effects of leakage currents are well known. In general there are two types of guarding circuits used to prevent or inhibit leakage currents. One type, known as passive guarding, utilizes one or more conductors positioned adjacent to the active or signal circuits of concern and grounded to a common bus to serve as a shield, receptor, or sink of stray currents due to leakage effects. The other type is an active guard circuit which utilize conductors suitably placed adjacent to the active or signal circuits of concern, but provided with voltage potentials derived from the circuit of concern itself and arranged to divert leakage currents in such a manner as to minimize the effect of such currents on the circuit of concern. For a discussion of several design techniques, see an article entitled "New Design Techniques for FET Op Amps" published in the National Semiconductor Application Note (pages 5 and 6) AN-63 (March 1972).
Nevertheless, in certain applications, such as in air pollution control, medical electronics, space, instrumentation devices of high sensitivity and, in general, any application in which a high impedance circuit may be subject to deleterious effects of leakage current are still of concern, there is a need for a guard circuit that will minimize if not inhibit leakage currents, particularly, in the environment of printed circuit boards, hybrid circuit substrates, and integrated circuits.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a non-inverting amplifier schematic diagram embodying a circuit guard of the present invention.
FIG. 2 illustrates a printed circuit board embodying a portion of the circuit guard shown in FIG. 1.
FIG. 3 illustrates an inverting amplifier arrangement that includes a circuit guard according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a guard circuit 10 formed of resistor components R 1 ' and R 2 ' and R 3 ' joined at "nodes" E 1 ' and E 2 ' defined by the connection between the associated resistors and coupled between ground and output terminal 17 of operation amplifier (op-amp) 16. The signal circuit elements for op-amp 16 include resistors R 1 , R 2 , and R 3 joined at corresponding nodes E 1 and E 2 and coupled between ground, inverting (-) input terminal of op-amp 16, and output terminal 17 of op-amp 16 and compensation resistor R c coupled between terminal 19 and the non-inverting (+) terminal of op-amp 16.
The resistors of both the signal circuit and the guard circuit are of the discrete type suitably disposed on a printed circuit board. Their respective leads are connected to printed conductors or printed circuit traces 17 20, 22, 24, 26, 28, and 30 formed or mounted on the board.
Corresponding terminals of the guard circuit and signal circuit, as will be explained, are arranged to be at the same potential so as to provide an environment that will inhibit leakage currents from the signal circuit at the junctions of the resistor elements. These terminal and junction areas are termed herein "nodes".
Nodes E 1 , E 2 , E 1 ', and E 2 ' are each formed of an arrangement of conductors disposed on the circuit board and surrounding each terminal in such a manner as to isolate the protected terminal from the remaining portion of the board to thereby prevent surface current from flowing to or from the terminal. Such arrangements are known in the art as "guards."
FIG. 2 illustrates a typical implementation of nodes E 2 and E 2 ' on a printed circuit board layout for the circuit of FIG. 1 as illustrated. Note that the leads from resistors R 2 and R 3 terminate at node E 2 at their respective terminals 24a and 24b but do not touch guard conductor 14. In the actual physical construction of a double-sided printed circuit board array, such guard conductors should be repeated on the opposing side of the printed circuit board because leakage currents can occur on either side of the board so long as signal circuit potentials exist to generate an electric field.
The physical dimensions of the guard circuit arrangement is determined by the configuration of the circuit and other factors well known in the art.
Conductor 14 serves as a guard that isolates node E 2 of the signal circuit disposed in close proximity to node E 2 and is extended to terminate at node E 2 ' of the guard circuit. Guard conductor 14 intercepts any current leakage that may exist due to the potential of node E 2 and provides a low resistance path for such leakage current into the guard path 10.
Conductor 12 of FIG. 1 also serves as a guard that isolates the signal path at node E 1 between the terminals of resistors R 2 and R 1 . Guard 12 is used to intercept any leakage currents that may exist due to the potential of node E 1 and direct the leakage flow towards node E 1 '.
Conductor 18 in like manner serves as a guard for the non-inverting (+) input of op-amp 16 to intercept or inhibit leakage current at or about the (+) input. Resistor R c is coupled between the (+) input of op-amp 16 and terminal 19 to which an input voltage V in is applied. When the voltages V in and V out are within the linear range of op-amp 16 conductor 18 is essentially at the same potential as node E 1 and conductor 12, because the negative feedback effects maintain a substantially zero voltage difference between the input terminals of op-amp 16. Thus guarding of both node E 1 and terminal 30 is achieved with guard conductors 12 and 18 connected together.
Guard circuit 10 is arranged to generate voltages at the nodes (E 1 ', E 2 ', etc.), and thus at the guard conductors, (12, etc.), that are substantially equal to the respective voltages at corresponding terminals (26, 28, 30, 24, etc.) of the signal circuit (op-amp 16 and feedback resistors R 3 and R 2 , etc.). In general, the output voltage (V out ) of the op-amp circuit of FIG. 1 may be determined from the relation: ##EQU1## where R 1 , R 2 , and R 3 are the ohmic values of the resistors indicated, and V in is the input signal voltage. According to the invention, the guard circuit 10 relation to the signal circuit is arranged such that:
R.sub.1 /R.sub.1 ' = R.sub.2 /R.sub.2 ' = /R.sub.3 /R.sub.3 ' = k (2)
where
k >> 1
The lower impedance of guard circuit (10) is necessary so that leakage currents do not substantially disturb the voltages at nodes E 1 ' etc. of the guard circuit.
The relative value of the corresponding resistors of the guard circuit are conveniently determined by the relation:
R.sub.1 ' = R.sub.1 /K; R.sub.2 ' = R.sub.2 /K; R.sub.3 ' = R.sub.3 /K (3)
although the embodiment described utilizes resistive components, it should be understood that since any impedance circuit arrangement may be used for the signal circuit, the leakage compensation or inhibiting guard circuit (10) will also be formed of corresponding impedance components of the general form Z = R + jX. Thus, for uses of an inductive component, L n ' = L n /K, and for a capacitive component, C n ' = K C n , where the subscript (n) indicates the nth component of a general network. The particular guard circuit or network arrangement needed to meet a particular application of this invention will be readily apparent to those skilled in this art following the principles described above.
FIG. 3 illustrates a typical implementation of guard network (10) on a printed circuit board layout for a general case of "n" elements in a feedback circuit of an inverting amplifier configuration. The lower impedance guard circuit elements from Z 1 ' to Z n ' operate so that nodes E 1 ' through node E n-1 ' are at the same voltage potential as nodes E 1 through E n-1 of the signal circuit. As described above, the impedance components in the guard circuit (10) must be of a lower impedance value so that leakage current will tend to flow in the guard circuit thereby diverting any possible deleterious leakage current away from the signal circuit. Resistor Z k is used as a compensation resistor to compensate for input voltage offset while guard conductor 18 is used to intercept or inhibit leakage current which may interfere with the non-inverting (+) input of amplifier 16.
A circuit made in accordance with FIG. 1 had the following values for the impedances:
R 2 , R 3 = 20 Megohms
R 1 = 1 Megohm
R 2 ', R 3 ' = 200 Kilohms
R 1 ' = 10 Kilohms
R c = 1 Megohm | Current leakage from high impedance signal circuits or networks of the type useful in the feedback paths of operational amplifiers is inhibited or prevented by circuit guarding. A lower impedance, parallel path provides a guard circuit that protects the signal circuit elements from excessive self-generated current leaks during closed loop use of operational amplifiers. The guard circuit includes equal potential nodes in the lower impedance path that are juxtaposed to corresponding nodes of the signal circuit elements. Current leakages, that may occur in the signal path, are mostly intercepted by the lower impedance guard circuit preventing the formation of electric fields or current leakage paths that would affect normal signal circuit performance. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This Application claims the benefit under 35 USC §120 of co-pending U.S. patent application Ser. No. 11/078,980 filed Mar. 11, 2005.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to organizers for computer cables, electrical cords, and the like. The present invention relates more specifically to a mounting cabinet having a number of slots for inserting and securing individual cord wrapping bars.
2. Description of the Related Art
Some efforts have been made in the past to provide an apparatus which is capable of organizing multiple cords such as those found on a computer system or an entertainment system. These efforts have generally been directed to devices that provide an element for winding, tensioning, or wrapping the cords, cables, or wires in place in order to shorten the amount of cord or cable remaining loose. In general, however, these devices do not provide a simple unit for the secure and precise organization of multiple cords of varying length.
Some of these past efforts include winding reels, such as U.S. Pat. No. 2,533,341 issued to Alfano which is directed to a set of simple reels adapted to take up the slack in electrical cables and prevent unwinding. U.S. Pat. No. 3,924,819 issued to Lapinskas is directed to a spool-like device having a long hub with an outer surface on which a cord may be wrapped, as well as retaining rims and releasable clips for securing the cord. U.S. Pat. No. Des. 376,530 issued to Hawthorne is directed to the ornamental design for a cord organizer container having a number of spools with notched openings above each spool, openings on the side panels of the container, and a cover for the container.
Other prior art devices for cord storage include containers or canisters such as U.S. Pat. No. 4,705,484 issued to Lerner et al. which discloses a canister that includes a protective cover and an internal cylinder around which cords can be wound, having adjustable notched rings capable of holding cords in place. U.S. Pat. No. 4,721,268 issued to Lerner et al. is directed to an organizer consisting of identical elongated containers which can be used singly or attached in multiple units, the combination of which creates a base upon which other objects or small electrical appliances may be placed. U.S. Pat. No. 3,089,210 issued to Ritter is directed to a molded plastic cord holder for shortening and storing the intermediate portions of a cord by winding them around multiple partitions within the device in order to achieve the desired length. U.S. Pat. No. 6,039,280 issued to Stephens et al. is directed to a cable caddy for shortening and housing medical monitor cables in the operating room and at the bedside. The cable caddy includes a base and a number of cable cartridges having a winding surface and, optionally, one or more end flanges with cable grasps.
U.S. Pat. No. 4,858,846 issued to McDonald is directed to a harness to remove slack from coaxial type cables utilized with various electronic components. A container is provided with a number of telescoping heads to orient and secure the cables. Alternatively, spring biased spools may be used to enable a tensioned withdrawal of unused cable from the container. U.S. Pat. No. 6,590,785 B1 issued to Lima et al. is directed to a cable manager that arranges a number of cables which are engaged by bobbins and troughs forming a tray-like structure, wherein the cables may be additionally secured with clips or locks. U.S. Pat. No. 6,607,169 B1 issued to Gershfield is directed to an organizer designed to be attached to a table top, having a base with a cable guide extending at an angle for receiving the cables, and prongs with cable retainers extending upward above the base for guiding and arranging the cables.
While many attempts have been made in the past to provide an apparatus for organizing multiple cords and cables, some of which secure the cords into position, few if any of the devices provide a simple way to precisely shorten cords and/or add or remove individual cords, and at the same time provide frames or enclosures that are compact and easy to handle. Such features are not met by any system described in the prior art. It would be desirable therefore to have a versatile caddy design for power cord organization which includes a simple structure with slots to hold a plurality of bars with means on each bar for securing a cord or cable to a desired length to keep the cable from unwinding. The device should be of modular design wherein the reel components may be used alone or attached in multiple units within the organizer.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a system that combines a modular concept for storing and organizing cords with a simple design that permits easy removal or addition of cords and a straightforward method for wrapping and securing an individual cord to a desired length. The present invention utilizes a rectangular box design having slotted side panels which are slanted and sized such that a plurality of bars may be inserted therein and will not slip out accidentally. Each modular cord bar is designed with a number of notches for winding and holding a cord in place at varying lengths and allowing the user to leave only the desired amount of cord loose. The user can select the number of bars necessary for the specific components in use. Additionally, each bar can be removed separately to facilitate replacement or reorganization of the individual components without disruption of the other cord bars.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the cord organizer of the present invention without the front cover in place;
FIG. 2 is a perspective view of the cord organizer of the present invention with the front cover in place;
FIG. 3A is a detailed front view of an individual cord reel of the cord organizer of the present invention;
FIG. 3B is a detailed front view of an individual cord reel of the cord organizer of the present invention showing the first step in the method of wrapping a cord on the reel;
FIG. 3C is a detailed front view of a cord reel of the cord organizer of the present invention showing one configuration of completing the wrapping and securing of a cord on the reel;
FIG. 4 is a front view of the cord organizer of the present invention without the front cover in place showing an attached electric outlet strip;
FIG. 5 is a side view of the cord organizer of the present invention showing the placement of the cord reels in the side slots of the organizer;
FIG. 6 is a front view of the cord organizer of the present invention showing typical connections to electrical equipment and mounting to a table top; and
FIG. 7 is a detailed perspective view of the cord holder component of the cord organizer of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is made first to FIG. 1 for a brief overall description of the cable organizer apparatus 10 of the present invention. The cabinet frame 12 is generally shaped as a rectangular enclosure having a top frame panel 22 , a bottom frame panel 24 , and a back frame panel 26 . Additionally, a left side panel 18 and a right side panel 20 are slotted with a plurality of angled reel slots 16 a - 16 h for the insertion of one or more cable reels. Continuing in FIG. 1 , a first cable reel 14 a is shown fitted into angled reel slots 16 c and 16 d and a second cable reel 14 b is shown fitted into angled reel slots 16 e and 16 f . A first wire cable 15 a is wound around first cable reel 14 a to the desired length and a second wire cable 15 b is wound around second cable reel 14 b to the desired length.
FIG. 2 illustrates the cable organizer 10 of the present invention with cabinet frame cover panel 28 positioned in place on cabinet frame 12 , covering and further securing the cable reels 14 a and 14 b (as examples) into the angled reel slots 16 e and 16 f . The process of using the present invention involves a number of steps. First, the wire cables are wound around the cable reels to the desired lengths (as described in more detail below). Next, the cable reels are positioned within the angled reel slots. Finally, the cabinet frame cover panel is secured over the cabinet frame to help retain the cable reels within the reel slots and to protect the cables and wires from exposure.
Reference is now made to FIGS. 3A , 3 B, and 3 C which provide detailed front views of a cable reel of the present invention in various stages of being wrapped with a cable. Referring first to FIG. 3A , a representative cable reel 14 is shown in the preferred embodiment with the reel bar 30 having a plurality of winding apertures 38 a , 38 b , and 38 c , as well as aperture slots 40 a , 40 b , and 40 c . At either end of the reel bar 30 are the left side bar horn 34 a and the right side bar horn 34 b that fit into the slotted side panels of the cabinet frame 12 as shown above. Adjacent to the bar horns are the left side cable guide 32 a and the right side cable guide 32 b through which the cable is secured to the reel bar 30 as it enters and exits the cabinet frame 12 . Also located at either end of the cable reel bar 30 are left side bar end slot 36 a and right side bar end slot 36 b around which the cable length may be wound. Thus, a wire cable is first secured to the cable reel bar through either the right or left side cable guide (see FIG. 3B ). The wire cable is then drawn across and around the cable reel the required number of times and looped through an appropriate aperture slot into the corresponding winding aperture, depending on the length of the excess cable to be wound. The wire cable may be looped around the cable reel side bar end slot, an intermediate aperture slot, or both, as required to achieve the desired cable tension and length.
As shown in FIG. 3B , entering cable 15 is secured to the left side bar horn 34 a under the left side cable guide 32 a and wrapped across the reel bar 30 to the right side bar end slot 36 b . Continuing in FIG. 3C , the cable 15 is wound behind cable reel bar 30 to the left side bar end slot 36 a and again in front of the reel bar back to the right side bar end slot 36 b . Upon nearing the appropriate cable length, the cable 15 is wrapped around the reel bar through the half aperture slot 40 b to the half winding aperture 38 b and across to the right side bar horn 34 b where it is secured by the right side cable guide 32 b , where the cable 15 , now shortened to the desired length, exits the cabinet frame 12 . The various slots and apertures 40 a , 40 b , and 40 c and 38 a , 38 b , and 38 c are selected for use depending on the cable length and the amount of excess cable remaining for the particular use desired.
FIG. 4 illustrates the cable organizer apparatus of the present invention with the cabinet frame 12 holding a plurality of cable reels 14 a , 14 b , 14 c , and 14 d and securing a plurality of cables 15 a , 15 b , 15 c , and 15 d of varying lengths and types (cable 15 a has an RCA cable plug 52 , cables 15 b and 15 c are standard power cords, and cable 15 d has a coaxial cable plug 54 ). Each cable is secured to a particular reel bar and is attached to a bar horn by a cable guide. The particular cable is then wrapped around the reel bar to the desired length and attached by a cable guide to the bar horn at the opposite end of the reel bar. The reel bar is then inserted into the angled reel slots in the side panels of the cabinet frame as described in more detail below. A plurality of reel bars with associated secured cables may be inserted into the side panels of the cabinet frame.
At one side of the cabinet frame 12 are upper and lower power strip brackets 45 a and 45 b which secure an electrical power strip 44 to accommodate the cable electrical power plugs as required. A power strip cord 46 is attached to the electrical power strip 44 near the lower power strip bracket 45 b . A power strip plug 50 is attached to the distal end of the power strip cord 46 for insertion into an electrical wall outlet. A power strip switch 48 is positioned on the electrical power strip 44 as is known in the art.
FIG. 5 illustrates a side view of the cabinet frame 12 of the cable organizer apparatus of the present invention. As shown in FIG. 5 , the wire cables 15 a , 15 b , 15 c , 15 d , 15 e , and 15 f are positioned in the cable guides of the cable reels 14 a , 14 b , 14 c , 14 d , 14 e , and 14 f which are positioned within angled reel slots 16 a , 16 c , 16 e , and 16 g respectively, of cabinet frame 12 . An angled reel slot may hold more than one cable reel (i.e., cable reels 14 a and 14 e are each positioned within angled reel slot 16 a , while cable reels 14 c and 14 f are each positioned within angled reel slot 16 e ). It is understood that the cable reels shown in FIG. 5 are each supported on an opposite end thereof by the corresponding reel slots on the opposing side slotted panel.
FIG. 6 illustrates a front view of the cable organizer 10 of the present invention showing typical connections to electrical/electronic equipment and devices ( 64 , 66 , and 68 ). The organizer is shown with the cabinet frame cover panel 28 in position over the cabinet frame 12 and attached to a desk or table top 62 by left side hanger bracket 60 a and right side hanger bracket 60 b . The cable organizer provides a versatile solution for arranging and storing multiple wire cables which serve a variety of purposes. As shown in FIG. 6 , wire cable 15 a connects electrical/electronic equipment 66 and 68 , while wire cable 15 d connects electrical/electronic equipment 64 and 68 . In this configuration, the wire cable connecting the electrical/electronic devices may be shortened to the desired length by securing either end of the cable with a cable guide and wrapping the excess cable around a cable reel through the desired aperture. Wire cables ( 15 b and 15 c ) coming from electrical devices 66 and 64 respectively are power cords in this example and may be connected to the electrical power strip after being secured to the desired length around a cable reel. When all of the wire cables are properly positioned within the cable organizer system, the cabinet frame cover panel 28 is secured to the system and the power strip cord 46 is connected to an electrical outlet.
FIG. 7 illustrates a detailed perspective view of a typical cord holder positioned on each end of each cable reel of the system of the present invention. Specifically, FIG. 7 shows a cable reel 14 having a typical reel bar horn 34 with a typical flex cable guide 32 having cable guide slot 70 . The flex cable guide 32 is adhered to the reel bar horn 34 by any of a number of means well known in the art. A wire cable may be inserted through cable guide slot 70 and securely held in position against the cable reel 14 by flex cable guide 32 . As shown in FIG. 2 and FIG. 5 , the slot configuration of side panels 18 and 20 of cabinet frame 12 helps to “close” cable guide slot 70 as cable reel 14 is pushed into angled reel slot 16 . Also, no cutting or abrasion of the wire cable 15 on the side panel occurs because of the protection afforded by the flexible cable guide 32 .
It is anticipated that further variations in both the structure and method of use of the device of the present invention will be apparent to those skilled in the art after a reading of the present disclosure and a discernment of the attached drawing figures. Such variations, while not explicitly described and defined herein, may be seen to fall within the spirit and scope of the present invention. For example, but without limitation, the cabinet frame component of the structure of the invention as described is generally shown as rectangular. Those skilled in the art will recognize that alternate structural shapes (such as square) are possible. Likewise, the material from which these component sections might be constructed could be any of a number of rigid or semi-rigid compositions available for such structural elements. Various components may be transparent for optimal appearance, visibility and ease of use. For example, but again without limitation, the cable reels might be constructed of strong plastic or metal components. Those skilled in the art will recognize the balance required between rigidity and flexibility in selecting the most appropriate materials.
Likewise, it is anticipated that the present invention will find use in conjunction with a variety of cable or cord-like structures. To be inclusive in scope, the claims that follow refer to the use of the present invention in connection with “cords,” which terminology contemplates a definition that includes “cables, ropes, strings, lines, wires, tubes and similar objects generally characterized by being long, having a small diameter or cross-section, and being flexible.” | A versatile modular device for organizing, shortening, and securing a plurality of cords such as cables, ropes, strings, lines, tubes and wires, having a simple design which permits easy removal or addition of cords and a straightforward method for wrapping and securing an individual cord to a desired length. The device utilizes a rectangular box design having slotted side panels. The side panel slots are slanted and sized such that a plurality of modular reel bars may be inserted therein, will not slip out accidentally, and may be removed or added without disturbing the other modules. Each reel bar is designed with a plurality of apertures for securing a cord at varying lengths, leaving only the desired amount of cord loose. The device includes an electrical power strip for streamlined electrical power access and may be secured to a desk or table by appropriate attachment means. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 11/544,732, filed Oct. 10, 2006, which claims priority to Japanese Patent Application No. 2005-298186, filed Oct. 12, 2005, the contents of all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wiring board that allows semiconductor devices and the like to be very densely mounted with high precision and that allows a package and module having excellent high-speed and reliability characteristics to be obtained, to a semiconductor device that uses the wiring board, and to a method of manufacturing the same.
2. Description of the Related Art
The semiconductor device described in Japanese Laid-open Patent Application No. 2001-345418 is an example of a conventional semiconductor device. In this publication, a two-sided mounted structure is disclosed in which semiconductor devices are placed by flip-chip mounting on the two sides of a circuit board. In accordance with the prior art, production yield and reliability can be improved by adjusting the glass transition temperature of the sealing resin that seals the mounted semiconductor devices.
However, in the prior art described above, the connection precision and quality tends to degrade due to the difference in the coefficient of thermal expansion between the substrate and the board of the semiconductor elements. For this reason, there are problems in that it is difficult to make very small wiring connections to the semiconductor elements, and the connection reliability is poor. It is therefore difficult to implement a large number of connections between chips having high wiring density by using this prior art.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a wiring board having high connection reliability, a semiconductor device, and a manufacturing method of the same that allow very small wiring connections to be made, and that allow highly dense connections to be made among a plurality of semiconductor elements.
The wiring board according to the first aspect of the present invention comprises one or a plurality of insulation layers, one or a plurality of wiring layers, and one or a plurality of vias formed in the insulation layers, the wiring board further comprising external connection terminals disposed on both surfaces of the wiring board, wherein connection points between at least a portion of lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, and the wiring layers formed in the same plane as the lands, are unevenly distributed toward one side of the wiring board.
The wiring board according to the second aspect of the present invention comprises one or a plurality of insulation layers, one or a plurality of wiring layers, and one or a plurality of vias formed in the insulation layers; the wiring board further comprising external connection terminals disposed on both surfaces of the wiring board, wherein connection points between all lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, and the wiring layers formed in the same plane as the lands, are unevenly distributed toward one side of the wiring board.
The wiring board according to the third aspect of the present invention comprises one or a plurality of insulation layers, one or a plurality of wiring layers, and one or a plurality of vias formed in the insulation layers; the wiring board further comprising external connection terminals disposed on both surfaces of the wiring board, wherein connection points between lands disposed in positions in which the external peripheral edges of the semiconductor elements transverse the interior of the lands as viewed vertically from above, which lands are selected from land portions on which the external connection terminals are formed, and the wiring layers formed in the same plane as the lands, are unevenly distributed toward one side of the wiring board.
The wiring board according to the fourth aspect of the present invention comprises one or a plurality of insulation layers, one or a plurality of wiring layers, and one or a plurality of vias formed in the insulation layers; the wiring board further comprising external connection terminals disposed on both surfaces of the wiring board, wherein at least a portion of lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, are shaped so as to gradually increase and then gradually decrease in width in the direction away from portions connected to the wiring layers formed in the same plane as the lands, and toward one side of the wiring board.
The wiring board according to the fifth aspect of the present invention comprises one or a plurality of insulation layers, one or a plurality of wiring layers, and one or a plurality of vias formed in the insulation layers; the wiring board further comprising external connection terminals disposed on both surfaces of the wiring board, wherein all the lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, are shaped so as to gradually increase and then gradually decrease in width in the direction away from portions connected to the wiring layers formed in the same plane as the lands, and toward one side of the wiring board.
The wiring board according to the sixth aspect of the present invention comprises one or a plurality of insulation layers, one or a plurality of wiring layers, and one or a plurality of vias formed in the insulation layers; the wiring board further comprising external connection terminals disposed on both surfaces of the wiring board, wherein lands disposed in positions in which the external peripheral edges of the semiconductor elements transverse the interior of the lands as viewed vertically from above, which lands are selected from land portions on which the external connection terminals are formed, are shaped so as to gradually increase and then gradually decrease in width in the direction away from portions connected to the wiring layers formed in the same plane as the lands, and toward one side of the wiring board.
The wiring board according to the seventh aspect of the present invention comprises one or a plurality of insulation layers, one or a plurality of wiring layers, and one or a plurality of vias formed in the insulation layers; the wiring board further comprising external connection terminals disposed on both surfaces of the wiring board, wherein portions connected to the wiring layers formed in the same plane as the lands in at least a portion of lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, are tapered only toward one side of the wiring board.
The wiring board according to the eighth aspect of the present invention comprises one or a plurality of insulation layers, one or a plurality of wiring layers, and one or a plurality of vias formed in the insulation layers; the wiring board further comprising external connection terminals disposed on both surfaces of the wiring board, wherein portions connected to the wiring layers formed in the same plane as the lands in all the lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, are tapered only toward one side of the wiring board.
The wiring board according to the ninth aspect of the present invention comprises one or a plurality of insulation layers, one or a plurality of wiring layers, and one or a plurality of vias formed in the insulation layers; the wiring board further comprising external connection terminals disposed on both surfaces of the wiring board, wherein portions connected to the wiring layers formed in the same plane as the lands in lands in which the external peripheral edges of the semiconductor elements transverse the interior of the lands as viewed vertically from above, which lands are selected from land portions on which the external connection terminals are formed, are tapered only toward one side of the wiring board.
The semiconductor device according to the tenth aspect of the present invention comprises a flat wiring board; a first semiconductor element disposed on one surface of the wiring board; a sealing resin for covering the one surface and a side face of the first semiconductor device; a second semiconductor element disposed on another surface of the wiring board, the wiring board having a wiring layer, a support layer for supporting the wiring layer, and a through-electrode that passes through the wiring layer and the support layer; and the first semiconductor element and the second semiconductor element being electrically connected by way of the wiring board; wherein connection points between at least a portion of lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which external connection terminals are disposed, and the wiring board formed in the same plane as the lands, are unevenly distributed toward one side of the wiring board.
The semiconductor device according to the eleventh aspect of the present invention comprises a flat wiring board; a first semiconductor element disposed on one surface of the wiring board; a sealing resin for covering the one surface and a side face of the first semiconductor device; a second semiconductor element disposed on another surface of the wiring board; the wiring board having a wiring layer, a support layer for supporting the wiring layer, and a through-electrode that passes through the wiring layer and the support layer; and the first semiconductor element and the second semiconductor element being electrically connected by way of the wiring board; wherein connection points between all the lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which external connection terminals are disposed, and the wiring board formed in the same plane as the lands, are unevenly distributed toward one side of the wiring board.
The semiconductor device according to the twelfth aspect of the present invention comprises a flat wiring board; a first semiconductor element disposed on one surface of the wiring board; a sealing resin for covering the one surface and a side face of the first semiconductor device; a second semiconductor element disposed on another surface of the wiring board; the wiring board having a wiring layer, a support layer for supporting the wiring layer, and a through-electrode that passes through the wiring layer and the support layer; and the first semiconductor element and the second semiconductor element being electrically connected by way of the wiring board; wherein connection points between lands disposed in positions in which the external peripheral edges of the semiconductor elements transverse the interior of the lands as viewed vertically from above, which lands are selected from land portions on which the external connection terminals are formed, and the wiring board formed in the same plane as the lands, are unevenly distributed toward one side of the wiring board.
The semiconductor device according to the thirteenth aspect of the present invention comprises a flat wiring board; a first semiconductor element disposed on one surface of the wiring board; a sealing resin for covering the one surface and a side face of the first semiconductor device; a second semiconductor element disposed on another surface of the wiring board; the wiring board having a wiring layer, a support layer for supporting the wiring layer, and a through-electrode that passes through the wiring layer and the support layer; and the first semiconductor element and the second semiconductor element being electrically connected by way of the wiring board; wherein at least a portion of lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, are shaped so as to gradually increase and then gradually decrease in width in the direction away from portions connected to the wiring board formed in the same plane as the lands, and toward one side of the wiring board.
The semiconductor device according to the fourteenth aspect of the present invention comprises a flat wiring board; a first semiconductor element disposed on one surface of the wiring board; a sealing resin for covering the one surface and a side face of the first semiconductor device; a second semiconductor element disposed on another surface of the wiring board; the wiring board having a wiring layer, a support layer for supporting the wiring layer, and a through-electrode that passes through the wiring layer and the support layer; and the first semiconductor element and the second semiconductor element being electrically connected by way of the wiring board; wherein all the lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, are shaped so as to gradually increase and then gradually decrease in width in the direction away from portions connected to the wiring board formed in the same plane as the lands, and toward one side of the wiring board.
The semiconductor device according to the fifteenth aspect of the present invention comprises a flat wiring board; a first semiconductor element disposed on one surface of the wiring board; a sealing resin for covering the one surface and a side face of the first semiconductor device; a second semiconductor element disposed on another surface of the wiring board; the wiring board having a wiring layer, a support layer for supporting the wiring layer, and a through-electrode that passes through the wiring layer and the support layer; and the first semiconductor element and the second semiconductor element being electrically connected by way of the wiring board; wherein lands disposed in positions in which the external peripheral edges of the semiconductor elements transverse the interior of the lands as viewed vertically from above, which lands are selected from land portions on which the external connection terminals are formed, are shaped so as to gradually increase and then gradually decrease in width in the direction away from portions connected to the wiring board formed in the same plane as the lands, and toward one side of the wiring board.
The semiconductor device according to the sixteenth aspect of the present invention comprises a flat wiring board; a first semiconductor element disposed on one surface of the wiring board; a sealing resin for covering the one surface and a side face of the first semiconductor device; a second semiconductor element disposed on another surface of the wiring board; the wiring board having a wiring layer, a support layer for supporting the wiring layer, and a through-electrode that passes through the wiring layer and the support layer; and the first semiconductor element and the second semiconductor element being electrically connected by way of the wiring board; wherein portions connected to the wiring board formed in the same plane as the lands in at least a portion of lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, are tapered only toward one side of the wiring board.
The semiconductor device according to the seventeenth aspect of the present invention comprises a flat wiring board; a first semiconductor element disposed on one surface of the wiring board; a sealing resin for covering the one surface and a side face of the first semiconductor device; a second semiconductor element disposed on another surface of the wiring board; the wiring board having a wiring layer, a support layer for supporting the wiring layer, and a through-electrode that passes through the wiring layer and the support layer; and the first semiconductor element and the second semiconductor element being electrically connected by way of the wiring board; wherein portions connected to the wiring board formed in the same plane as the lands in all the lands in the vicinity of the mounting positions of semiconductor elements, which lands are selected from land portions on which the external connection terminals are formed, are tapered only toward one side of the wiring board.
The semiconductor device according to the eighteenth aspect of the present invention comprises a flat wiring board; a first semiconductor element disposed on one surface of the wiring board; a sealing resin for covering the one surface and a side face of the first semiconductor device; a second semiconductor element disposed on another surface of the wiring board; the wiring board has a wiring layer, a support layer for supporting the wiring layer, and a through-electrode that passes through the wiring layer and the support layer; and the first semiconductor element and the second semiconductor element being electrically connected by way of the wiring board; wherein portions connected to the wiring board formed in the same plane as the lands in those lands in which the external peripheral edges of the semiconductor elements transverse the interior of the lands as viewed vertically from above, which lands are selected from land portions on which the external connection terminals are formed, are tapered only toward one side of the wiring board.
The wiring board according to the present invention is preferably one in which the support layer is an insulation layer composed of an organic resin.
The semiconductor device according to the present invention is preferably one which the support layer is an insulation layer composed of an organic resin.
In accordance with the wiring board and semiconductor device of the present invention, a semiconductor device having a short wiring length for connecting to a plurality of semiconductor elements can be provided, and high-speed operation is made possible. Also, since the strength of portions in which stress is concentrated during the manufacturing process is high, high-yield production is made possible without generating wiring breakages and cracks. Reliability is high in the temperature cycles of the semiconductor device itself, and secondary mounting reliability when a semiconductor device is mounted on a printed board is also increased, because the wiring is free from internal stress or very small cracks that cannot be observed from the exterior.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the wiring board and semiconductor device of the first embodiment of the present invention;
FIGS. 2A to 2C are diagrams showing the method of manufacturing the wiring board and semiconductor device of the present embodiment;
FIGS. 3A to 3C are diagrams showing the method of manufacturing the wiring board and semiconductor device of the present embodiment, and are steps that follow those in FIG. 2 ;
FIGS. 4A and 4B are diagrams showing the peeling direction in the method of manufacturing the wiring board and semiconductor device of the present embodiment;
FIGS. 5A to 5C are diagrams showing the method of manufacturing the wiring board and semiconductor device of the present embodiment;
FIG. 6 is a diagram showing the planar structure of the wiring board and semiconductor device of the present embodiment;
FIG. 7 is a diagram showing the planar structure of the wiring board and semiconductor device of the present embodiment;
FIG. 8 is an enlarged view of the planar structure of the wiring board and semiconductor device of the prior art;
FIG. 9A and FIG. 9B is an enlarged view of the planar structure of the wiring board and semiconductor device of the present embodiment;
FIG. 10A and FIG. 10B is an enlarged view showing the planar structure of the wiring board and semiconductor device of the second embodiment of the present invention;
FIG. 11A and FIG. 11B is an enlarged view showing the planar structure of the wiring board and semiconductor device of the third embodiment of the present invention; and
FIG. 12 is a locally enlarged view of the same.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention are described in detail below with reference to the attached diagrams. Described first is the first embodiment of the present invention. FIG. 1 is a diagram that shows the cross-sectional structure of the wiring board 606 of the present embodiment and a semiconductor device 700 that uses the wiring board. BGA balls 504 are connected to the wiring board 606 , and the distinctive features are the shape of the BGA lands and the structure for connecting the conductor wiring 501 to the BGA lands 301 to which the BGA balls (not shown in FIG. 1 ) are connected in specific locations.
First, the method of manufacturing the wiring board and semiconductor device of the present embodiment is described with reference to FIGS. 2 to 5 . FIGS. 2 to 5 are cross-sectional diagrams showing, as a sequence of steps, the method of manufacturing the wiring board and semiconductor device of the present embodiment. A release layer 200 and a wiring layer ultimately provided with second LST connection pads 201 and second BGA lands 401 are formed on a silicon board 100 , as shown in FIG. 2A . An insulation resin 601 is subsequently formed on the wiring layer, and conduction vias 502 and conduction through-holes 503 are formed in required locations, as shown in FIG. 2B . Conductive wiring 501 is then formed so as to fill in the conduction vias and conduction through-holes, as shown in FIG. 2C .
Next, first LSI connection pads 101 and connection pads 103 are connected using first LSI connection bumps 102 to mount a first LSI 104 , as shown in FIGS. 1 and 3A . An underfill resin 105 is injected, and the structure is sealed using a mold resin 106 , as shown in FIG. 3B . A mold wafer portion 605 is peeled away from the silicon board in a single direction 604 , as shown in FIG. 3C .
The state of this peeling process is shown in FIG. 4 . FIG. 4A shows the state in which a plurality of first LSIs 104 are connected to a wiring layer on the silicon board 100 . The mold wafer portion 605 is separated from the silicon board 100 by mechanical force applied from the pealing direction 604 . At this point in the step for removing the silicon board 100 , a material is selected in advance that reduces the adhesive strength of the boundary between the silicon board 100 and the release layer 200 , and between the release layer 200 and the wiring layers 201 and 401 ; and a mechanical force is applied to peel away the silicon board 100 . By selecting as the release layer 200 a material that dissolves in a specific solution or a material whose adhesion to the wiring layers 201 and 401 or to the silicon board 100 is dramatically reduced when permeated by a solution, it is possible to allow the solution to permeate the material via the surface facing the release layer 200 and to then peel away the silicon board 100 . If a material that thermally decomposes is used as the release layer 200 , the wiring layers 201 and 401 and the silicon board 100 can be separated by heating the layer to the thermal decomposition temperature or higher in the step for removing the silicon board 100 . In this case, heating is preferably carried out using a laser or another method for providing localized heating. The release layer 200 alone can be locally heated by setting the wavelength of the laser to a level at which the light passes through the silicon board 100 but does not pass through the release layer 200 . In the present embodiment, a low-adhesive polyimide film is used as the release layer 200 , the adhesive strength of the boundary between the release layer 200 and the wiring layers 201 and 401 is reduced, and mechanical force is applied to peel away the silicon board 100 .
Next, a wiring layer is disposed on second LSI connection pads 201 and second BGA lands 401 , and second LSI connection pads 201 and connection pads 203 are thereafter connected using second LSI connection bumps 202 to mount a second LSI 204 , as shown in FIG. 5A . An underfill resin 205 is then injected.
Next, each segmented semiconductor device is separated, as shown in FIG. 5B ; BGA balls 504 , which are the ultimate external terminals, are thereafter mounted; and the semiconductor device 700 is completed, as shown in FIG. 5C .
In such a semiconductor device 700 , the communication speed between the LSIs in the semiconductor device can be improved in comparison with ordinary wire bonding because the first LSI 104 having a large chip size and the second LSI 204 having a small chip size can be connected with a short distance using very small conduction vias. The degree of freedom in selecting the size of the LSIs to be mounted is increased, and, depending on the number of BGA balls, which are the ultimate external terminals, a structure can be created in which the external shape of the LSI would include the BGA ball portion as well, as shown in FIG. 6 .
FIG. 6 is a top view showing the semiconductor device 700 of the embodiments of the present invention. Shown in the diagram are BGA lands 301 , as well as two LSIs 104 and 204 mounted on the two sides of a wiring board disposed therebetween. FIG. 7 is a diagram showing the result of distinguishing two types of BGA lands of the semiconductor device shown in FIG. 6 , i.e., boundary second BGA lands 402 disposed in positions in which the external peripheral edge of the semiconductor element transverse the interior of the lands, and the other lands 401 . FIGS. 8A and 8B are enlarged views of the portions ( 701 and 702 ) surrounded by the broken lines in FIG. 7 in the prior art. The peeling direction 604 is also indicated in FIG. 8 . In the prior art, the conductive wiring and the BGA lands are radially connected from the center of the semiconductor device toward the external periphery, as shown in portion A of FIG. 8B .
It is apparent from research conducted by the inventors that when the BGA lands and the conductive wiring are radially connected in this manner, defects do not particularly occur when peeling first progresses from the BGA lands side, but when peeling first progresses from the narrow wiring side and the BGA lands are left unpeeled, stress becomes concentrated in the narrow wiring during peeling of the BGA lands portion, resulting in cases in which breaks and cracks are produced in the wiring. In particular, many defects are produced in locations (lands and connections) in which the width rapidly increases from the wiring to the circular lands. It was discovered from a detailed analysis of the results that, in this case, the peeling section is a curved surface having a particular curvature, and that a rapid change in the stress applied to the boundary area produces wiring breakages when peeling progresses to such locations. This change is produced because the deformation of the harder silicon is less than the deformation of the mold resin in the vicinity of the boundary (vicinity of the boundary second BGA lands 402 ) in which the silicon LSI having a different hardness level is sealed in the mold resin. In areas in which a silicon LSI is not present and in areas other than those in the vicinity of the boundary with the silicon LSI, peeling can be conducted without particularly producing any defects in the wiring area, even if peeling progresses from the wiring side toward the BGA side. As used herein, the term “vicinity” refers to two rows of lands each on the outer and inner sides of the boundary second BGA lands.
FIGS. 9A and 9B are enlarged views of the portions ( 702 and 702 ) surrounded by the broken lines in FIG. 7 in the present embodiment. The present embodiment features wiring and connection portions that are disposed in the opposite direction from the peeling direction for the BGA lands in the vicinity of the boundary with the silicon LSI, where the peeling direction is the direction from the wiring side toward the BGA lands, as shown in portion B of FIG. 9B .
Adopting such a structure allows wiring cracks and breakages caused by locally concentrated stress during peeling to be prevented and high-yield production of semiconductor devices to be achieved. FIG. 9 shows a structure in which the connection direction is opposite from the peeling direction only in the lands on the boundary with the silicon LSI, but the present invention remains substantially effective as long as connection portions in at least a portion of lands selected from the lands in the vicinity of the silicon LSI are varied. It is apparent that good effect can be achieved for all the lands in the vicinity as long as the connection portions are varied, and the connection portions may be varied in relation to all or a portion of the lands on the boundary with the silicon LSI for convenience in wiring and determining the number of pins.
FIGS. 10A and 10B are enlarged views showing the second embodiment of the present invention. The present embodiment features BGA lands in the vicinity of the boundary with the silicon LSI, where peeling is directed from the wiring toward the BGA lands. These lands are shaped so as to gradually increase and then gradually decrease in width in the direction away from the portions connected to the wiring layers formed in the same plane as the lands, and toward one side of the wiring board, as shown in portion C of FIG. 10B .
The BGA lands and the wiring are radially connected from the center of the semiconductor device toward the external periphery in the same manner as in the prior art. In FIG. 10 , the lands are triangularly shaped, and adopting such a shape makes it possible to prevent peeling-induced wiring breakages and cracks from occurring. The cracks and breakages can be prevented because the width of the conductor during peeling does not rapidly increase in contrast to a circular land, even if peeling is first started from the wiring portion. The lands are not limited to a triangular shape and can have any shape as long as the width of the lands does not rapidly vary. However, the surface areas are preferably substantially equal to other circular lands in order to align the height of the BGA, which forms the ultimate external terminals. FIG. 10 shows a structure having a different shape only in the lands on the boundary with the silicon LSI, but the present invention remains substantially effective as long as at least a portion of lands selected from lands in the vicinity of the silicon LSI is varied. It is apparent that good effect can be achieved for all the lands in the vicinity as long as the connection portions are varied, and the connection portions may be varied in relation to all or a portion of the lands on the boundary with the silicon LSI. The structure of the present second embodiment has the effect of allowing compatibility with a narrower land pitch than in the first embodiment because the wiring is not required to be drawn to the opposite side of the BGA.
FIGS. 11A and 11B are diagrams showing the third embodiment of the present invention. The present embodiment features tapered shapes in the wiring and connection portions only in the BGA lands in the vicinity of the boundary with the silicon LSI, where peeling is directed from the wiring toward the BGA lands. FIG. 12 is an enlarged view of portion D in FIG. 11B . By adopting such a shape, wiring breakages and cracks do not occur due to peeling because the width of the conductor during peeling does not rapidly increase in contrast to a circular land, even if peeling is first started from the wiring portion. The tapered shape is not limited to the structure shown in FIG. 11 , and any structure can be used as long as the width of the wiring does not rapidly vary. FIG. 11 shows a structure having a tapered shape only in the lands on the boundary with the silicon LSI, but the present invention remains substantially effective as long as at least a portion of lands selected from lands in the vicinity of the silicon LSI is tapered. It is apparent that good effect can be achieved as long as all the lands in the vicinity are tapered. It is also possible for all or a portion of the lands solely on the boundary with the silicon LSI to be tapered. The structure of the third embodiment has the effect of allowing compatibility with a very small land pitch and dispensing with the need to draw the wiring to the opposite side of the BGA in contrast to the first and second embodiments. Since the land shapes are circular and merely a tapered shape is imparted, good secondary mounting reliability can also be obtained because the ultimate shapes of the BGA terminals are substantially the same.
The wiring board and semiconductor device of the present invention features land shapes and shapes for connecting the wiring to the lands, and the process for peeling structures from a silicon board, which is the substrate, plays a particularly important role. It is therefore very important that peeling in the present invention be limited to a fixed direction, and the characteristic structure of the present invention described in the first to third embodiments requires that a manufacturing method be adopted in which the peeling direction is always to the downstream side.
An example of a silicon board as the substrate was described in the above embodiments, but the present invention is not limited to a silicon board, and any substrate can be used as long as the board has suitable rigidity in the steps in which wiring and insulation layers are formed. Examples of materials that can be used include GaAs and other semiconductor wafer materials; sapphire; copper and other metal plates; and quartz, glass, ceramic, and printed boards. In the particular case that a silicon board is used, an effect is obtained in which the mounting precision is further increased because the coefficients of thermal expansion of the board and LSI are kept equal to each other when the LSI is mounted.
In the embodiments described above, an example of two LSIs constituting a semiconductor device was described, but the present invention is not limited to two LSIs, and two or more LSIs may be mounted on one or both sides of the wiring board. In such a case, two or more LSIs may be stacked in the vertical direction, or may be laterally mounted in the horizontal direction. In either case, the same effects can be obtained as long as the features in the embodiments described above are imparted to lands in the vicinity of the mounted positions of the LSI, which lands have external connection terminals disposed therein. In particular, when multiple layers of memory chips having a large chip size are stacked, semiconductor device performance can be considerably improved because logic chips that perform signal processing can access large-capacity memory at high speed.
In the embodiments described above, an example of a wiring board having two wiring layers was described, but it is apparent that the effects of the present invention are not limited to bilayer wiring.
In the embodiments described above, thin-film capacitors may also be disposed in desired positions on the wiring board. The dielectric material constituting the thin film capacitors is preferably titanium oxide, tantalum oxide, aluminum oxide, zirconium oxide, hafnium oxide, silicon oxide, silicon nitride, or a compound composed of these; BST (Ba x Sr 1-x TiO 3 ), PZT (PbZr x Ti 1-x O 3 ), PLZT (Pb 1-y La y Zr x Ti 1-x O 3 ), or another perovskite material (0≦x≦1 and 0<y<1); or SrBi 2 Ta 2 O 9 or another Bi-based layered compound. Also, an organic material or the like in which an inorganic material or a magnetic material is added may be used as the dielectric material constituting the thin-film capacitors. Chip capacitors, chip resistors, chip inductors, and other separate chip components may furthermore be housed in place of the thin-film capacitors. | A semiconductor device comprising a flat wiring board, a first LSI disposed on one surface of the wiring board, a sealing resin for covering the one surface and a side face of the first semiconductor element, and a second LSI disposed on another surface of the wiring board. The wiring board has conductive wiring as a wiring layer, an insulation resin as a support layer for the wiring layer, and a conductive through-hole that passes through the wiring layer and the support layer. Connection points between lands disposed in positions in which the external peripheral edges of the semiconductor elements transverse the interior of the lands as viewed vertically from above, which lands are selected from land portions on which the external connection terminals are formed, and the wiring board formed in the same plane as the lands, are unevenly distributed toward one side of the wiring board. Connections for very small wiring are thereby made possible, and a plurality of semiconductor elements can be very densely connected. | 7 |
BACKGROUND OF THE INVENTION
This application is a Divisional of application Ser. No. 10/079,556, filed on Feb. 22, 2002 and now U.S. Pat. No. 6,673,299, the entire contents of which are hereby incorporated by reference and for which priority is claimed under 35U.S.C. § 120; and this application claims priority of Application No. 01200691 filed in Europe on Feb. 23, 2001 under 35 U.S.C. § 119.
FIELD OF THE INVENTION
The present invention relates to a method and a mold for manufacturing pellets of hot-melt ink.
BACKGROUND ART
Certain types of inkjet printers employ a so-called hot-melt ink i.e. a wax-like ink material that is solid at room temperature and has a melting point in the order of, for example, 80 to 150° C. In the printhead of the printer, the ink is heated above its melting point, so that droplets of liquid ink can be expelled through the nozzles of the printhead. In order to obtain a high quality of the printed image, the viscosity and hence the temperature of the molten ink in the printhead should be maintained essentially constant. However, since the ink is consumed in the course of the printing process, and the ink reservoir accommodating the liquid ink within the printhead is preferably of a limited size, it is necessary to supply and melt solid ink while the printer is operating. The latent heat required for melting the ink tends to decrease the temperature in the ink reservoir. For this reason, it is desirable that the amount of solid ink supplied to the ink reservoir is precisely controlled and metered, and, to this end, it is advantageous that the ink is supplied in the form of pellets having a predetermined size and shape, e.g. in the form of small spherical pills or pellets.
Since the hot-melt ink is a thermoplastic material, the pellets having the desired shape and size can be manufactured by means of a molding process similar to injection molding processes known for manufacturing articles from thermoplastic resins. The molding process however should be adapted to the specific properties of hot melt ink, which are, in certain respects, different from those of thermoplastic synthetic resins. Since the amount of shrinkage which the hot-melt ink experiences when it is solidified is comparatively low, and since a certain amount of shrinkage can be tolerated because the final appearance of the molded ink pellets is not critical, it is not necessary to apply high locking forces for keeping the mold closed during the molding process. On the other hand, since the hot-melt ink has a relatively high melting point, it tends to solidify immediately when it comes into contact with the walls of the mold cavity. This effect and the fact that the surface of the ink pellet is somewhat tacky, even when the temperature has dropped below the melting point, increases the tendency of the pellet to adhere to the walls of the mold cavity. This makes it more difficult to reliably and reproducingly remove the molded pellet from the mold die. Especially when the upper and lower dies of the mold are symmetrical, as must be the case for example when the pellet has a spherical shape, it is not predictable whether the pellet will adhere to the upper die or to the lower die when the dies of the molds are separated. This tends to reduce the productivity of the molding process and/or necessitates the use of complex mechanisms for ejecting the molded product from the die.
It is well known that the removal of a molded product from a die can be facilitated by employing a separating agent which reduces the adherence between the molded product and the walls of the mold cavity. In this case, however, a portion of the separating agent will inevitably be dispersed or diluted in the molten material, and this is not acceptable in the case of hot-melt ink because it deteriorates the quality of the ink. For example, even minute particles of the separating agent, when dispersed in the ink, tends to clog the extremely fine nozzles of the printhead or change the ink properties such as its surface tension or crystallization point.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for manufacturing pellets of hot-melt ink, in which the pellets can be reliably and reproducibly withdrawn from the mold cavity.
According to the present invention, this object is achieved by a method comprising the steps of:
filling the molten ink into a mold cavity defined between a first die and a second die of a mold, allowing the ink to cool down and to solidify in the mold cavity, and heating at least one of the first and second dies for remelting only the surface of the ink pellet to be removed from the mold cavity.
According to the present invention, the molded pellet is separated from the wall of the mold cavity by heating at least a portion of the mold, so that a surface layer of the pellet is remelted. This can be achieved within a very short time. Thus, it is possible to remove the pellet from the mold cavity efficiently and in a well-defined manner. Since it is not necessary to employ a separating agent, the quality of the hot-melt ink will not be degraded.
When the lower die of the mold is heated before the upper and lower dies are separated, it is possible to positively release the pellet from the lower die and to withdraw it from the lower die, taking advantage of the fact that the pellet tends to adhere to the upper die which is not heated. Then, the pellet is released from the upper die by any suitable means, thereby allowing the pellet to simply drop out of the upper die. The pellets dropping out of the upper dies may be collected by any suitable collection means such as a chute which is brought in position underneath the pellets that have been withdrawn from the lower dies.
Further, it is possible to release the pellet from the upper die by heating the latter. In a preferred embodiment, the method comprises the steps of first heating the lower die, then separating the upper and lower dies with the pellets adhering to the upper die, and heating the upper die, thereby allowing the pellet to drop out. The release of the pellet from the upper die may be assisted and accelerated by blowing air into the runner hole of the upper die. As an alternative, an ejector pin may be inserted through the runner hole. In this case, the ejector pin may be arranged stationary, so it enters into the runner hole and engages the pellet adhered thereto when the upper die and the pellet are lifted from the lower die.
A mold for manufacturing pellets of hot-melt ink in accordance with the method described above comprises first and second dies defining a mold cavity, wherein at least one of the first and second dies has a wall thickness which is smaller than half the diameter of the mold cavity. If the mold cavity is not spherical, the wall thickness of the die is smaller than half the average diameter.
Due to the small wall thickness, the die has a very low heat capacity, such that the surface layer of the molded pellet can be remelted very quickly by heating the die. The small heat capacity of the die has the further advantage that the molten ink in the mold cavity can be cooled and solidified more rapidly, so that the productivity of the molding process is increased.
Preferably, both dies of the mold have a small wall thickness and hence a small heat capacity and are made of a material having a high heat conductivity, e.g. aluminium. Also stainless steel is useable if the wall thickness is small enough. In a preferred embodiment, the wall thickness of the dies is smaller than a quarter of the diameter of the mold cavity. For example, if the mold cavity is spherical and has a diameter in the order of 10 mm, the wall thickness of the dies may be 1.5 mm or less.
Rapid cooling and re-heating of the dies may be achieved in a very simple manner e.g. by blowing cold and hot air or even a liquid against the dies. A number of other heating or cooling devices can be used.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention will now be described in conjunction with accompanying drawings, in which:
FIGS. 1 to 5 illustrate successive steps of a process for molding hot-melt ink pellets and removing them from the mold cavity.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a group of three molds 10 , each of which comprises an upper die 12 and a lower die 14 each of which have a semi-spherical cup shape and, together, define a mold cavity 16 which is filled with molten hot-melt ink 18 . The upper die 12 is integrally formed with a top flange 20 and has a runner hole 22 formed in the center of the flange 20 , so that molten ink can be poured into the mold cavity 18 through a nozzle 24 .
The lower die 14 is essentially mirror-symmetric relative to the upper die 12 and is supported on a bottom 26 formed integrally therewith. The lower edge of the upper die 12 and the upper edge of the lower die 14 are surrounded by circumferential flanges 28 , 30 which are held in firm engagement with one another in order to sealingly close the mold cavity 16 .
When the ink 18 has been poured in, as is shown in FIG. 1 , the molds are transferred to a cooling stage illustrated in FIG. 2 , where cold air 32 is blown against the outer surfaces of the dies 12 , 14 from above and below, so that the ink in the mold cavities is cooled and solidified to form spherical pellets 34 .
Then, the molds 10 are transferred to a first heating stage which is shown in FIG. 3 . This heating stage comprises a heating block 36 having a number of recesses 38 for accommodating the lower dies 14 of the molds. The recesses 38 have a flat bottom, which defines a large contact area with the bottom flanges 26 of the lower dies 14 . Hot air is supplied into a system of passages 40 formed in the heating block 36 and is evenly blown out against the circumferential walls of the lower dies 14 of each mold 10 , as indicated by arrow 42 . The dies 12 , 14 of the molds 10 are made of aluminium and have relatively thin walls (at least in the portion defining the mold cavity), so that their heat capacity is low, but their heat conductivity is high. As a result, the hot air blown against the walls of the dies 14 rapidly raise the temperature of these dies, and surface layers of the pellets 34 facing the lower dies 14 are re-melted, so that the pellets 34 can easily be released from the lower dies 14 . However, since the upper dies 12 have not been heated, the solidified material of the pellets 34 still adheres to the upper die 12 . Since the heating block 36 is constantly maintained at a high temperature (e.g. by the hot air passing therethrough), heating of the lower die 14 is accelerated by heat radiation and thermal contact between the block 36 and the bottom flange 26 .
Then, as is shown in FIG. 4 , the upper and lower dies of each mold 10 are separated from one another, either by lifting the upper dies 12 or by lowering the heating block 36 and the lower dies 14 . Since the pellets 34 stick to the upper dies 12 , they are withdrawn from the lower dies 14 .
Finally, the upper dies 12 with the pellets 34 held therein are transferred to a second heating stage shown in FIG. 5 . This heating stage comprises a heating block 44 which has essentially the same configuration as the heating block 36 described above, but is arranged in an inverted position so that the recesses 38 face downward for accommodating the top flanges 20 of the upper dies 12 . In addition to the system of passages 40 for blowing hot air against the outer surfaces of the dies 12 , the heating block 44 has another air supply system 46 through which air can be blown with a suitable pressure into the runner holes 22 of the dies 12 . Again, by blowing hot air, indicated by arrows 48 , against the dies 12 , surface layers of the pellets 34 are re-melted, so that the pellets will no longer adhere to the dies 12 but will drop down into a chute 50 . This process is assisted and accelerated by blowing pressurized air into the runner holes 22 . Thus, the molding process for manufacturing the pellets 34 is completed, and the upper and lower dies 12 , 14 may be re-circulated for use in another molding cycle.
Although not shown in the drawings, the dies 12 , 14 of the molds 10 , the total number of which may be significantly larger than three, may be mounted to an endless conveyor in any known manner allowing to hold the molds 10 closed in the step illustrated in FIGS. 1 to 3 and to move the upper dies 12 and the lower dies 14 relative to one another in vertical direction in the step illustrated in FIG. 4 . Thus, the process described above lends itself to an efficient mass production of hot-melt ink pellets 34 . | A method for manufacturing pellets of hot-melt ink which includes the steps of filling molten ink into a mold cavity defined by a first die and a second die of a mold, allowing the ink to cool down and solidify in the mold cavity, and heating at least one of the first and second dies for re-melting the surface of the ink pellet to facilitate its removal from the mold cavity. | 1 |
This application claims priority of prior filed Provisional Application Ser. No. 60/475,544 filed Jun. 3, 2003. This application also claims priority of PCT/EP03/04132 filed Apr. 22, 2003, which in turn claims priority of German Application Serial No. DE 102 17 840.2 filed Apr. 22, 2002.
FIELD OF THE INVENTION
The invention pertains to a packaged, highly compressed bale of filter tow material in block or cuboid form without any interfering bulges or constrictions in the top or bottom of the bale and to a process for its production.
BACKGROUND OF THE INVENTION
In the production of filter tow for use in making filter rods for the cigarette industry, the tow is laid in so-called “filling cans”. During this process, the filter tow is distributed in uniform layers over the cross-sectional area of the can by the movements of a laying unit, which moves alternately in the lengthwise and crosswise direction. As a result, a large number of layers are laid on top of each other until the filter tow package has reached the desired weight and height in the can. Package weights of several hundred kilograms are conventional in this area. A highly compressed bale and a process for the optimal filling of a can for the purpose of avoiding consequent processing problems is described in WO 02/32,238 A2.
The content of the can which has been filled in this way is then compressed in the direction in which the layers were superimposed. After it has been compressed, the filter tow package is wrapped with packaging material while still inside the pressing device and therefore still under compressive stress. The pressing device is then opened completely, so that the filter tow package, now called the “bale”, is held together by the packaging material. Conventional packaging materials include cardboard, which is held mechanically together by strapping or by an adhesive, and synthetic fabric, which is closed by, for example, a Velcro fastening. An example of a glued package is described in German Utility Patent No. 76-35,849.1. Information on a filter tow package wrapped with synthetic fabric can be found in the company prospectus “Some Useful Information about the Reusable Packaging for Rhodia Filter Tow”, published by RHODIA Acetow GmbH, Engesserstrasse 8, D-79108 Freiburg. The two latter types of packaging require no additional strapping.
The types of packaging described above which do not make use of any strapping suffer from the problem that, after the pressure on the bale has been released at the end of the pressing operation, the elastic restoring force of the compressed filter tow leads to a pressure on the packaging, this pressure being exerted primarily in the direction opposite that in which the bale was compressed. This leads to an increase in the volume of the package and thus to undesirable bulges at the top and bottom of the bale. If the measures described in WO 02/32,238 A2 are taken, these bulges do not interfere with the intended use of the filter tow, but they do prevent the filter tow packages from being stacked securely. This problem is solved in the state of the art either by stacking the bales on their sides or by the use of special pallets, such as those described in the Rhodia publication cited above. Problems associated with the bursting-open of the packages because of excessive internal pressure also occur frequently.
A solution to the difficulties associated with strapping is described in U.S. Pat. No. 4,577,752. In cases where filter tow which has been packaged with straps is used as intended, the bulges are less of a problem than the constrictions, which cause the variations in puff resistance described in WO 02/32,238 A2. And even strapped bales can burst open. It is also standard practice in the packaging of filter tow to use liners between the filter tow and the above-mentioned mechanically supportive packaging materials. The liner protects the filter tow from contamination, especially from odor contamination, and from the diffusion of water vapor into and out of the package. The liner usually consists of three pieces, which are laid loosely inside the external packaging.
The disadvantages of the transport packaging normally used today have already been discussed above in the description of the state of the art. It is especially the bulges at the top and bottom of the bales which interfere with transport of multiple layers. This problem has been solved in the past by transporting the bales not in their so-called working position but rather in a sideways storage position. Two additional work steps are required to do this, however; namely, the bale must be turned 90° before transport and then turned back into the working position after transport. The constrictions which are formed by strapping are also a source of trouble. Even when the bale is used as intended, these constrictions cause considerable variations in the puff resistance of the filter rods produced from the filter tow. More than 5% of the filter rods produced from a bale are affected by these variations. The greater the packing density of the bale, the greater the severity of these two problems. The problems occur as soon as the packing density exceeds 300 kg/m 3 .
SUMMARY OF THE INVENTION
According to one embodiment, the invention provides a highly compressed bale of filter tow in cuboid or block form without the bulges which interfere with the transport of the bales and without the constrictions in the top and bottom of the bale which interfere with the pay-out of the filter tow. The compressive load to which the packaged filter tow is subjected is reduced, so that in particular the bursting-open of the package under the effect of internal pressure can be almost completely avoided. According to another embodiment, the invention provides a corresponding packaging process.
In accordance with one aspect of the present invention, a packaged, highly compressed bale of filter tow is provided. In one embodiment, the bale of filter tow includes a plurality of layers of filter tow material defining an upper and lower side having a packing density. The packing density is at least 300 kg/m 3 . The bale further includes a resilient packaging material fully enclosing the bale. The packaging material includes at least one convective air-tight connection. The upper side and lower sides of the bale are substantially planar.
In accordance with yet a further aspect of the invention, a packaged, highly compressed bale of filter tow is provided. The bale of filter tow includes a plurality of layers of filter tow material defining an upper and lower side having a packing density. The packing density is at least 300 kg/m 3 . An elastic packaging material is provided which fully encloses the bale. The packaging material includes at least one joint which is air-tight with respect to convection. The upper and lower sides of the bale are substantially planar, such that when an unopened bale is placed on a horizontal surface, a flat plate can be pressed onto the upper side of the bale with a force of 100N acting in the normal direction on a center of the bale wherein a rectangle can be inscribed in a vertical projection of the bale onto the pressed on plate, and at least 90 percent of the area of the upper side which is located within the inscribed rectangle is less than 40 mm from the plate.
In accordance with another aspect of the invention, a method for packaging a filter tow bale is provided. The method includes the steps of providing a plurality of filter tow material in a filling can, and compressing the layers of filter tow into a bale using a pressing device having a load. The method further includes wrapping the bale with a packaging wrapper, sealing the packaging wrapper, and releasing the load from the bale.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in greater detail below on the basis of a preferred embodiment with reference to the attached drawing:
FIGS. 1 a - 1 c show the individual steps of an embodiment of the process according to the invention;
FIGS. 2 a and 2 b show an elaborated form of the package obtained according to the process of the invention;
FIG. 3 a shows a graph, which represents the change over time in the properties of a package obtained according to the process of the invention with the use of polyethylene film;
FIG. 3 b shows a graph similar to that of FIG. 3 a , which applies to a laminated film of polyethylene and polyamide;
FIG. 4 a shows various curves which illustrate the relationship between the packing height and the height of the bale for various negative pressures; and,
FIG. 4 b shows various curves which illustrate the relationship between additional vacuum and the height of the bale at elevated temperature and reduced air pressure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
After a series of failed experiments, the surprising discovery was made that it is possible to prepare a block-shaped bale without the bulges which interfere with transport and without the constrictions which interfere with the intended use of the filter tow by sealing the packaging air-tight during the packaging process. On the basis of practical considerations, therefore, a bale according to one embodiment is completely wrapped with a mechanically self-supporting, elastic packaging material. The packaging material can have one or more joints which are air-tight with respect to convection.
Upon a preliminary, superficial analysis, it might appear that the bale according to the invention is a vacuum-packed bale and thus a vacuum package such as that familiar to all consumers on the basis of daily experience. This is not the case, however. The goal to be achieved with the block-shaped bale according to the invention is to create a defined shape. The air-tight packaging has the task of absorbing and equalizing the pressure gradients which occur at the top and bottom of the bale during the production process. It turned out that it was no longer necessary to impose requirements on the packaging with respect to its mechanical strength, its permeability to air and moisture, etc. It was found instead that the bale according to the invention would retain its properties even if the previously air-tight material were to be perforated over large areas after the packaging process. On the basis of practical considerations, such an additional measure will not be taken.
The geometry of the bale according to the invention can be described as having a top and bottom side that are substantially planar, such that when the unopened bale is placed on a horizontal surface, a flat plate completely covering the bale can be pressed onto the top of the bale with a force of 100N acting in the normal direction on the center of the bale with the result that, within the largest rectangle which can be inscribed in a vertical projection of the bale onto the pressed on plate, at least 90% of the area of the top surface of the bale which is located within the inscribed rectangle is less than 40 mm away from the flat plate. The distance of the individual points on the top surface of the bale from the plate can be determined, for example, by using a transparent plate and by determining the distances between the individual points and the plate by measuring the reflections. As an alternative, any other continuous method of distance measurement can also be used. Within the scope of the principle according to the invention, it is especially preferred for 90% of the area of the top surface of the bale which lies within the previously mentioned inscribed rectangle to be less than approximately 25 mm, preferably less than approximately 10 mm, away from the flat plate.
In regard to the packing volume of the bale, it is has been found advantageous for the bale to have a volume of more than 0.9 m 3 and/or for the packing density to be between 350 kg/m 3 and 800 kg/m 3 . In connection with the loading of the packages into containers, it is has been found to be especially suitable for the bale to have the form of a cuboid or block with a height of at least approximately 900 mm, preferably of at least approximately 970 mm. In this case the bales can be stacked in double layers in the container. Packaged blocks with heights of 970-1,200 mm are especially favorable, since such blocks can be placed in the form of individual stacks in the containers. It is also possible to produce much taller bales, which reduces the packaging work relative to the amount of fibers to be packaged. In cases where the packaged material is filter tow, these large packages offer the advantage that, when the filter is used to produce cigarette filters in a filter rod machine, the frequency of replacing the bales is reduced.
The packaging wrapper is preferably made of a plastic film. The convectively air-tight joint can be made as a convectively air-impermeable seam, which is advantageously designed as a heat-sealed overlapping or finned seam.
The film consists preferably of polyethylene, especially LDPE, or modified polyethylene (LLDPE), or of a laminated film including a layer of polyamide and a layer of polyethylene. For advertising and aesthetic purposes, colored or printed film can be used as the packaging film. This is especially advisable when the filter tow to be packaged is sensitive to light and/or is subjected to light. The film can also be provided with adhesive labels, which provide information on the content of the package, for example. Another possibility of allowing the package to convey information is to impress a relief into it, which is visible through the film, which conforms tightly to the surface of the package as a result of negative pressure. In addition to the name of the product, the relief can also contain a company and/or customer logo. The film preferably has properties which make it a reliable transport packaging material. Films with thicknesses in the range of 100-400 μm can be used. If desired, a transport packaging of cardboard, synthetic fabric, etc., can be placed around the film after the package wrapping or film itself has been sealed, that is, after the block-shaped bale has been completed. This transport packaging can then be strapped as well. As a result, the mechanical stability of the packaging is increased, so that thinner and therefore less expensive film can be used. It must be emphasized, however, that transport packaging of this type is not mandatory within the scope of the invention.
A process for packaging a filter tow bale according to the invention comprises the following process steps:
(a) the filter tow is prepared in compressed form with a pressing device having a load; (b) the compressed filter tow is wrapped with packaging film; (c) the package wrapper is sealed air-tight; and, (d) the load on the wrapped bale is released.
When the load on the bale, which has been sealed air-tight, is released, a negative pressure develops inside the package wrapper, which is preferably at least 0.01 bar below ambient pressure and which according to an especially advantageous method is in the range of 0.15-0.7 bar below ambient pressure.
Because of the air-tight seal of the package wrapper, the negative pressure thus produced inside the region surrounded by the wrapper can be maintained. This negative pressure reduces the pressure which the elastic restoring force of the flexible material exerts on the packaging from the inside. For this reason, the bulges which normally develop on the filter tow bales according to the state of the art are avoided. It thus becomes much easier to stack the packaged bales thus produced. Because the mechanical pressure acting from the inside on the packaging is reduced (by the negative pressure), the risk of failure or the tendency of the packaging to rip open is also reduced. A higher packing density can thus also be achieved, which leads to the advantage of more compact packages and thus to the ability to reduce the storage and transport volumes. In particular it is possible in this way to make optimal use of the holding capacity of containers, in which such packaged filter tow is stored.
The provision of filter tow in compressed form is usually accomplished with the help of known pressing devices. The process according to the invention can be conducted in such a way that the quantity of filter tow intended for the package is first mechanically compressed in the pressing device and then wrapped with the package wrapper. In this case the package wrapper is sealed while it is still inside the pressing device. This embodiment offers the advantage that the entire process is completed at a single location.
It is also possible to compress the filter tow at a separate station as a preparatory step. In this case, the precompressed filter tow is provided with “auxiliary packaging”, which can consist of retaining clamps, for example, and then sent to the packaging station, where the auxiliary packaging is removed, the compressed filter tow is wrapped with the package wrapper, the negative pressure is produced, and the package wrapper is sealed air-tight. This embodiment offers the advantage that the pressing device can have greater availability, because the entire process is not completed at one location. In addition, the duration of the pressing cycle is decreased, and there are more degrees of freedom available with respect to the application of the package wrapper, because the compressed bale is accessible from all sides in the packaging station.
In contrast to the state of the art, the use of the process according to the invention makes it possible to eliminate the liner intended to protect the bale from contamination and water vapor, because these tasks are already accomplished by the wrapper used as packaging.
The negative pressure required initially in the process according to the invention can be obtained in various ways. According to an especially simple embodiment, the negative pressure is generated by the “natural” expansion of the compressed filter tow material. After the filter tow has been wrapped in the compressed state with the package wrapper and this has been sealed air-tight, the external pressure on the packaged material is released. As a result, the material expands inside the package under the action of its own elastic restoring force. Because of the increase in the volume of the package, a negative pressure develops inside the region surrounded by the wrapper. The package size is preferably selected so that the compressed filter tow cannot expand completely, that is, so that the filter tow inside the wrapper is still compressed to a certain degree inside the package even after its partial expansion. This embodiment has the advantage that no additional means are required to generate the negative pressure. It therefore represents an especially low-cost possibility.
According to another embodiment, which can be used as an alternative or as an addition to the previously described variant, the negative pressure is produced by exhausting air from the interior area surrounded by the wrapper. In this way, a vacuum higher than the “natural” vacuum described above can be obtained. It is also possible by this method to adjust the desired negative pressure with a high degree of accuracy.
The air can be exhausted by means of, for example, one or more vacuum pumps. These are first connected on the suction side to the interior of the otherwise air-tight package and then put into operation. After the desired negative pressure has been reached, the pumps are disconnected from the package, and the exhaust connection points in the packaging wrapper are sealed air-tight again.
A combination of the two previously described embodiments offers the advantage that the evacuation times can be kept short, because the negative pressure is obtained by two different measures, which can be performed simultaneously. In addition, the necessary compression forces are smaller, because a larger packing height can be selected, where the term “packing height” refers to the height of the filter tow bale after it has been sealed air-tight in the device used to compress the filter tow. Finally, it is possible in this way to regulate the height of the filter tow bale with good accuracy. As a result, external influences such as those associated in particular with the seasons, with titer, and with weight, etc., can be moderated.
In the process according to the invention, a negative pressure of approximately 0.15 bar to 0.7 bar below ambient pressure is preferably produced. This corresponds to an absolute pressure of approximately 0.30-0.85 bar inside the film-wrapped volume. The vacuum in question is therefore in the “low vacuum” range, which is usually completely sufficient for the process according to the invention. A negative pressure of approximately 0.2-0.4 bar, corresponding to an absolute pressure of approximately 0.6-0.8 bar, has proven to be especially suitable. The choice of the concrete range for the negative pressure depends on various parameters, especially on the type and quantity of the material to be packaged, on the desired packing density, on the package wrapper used, etc. In principle, it must be remembered that the stronger the vacuum or negative pressure, the more compact the packages which can be obtained. Increasing the negative pressure also has the effect of reducing the bulges. It must also be taken into consideration, however, that choosing a higher vacuum leads to a disproportionate increase in the time required to achieve that desired negative pressure.
As far as the packaging wrapper used in the process according to the invention is concerned, it should be selected so that the desired stability of the produced negative pressure over time and the desired mechanical stability of the packaging are guaranteed. Depending on the type of package material or film and on the manner in which it is used, the desired stability over time will usually vary between a few days and several months or even years. Accordingly, films with different air permeabilities can be used.
According to one embodiment, preferably a film of polyethylene or modified polyethylene such as LLDPE or LDPE can be used as the package wrapper. LDPE is low-density polyethylene, which is produced under high pressure; LLDEP is the designation for low-density polyethylene with a linear structure. A plastic film of this type offers the advantage that it is a pure material and can be obtained at low cost. A sheet of polyethylene, however, is not very strong and is therefore suitable especially for relatively low packing densities and small quantities of packaged material. Because of the relatively high permeability to air of standard polyethylene film, it is more suitable for uses in which the storage time does not exceed a few weeks.
As an alternative, it is possible advantageously to use a laminated film made of polyamide and polyethylene as the package wrapper. This laminate is characterized by a very low degree of permeability to air and by high strength, which means that the negative pressure can be kept constant over a long period. The polyamide layer preferably represents approximately ⅓ of the laminate, the polyethylene layer approximately ⅔.
The gas permeability of the package wrapper or film to air is preferably less than 10,000 cm 3 /(m 2 *d*bar), preferably less than 200 cm 3 /(m 2 *d*bar), and even more preferably less than 20 cm 3 /(m 2 *d*bar). These values are measured according to DIN 53,380-V at 23° C. and 75% relative humidity. As a result, it can be guaranteed that the vacuum will last for a sufficient length of time and that the package will not become loose and will remain as compact as possible. This range, furthermore, is covered by standard commercial films (e.g., PA-PE laminates). It must be emphasized that no air is transported by convection through the film; mass transport occurs only via diffusion across the film. The values indicated for permeability are based on a composition analogous to ambient air (approximately 78% N 2 , 21% O 2 , 1% other gases). The only important values are those pertaining to the permeability for oxygen and nitrogen. In addition to films, it is also possible within the scope of the present invention to use other air-tight materials which fulfill the above conditions.
The permeability of the film or other wrapping material to water vapor should preferably be less than 5 g/(m 2 *d), preferably less than 2 g/(m 2 *d), measured according to DIN 53,122, Part 2, at 23° C. and 85% relative humidity. The permeability to water vapor is not relevant to the shape-giving function of the packaging, but a packaging which is impermeable not only to air but also to water vapor offers the advantage that the product moisture content of the filter tow remains preserved by such a packaging. This is very important in the case of filter tow. Thus the moisture content will equalize over the bale, and there will be no exchange of moisture with the environment. Polyethylene films with a thickness of 100 μm have an approximate water vapor permeability of 1 g/(m 2 *d).
In regard to the mechanical strength, the package wrapper or film should advisably have a tear strength of at least approximately 10 N/15 mm, preferably of more than 100 N/15 mm, and even more preferably of more than 200 N/15 mm, measured according to DIN EN ISO 527-3. Each of the cited values pertains to the minimum tear strength value in the longitudinal and transverse directions of the film. The selection with respect to tear strength can be made as a function of whether or not the film-wrapped bale will be repackaged for transport. In this context, possible materials include PE with a tear strength of 15-30 N/15 mm at a thickness of 100 μm and PA6 with a tear strength of 150-300 N/15 mm at a thickness of 100 μm.
In general, plastic films with air-barrier layers such as layers of polyamide, polyester, or ethylene-vinyl alcohol copolymer (EVOH) or with a metal oxide coating such as a coating of SiO x , aluminum oxide, etc., and aluminum foils have been found to be especially advantageous. This list of films is not to be considered exhaustive, however. Because of the impermeability of the film to air, aroma protection, that is, protection against the intrusion of aromas from the outside, is also afforded, which can be advantageous for various types of packaged materials. A certain toughness is important for the mechanical stability of the film. This property is offered especially by polyamide.
One possibility of obtaining an air-tight seal of the package wrapper or film is to weld or to heat-seal it. Accordingly, the selected film should preferably be weldable or heat-sealable. In this regard, favorable film materials are those with low melting points. For example, polyolefins such as polyethylene and polypropylene or copolymers with ethylene and propylene such as EVA, LLDPE, etc., can be mentioned here. Materials which satisfy the prerequisite of weldability or heat-sealability are called the “sealing layer” in the description that follows. A film can consist possibly of a sealing layer of this type alone or of a laminate consisting of one or more sealing layers and additional layers, which are designed to provide, for example, the mechanical strength.
To ensure that the packaging can be opened easily, the sealing layers can be “peelable”; that is, they can be sealed in an inhomogeneous manner. An inhomogeneous sealing layer of this type can be produced in various ways, such as by adding polybutylene at certain points to the sealing layer or by sealing polypropylene against LLDPE. Another possibility of facilitating the opening process consists in providing a tear-open strip in the packaging film. This possibility is especially intended for films of low toughness. Finally, projecting corners or the like can be provided, which are intended to be cut off when package is to be opened. After the projecting corner has been cut off, air can pass into the interior of the package, and the package becomes loose. Then it can be opened easily with a film-cutting knife without causing damage to the package contents.
As an alternative, the packaging wrapper or film can be sealed by an adhesive. This embodiment offers the advantage that there is no need for a heat-sealing device. Of course, other suitable methods for sealing the packaging film can also be used as long as they provide the desired properties with respect to leak-tightness and also with respect to mechanical tensile strength required for the area of application in question.
The heat-sealing or welding can be accomplished, for example, in such a way as to form an overlapping seam. An overlapping seam can absorb comparatively high tensile forces and thus hold the packaged material together reliably even in the freshly packaged state and even if the package should have a leak and thus the full elastic restoring force of the material acts on the packaging from the inside. This type of closure is thus very secure, and the film in this case should advisably have a heat-sealing layer on both sides (or consist exclusively of such a heat-sealing layer).
According to another embodiment, the welding or heat-sealing can be accomplished in such a way as to form a finned seam, which is known to the expert in the area of film processing. This offers the advantage of being easy to produce from the outside, but the ability of such a seam to withstand tensile stresses is less than that of the overlapping seam.
The packaging wrapper or film can be designed in the form of, for example, a one-piece bag. The prepared filter tow in this case is wrapped in a manner similar to that in which a piece of candy is wrapped. As an alternative, the film can consists of a bottom, a top, and a circumferential collar. In this case, the overall length of the joint seams is increased, because the individual parts must be joined together. According to another preferred embodiment, the film packaging consists of a top and a bottom, which can possibly be fabricated, that is, deep-drawn or made into a bag, etc., before use. Finally, there is also the possibility of cutting the film into two interlocking pieces in tennis ball fashion. It would also be possible to imagine other suitable ways of designing a film packaging within the scope of the invention.
If desired, the final sealing of the package wrapper or film, that is, the completion of the film packaging, can be followed by repackaging the bale with cardboard, synthetic fabric, etc., which is placed around the film. This has the result of increasing the mechanical strength of the packaging, so that thinner and thus less expensive films can be selected. It must be emphasized, however, that repackaging of this type is not mandatory within the scope of the invention.
When external repackaging is used as described above, it is possible for the film packaging to be designed intentionally with less air-tightness, so that the negative pressure is equalized within one to two days with respect to the ambient pressure. In other words, the package “loses” its vacuum within this period. The packaged filter tow thus expands into the external packaging, but in comparison with filter tow packaged according to a process of the state of the art, it has less pronounced bulging at the top and bottom of the package.
The film used in the process according to the invention preferably has a thickness of approximately 100-400 μm, where a range of 200-300 μm and especially of 250-300 μm has proven to be especially suitable. The exact thickness of the film used will be selected as a function of the size and the weight of the fiber material to be packaged, of the degree of compression, that is, of the packing density, and of the type of film material used. As already explained above, a somewhat thinner film can possibly be selected when additional external packaging, especially an outer packaging of cardboard, is used.
The compressible filter tow to be packaged is thus in particular made available in the optimal block form. As a result, packages can be obtained which are especially easy to stack and to handle and easy to store. The filter tow, which is in the form of cables, is preferably laid in layers, one on top of the other, as already described in connection with the process according to the state of the art.
Referring now to FIGS. 1-5 , a bale of a compressible, flexible, fibrous material 1 , which is filter tow in the present case, is there illustrated. The fibrous material 1 can be wrapped with a film 2 and introduced into a pressing device 3 ( FIG. 1 a ). In the pressing device 3 , which is able to exert a pressure or load of, for example, 300-400 tons, the bale is compressed to the desired packing height. Then the film 2 is sealed air-tight except for a small area, which can serve as a connection point for the suction hose of a vacuum pump 4 , such as a sliding vane rotary pump or the like. The interior of the region wrapped by the film 2 can be evacuated by the vacuum pump 4 to a desired negative pressure. Once this has been reached, the hose of the vacuum pump is disconnected from the film, and the connecting point is sealed air-tight. As previously mentioned, the use of a vacuum pump can be omitted if only a small degree of negative pressure is desired, such as that which can be obtained by the expansion of the bale.
In the next step, shown in FIG. 1 b , the pressing device 3 is opened. The bale thus expands again to the extent allowed by the size of the film packaging. The filter tow bale in its finished packaging can now be removed from the pressing device and is in a state in which it can be transported and stored, as indicated in FIG. 1 c . The height of the packaged bale depends on various factors, including the strength of the vacuum which was produced.
FIGS. 2 a and 2 b show another stage of the process according to the invention, namely, the optional provision of the packaged filter tow bale with external packaging 5 . This can be provided in particular for the purpose of transport and can consist, for example, of light-weight cardboard. These types of outside packaging materials are known to the expert and thus do not need to be explained in detail here.
FIGS. 3 a and 3 b show graphs which represent the change over time in the properties of packages produced by the process according to the invention based on the use of a film of polyethylene and of a laminated film of polyethylene and polyamide The polyethylene film of FIG. 3 a has a gas permeability of approximately 600 ml/(m 2 *d*bar), whereas the gas permeability of the laminated film of FIG. 3 b is only about 10 ml/(m 2 *d*bar). As can be derived from a comparison of the two graphs, the negative pressure produced in the case of the laminated film remains essentially constant over the course of several hundred days, as does the height of the bale. In contrast, the negative pressure in the case of the bale wrapped in polyethylene film has already decreased by half after only a little more than 100 days, whereas the height of the bale has increased by more than 10 cm in the same time period. If the bales are to be stored for up to two years or more, the laminated film is therefore to be preferred despite its higher cost.
As can be seen in FIG. 4 a , the height of the bale can be decreased by increasing the strength of the vacuum. Three different curves are shown in the figure. The one at the top shows the achievable height of the bale as a function of the packing height without the use of a vacuum pump. The curve in the middle shows the results obtained when an additional vacuum of 0.1 bar is applied, and the curve at the bottom shows the results obtained when an additional vacuum of 0.2 bar is applied. Filter tow of type 3Y35 with a bale weight of 580 kg was processed at a pressure of 370 tons. Under these conditions, an additional vacuum of 0.1 bar can be produced reliably in about 60 seconds.
FIG. 4 b shows the height of the bale under modified ambient conditions as a function of the strength of the additional vacuum, where the air temperature was approximately 40° C. and the pressure of the ambient air was approximately 0.05 bar higher than in the example of FIG. 4 a . It can be seen that the height of the bale increases at lower air pressures and higher temperatures.
A laminated film of polyethylene and polyamide with a thickness of approximately 200 μm was used in the exemplary embodiment described above. The film was heat-sealed by hand with a sealing device, where a collar part was joined to a top and a bottom element, each of which was pretrimmed in the press. The pressing force was 370 tons in all cases. The packaging costs could be considerably reduced by means of the process according to the invention.
According to another experiment, a bale of the same weight with a packing height of 900 mm was wrapped in a laminated film of polyamide and polyethylene, which was then welded shut. After the pressing device was opened, the height of the bale was 970 mm. There were no bulges anywhere in the packaged bale. By virtue of the increase in the volume of the air inside the bale, a negative pressure of 0.12 bar, corresponding to an absolute pressure of 0.88 bar, was reached. This negative pressure was achieved without the help of a vacuum pump.
In another experiment, a bale of the same weight with a packing height of 900 mm was wrapped in a laminated film of polyamide and polyethylene, which was then welded shut. The interior of the package was evacuated by means of a vacuum pump to a negative pressure of 550 bars, corresponding to an absolute pressure of 450 bars. After the pressing device was opened, the height of the bale increased to approximately 930 mm. The pressure in the interior of the package was calculated at 0.42 bar, corresponding to a negative pressure of 0.58 bar. Again, there were no bulges in the packaged bale.
The invention has been described with reference to several embodiments. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims and the equivalents thereof. | Disclosed is a packed, highly compressed cuboid-shaped filter tow bale, the top side and bottom side of which are free from noisome curvatures or constructions. A method for producing the bale comprises the following: (a) filter tow is supplied in a compressed form: (b) the compressed filter tow is enveloped in a wrapping; (c) the wrapping is closed in an airtight manner; and (d) the wrapped bale is relieved of the load. The wrapping of such a bale is largely prevented from bursting as a result of the prevailing internal pressure. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the priority benefit of French patent application number 08/54448, filed on Jul. 1, 2008, entitled “INTEGRATED DIRECTIONAL COUPLER,” which is hereby incorporated by reference to the maximum extent allowable by law.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to the electronics industry and, more specifically, to radiofrequency transceiver systems. The present invention more specifically relates to a directional coupler and applications thereof.
2. Discussion of the Related Art
A coupler is generally used to sample part of the power present on a so-called main or primary transmission line, with respect to another so-called coupled or secondary line, located nearby.
Couplers can be classified in two categories according to whether they are formed of discrete passive components (couplers with lumped elements) or of conductive lines arranged close to one another to be coupled (distributed couplers). The present invention relates to the second category of couplers.
In many applications, it is needed to sample part of the power transmitted over a line, for example, to control the power of an amplifier in a transmit circuit, to control the linearity of a transmit amplifier according to the losses linked to the reflection of an antenna, to dynamically match an antenna, etc.
A coupler is defined, among others, by its directivity which represents the power difference (expressed in dB) between the two access ports of its coupled or secondary line. Theoretically, an ideal coupler has an infinite directivity, that is, no power is present on the port of its secondary line located opposite to the output port of its main line when a signal runs through this main line from the input port to this output port. In practice, a coupler is said to be directional when its directivity is sufficient (typically greater than +20 dB) for the powers recovered from the access ports of its secondary line to enable to make out the direction of the power flow in its main line. When the two ports of the secondary line of the coupler can be used to simultaneously have the power information, the coupler is said to be bidirectional. In this case, the respective input and output ports of the main line and of the secondary line may be inverted.
If all ports are perfectly matched (typically, at 50 ohms), no stray reflection occurs and the coupler operates ideally. Such a perfect matching can unfortunately not be obtained in practice. In particular, the output port (typically, to which an antenna is connected) may undergo impedance modifications even in real time under the effect of modifications in the environment of the antenna. Such modifications generate stray reflections, which results in return loss, to be taken into account in the transmission chain.
A lack of directivity of the coupler adversely affects the accuracy of the measurements of a mismatch of the main line output port. Now, this mismatch is an important criterion of the transmission. The return loss is assessed on one of the ports of the secondary line of the coupler. Its measurement is, for example, used to modify the parameters of an impedance matching network interposed between the main coupler line and the antenna.
The signal sampled from the secondary line is tainted with non-negligible errors and is no longer usable when the coupler directivity is lower than 20 dB. The output impedance of the coupler can then no longer be controlled, whereby the return loss cannot be corrected.
To overcome a possible mismatch of the port of the secondary line of the coupler from which the data are sampled, the ends of the secondary line are sometimes equipped with attenuators. Such attenuators have no effect on the actual directivity of the coupler.
SUMMARY OF THE INVENTION
It would be desirable to improve the directivity of a coupler to overcome all or part of the disadvantages of usual couplers.
It would also be desirable to avoid using attenuators on the secondary line.
To achieve all or part of these objects as well as others, at least one embodiment of the present invention provides a distributed directional coupler comprising a first conductive line intended to convey a signal to be transmitted between first and second terminals;
a second conductive line, coupled to the first one and having one end intended to provide, on a third terminal, data relative to a signal reflected on the second terminal; and
an inductive and/or capacitive impedance matching circuit, interposed between the other end of the second line and a fourth terminal of the coupler.
According to an embodiment of the coupler, the components of the inductive and/or capacitive matching circuit are determined to compensate, on the third terminal, a signal originating from the first terminal.
According to an embodiment of the coupler, said matching circuit brings is an inductance ranging between 0 and 10 nH and a capacitance ranging between 0 and 20 pF.
At least one embodiment of the present invention also provides a circuit for transmitting or receiving radiofrequency signals, comprising:
at least one amplifier;
at least one coupler with an impedance-matching circuit; and
at least one circuit for measuring data sampled from the third terminal.
The foregoing objects, features, and advantages of the present invention will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an example of a conventional distributed coupler;
FIGS. 2A , 2 B, and 2 C are simplified representations of the coupler of FIG. 1 illustrating its operation for three directivity values;
FIG. 3 shows a Smith chart illustrating the mismatch circles for the three examples of directivity of FIGS. 2A to 2C and four examples of voltage standing wave ratios;
FIG. 4 shows another example of a conventional distributed coupler;
FIG. 5 shows an embodiment of a coupler;
FIGS. 6A and 6B are simplified representations of the coupler of FIG. 5 illustrating its operation;
FIGS. 7A and 7B show Smith charts corresponding to FIGS. 6A and 6B ; and
FIG. 8 is an example of architecture of a radiofrequency transmission path.
DETAILED DESCRIPTION
The same elements have been designated with the same reference numerals in the different drawings. Further, for clarity, only those elements which are useful to the understanding of the present invention have been shown and will be described. In particular, the different possible uses of the signal sampled from the secondary line of the coupler have not been detailed, the present invention being compatible with any typical use.
FIG. 1 is a simplified view of a distributed coupler. A main line 2 of coupler 1 is intended to be interposed on a transmission line and comprises two respective so-called input and output ports or terminals IN and OUT (or DIR). A secondary line 3 , coupled to the first one, comprises two respective so-called coupled and isolated ports or terminals CPLD (on the side of terminal IN) and ISO (on the side of terminal OUT), and is intended to convey the information proportional to the power transmitted in line 2 . The lengths of the lines depend on the desired operating frequency. Their width depends on the searched characteristic impedance.
The coupler of FIG. 1 is desired to be directional, that is, with signals present on ports CPLD and ISO exhibiting different levels. Such a coupler is however symmetrical, which makes it bidirectional, that is, in the same way as a signal applied on terminal IN is coupled on terminal CPLD, a signal applied on terminal OUT is coupled at the level of terminal ISO. Accordingly, a reflection from an antenna connected to terminal OUT appears on port ISO of the coupler. In a symmetrical directional coupler such as illustrated in FIG. 1 , the terminals are defined by the coupler connections to the other elements.
The main parameters of a coupler are:
the insertion loss, which represents the transmission loss between the access ports (IN and OUT) of the main line (the insertion loss is defined with the other two ports of the coupler loaded with a 50-ohm impedance);
the coupling, which represents the transmission loss between input port IN and coupled port CPLD (the coupling is defined with the other two ports OUT and ISO loaded with a 50-ohm impedance);
the isolation, which represents the transmission loss between input port IN and isolated port ISO opposite to the coupled port (the isolation is defined with the other two ports OUT and CPLD loaded with a 50-ohm impedance); and
the directivity which represents the transmission loss difference between isolated and coupled ports ISO and CPLD, from port IN.
FIGS. 2A , 2 B, and 2 C illustrate the operation of the coupler of FIG. 1 in three situation examples.
In all these examples, the case of a −30-dB coupling is considered, which corresponds to sampling, from the secondary line, 1/1000 of the power transmitted over the main line. A non-zero return coefficient of the antenna is further assumed. This results in a return loss RL which reaches port OUT. The return loss is assumed to be 20 dB. The measurement of the return loss exploits the coupling between terminals OUT and ISO and is performed by calculating the difference between the signals present on ports CPLD and ISO. In the drawings, the return operating data are illustrated in brackets.
FIG. 2A illustrates a theoretical example of coupler operation where the directivity is infinite. Assuming input IN to be driven by a signal, for example, at 0 dBm, the data received on terminal CPLD exhibit a −30-dBm level due to the 30-dB coupling coefficient. With a 20-dB return loss, the antenna returns a −20-dBm signal on terminal OUT. Since the coupler is symmetrical, a signal on terminal OUT is coupled on terminal ISO with a −30-dB coupling (dotted lines between ports OUT and ISO). As a result, the reflected signal exhibits a −50-dBm level on terminal ISO. In such a case, it can be seen that a measurement of the signal on port ISO enables to measure the variations of the return loss linked to the antenna, and thus a mismatching of the antenna.
FIG. 2B illustrates another example according to which the coupler directivity is 30 dB, which, with a −30-dB coupling, provides a −60-dB isolation between terminals IN and ISO. Taking the example of a signal driving terminal IN with a 0-dBm level, terminal CPLD still exhibits a −30-dBm level. With an antenna having a −20-dB return loss, the signal returned at −20 dBm on terminal OUT is at a −50-dBm level again on terminal ISO. However, port ISO sees not only this −50-dBm signal, but also a −60-dBm signal linked to the directivity (isolation signal). The signal on port ISO is thus disturbed by the signal leakage due to the non-perfect directivity of the coupler. As will better appear from the description of FIG. 3 , the possible error of the measurement on the isolated port will depend on the relative phase between the signal resulting from the return loss coupling and the isolation signal.
FIG. 2C illustrates a third example in which the coupler directivity is −15 dB only, which, with a 30-dB coupling, amounts to an isolation signal attenuated by −45 dB (on port ISO) with respect to that driving port IN. With the same data as in the previous examples, a parasitic signal linked to the lack of isolation of a −45-dBm level is obtained on port ISO. This parasitic signal has an amplitude greater than that of the −50-dBm signal useful for the measurement. The measured signal thus becomes impossible to use to detect a possible mismatching of the antenna.
FIG. 3 is a Smith chart illustrating the impact of the coupler directivity for different voltage standing wave ratios (VSWR). The coupler directivity conditions, independently from the voltage standing wave ratio, the position of the mismatch circle. FIG. 3 shows examples of mismatching circles for voltage standing wave ratios of 1, which amounts to a point (no reflection from the antenna), of 3 (−6-dB reflection), and of 10 (−1.7-dB reflection), for couplers having directivities which are infinite (point 1-1 ∞ , circles 1-3 ∞ and 1-10 ∞ ), of 20 dB (point 1-1 20 , circles 1-3 20 and 1-10 20 ), of 30 dB (point 1-1 30 , circles 1-3 30 and 1-10 30 ), and of 15 dB (point 1-1 15 , circles 1-3 15 and 1-10 15 ). It can be seen that when the directivity becomes too low, the measurement is tainted with error since, for certain phases, a measurement may suggest a mismatching (change of the voltage standing wave ratio) while the variation is due to the coupler directivity.
FIG. 4 shows a coupler 1 ′ having its ports CPLD and ISO loaded with attenuators 4 . In the example, attenuators formed of three pi-connected resistors R are assumed. A first resistor R is interposed in series at each end of the line while the other two resistors ground the two ends of the first resistor. The function of attenuators 4 is to overcome possible mismatches on ports CPLD and ISO to attenuate stray reflections. They are, however, ineffective on the coupler directivity. Further, the presence of attenuators on ports CPLD and ISO increases the coupling, and thus insertion losses.
FIG. 5 shows an embodiment of a coupler 10 . This drawing should be compared with FIGS. 1 and 4 . It shows main line 2 between ports IN and OUT and secondary line 3 between ports CPLD and ISO. However, an impedance matching element 5 is interposed between end 31 of secondary line 3 and port CPLD. Matching element 5 is of inductive and capacitive type (LC). In the simplified version illustrated in FIG. 5 , it is formed of an inductive element L in series with a capacitor C between end 31 of line 3 and port CPLD. The function of element 5 is to modify the impedance on the coupled port to cancel the parasitic signal due to the intrinsic directivity of the coupler. The assembly of real coupler 1 and network 5 then operates as an ideal coupler 10 with an infinite directivity.
Matching element 5 has an impedance different from the normalized 50-ohm impedance and is different from an attenuator which only brings a real part to the impedance of the coupled port.
Matching element 5 is placed on the port opposite to that from which the information is sampled. Thus, to measure the return loss of the antenna, the measurement is performed on port ISO and element 5 is placed on port CPLD.
Since the directivity is linked to the intrinsic performance of the coupler and to its manufacturing, especially in terms of length, spacing, and operating frequency, matching network 5 is preferably determined, in a simulation, by determination of the impedance to be presented on the coupled port to cancel an intrinsic parasitic signal of the coupler obtained by simulation. The isolation signal (between port IN and port ISO), noted S 2 and linked to the intrinsic directivity of the coupler, may be written as S 2 =A. cos(ωt+φ), where A designates the amplitude, ω designates the pulse, and φ designates the intrinsic phase shift introduced by the real coupler part 1 between ports CPLD and ISO. In an ideal coupler, signal S 2 is zero.
The provided solution amounts to generating, with matching network 5 , a return coefficient on port CPLD such that the signal, noted S 3 , between ports CPLD and ISO compensates the isolation signal of part 1 . One needs to obtain S 3 =A. cos(ωt+φ+π). Indeed, the amplitude of the return coefficient needs to be equal to the amplitude of isolation signal S 2 and its phase needs to be opposite to that of this isolation signal (corrected with intrinsic phase-shift φ between terminals CPLD and ISO).
FIGS. 6A and 6B are simplified representations of real coupler part 1 and of complete coupler 10 of FIG. 5 illustrating the implementation of the method for sizing element 5 .
FIGS. 7A and 7B show Smith charts corresponding to FIGS. 6A and 6B .
FIG. 6A illustrates part 1 , that is, coupler 10 with no matching element. On the side of terminal ISO, the return loss of port OUT (xdBm providing (−x−30) dBm after coupling) appears along with isolation signal S 2 . FIG. 7A shows the corresponding Smith chart. Point 1-1 X and mismatch circles 1-1.5 X , 1-3 X , and 1-10 X have been illustrated for a return loss representing voltage standing wave ratios of 1, 1.5, 3, and 10. Point 1-1 ∞ reminds the ideal coupler. Amplitude A corresponds to the module between points 1-1 ∞ and 1-1 X . Intrinsic phase φ corresponds to the angle formed by the straight line connecting these points. Data A and φ can thus be obtained by simulation based on the characteristics of the bare coupler. Based on data A and φ, and knowing operating frequency f=2π/ω of the coupler (for example, the central frequency of the envisaged bandwidth), the values to be given to components L and C of element 5 so that it generates a reflection coefficient such that reflected signal S 3 is of amplitude A and of phase φ+π can be determined.
FIG. 6B shows coupler 10 obtained with element 5 . Since parasitic signal S 2 is canceled by the reflection S 3 generated by the impedance presented on the coupled port, the sum of these signals on isolated port ISO cancels. Accordingly, there only remains useful signal (−x−30) dBm linked to the return loss (x dBm), which becomes perfectly measurable. FIG. 7B illustrates the corresponding Smith chart. It shows a point 10 - 1 X and mismatch circles 10 - 1 . 5 X , 10 - 3 X , and 10 - 10 X corresponding to those of a coupler of infinite directivity (see FIG. 3 ).
The determination of the inductive and capacitive elements of matching network 5 , by simulation, is perfectly compatible with the forming of the couplers on isolating substrates by using printed circuit or integrated circuit technology.
The structure of the matching circuit depends on the intrinsic characteristics of the coupler, the inductive and/or capacitive circuit having a function of impedance matching to the operating frequency of the coupler. A circuit which only decouples a D.C. voltage is not considered as an impedance matching circuit.
As a specific embodiment, the inductive elements will in most cases range between 0 and 10 nH, and the capacitive elements will range between 0 and 20 pF.
It is thus possible to considerably improve the directivity of a coupler intrinsically having a low directivity. In a practical implementation, this enables decreasing the size of the actual coupler. Further, the matching in terms of effective directivity to the operating frequency is easier.
Further, it is thus possible to take into account possible parasitic signals introduced when the coupler is used in its definitive application circuit. Indeed, the performed simulations may take these different parasitic signals into account, which is a significant advantage over the usual coupler.
FIG. 8 is a block diagram of a radiofrequency transmission line using a coupler 10 . Coupler 10 comprises a network 5 such as described hereinabove.
A transmission circuit 11 (SEND) sends a signal Tx to be transmitted to an amplifier 12 (PA) having its output intended to be connected to an antenna 13 . A main line of coupler 10 is interposed between the output of amplifier 12 and antenna 13 . Port IN is on the side of amplifier 12 while so-called output port OUT (sometimes also designated as DIR) is on the side of antenna 13 . A coupled or secondary line of coupler 10 samples part of the power of the main line. Coupler 1 is used, in this example, at least to measure the return loss in the antenna. This measurement is used to detect a mismatching of antenna 13 to control, via a control circuit 14 (CTRL), an impedance matching circuit 15 (MATCH) interposed between the coupler (output OUT) and antenna 13 . Circuit 14 exploits data that it samples from terminal ISO of coupler 10 .
In the example of FIG. 1 , port CPLD of the coupler, corresponding to the end of the secondary line on the side of port IN, further provides data which may also be exploited to adapt the amplifier gain by means of a circuit 16 (CTRL) receiving the data sampled from port CPLD and controlling the gain of amplifier 12 . This control of the gain of amplifier 12 may replace the dynamic matching of the antenna (by network 15 or by elements integrated to the antenna).
A path splitter 17 (SPLIT) may be interposed between coupler 1 (or network 15 ) and antenna 13 . Such a splitter is used to separate the transmission from the reception (flow Rx in FIG. 1 ), which is processed by a radiofrequency reception line, not shown.
Specific embodiments have been described. Various alterations and modifications will occur to those skilled in the art. In particular, the dimensions of the lines according to the frequency bands desired for the couplers can be determined by those skilled in the art by using usual methods. Further, the selection of the matching network and of the proportion of this network between the capacitive elements and the inductive elements depends on the application and on other possible technological constraints, provided to respect the above functional indications.
Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and the scope of the present invention. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The present invention is limited only as defined in the following claims and the equivalents thereto. | A coupler including: a first conductive line intended to convey a signal to be transmitted between first and second terminals; a second conductive line, coupled to the first one and having one end intended to provide, on a third terminal, data relative to a signal reflected on the second terminal; and an inductive and/or capacitive impedance matching circuit, interposed between the other end of the second line and a fourth terminal of the coupler. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 USC §119(e) to U.S. Provisional Patent Application 61/468,926 filed Mar. 29, 2011, the entirety of which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention is directed to aquaponic systems and methods.
BACKGROUND
Aquaponics is a sustainable method of food production that combines aquaculture (fish farming) with hydroponic plant production. The main method of aquaponics that is used in aquaponic food production is the raft system, which was primarily developed at the Agriculture Experiment Station, University of the Virgin Islands over a 30 year period.
Conventional aquaponic systems typically include multiple fish tanks, raft tanks in which the plants are grown, and basic filtration components. Examples of conventional aquaponic systems are described in U.S. Pat. Pub. 2010/0031893 to Bodlovich et al. and U.S. Pat. Pub. 2009/0301399 to Brown et al. Nitrification, a process that generates nitrogen, is conventionally performed directly in the raft tanks. Conventional aquaponic raft systems typically produce daily discharge of water and fish waste. This discharge discards material that could otherwise be used to increase plant production.
There is a need for an aquaponic system that nearly eliminates the water and waste discharge associated with conventional aquaponic systems and increases plant production.
SUMMARY OF THE INVENTION
The invention described herein includes aquaponic systems and methods that address the aforementioned needs.
One version of the invention is an aquaponic system that includes a solids separator configured to accept waste water and separate settleable solids from suspended-waste water, a first component configured to receive the suspended-waste water and convert the suspended-waste water to nutrient-rich water suitable for hydroponic plant growth, a hydroponic growth apparatus configured to receive the nutrient-rich water for supporting hydroponic growth and to convert the nutrient-rich water to nutrient-depleted water, a fish tank configured to receive the nutrient-depleted water and convert the nutrient-depleted water to the waste water, and a second component configured to receive the settleable solids and convert the settleable solids to nutrient-rich sludge.
The first component preferably comprises a nutrification tank configured to convert the suspended-waste water to mineralized water, a nitrification tank configured to convert mineralized water to nitrified water, and a degassing tank configured to convert the nitrified water to the nutrient-rich water.
The hydroponic growth apparatus preferably comprises an apparatus selected from the group consisting of a hydroponic raft tank and a nutrient film technique apparatus.
The second component preferably comprises a solids filter configured to collect and process the settleable solids and to generate nutrient-rich filtrate water and the nutrient-rich sludge from the processed settleable solids, wherein the nutrient-rich filtrate water is preferably delivered back to the first component.
The system preferably further includes a substrate-based growth apparatus configured to receive the nutrient-rich sludge for supporting plant growth. The substrate-based growth apparatus is preferably a soilless media-filled growth bed.
The system also preferably further includes a sludge sump configured to receive nutrient-rich sludge from the second component and nutrient-depleted sludge from the substrate-based growth apparatus to generate a mixture, wherein the mixture is delivered to the substrate-based growth apparatus to support plant growth.
Another version of the invention is an aquaponic method that includes the steps of separating waste water into settleable solids and suspended-waste water, converting the suspended-waste water to nutrient-rich water suitable for hydroponic plant growth, growing plants in a hydroponic growth apparatus with the nutrient-rich water wherein the growing includes converting the nutrient-rich water to nutrient-depleted water, converting the nutrient-depleted water to the waste water, and converting the settleable solids to nutrient-rich sludge.
The step of converting the suspended-waste water to the nutrient-rich water preferably comprises sequentially converting the suspended-waste water to mineralized water comprising ammonia while controlling denitrification, converting the mineralized water to nitrified water by converting ammonia to nitrate, and converting the nitrified water to the nutrient-rich water by removing gasses from the nitrified water.
The step of growing the plants in the hydroponic growth apparatus preferably comprises a step selected from the group consisting of growing the plants in a hydroponic raft tank and growing the plants in a nutrient film technique apparatus.
The step of converting the settleable solids to nutrient-rich sludge preferably comprises filtering the settleable solids to generate nutrient-rich filtrate water, wherein the method further comprises converting the nutrient-rich filtrate water to the nutrient-rich water used for growing the plants in the hydroponic growth apparatus.
The method preferably further includes a step of growing plants in a substrate-based growth apparatus, such as a soilless media-filled growth bed, with the nutrient-rich sludge.
The method preferably further includes steps of mixing nutrient-depleted sludge resulting from plant growth in the substrate-based growth apparatus with the nutrient rich sludge to generate a mixture, and delivering the mixture to the soilless media-filled growth bed.
The aquaponic systems and methods described herein nearly eliminate the water and waste discharge associated with conventional aquaponic systems and drastically increase the plant production compared to those systems. The system components fully use all fish waste as fertilizer for plant growth and allow integration of leafy and fruiting crops in one system. The components also allow the grower to manipulate the ratios of nitrogen to other elements in the solution, optimizing plant growth and quality. The increased nutrient availability also allows new planting and spacing methods, further increasing plant production.
The aquaponic systems and methods described herein move aquaponics from a concept that is being applied on a small scale to one that can produce mass amounts of food (protein and vegetables) for commercial ventures and for feeding the hungry and the growing global population.
The aquaponic systems and methods described herein enhance biological activities including nitrification, which generates nitrogen, and nutrification, which generates other elements needed for plant growth, resulting in a clear, highly mineralized nutrient solution for the plants and a clean system with nearly zero discharge. Nutrient-rich water processed from waste-water suspensions is delivered to hydroponic growth apparatuses to increase production. Solid fish wastes are captured, processed, and utilized in additional plant culture systems, diversifying crops and further increasing crop production.
The objects and advantages of the invention will appear more fully from the following detailed description of the preferred embodiment of the invention made in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a schema of an exemplary aquaponic system of the present invention.
FIG. 2 depicts a schema of an exemplary hydroponic growth apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The aquaponic systems of the present invention may include various combinations of elements selected from the group consisting of a solids separator 1 , a nutrification tank 2 , a nitrification tank 3 , a degassing tank 4 , any of a variety of hydroponic growth apparatuses 5 such as a hydroponic raft tank 51 and/or a nutrient film technique apparatus 52 , a sump tank 6 , a fish tank 7 , a solids filter 8 , a sludge sump 9 , and a substrate-based growth apparatus 10 . An exemplary aquaponic system 100 of the present invention is provided in FIG. 1 .
The solids separator 1 treats fish waste water 21 received from fish tanks 7 by separating settleable solids 28 from suspended-waste water 22 . “Settleable solids” refers to particulates that are capable of settling out of the waste water 21 . “Suspended-waste water” refers to the water residue remaining after removal of settleable solids, and includes fish-waste particulates not capable of settling out of the waste water 21 suspended therein. Various solids separators are known in the art. Non-limiting examples of suitable solids separators 1 include clarifiers, swirl separators, Imhoff tanks or cones, etc. In preferred versions, the solids separator 1 is a non-filtration solids separator.
The nutrification tank 2 is a multi-staged tank or set of tanks that provide habitat for heterotrophic bacteria to mineralize the suspended fish waste in the suspended-waste water 22 into usable nutrients for the fish, thereby generating mineralized water 23 . The term “mineralize” is used herein as in the art and refers to the break-down of solid, organic waste material (fecal material from fish) to carbon dioxide, ammonia, and other compounds and components. By design, these tanks enhance removal of organic materials and control denitrification (i.e., the conversion (reduction) of nitrites and nitrate to gaseous nitrogen (N 2 , NO, N 2 O)). Mineralization is accomplished by any of a number of species of heterotrophic bacteria known in the art. Heterotrophic bacteria can be either gram-positive (e.g., Bacillus ) or gram-negative (e.g., Pseudomonas, Escherichia ). Some are strictly aerobic, but many are facultative anaerobes (they can survive in both the presence and absence of oxygen). Many species tolerate a wide range of environmental conditions, including temperature, pH, salinity, etc.
The nitrification tank 3 provides habitat for nitrifying bacteria to convert the mineralized water 23 to nitrified water 24 . The nitrifying bacteria perform nitrification, the biological oxidation of ammonia to nitrite and then nitrate. Nitrate is the primary form of nitrogen used by plants. The nitrification process consists of two steps: (1) Oxidation of ammonia (NH 3 ) to nitrite (NO 2 ); and (2) Oxidation of nitrite (NO 2 ) to nitrate (NO 3 ). Five genera are generally accepted as ammonia oxidizers and four genera as nitrite oxidizers. Of these, Nitrosomonas (ammonia oxidizers) and Nitrobacter (nitrite oxidizers) are the most important. The sustained growth of nitrifying bacteria is a function of several parameters. Nitrifying bacteria are aerobic bacteria. This means they require dissolved oxygen in order to metabolize, grow, and reproduce. Sufficient alkalinity is also important. Alkalinity of water is a measure of its capacity to neutralize acids. A variety of compounds, including bicarbonates, salts of weak acids, and hydroxides contribute to alkalinity. When ammonia is oxidized during nitrification, protons (H+) are liberated. Alkalinity is needed to neutralize these protons. In fact, 8.64 mg/l of alkalinity are consumed for each mg/l of ammonia that is oxidized. Without sufficient alkalinity, the pH will drop, and nitrification will slow down or even stop. Nitrification works best when the pH is between 6.5 and 8.5. The process slows considerably at pH values outside this range. Optimal temperature is also important, as extreme temperatures can impair nitrification efficiency.
The degassing tank 4 is configured to remove gasses dissolved in the water in the system 100 , such as nitrified water 24 and/or nutrient-rich filtrate water 34 , thereby generating nutrient-rich water 25 suitable for sustaining hydroponic growth. The gasses are introduced into the water as a result of the biological processes that generate nutrients, such as those involved in the nutrification and nitrification steps. Various degassing tanks are well-known in the art and are suitable for use in the present system 100 .
The hydroponic growth apparatus 5 may comprise any apparatus or group of apparatuses configured for supporting hydroponic growth. As shown in FIGS. 1 and 2 , two exemplary apparatuses suitable for inclusion in the hydroponic growth apparatus 5 include hydroponic raft tanks 51 and nutrient film technique (NFT) apparatuses 52 . In the process of supporting hydroponic growth, the hydroponic growth apparatus 5 converts the nutrient-rich water 25 to nutrient-depleted water 27 .
Hydroponic raft tanks 51 generally comprise a tank of water with a water inlet and a water outlet and hydroponic rafts floating on or suspended above the water. The hydroponic rafts are generally made from construction grade polystyrene sheets and comprise holes with various pots contained therein. Non-limiting examples of suitable pots include hydroponic net pots, horticultural horticubes, and rockwool cubes. Plants are grown in the pots in such a manner that their roots extend to and within the water.
NFT apparatuses 52 generally comprise water channels, preferably sloping channels; a table frame to support the channels; water inlets and outlets on either side of the channels; and, in some cases, a reservoir for capturing water from the channels and recirculating the water to the channels before returning the water back to other components of the system 100 . A very shallow stream of water containing dissolved nutrients is circulated past the bare roots of plants in the channels, the latter of which constitute watertight gullies. The depth of the recirculating stream is very shallow, with little more than a film of water, thereby forming a “nutrient film.” A thick root mat develops in the bottom of the channel and has an upper surface, which, although moist, is exposed to the air. NFT apparatuses 52 are exceptional for exposing plants to adequate supplies of water, oxygen, and nutrients. NFT apparatuses 52 are useful for growing leafy crops such as lettuce and herbs.
A preferred configuration for the hydroponic growth apparatus 5 , shown in FIG. 2 , includes one NFT apparatus 52 and two hydroponic raft tanks 51 . The NFT apparatus 52 is configured in parallel with respect to the hydroponic raft tanks 51 , and the hydroponic raft tanks 51 are configured in series with respect to each other. An excess of hydroponic raft tanks 51 included within a system may require diluting the water in the system with “make-up” water from outside the system, which decreases nutrient availability to all plants. Inclusion of NFT apparatuses 52 increases plant production without diluting the water in the system or affecting the ratio of water to fish within the system 100 .
The sump tank 6 serves as a reservoir for the system 100 . In the preferred version, it is disposed between the hydroponic growth apparatus 5 and the fish tank 7 to store the nutrient-depleted water. However, the sump tank 6 may be disposed between any two components involved in the first flow path, described in detail below.
The fish tank 7 receives nutrient-depleted water 27 and houses fish therein. In so doing, the nutrient-depleted water 27 is converted to waste water 21 .
The solids filter 8 collects, processes, and blends settleable solids 28 , such as those received from the solids separator 1 . Such settleable solids 28 would not be used in a conventional raft system. The solids filter 8 also filters the processed and blended settleable solids 28 to generate clear, nutrient-rich filtrate water 34 and nutrient-rich sludge 29 as a retentate. The solids filter 8 preferably includes a filtration tank, a bead filter, a pump to run the filter, and appropriate plumbing for carrying out the above-mentioned processes. Collection and subsequent use of the nutrient-rich sludge 29 and return of the nutrient-rich filtrate water 34 to the first flow path, as described below, results in nearly zero waste and at least doubles the plant production compared to conventional aquaponic systems.
The sludge sump 9 is a reservoir for the nutrient-rich sludge 29 generated by the solids filter 8 . The nutrient-rich sludge 29 can be pumped from the sludge sump 9 to various substrate-based growth apparatuses 10 for use as fertilizer. The sludge sump 9 includes a sump tank, a pump for pumping the sludge from the sump tank, and appropriate plumbing. As nutrient-rich sludge 29 in the sludge sump 9 is preferably configured not to return to the hydroponic growth apparatus 5 in the first flow path (see FIG. 1 ), adjustments to the pH and/or nutrient composition can be made in the sludge sump 9 to accommodate specific crop needs in the substrate-based growth apparatuses 10 .
The substrate-based growth apparatus 10 includes one or more apparatuses configured to grow plants in a solid or semi-solid substrate. Various non-limiting examples of substrate-based growth apparatuses 10 include soilless media-filled growth beds and soil-filled growth beds. The beds may be contained indoors or outdoors and may be raised beds or in-ground beds.
A preferred substrate-based growth apparatus 10 includes raised, soilless media-filled growth beds that include a frame, a liner, a soilless medium, aeration, and plumbing. The frame is covered with a liner and is filled with a soilless medium, such as expanded clay. Nutrient-rich sludge, such as from the sludge sump 9 , is pumped into the media bed and distributed throughout the bed. The sludge is very rich in nutrients and is further broken down by microbes through the mineralization process to release more nutrients over time. Aeration that runs the length of the bottom of the media bed enhances this microbial activity. Indoor, soilless media-filled growth beds are preferred for growing fruiting crops such as tomatoes, peppers, beans, squash, etc.
As shown in FIG. 1 , the components of the system 100 described above are preferably configured in two main flow paths. A first flow path generates nutrient-rich water 25 from nutrient-depleted water 27 for use by the hydroponic growth apparatus 5 . The second flow path generates nutrient-rich sludge for use as fertilizer, for example, by the substrate-based growth apparatus 10 .
In the first flow path, nutrient-depleted water 27 stored in the sump tank 6 is pumped to the fish tank 7 . In the fish tank 7 , the nutrient-depleted water 27 becomes replete with fish waste and flows to the solids separator 1 as waste water 21 . The solids separator 1 separates the waste water 21 into settleable solids 28 and suspended-waste water 22 . The settleable solids 28 are sent to the second flow path, described below. The suspended-waste water 22 flows to the nutrification tank 2 to generate mineralized water 23 . The mineralized water 23 flows to the nitrification tank 3 to generate nitrified water 24 . The nitrified water 24 flows to the degassing tank 4 to generate nutrient-rich water 25 . From there, the nutrient-rich water 25 is transported to the hydroponic growth apparatus 5 to support plant growth. In the process of supporting plant growth, the nutrient-rich water 25 becomes nutrient-depleted water 27 , the latter of which flows back to the sump tank 6 for storage.
In a second flow path, the settleable solids 28 separated in the solids separator 1 flow to the solids filter 8 . The settleable solids 28 may contain just enough water required to move them through the system 100 . However, the amount of water in the settleable solids 28 can be varied depending on how much water is needed in the downstream substrate-based growth apparatuses 10 . The settleable solids 28 in the solids filter 8 are preferably mixed with water draining from the nutrification tank 2 and nitrification tank 3 (path not shown). The settleable solids 28 are processed in the solids filter 8 , and nutrient-rich sludge 29 and nutrient-rich filtrate water 34 are separated by filtration. The nutrient-rich filtrate water 34 is transferred to a component of the first flow path, such as the nutrification tank 2 , nitrification tank 3 , or, preferably, the degassing tank 4 (see FIG. 1 ). Transferring the nutrient-rich filtrate water 34 back to the first flow path makes additional water and nutrients available to the hydroponic growth apparatus 5 for increased plant production and reduces the amount of make-up water required in the system 100 . The nutrient-rich sludge 29 is pumped to the sludge sump 9 and then the substrate-based growth apparatus 10 , where heterotrophic bacteria further process it to release nutrients, thereby supporting additional plant growth. If a soilless media-filled growth bed is employed as a substrate-based growth apparatus 10 , nutrient-depleted sludge 39 is preferably recycled from the substrate-based growth apparatus 10 back to the sludge sump 9 and mixed with the nutrient-rich sludge 29 entering from the solids filter 8 . As an alternative to or in addition to using the nutrient-rich sludge 29 as fertilizer on-site in a substrate-based growth apparatus 10 , the nutrient-rich sludge 29 may be packaged and sent off-site for use as fertilizer.
Pumps are preferably disposed throughout the system 100 to promote flow in the two flow streams. A pump may be operationally connected to the sump tank 6 for pumping nutrient-depleted water 27 to the fish tank 7 . Another pump may be operationally connected to degassing tank 4 to deliver nutrient-rich water 25 to the NFT apparatus 52 . Another pump may be operationally disposed within the solids filter 8 to drive filtration. Yet another pump may be operationally connected with the sludge sump 9 to pump the nutrient-rich sludge 29 therefrom. The materials (water and sludge) in the system 100 otherwise travels throughout the system 100 by gravity flow.
The system 100 may include one or more of any of the elements described herein. If more than one of a particular element is included, the elements may be connected in series or in parallel. A preferred version includes four fish tanks 5 ; four solids separators 1 , each fed by a corresponding one of the four fish tanks 5 ; two nutrification tanks 2 disposed in series; one nitrification tank 3 ; a degassing tank 4 with separate, parallel outlets to each of a hydroponic raft tank 51 and an NFT apparatus 52 ; a hydroponic growth apparatus 5 comprising two hydroponic raft tanks 51 mutually disposed in series and disposed in parallel with an NFT apparatus 52 ; one sump tank 5 ; one sludge sump 9 ; and two, parallel substrate-based growth apparatuses 10 independently connected to the sludge sump 9 to recycle sludge therebetween.
In a conventional aquaponic system, any settleable solids and associated water would be discarded. By contrast, the aquaponic system 100 described herein eliminates waste and retains water and nutrients within the system 100 without diluting the water by adding extra, fresh makeup water. The use of the two streams, as well as the feedback from the second flow stream to the first, provides at least double the plant production compared to conventional aquaponic systems. In a convention raft aquaponic system, the plant-to-fish production ratio is about 10-to-1. With the system 100 described herein, the plant to fish production ratio can be about 20-to-1.
The elements and method steps described herein can be used in any combination whether explicitly described or not. All combinations of method steps as described herein can be performed in any order, unless otherwise specified or clearly implied to the contrary by the context in which the referenced combination is made.
As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. For example, reference to “a substrate-based growth apparatus” may include one, two, three, or more substrate-based growth apparatuses.
All patents and patent publications cited herein are expressly incorporated by reference to the same extent as if each were specifically and individually indicated as being incorporated by reference. In case of conflict between the present disclosure and the incorporated references, the present disclosure controls.
It is understood that the invention is not confined to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims. | High-production, minimal-discharge aquaponic systems and methods. The aquaponic systems separate waste water generated from fish tanks into two flow streams. In the first flow stream, suspended-waste water generated from the waste water is converted to nutrient-rich water and used for hydroponic plant growth. Nutrient-depleted water resulting from the hydroponic plant growth is fed back into fish tanks to continue the cycle. In the second flow stream, settleable solids generated from the waste water is converted to nutrient-rich sludge and used for solid or semi-solid substrate-based plant growth. Excess nutrient-rich water derived from the second flow stream is fed back into the first flow stream, thereby conserving water and nutrients within the system. | 8 |
INDEX TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/368,454 filed Jul. 28, 2011 the disclosure of which is incorporated herein by reference in its entirety.
FIELD OF INVENTION
[0002] The subject invention relates to a multi use cell phone holder and stand.
BACKGROUND OF THE INVENTION
[0003] The cellular telephone is an ever present fixture in our world today. Along with advances in cellular technology, there are advances in articles to be utilized with cellular telephones. Cell phone holders come in many sizes, shapes and configurations. A significant limitation in cell phone holders and cases is that they must me sized and shaped for every size and shape of cell phone. This task is difficult and presents a problem relating to manufacturing.
[0004] The current invention not only addresses this problem, but the present invention is configured to be utilized with a vast variety of cell phones in a single configuration.
SUMMARY OF THE INVENTION
[0005] In one embodiment the present invention is an article for holding and standing a cell phone having:
a. a main body; b. an arm extending upward from said main body; c. a holder incorporated on an upper terminal end of said arm; d. a standing leg extending attached to said main body; e. a pivot pin constructed and arranged such that said leg is moved from a position substantially coplanar with said main body to a position out word from said main body.
[0011] The article main body is attached directly to a cell phone, a user supplied cell phone case/holder, or a user supplied cell phone skin.
[0012] The article has a holder that is integral with a retractable arm and formed of a single contiguous piece. In one embodiment, the holder is a retractable ring assembly formed integral along two leg portions that slide outward from the main body and are retractable to within the main body.
[0013] In one embodiment, leg extending downward from said main body is constructed and arranged to pivot from angles between 0-90° relative to the plane in which said main body lies.
[0014] The standing leg moves away from the main body and is used to stand the article in either a horizontal or vertical position.
[0015] The holder in one embodiment is a ring assembly.
[0016] The arm is constructed and arranged to slidably extend and retract along a coplaner orientation with said main body.
[0017] The arm is constructed and arranged to slidably extend and retract along a coplaner orientation with said main body and wherein said arm is constructed to prevent complete separation from said main body.
[0018] In one embodiment, the holder is configured to be held by at least one human finger.
[0019] The holder is also configured to be hung on a hanger.
[0020] Hanger would mean any article capable of engaging the hanger or ring and hanging the article thereon.
[0021] The present invention further contemplates A kit having:
the article as described herein; and a hanging device for hanging said article thereon.
[0024] The hanging device, in one embodiment, is supplied in the kit of the invention as a hanging hook with mounting adhesive incorporated thereon.
[0025] Additional aspects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The aspects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0026] FIG. 1 is a perspective view of the invention in an environment of use.
[0027] FIG. 2 is a perspective view of the invention with leg assembly extended.
[0028] FIG. 3 is a perspective view of the invention in a horizontal orientation with leg assembly extended.
[0029] FIG. 4 is a front view of the invention in an environment of use showing placement of a finger through a ring and ring cavity.
[0030] FIG. 5 is a perspective View showing the assembly hanging on a hanger.
[0031] FIG. 6 is a front view showing the ring assembly fully extended.
[0032] FIG. 7 is a back view showing the assembly of an invention showing the assembly of the invention with an adhesive attaching area.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] As seen in FIG. 1 , the present invention is an article whereby assembly 10 comprises a main body 21 that attaches to a cell phone case 25 or in the alternative the actual backing of a cell phone (not shown). Standing leg 22 terminates in a leg end 24 . Ring assembly 23 is extendable outward from main body 21 .
[0034] As seen in FIG. 2 , standing leg assembly 22 is pivotably extended from main body 21 and includes a leg end 24 for use as a stand.
[0035] As seen in FIG. 3 , main body 21 can be oriented in a horizontal position such that when standing leg 22 is extended, leg end 24 will also support the cell phone in a standing position.
[0036] As seen in FIG. 4 , ring assembly 23 is extendable upward from main body 21 such that ring 28 defines a ring cavity 29 and is constructed and arranged for a person's finger 40 to pass through ring cavity 29 . In this orientation, a person can hold the assembly by passing their finger 40 through ring cavity 29 . As seen in FIG. 5 , a hanger 30 is utilized with the assembly. Hanger 30 has incorporated thereon adhesive 31 , which allows for adhesive mounting to a flat surface. In one embodiment, the adhesive mounting 31 may be affixed to an automobile dashboard such that the assembly may be hung in an automobile. Incorporated with hanger 30 are one or more hanger arms 32 constructed and arranged such that ring 28 interacts therewith and allows for hanging of the cell phone assembly 10 . Ring assembly 23 is extendable and retractable from main body 21 by means of a first arm 33 and a second arm 34 attached to ring assembly 23 . Each of first arm 33 and second arm 34 are constructed and arranged such that they extend outward from main body 21 and have internal structure to prevent complete disassembly from main body 21 . As seen in FIG. 6 which is a cutaway of main body 21 showing each of first arm 33 and second arm 34 that extend outward from main body 21 and corresponding first track 35 and second track 36 therein which facilitates the extension and retraction of ring assembly 23 from main body 21 .
[0037] In the embodiment shown in FIG. 7 , main body 21 has an adhesive surface 38 incorporated thereon. Adhesive surface 38 can be attached to a conventional cell phone cover 25 or in the alternative maybe attached directly to a cell phone casing. In one embodiment demonstrating use, the article is used by attaching assembly 10 to a cell phone. By attaching, it is understood that the article is attached directly to a cell phone housing, or, in alternative, to an existing cell phone cover 25 or skin (not shown). The present invention offers a distinct advantage in that it need not be offered in multiple configurations to accommodate different cell phone sizes and shapes. A single configuration attaches either to the actual cell phone housing or to a cover 25 or skin whereby the cover or skin is the article sized and shaped for a particular cell phone. Main body 21 has adhesive 38 disposed thereon. Adhesive 38 is attached directly to a cover 25 , cell phone skin, or directly to a cell phone housing.
[0038] The present invention is constructed and arranged to function as a stand and to stand a phone in a vertical position, as in FIG. 2 , or a horizontal position, as in FIG. 3 .
[0039] Standing is accomplished by pivotably moving standing leg 22 outward from main body 21 . Standing leg 22 has end 24 that is elongated and the elongated configuration allows for stablization of article 10 when used as a stand.
[0040] Ring assembly 23 slidably extends out from a retracted position in which most of each of first leg 33 and second leg 34 are contained within the inner portion of main body 21 . First arm 33 and second arm 34 extend outward from main body 21 and slide along corresponding first track 35 and second track 36 constructed on the interior of main body 21 . The sliding facilitates the extension and retraction of ring assembly 23 from main body 21 . First leg 33 and second leg 34 each have a flanged terminal end 40 and 41 respectively wherein each flanged terminal end 40 and 41 is integral with respective first leg 33 and second leg 34 and opposite ring assembly 23 . Each flanged terminal end 40 and 41 inhibits first leg 33 and second leg 34 from being retracted completely outside of main body 23 by configuration of a first curved edge 42 and a second curved edge 43 along the uppermost edge of each of first track 35 and second track 36 . When ring assembly 23 is extended outward from main body 21 , the first flanged end 40 and second flanged end 41 will contact first curved edge 42 and a second curved edge 43 along the uppermost edge of each of first track 35 and second track 36 and inhibit ring assembly 23 from being completely separated from main body 21 .
[0041] Once ring assembly 23 is retracted, ring cavity 29 defined by ring 28 is accessed as needed.
[0042] One embodiment of access is for a user to insert a finger 40 through ring cavity 29 and hold assembly 10 on finger 40 .
[0043] Another embodiment allows assembly 10 to be hung utilizing any suitable hanging device. In one embodiment, a hanging hook 30 is provided with article 10 and hanging hook 30 is adhesively attached utilizing adhesive 31 disposed thereon.
[0044] While the invention has been described in its preferred form or embodiment with some degree of particularity, it is understood that this description has been given only by way of example and that numerous changes in the details of construction, fabrication, and use, including the combination and arrangement of parts, may be made without departing from the spirit and scope of the invention. | An article for holding and standing a cell phone having a main body; an arm extending upward from said main body; a holder incorporated on an upper terminal end of said arm; a standing leg; and a pivot pin constructed and arranged such that the standing leg is moved from a position substantially coplanar with said main body to a position outward from said main body. | 5 |
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